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How is Slc22a3 imprinted? | Two novel imprinted genes, Slc22a2 and Slc22a3 are described here that lie 110 and 155 kb 3' to Igf2r and that are not overlapped by the Air transcript but are regulated by the Igf2r-ICE, as previously shown for Igf2r. A bidirectional silencer for a 400-kilobase region that contains three imprinted, maternally expressed protein-coding genes (Igf2r/Slc22a2/Slc22a3) has been shown by targeted deletion to be located in a sequence of 3.7 kilobases, which also contains the promoter for the imprinted, paternally expressed non-coding Air RNA. Silencing of the paternal allele of three imprinted genes (Igf2r, Slc22a2 and Slc22a3) requires cis expression of the Air RNA | Imprinting of the maternally-expressed Igf2r gene is controlled by an intronic
imprint control element (ICE) known as Region2 that contains the promoter of the
noncoding Air RNA, whose transcript overlaps the silenced paternal Igf2r
promoter in an antisense orientation. Two novel imprinted genes, Slc22a2 and
Slc22a3 are described here that lie 110 and 155 kb 3' to Igf2r and that are not
overlapped by the Air transcript but are regulated by the Igf2r-ICE, as
previously shown for Igf2r. These results identify a new cluster of imprinted
genes whose repression by the bidirectional action of the Region2-ICE is
independent of transcript overlap by the Air RNA. In genomic imprinting, one of the two parental alleles of an autosomal gene is
silenced epigenetically by a cis-acting mechanism. A bidirectional silencer for
a 400-kilobase region that contains three imprinted, maternally expressed
protein-coding genes (Igf2r/Slc22a2/Slc22a3) has been shown by targeted deletion
to be located in a sequence of 3.7 kilobases, which also contains the promoter
for the imprinted, paternally expressed non-coding Air RNA. Expression of Air is
correlated with repression of all three genes on the paternal allele; however,
Air RNA overlaps just one of these genes in an antisense orientation. Here we
show, by inserting a polyadenylation signal that truncates 96% of the RNA
transcript, that Air RNA is required for silencing. The truncated Air allele
maintains imprinted expression and methylation of the Air promoter, but shows
complete loss of silencing of the Igf2r/Slc22a2/Slc22a3 gene cluster on the
paternal chromosome. Our results indicate that non-coding RNAs have an active
role in genomic imprinting. Silencing of the paternal allele of three imprinted genes (Igf2r, Slc22a2 and
Slc22a3) requires cis expression of the Air RNA that overlaps the promoter of
one of them (Igf2r). Air is a non-coding RNA whose mode of action is unknown. We
tested the role of the Igf2r promoter and the role of transcriptional overlap
between Igf2r and Air in silencing in this cluster. We analyzed imprinted
expression in mice in which the Igf2r promoter is replaced by a thymidine kinase
promoter that preserves a transcription overlap with Air, and in mice with a
deleted Igf2r promoter that lack any transcriptional overlap with Air. Imprinted
silencing of Air, Slc22a2 and Slc22a3 is maintained by the replacement promoter
and also in the absence of transcriptional overlap with Air. These results
exclude a role for the Igf2r promoter and for transcriptional overlap between
Igf2r and Air in silencing Air, Slc22a2 and Slc22a3. Although these results do
not completely exclude a role for a double-stranded RNA silencing mechanism,
they do allow the possibility that the Air RNA has intrinsic cis silencing
properties. Epigenetic mechanisms restrict the expression of imprinted genes to one parental
allele in diploid cells. At the Igf2r/Air imprinted cluster on mouse chromosome
17, paternal-specific expression of the Air noncoding RNA has been shown to
silence three genes in cis: Igf2r, Slc22a2, and Slc22a3. By an unbiased mapping
of DNase I hypersensitive sites (DHS) in a 192-kb region flanking Igf2r and Air,
we identified 21 DHS, of which nine mapped to evolutionarily conserved
sequences. Based on the hypothesis that silencing effects of Air would be
directed towards cis regulatory elements used to activate genes, DHS are
potential key players in the control of imprinted expression. However, in this
192-kb region only the two DHS mapping to the Igf2r and Air promoters show
parental specificity. The remaining 19 DHS were present on both parental alleles
and, thus, have the potential to activate Igf2r on the maternal allele and Air
on the paternal allele. The possibility that the Igf2r and Air promoters share
the same cis-acting regulatory elements, albeit on opposite parental
chromosomes, was supported by the similar expression profiles of Igf2r and Air
in vivo. These results refine our understanding of the onset of imprinted
silencing at this cluster and indicate the Air noncoding RNA may specifically
target silencing to the Igf2r promoter. |
What are the effects of 14-3-3 dimers on Tau phosphorylation? | 14-3-3 dimers regulate steady-state phosphorylation of both wild-type and the R406W mutant Tau, but they are not essential for toxicity of either variant. Furthermore, recruitment of dimers on accumulating wild- type Tau increases its steady- state levels ostensibly by occluding access to proteases in a phosphorylated-dependent manner. | Neurodegenerative dementias collectively known as Tauopathies involve aberrant
phosphorylation and aggregation of the neuronal protein Tau. The largely
neuronal 14-3-3 proteins are also elevated in the central nervous system (CNS)
and cerebrospinal fluid of Tauopathy patients, suggesting functional linkage. We
use the simplicity and genetic facility of the Drosophila system to investigate
in vivo whether 14-3-3s are causal or synergistic with Tau accumulation in
precipitating pathogenesis. Proteomic, biochemical and genetic evidence
demonstrate that both Drosophila 14-3-3 proteins interact with human wild-type
and mutant Tau on multiple sites irrespective of their phosphorylation state.
14-3-3 dimers regulate steady-state phosphorylation of both wild-type and the
R406W mutant Tau, but they are not essential for toxicity of either variant.
Moreover, 14-3-3 elevation itself is not pathogenic, but recruitment of dimers
on accumulating wild-type Tau increases its steady-state levels ostensibly by
occluding access to proteases in a phosphorylation-dependent manner. In
contrast, the R406W mutant, which lacks a putative 14-3-3 binding site, responds
differentially to elevation of each 14-3-3 isoform. Although excess 14-3-3ζ
stabilizes the mutant protein, elevated D14-3-3ɛ has a destabilizing effect
probably because of altered 14-3-3 dimer composition. Our collective data
demonstrate the complexity of 14-3-3/Tau interactions in vivo and suggest that
14-3-3 attenuation is not appropriate ameliorative treatment of Tauopathies.
Finally, we suggest that 'bystander' 14-3-3s are recruited by accumulating Tau
with the consequences depending on the composition of available dimers within
particular neurons and the Tau variant. |
Is the tyrosine kinase BTK implicated in autoimmunity? | Autoimmunity, hypersensitivity to B cell receptor (BCR) cross-linking, and splenomegaly caused by myeloerythroid hyperplasia were alleviated by Btk deficiency in lyn-/- mice. Augmented TLR9-induced Btk activation in PIR-B-deficient B-1 cells provokes excessive autoantibody production and autoimmunity. Autoimmunity was fully dependent on Btk kinase activity, because Btk inhibitor treatment (PCI-32765) could normalize B-cell activation and differentiation, and because autoantibodies were absent in Btk transgenic mice overexpressing a kinase inactive Btk mutant. | Transphosphorylation by Src family kinases is required for the activation of
Bruton's tyrosine kinase (Btk). Differences in the phenotypes of Btk-/- and
lyn-/- mice suggest that these kinases may also have independent or opposing
functions. B cell development and function were examined in Btk-/-lyn-/- mice to
better understand the functional interaction of Btk and Lyn in vivo. The
antigen-independent phase of B lymphopoiesis was normal in Btk-/-lyn-/- mice.
However, Btk-/-lyn-/- animals had a more severe immunodeficiency than Btk-/-
mice. B cell numbers and response to T cell-dependent antigens were reduced. Btk
and Lyn therefore play independent or partially redundant roles in the
maintece and function of peripheral B cells. Autoimmunity, hypersensitivity
to B cell receptor (BCR) cross-linking, and splenomegaly caused by
myeloerythroid hyperplasia were alleviated by Btk deficiency in lyn-/- mice. A
transgene expressing Btk at approximately 25% of endogenous levels (Btklo) was
crossed onto Btk-/- and Btk-/-lyn-/- backgrounds to demonstrate that Btk is
limiting for BCR signaling in the presence but not in the absence of Lyn. These
observations indicate that the net outcome of Lyn function in vivo is to inhibit
Btk-dependent pathways in B and myeloid cells, and that Btklo mice are a useful
sensitized system to identify regulatory components of Btk signaling pathways. Pathogens are sensed by Toll-like receptors (TLRs) expressed in leukocytes in
the innate immune system. However, excess stimulation of TLR pathways is
supposed to be connected with provocation of autoimmunity. We show that paired
immunoglobulin (Ig)-like receptor B (PIR-B), an immunoreceptor tyrosine-based
inhibitory motif-harboring receptor for major histocompatibility class I
molecules, on relatively primitive B cells, B-1 cells, suppresses TLR9 signaling
via Bruton's tyrosine kinase (Btk) dephosphorylation, which leads to attenuated
activation of nuclear factor kappaB p65RelA but not p38 or Erk, and blocks the
production of natural IgM antibodies, including anti-IgG Fc autoantibodies,
particularly rheumatoid factor. The autoantibody production in PIR-B-deficient
(Pirb(-/-)) mice was further augmented in combination with the Fas(lpr)
mutation, which might be linked to the development of autoimmune
glomerulonephritis. These results show the critical link between TLR9-mediated
sensing and a simultaneously evoked, PIR-B-mediated inhibitory circuit with a
Btk intersection in B-1 cells, and suggest a novel way toward preventing
pathogenic natural autoantibody production. INTRODUCTION: Systemic lupus erythematosus is a chronic autoimmune disease
characterized by an abundance of autoantibodies against nuclear antigens.
Bruton's tyrosine kinase (Btk) is a proximal transducer of the BCR signal that
allows for B-cell activation and differentiation. Recently, selective inhibition
of Btk by PCI-32765 has shown promise in limiting activity of multiple cells
types in various models of cancer and autoimmunity. The aim of this study was to
determine the effect of Btk inhibition by PCI-32765 on the development of lupus
in lupus-prone B6.Sle1 and B6.Sle1.Sle3 mice.
METHODS: B6.Sle1 or B6.Sle1.Sle3 mice received drinking water containing either
the Btk inhibitor PCI-32765 or vehicle for 56 days. Following treatment, mice
were examined for clinical and pathological characteristics of lupus. The effect
of PCI-32765 on specific cell types was also investigated.
RESULTS: In this study, we report that Btk inhibition dampens humoral
autoimmunity in B6.Sle1 monocongenic mice. Moreover, in B6.Sle1.Sle3 bicongenic
mice that are prone to severe lupus, Btk inhibition also dampens humoral and
cellular autoimmunity, as well as lupus nephritis.
CONCLUSIONS: These findings suggest that partial crippling of cell signaling in
B cells and antigen presenting cells (APCs) may be a viable alternative to total
depletion of these cells as a therapeutic modality for lupus. BTK and ITK are cytoplasmic tyrosine kinases of crucial importance for B and T
cell development, with loss-of-function mutations causing X-linked
agammaglobulinemia and susceptibility to severe, frequently lethal, Epstein-Barr
virus infection, respectively. Over the last few years, considerable efforts
have been made in order to develop small-molecule inhibitors for these kinases
to treat lymphocyte maligcies, autoimmunity or allergy/hypersensitivity. The
rationale is that even if complete lack of BTK or ITK during development causes
severe immunodeficiency, inactivation after birth may result in a less severe
phenotype. Moreover, therapy can be transient or only partially block the
activity of BTK or ITK. Furthermore, a drug-induced B cell deficiency is
treatable by gamma globulin substitution therapy. The newly developed BTK
inhibitor PCI-32765, recently renamed Ibrutinib, has already entered several
clinical trials for various forms of non-Hodgkin lymphoma as well as for
multiple myeloma. Experimental animal studies have demonstrated highly promising
treatment effects also in autoimmunity. ITK inhibitors are still under the early
developmental phase, but it can be expected that such drugs will also become
very useful. In this study, we present BTK and ITK with their signalling
pathways and review the development of the corresponding inhibitors. BTK is a cytoplasmic protein-tyrosine kinase, whose corresponding gene was
isolated in the early 1990s. BTK was initially identified by positional cloning
of the gene causing X-linked agammaglobulinemia and independently in a search
for new kinases. Given the phenotype of affected patients, namely lack of
B-lymphocytes and plasma cells with the ensuing inability to mount humoral
immune responses, BTK inhibitors were anticipated to have beneficial effects on
antibody-mediated pathologies, such as autoimmunity. In contrast to, for
example, the SRC-family of cytoplasmic kinases, there was no obvious way in
which structural alterations would yield constitutively active forms of BTK, and
such mutations were also not found in leukemias or lymphomas. In 2007, the first
efficient inhibitor, ibrutinib, was reported and soon became approved both in
the United States and in Europe for the treatment of three B-cell maligcies,
mantle cell lymphoma, chronic lymphocytic leukemia and Waldenström's
macroglobulinemia. Over the past few years, additional inhibitors have been
developed, with acalabrutinib being more selective, and recently demonstrating
fewer clinical adverse effects. The antitumor mechanism is also not related to
mutations in BTK. Instead tumor residency in lymphoid organs is inhibited,
making these drugs highly versatile. BTK is one of the only 10 human kinases
that carry a cysteine in the adenosine triphosphate-binding cleft. As this
allows for covalent, irreversible inhibitor binding, it provides these compounds
with a highly advantageous character. This quality may be crucial and bodes well
for the future of BTK-modifying medicines, which have been estimated to reach
annual multi-billion dollar sales in the future. |
What is the BioPlex network? | Protein interactions form a network whose structure drives cellular function and whose organization informs biological inquiry. BioPlex contains 23,744 interactions among 7,668 proteins with 86% previously undocumented. BioPlex accurately depicts known complexes, attaining 80%-100% coverage for most CORUM complexes. The network readily subdivides into communities that correspond to complexes or clusters of functionally related proteins. More generally, network architecture reflects cellular localization, biological process, and molecular function, enabling functional characterization of thousands of proteins. Network structure also reveals associations among thousands of protein domains, suggesting a basis for examining structurally related proteins. BioPlex, in combination with other approaches, can be used to reveal interactions of biological or clinical significance. For example, mutations in the membrane protein VAPB implicated in familial amyotrophic lateral sclerosis perturb a defined community of interactors. | Protein-protein interaction (PPI) networks are emerging as valuable prototypes
to study important problems in molecular cellular biology and systems
biomedicine. An analysis of the topological properties of a PPI network is very
helpful for understanding the function and structure of networks. In this study,
we analyzed the topological patterns in the BioPlex network containing
interactions among 10,961 proteins; most interactions were previously
undocumented. The BioPlex network is a comprehensive map of human protein
interactions and represents the first phase of a long-term effort to profile the
entire human ORFEOME collection. Similar to other biological networks, we
observed that the BioPlex network has several topological properties. We also
quantified correlations profiles for the BioPlex network and compared them to
randomized versions of the same network. We found that for the BioPlex network,
edges between proteins with intermediate degrees were strongly suppressed,
whereas edges between low-connected proteins were favored. Finally, the degrees
of essential genes were compared with the degrees of non-essential genes and
randomly selected proteins. There were no significant differences between the
groups. The development of large-scale data sets requires a new means to display and
disseminate research studies to large audiences. Knowledge of protein-protein
interaction (PPI) networks has become a principle interest of many groups within
the field of proteomics. At the confluence of technologies, such as
cross-linking mass spectrometry, yeast two-hybrid, protein cofractionation, and
affinity purification mass spectrometry (AP-MS), detection of PPIs can uncover
novel biological inferences at a high-throughput. Thus new platforms to provide
community access to large data sets are necessary. To this end, we have
developed a web application that enables exploration and dissemination of the
growing BioPlex interaction network. BioPlex is a large-scale interactome data
set based on AP-MS of baits from the human ORFeome. The latest BioPlex data set
release (BioPlex 2.0) contains 56 553 interactions from 5891 AP-MS experiments.
To improve community access to this vast compendium of interactions, we
developed BioPlex Display, which integrates individual protein querying, access
to empirical data, and on-the-fly annotation of networks within an easy-to-use
and mobile web application. BioPlex Display enables rapid acquisition of data
from BioPlex and development of hypotheses based on protein interactions. |
Which algorithm has been developed for detecting expansions of tandem repeats? | Identifying large expansions of short tandem repeats (STRs), such as those that cause amyotrophic lateral sclerosis (ALS) and fragile X syndrome, is challenging for short-read whole-genome sequencing (WGS) data. A solution to this problem is an important step toward integrating WGS into precision medicine. For that purpose, ExpansionHunter has been developed as a software tool that, using PCR-free WGS short- read data, can genotype repeats at the locus of interest, even if the expanded repeat is larger than the read length. | Identifying large expansions of short tandem repeats (STRs), such as those that
cause amyotrophic lateral sclerosis (ALS) and fragile X syndrome, is challenging
for short-read whole-genome sequencing (WGS) data. A solution to this problem is
an important step toward integrating WGS into precision medicine. We developed a
software tool called ExpansionHunter that, using PCR-free WGS short-read data,
can genotype repeats at the locus of interest, even if the expanded repeat is
larger than the read length. We applied our algorithm to WGS data from 3001 ALS
patients who have been tested for the presence of the C9orf72 repeat expansion
with repeat-primed PCR (RP-PCR). Compared against this truth data,
ExpansionHunter correctly classified all (212/212, 95% CI [0.98, 1.00]) of the
expanded samples as either expansions (208) or potential expansions (4).
Additionally, 99.9% (2786/2789, 95% CI [0.997, 1.00]) of the wild-type samples
were correctly classified as wild type by this method with the remaining three
samples identified as possible expansions. We further applied our algorithm to a
set of 152 samples in which every sample had one of eight different pathogenic
repeat expansions, including those associated with fragile X syndrome,
Friedreich's ataxia, and Huntington's disease, and correctly flagged all but one
of the known repeat expansions. Thus, ExpansionHunter can be used to accurately
detect known pathogenic repeat expansions and provides researchers with a tool
that can be used to identify new pathogenic repeat expansions. |
Which clotting factor is in the Andexxa? | Andexxa(r) is a first-in-class recombinant modified factor Xa protein. It is available to reverse life-threatening or uncontrolled bleeding with the factor Xa inhibitors apixaban and rivaroxaban. | Intravenous andexanet alfa [coagulation factor Xa (recombit),
inactivated-zhzo; Andexxa®] is a first-in-class recombit modified factor Xa
protein that has been developed by Portola Pharmaceuticals as a universal
antidote to reverse anticoagulant effects of direct or indirect factor Xa
inhibitors. In May 2018, andexanet alfa received its first global approval in
the USA for use in patients treated with rivaroxaban and apixaban, when reversal
of anticoagulant effects is required in life-threatening or uncontrolled
bleeding. Intravenous andexanet alfa is under regulatory review in the EU and is
undergoing clinical development in Japan. This article summarizes the milestones
in the development of andexanet alfa leading to this first global approval for
reversing anticoagulation of rivaroxaban and apixaban in adults. The use of direct oral anticoagulants over traditional warfarin has increased in
the United States over the past 10 years because of advantages such as ease of
use, predictable pharmacokinetic response, and safety. In 2015, the U.S. Food
and Drug Administration approved idarucizumab (Praxbind) for the reversal of the
direct thrombin inhibitor dabigatran, but no reversal agent has been available
for oral factor Xa (FXa) inhibitors until recently. Andexanet alfa was approved
in May 2018, under the brand name ANDEXXA, for the reversal of 2 of FXa
inhibitors, apixaban and rivaroxaban, when life-threatening or uncontrolled
bleeding occurs. This accelerated approval was based on change in anti-FXa
activity from baseline that indicated a reversal of the anticoagulant effect.
Any expanded Food and Drug Administration indication will be contingent on
results demonstrating improved hemostasis and efficacy for reversing other FXa
inhibitors. The direct oral anticoagulants (DOACs) have gained popularity recently among
both patients and providers for their comparable or better efficacy and safety
profiles compared with warfarin and the lack of need for routine monitoring of
anticoagulant effect. One obstacle for the more widespread use of the DOACs in
clinical practice has been the lack of a reversal agent. Most DOACs act by
directly binding to and inhibiting the effects of factor Xa. Andexanet alfa
(Andexxa, Portola Pharmaceuticals, San Francisco, CA) is a modified form of
factor Xa that acts as a decoy binding entity for DOACs, thereby allowing
endogenous factor Xa to perform its normal clotting functions. Andexanet has
proven efficacious in clinical trials for reversing the anticoagulant effects of
apixaban, edoxaban, and rivaroxaban, although its impact on clinical outcomes
has not been adequately studied. Andexanet has a boxed warning for
thromboembolic risks, ischemic risks, cardiac arrest, and sudden death, with
these adverse events occurring in up to 18% of patients in clinical trials.
However, the occurrence of these adverse events needs to be considered in
relation to the fragile nature of patients who receive this agent. Because the
duration of the DOACs is much less than that of warfarin, it is unclear how many
patients would actually need andexanet in clinical practice, because cessation
of the DOAC may be all that is needed to effectively manage bleeding.
Nonetheless, having andexanet available in cases of DOAC-associated severe or
life-threatening bleeding represents a therapeutic advance and should provide an
added level of comfort with the clinical use of DOACs. Andexanet alfa (Andexxa®), a first-in-class recombit modified factor Xa
protein, is currently the only specific agent available to reverse
life-threatening or uncontrolled bleeding with the factor Xa inhibitors apixaban
and rivaroxaban. Andexanet alfa acts as a decoy and competes with endogenous
factor Xa to bind factor Xa inhibitors, thereby reversing the anticoagulant
effects of factor Xa inhibitors, and restoring the activity of endogenous factor
Xa. In adults with major bleeding associated with the use of apixaban or
rivaroxaban, intravenous administration of andexanet alfa effectively and
rapidly reduces anti-factor Xa levels, with reduced levels being maintained
during continued treatment. The tolerability profile of andexanet alfa in
patients is generally similar to that reported of other approved anticoagulation
reversal agents. With the known increased risk of thromboembolic events
following andexanet alfa treatment, anticoagulant therapy should be resumed as
soon as medically appropriate. |
How are nucleosome posisitions correlated with sites of 5'-methyl-cytosine (5mC) or 5-hydroxy-methyl-cytosine (5hmC)? | We find that Mbd3 and Brg1 antagonistically regulate a common set of genes by regulating promoter nucleosome occupancy. outside of CpG islands most CpGs are methylated, and the average methylation density oscillates so that it is highest in the linker region between nucleosomes we have investigated nucleosome organization around hypomethylated regions (HMRs) | Numerous chromatin regulators are required for embryonic stem (ES) cell
self-renewal and pluripotency, but few have been studied in detail. Here, we
examine the roles of several chromatin regulators whose loss affects the
pluripotent state of ES cells. We find that Mbd3 and Brg1 antagonistically
regulate a common set of genes by regulating promoter nucleosome occupancy.
Furthermore, both Mbd3 and Brg1 play key roles in the biology of
5-hydroxymethylcytosine (5hmC): Mbd3 colocalizes with Tet1 and 5hmC in vivo,
Mbd3 knockdown preferentially affects expression of 5hmC-marked genes, Mbd3
localization is Tet1-dependent, and Mbd3 preferentially binds to 5hmC relative
to 5-methylcytosine in vitro. Finally, both Mbd3 and Brg1 are themselves
required for normal levels of 5hmC in vivo. Together, our results identify an
effector for 5hmC, and reveal that control of gene expression by antagonistic
chromatin regulators is a surprisingly common regulatory strategy in ES cells. During differentiation of embryonic stem cells, chromatin reorganizes to
establish cell type-specific expression programs. Here, we have dissected the
linkages between DNA methylation (5mC), hydroxymethylation (5hmC), nucleosome
repositioning, and binding of the transcription factor CTCF during this process.
By integrating MNase-seq and ChIP-seq experiments in mouse embryonic stem cells
(ESC) and their differentiated counterparts with biophysical modeling, we found
that the interplay between these factors depends on their genomic context. The
mostly unmethylated CpG islands have reduced nucleosome occupancy and are
enriched in cell type-independent binding sites for CTCF. The few remaining
methylated CpG dinucleotides are preferentially associated with nucleosomes. In
contrast, outside of CpG islands most CpGs are methylated, and the average
methylation density oscillates so that it is highest in the linker region
between nucleosomes. Outside CpG islands, binding of TET1, an enzyme that
converts 5mC to 5hmC, is associated with labile, MNase-sensitive nucleosomes.
Such nucleosomes are poised for eviction in ESCs and become stably bound in
differentiated cells where the TET1 and 5hmC levels go down. This process
regulates a class of CTCF binding sites outside CpG islands that are occupied by
CTCF in ESCs but lose the protein during differentiation. We rationalize this
cell type-dependent targeting of CTCF with a quantitative biophysical model of
competitive binding with the histone octamer, depending on the TET1, 5hmC, and
5mC state. BACKGROUND: The interplay between epigenetic modifications and chromatin
structure are integral to our understanding of genome function. Methylation of
cytosine (5mC) at CG dinucleotides, traditionally associated with
transcriptional repression, is the most highly studied chemical modification of
DNA, occurring at over 70% of all CG dinucleotides in the genome. Hypomethylated
regions (HMRs) often occur in CG islands (CGIs), however, they also occur
outside of CGIs and function as cell-type specific enhancers. During the process
of differentiation, reorganization of chromatin and nucleosome arrangement at
regulatory regions is thought to occur in order for the establishment of
cell-type specific transcriptional programs. However, the specifics regarding
the organization of nucleosomes at HMRs and the potential mechanisms regulating
nucleosome occupancy in these regions are unknown. Here, we have investigated
nucleosome organization around hypomethylated regions (HMRs) identified in two
mouse primary cells.
RESULTS: Microccocal nuclease (MNase) digested mononucleosomes from primary
cultures of new-born female mouse dermal fibroblasts and keratinocytes were
mapped and compared to the HMRs obtained from single base-pair resolution
methylomes. In both cell types, we find that nucleosomes are enriched at HMR
boundaries. In contrast to the nucleosomes found at boundaries of HMRs in CGIs,
HMRs outside of CGIs are calculated to be preferentially bound by nucleosomes,
with phased nucleosomes propagating into the methylated region. Nucleosomes are
enriched at the tissue-specific HMRs (TS-HMR) boundaries in both cell types
suggesting that nucleosome organization surrounding HMR boundaries is
independent of methylation status. In addition, we find potential transcription
factor (TF) binding sites (E-box motifs) enriched in non-CGI TS-HMR boundaries.
CONCLUSIONS: Our results show that intrinsic nucleosome occupancy score (INOS)
positively correlate with the nucleosome organization surrounding non-CGI
TS-HMRs, suggesting that DNA sequence plays a role in the establishment of HMRs
in the genome. Since nucleosomes impact all processes involving the genome, our
results provide a link between epigenetic modifications, chromatin structure,
and regulatory function. |
Which drugs are included in the drug LONSURF? | Lonsurf includes trifluridine and tipiracil. It is a novel oral anti-tumor agent combining an anti-neoplastic thymidine-based nucleoside analogue (trifluridine) with a thymidine phosphorylase inhibitor (tipiracil hydrochloride) presents a new treatment option for metastatic colorectal cancer patients refractory or intolerant to standard therapies. | Evolocumab (Repatha) for patients with hypercholesterolemia whose condition has
not been controlled by statins and other therapies; trifluridine/tipiracil
(Lonsurf) for metastatic colorectal cancer; and blood coagulation factor VIII
(Nuwiq) for adults and children with hemophilia A. Within the past several years, no chemotherapy has been sufficient to increase
the overall survival of patients with chemorefractory colorectal cancer. TAS-102
(Lonsurf) is an oral fluoropyrimidine that is formed by the combination of 2
active drugs: trifluridine (a nucleoside analog) and tipiracil hydrochloride (a
thymidine phosphorylase inhibitor). This drug extended the median overall
survival by approximately 2 months compared with placebo in a randomized phase
III trial composed of Asian and non-Asian patients with refractory (or
intolerant) metastatic colorectal cancer. The clinical development of TAS-102
began approximately a decade ago and included 2 pivotal randomized studies,
which are discussed in this review. This drug has just been approved in Japan,
and as soon as possible, it will be marketed in Western countries as well; it
will therefore become the standard of care for this patient population. The
optimal combination of TAS-102 with other agents, as well as the mechanism of
resistance to this regimen should be defined in the near future. Trifluridine/tipiracil (Lonsurf(®)) is a novel, orally active, antimetabolite
agent comprised of trifluridine, a thymidine-based nucleoside analogue, and
tipiracil, a potent thymidine phosphorylase inhibitor. Trifluridine is
incorporated into DNA via phosphorylation, ultimately inhibiting cell
proliferation. Tipiracil increases systemic exposure of trifluridine when
coadministered. Trifluridine/tipiracil has recently been approved for the
treatment of adult patients with metastatic colorectal cancer (mCRC) who are
refractory to or are not considered candidates for, current standard
chemotherapy and biological therapy in the EU and USA and in unresectable
advanced or recurrent CRC in Japan. The approved regimen of oral twice-daily
trifluridine/tipiracil (35 mg/m(2) twice daily on days 1-5 and 8-12 of each
28-day cycle) significantly improved overall survival and progression-free
survival and was associated with a significantly higher disease control rate
than placebo when added to best supportive care in the multinational, pivotal
phase III trial (RECOURSE) and a phase II Japanese trial. Trifluridine/tipiracil
was associated with an acceptable tolerability profile, with adverse events
generally being managed with dose reductions, temporary interruptions in
treatment or administration of granulocyte-colony stimulating factor. The most
common grade 3-4 adverse events (≥10 %) were anaemia, neutropenia,
thrombocytopenia and leukopenia. In conclusion, trifluridine/tipiracil is a
useful additional treatment option for the management of mCRC in patients who
are refractory to, or are not considered candidates for, currently available
therapies. The FDA approved TAS-102 (Lonsurf; Taiho Oncology, Inc.) for the treatment of
patients with metastatic colorectal cancer (mCRC) who have been previously
treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy;
an anti-VEGF biological therapy; and if RAS wild type, an anti-EGFR therapy. In
an international, multicenter, double-blinded, placebo-controlled trial
(TPU-TAS-102-301, herein referred to as RECOURSE), 800 patients with previously
treated mCRC were randomly allocated (2:1) to receive either TAS-102 35 mg/m2
orally twice daily after meals on days 1 through 5 and 8 through 12 of each
28-day cycle (n = 534) or matching placebo (n = 266). The trial demonstrated a
statistically significant improvement in overall survival for those randomized
to receive TAS-102, with a median survival of 7.1 months in the TAS-102 arm
[confidence interval (CI), 6.5-7.8] and 5.3 months in the placebo arm [CI,
4.6-6.0; hazard ratio (HR), 0.68; 95% CI, 0.58-0.81; P < 0.001, stratified
log-rank test]. The trial also demonstrated a statistically significant
prolongation of progression-free survival (HR, 0.47; 95% CI, 0.40-0.55; P <
0.001). The most common adverse reactions, in order of decreasing frequency,
observed in the patients who received TAS-102 were anemia, neutropenia,
asthenia/fatigue, nausea, thrombocytopenia, decreased appetite, diarrhea,
vomiting, abdominal pain, and pyrexia. Adverse events led to discontinuation of
TAS-102 in 3.6% of patients, and 13.7% required a dose reduction. The most
common adverse reactions leading to dose reduction were neutropenia, anemia,
febrile neutropenia, fatigue, and diarrhea. Clin Cancer Res; 23(12); 2924-7.
©2017 AACR. BACKGROUND: Treatment-related adverse events (AEs) are common in patients with
metastatic colorectal cancer (mCRC) receiving chemotherapy. These AEs may affect
patient adherence, particularly with completely oral regimens, such as
trifluridine/tipiracil (TAS-102, Lonsurf®), an antimetabolite agent for patients
with mCRC refractory or intolerant to standard therapies.
.
OBJECTIVES: This article reviews strategies for promoting adherence and
educating patients and caregivers about oral therapy with
trifluridine/tipiracil.
.
METHODS: Recommended strategies for managing AEs are reviewed, with a focus on
the most common AEs reported in patients with mCRC receiving
trifluridine/tipiracil in clinical trials.
.
FINDINGS: Oncology nurses play an important role in educating and counseling
patients regarding treatment and its potential side effects. Among patients with
mCRC refractory or intolerant to standard therapies, trifluridine/tipiracil was
found to have a favorable safety profile. It is associated with hematologic AEs
as well as a low incidence of nausea, diarrhea, vomiting, anorexia, and fatigue. We have developed 3D-tumoroids and tumor slice in vitro culture systems from
surgical tumor specimens derived from patients with colorectal cancer (CRC) or
lung cancer to evaluate immune cell populations infiltrating cultured tissues.
The system incorporates patient's peripherally and tumor-derived immune cells
into tumoroid in vitro cultures to evaluate the ability of the culture to mimic
an immunosuppressive tumor microenvironment (ITM). This system enables analysis
of tumor response to standard therapy within weeks of surgical resection. Here
we show that tumoroid cultures from a CRC patient are highly sensitive to the
thymidylate synthase inhibitor 5-fluorouracil (adrucil) but less sensitive to
the combination of nucleoside analog trifluridine and thymidine phosphorylase
inhibitor tipiracil (Lonsurf). Moreover, re-introduction of isolated immune
cells derived from surrounding and infiltrating tumor tissue as well as CD45+
tumor infiltrating hematopoietic cells displayed prolonged (>10 days) survival
in co-culture. Established tumor slice cultures were found to contain both an
outer epithelial and inner stromal cell compartment mimicking tumor structure in
vivo. Collectively, these data suggest that, 3D-tumoroid and slice culture
assays may provide a feasible in vitro approach to assess efficacy of novel
therapeutics in the context of heterogeneous tumor-associated cell types
including immune and non-transformed stromal cells. In addition, delineating the
impact of therapeutics on immune cells, and cell types involved in therapeutic
resistance mechanisms may be possible in general or for patient-specific
responses. The National Institute for Health and Care Excellence (NICE) invited Servier,
the company manufacturing trifluridine and tipiracil (T/T; trade name:
Lonsurf®), to submit evidence for the clinical and cost effectiveness of T/T
compared with best supportive care (BSC) for metastatic colorectal cancer
(third-line or later). Kleijnen Systematic Reviews Ltd (KSR), in collaboration
with Maastricht University Medical Center, was commissioned as the Evidence
Review Group (ERG). This paper presents a summary of the company's submission
(CS), the ERG report and the development of the NICE guidance for the use of
this drug in England and Wales by the appraisal committee (AC). The ERG produced
a critical review of the clinical and cost effectiveness of T/T based upon the
CS. In the CS, pooled evidence of two trials (a phase II trial and RECOURSE)
showed that T/T resulted in a significant increase in overall survival [OS;
hazard ratio (HR) 0.67, 95% CI 0.58-0.78] and progression-free survival (PFS; HR
0.46, 95% CI 0.40-0.53). The AC considered the survival benefit of T/T
clinically meaningful although relatively small. The ERG highlighted that none
of the participants in the phase II trial and approximately half of the RECOURSE
participants (394 of 800) were from Europe, which might limit the applicability
of the study findings to the NHS. Moreover, the ERG's critical assessment of the
company's economic evaluation highlighted a number of concerns that resulted in
11 adjustments to the company's base-case analysis. The ERG adjustments that had
the largest impact were using the RECOURSE trial data only (instead of the
pooled evidence), fixing errors and violations and using the utilities from the
CORRECT trial (identified in the literature review) only. The ERG preferred to
use the RECOURSE trial data only given the suboptimal methodology used by the
company to pool the evidence. However, since there were no fundamental arguments
to prevent the two trials from being pooled, the ERG also presented its
base-case analysis based on the pooled effectiveness estimates. The company
base-case resulted in an incremental cost effectiveness ratio (ICER) of £44,032
per QALY gained while the ERG base-case resulted in ICERs of £52,695 and £49,392
per QALY gained based on the RECOURSE trial only and pooled evidence,
respectively. Since the AC concluded that the most plausible ICER was £49,392
per QALY gained, and that T/T meets end-of-life criteria, T/T was recommended as
a cost effective use of NHS resources. PURPOSE: Trifluridine/tipiracil (FTD/TPI; TAS-102, Lonsurf®), a novel form of
chemotherapy for metastatic colorectal cancer (mCRC), has shown clinical benefit
in the global, phase III RECOURSE trial, regardless of patient age. Here, we
report the safety and tolerability profile of FTD/TPI from an expanded-access
program (EAP) in the US patients with mCRC whose disease has progressed on the
standard therapies.
METHODS: A total of 549 patients (≥ 18 years) with histologically confirmed mCRC
following two or more regimens of standard therapy and an Eastern Cooperative
Oncology Group performance status of 0 or 1 participated in this open-label EAP.
During the 28-day treatment cycle, patients took FTD/TPI 35 mg/m2 twice daily
for 5 days followed by 2 days of rest for 2 weeks, with a 14-day rest period.
Data were collected for therapy duration, treatment discontinuation, and adverse
events. Age-based post hoc analysis was performed to determine the safety of
FTD/TPI in elderly (≥ 65 years) versus younger (< 65 years) patients.
RESULTS: FTD/TPI-treated patients in this EAP had a similar therapy duration and
time to treatment discontinuation to those in the RECOURSE trial. The safety
profile in elderly patients was consistent with that in younger patients, with
no unexpected safety concerns.
CONCLUSIONS: This USA-based, open-label EAP has confirmed a similar safety and
tolerability profile for FTD/TPI to that observed in the RECOURSE trial.
Furthermore, FTD/TPI is well tolerated and can be considered as a treatment
option in elderly patients with mCRC.
TRIAL REGISTRATION: NCT02286492. BACKGROUND: Trifluridine/tipiracil (TAS-102, Lonsurf®), a novel oral anti-tumor
agent combining an anti-neoplastic thymidine-based nucleoside analogue
(trifluridine, FTD) with a thymidine phosphorylase inhibitor (tipiracil
hydrochloride, TPI) presents a new treatment option for metastatic colorectal
cancer (mCRC) patients refractory or intolerant to standard therapies. FTD/TPI
was approved in the European Union (EU) in April 2016 and launched on the German
market in August 15, 2016.
METHODS: We investigated the characteristics of patients (pts) with mCRC treated
with FTD/TPI at 118 centers in Germany from January 12 to August 14, 2016 and
analyzed the safety in a clinical real-world setting.
RESULTS: In Germany, a total of 226 mCRC patients were included into a
compassionate-use-program (CUP) and received FTD/TPI. For 45.5% of patients
(n = 101), 253 adverse events (AE) were documented, most of them drug-related
(n = 135). From January 12 (2016) to March 2 (2017), 124 serious adverse events
(SAE) were reported (74 drug related). The most common serious adverse drug
reactions (SADR) were leukopenia (12 events), neutropenia (8 events), anemia (7
events), diarrhea and nausea (5 events each) (observation period January 12 2016
to October 7 2016). In total, 122 patients (54%) discontinued FTD/TPI treatment,
mostly due to progression (n = 75) followed by AEs (n = 21), deaths (n = 16),
and non-specified reasons (n = 16). Interestingly, 12 patients with ECOG PS ≥2
achieved up to 3 cycles of FTD/TPI and in this patient population only 3
treatment discontinuations due to AEs were documented and the safety profile was
comparable to the entire population.
CONCLUSION: The patient characteristics as well as the safety profile of FTD/TPI
documented in the German CUP were consistent with those reported in the pivotal
trial RECOURSE without unexpected safety signals. Background: The treatment options for patients with therapy refractory
metastatic colorectal cancer (mCRC) are sparse. TAS-102 (FTD/TPI) is a new oral
anti-tumour agent composed of a nucleoside analogue, trifluridine, and a
thymidine phosphorylase inhibitor, tipiracil, indicated for patients with mCRC
who are refractory to standard therapies. This study summarizes published and
unpublished experience with FTD/TPI in clinical practice settings. Patients and
methods: The Medline/PubMed, Embase and Cochrane Library databases were searched
to identify observational studies on FTD/TPI monotherapy for mCRC. Papers
describing use of FTD/TPI monotherapy outside clinical trials in series of
patients evaluable for effectiveness were eligible. The outcomes of interest
were median progression free survival (mPFS), median overall survival (mOS) as
well as mean PFS time restricted to six months (PFS6m) and mean OS time
restricted to one year (OS1y). Results of the pooled analyses of observational
studies were compared to the results of the Japanese phase II trial and the two
phase III trials, RECOURSE and TERRA. Results: Seven published and two
unpublished studies with 1008 patients from 64 centres were included for
analysis. The pooled mPFS was 2.2 months (95% CI 2.1 to 2.3 months), and the
pooled mOS was 6.6 months (95% CI 6.1 to 7.1 months). PFS6m was 2.9 months (95%
CI 2.6 to 3.1 months) and OS1y was 6.8 (95% CI 6.0 to 7.5) months. While these
results all reflect RECOURSE, the pooled mOS is lower than in the phase II trial
and the OS1y is inferior to both the phase II trial and TERRA. Conclusion: This
systematic review and a meta-analysis indicates that in real life settings, the
survival benefit of FTD/TPI monotherapy in patients with therapy refractory mCRC
reflects the outcomes in RECOURSE but is inferior to outcomes in the two Asian
efficacy trials. What is already known TAS 102 (Lonsurf) is an oral fixed dose
combination of trifluridine (FTD) and tipiracil (TPI) indicated as salvage-line
treatment in patients with therapy refractory metastatic colorectal cancer
(mCRC). A Japanese phase II trial and two phase III trials, RECOURSE and TERRA,
demonstrated that FTD/TPI prolonged overall survival. What this study adds This
systematic review and meta-analysis of real life data from 64 sites indicates
that the effectiveness in daily clinical practice settings of FTD/TPI
monotherapy in late stage mCRC reflects the outcomes in RECOURCE but is inferior
to the outcomes in the Japanese phase II trial and TERRA. Trifluridine/tipiracil (Lonsurf®) is a fixed-dose combination tablet comprising
trifluridine, an antineoplastic nucleoside analogue, and tipiracil, a thymidine
phosphorylase inhibitor. Trifluridine/tipiracil has recently been granted an
additional indication in the USA for the treatment of metastatic gastric cancer,
including gastroesophageal junction adenocarcinoma, in patients who have been
previously treated with at least two systemic treatment regimens, and has
received a positive opinion for this indication in the EU. In the large pivotal
phase III TAGS trial, trifluridine/tipiracil plus best supportive care (BSC)
significantly prolonged overall survival (OS; primary endpoint) compared with
placebo plus BSC in this patient group. Progression-free survival (PFS) and the
disease control rate were also improved with trifluridine/tipiracil relative to
placebo. Health-related quality of life was not adversely affected by the
addition of trifluridine/tipiracil to BSC and time to deterioration of Eastern
Cooperative Oncology Group (ECOG) performance status was significantly delayed.
The most common adverse events were mainly haematological (neutropenia,
leucopenia and anaemia) and gastrointestinal (nausea, vomiting and diarrhoea),
and were generally manageable with dosage modifications and/or supportive care.
Adverse events ≥ Grade 3 were most frequently haematological in nature. Thus,
trifluridine/tipiracil provides a valuable and much needed treatment option for
patients with metastatic gastric or gastroesophageal junction adenocarcinoma
that has progressed on at least two prior therapies. |
What is 23andMe? | We first take a look at how personal genomics services, exemplified by the company 23andMe, | As part of personalised medicine emerging from the human genomics revolution,
many websites now offer direct-to-consumer genetic testing. Here, we examine
three personal genomics companies--Navigenics, deCODEme and 23andMe--each of
which represents contrasting registers of 'personalisation'. We identify three
distinctive registers in these websites: a paternalistic (medical) register; a
translational (scientific) register and a democratic (consumerist) register. We
explore in detail the rhetorical and discourse devices employed in these
websites to assess how personalised healthcare is promised to the public.
Promising information that will empower prevention of common complex diseases
and ensure better quality of life is conflated with promising greater access to
personal information. The presence and absence of scientific legitimacy is
related to concerns about accuracy and validity on the one side, and fears of
paternalism and elitism on the other. Nevertheless, a common strategy uniting
these different styles of personalisation is consumer empowerment. Finally, we
consider the tension between the drive of translational medicine to make human
genomic research practically relevant, and the intrinsic uncertainties of
scientific research and show how, in the commercial domain, future risks are
transformed into discourses of promise by concealing these uncertainties. PURPOSE: 23andMe is back on the market as the first direct-to-consumer genetic
testing company that "includes reports that meet Food and Drug Administration
(FDA) standards…." But, whereas its front-end product is selling individual
genetic tests online, its back-end business model is amassing one of the largest
privately owned genetic databases in the world. What is the effect, however, of
the private control of bio/databases on genetic epidemiology and public health
research?
METHODS: The recent federal government notices of proposed rulemaking for: (1)
revisions to regulations governing human subjects research and (2) whether
certain direct-to-consumer genetic tests should require premarket FDA review,
were reviewed and related to the 23andMe product, business model, and consumer
agreements.
RESULTS: FDA regulatory action so far has focused on the return of consumer test
reports but it should also consider the broader misuse of data and information
not otherwise protected by human subjects research regulations.
CONCLUSIONS: As the federal government revises its decades-old human subjects
research structure, the Executive Office of the President (EOP) should consider
a cohesive approach to regulating private genetic bio/databanks. This strategy
should allow the FDA and other agencies to play a role in expanding current
regulatory coverage. BACKGROUND: Rapid advances in scientific research have led to an increase in
public awareness of genetic testing and pharmacogenetics. Direct-to-consumer
(DTC) genetic testing companies, such as 23andMe, allow consumers to access
their genetic information directly through an online service without the
involvement of healthcare professionals. Here, we evaluate the clinical
relevance of pharmacogenetic tests reported by 23andMe in their UK tests.
METHODS: The research papers listed under each 23andMe report were evaluated,
extracting information on effect size, sample size and ethnicity. A wider
literature search was performed to provide a fuller assessment of the
pharmacogenetic test and variants were matched to FDA recommendations.
Additional evidence from CPIC guidelines, PharmGKB, and Dutch Pharmacogenetics
Working Group was reviewed to determine current clinical practice. The value of
the tests across ethnic groups was determined, including information on linkage
disequilibrium between the tested SNP and causal pharmacogenetic variant, where
relevant.
RESULTS: 23andMe offers 12 pharmacogenetic tests to their UK customers, some of
which are in standard clinical practice, and others which are less widely
applied. The clinical validity and clinical utility varies extensively between
tests. The variants tested are likely to have different degrees of sensitivity
due to different risk allele frequencies and linkage disequilibrium patterns
across populations. The clinical relevance depends on the ethnicity of the
individual and variability of pharmacogenetic markers. Further research is
required to determine causal variants and provide more complete assessment of
drug response and side effects.
CONCLUSION: 23andMe reports provide some useful pharmacogenetics information,
mirroring clinical tests that are in standard use. Other tests are unspecific,
providing limited guidance and may not be useful for patients without
professional interpretation. Nevertheless, DTC companies like 23andMe act as a
powerful intermediate step to integrate pharmacogenetic testing into clinical
practice. Most genetic testing requires a doctor's prescription. In April 2017, however,
the U.S. Food and Drug Administration (FDA) gave genetics company 23andMe the
go-ahead to sell DNA tests assessing the user's level of risk for ten health
conditions, including Parkinson's disease and late-onset Alzheimer's disease.
This was followed nearly a year later by approval to sell tests for three
mutations in the genes BRCA1 and BRCA2 linked to increased breast cancer risk.
These remain the only FDA-approved direct-to-consumer (DTC) tests for genetic
risk of disease. |
Is induction of interferon by TLR7 higher in males? | Yes. TLR7 activation correlates with induction of interferon more strongly in males. | An efficient immune response against hepatitis C virus (HCV) is necessary to
clear infection. As HCV is a single-stranded RNA virus, a role for TLR7 in the
immune response against HCV is possible, and early clinical studies have
demonstrated an antiviral effect of TLR7 stimulation. We tested the hypothesis
that genetic variations of TLR7 are associated with chronic HCV-infection and
outcome of therapy. The prevalence of three TLR7 variations was analysed in 978
patients with chronic HCV-infection, 898 patients with chronic liver disease of
other aetiologies, and in 203 healthy controls. The prevalence of TLR7
variations was correlated with the response to interferon-alpha-based treatment
in 544 patients with chronic HCV-infection. We analysed TLR7 polymorphisms by
melting curve analysis and reconstructed haplotypes. The c.32A>T variation was
over-represented in female patients with chronic HCV-infection compared to
patients with other chronic liver diseases and to healthy controls (P < 0.05).
In contrast, c.2403 G>A was less prevalent in male patients with chronic
HCV-infection (P < 0.05). No association was observed for the third variant,
c.1-120T>G. Haplotype analysis confirmed the differential distribution of TLR7
variants between the groups. Within the group of female patients with chronic
HCV-infection, c.32T was predictive of an unfavourable outcome of
interferon-alpha therapy (P < 0.05). This study reports the association of TLR7
variants with chronic HCV-infection and with the response to interferon-alpha
therapy in patients with chronic HCV-infection. Our results suggest that
variations of TLR7 impair the immune response to HCV and imply a gender-specific
effect of this X-chromosomal variation. |
Cushing's disease is associated with a tumor in what part of the body? | Cushing's disease is associated with a tumor in the pituitary gland | BACKGROUND: Cushing's syndrome due to an ACTH-secreting pituitary tumor is
associated with serious morbidity and mortality. As there is no definitive
medical treatment, surgical removal of the tumor via the transsphenoidal route
remains the first choice. Postoperative hypocortisolemia is recognized as the
best indicator of cure.
OBJECTIVE: To report the postoperative outcome and long-term follow-up of
patients with surgically treated Cushing disease at the Rabin Medical Center.
METHODS: We reviewed the medical records of 27 patients with Cushing disease
operated on between the period 1990 and 2003. The same experienced surgeon
performed all surgeries.
RESULTS: Cushing disease accounted for 15% of all pituitary surgeries in our
center. The mean age was 46 years, and the female to male ratio was 25:2.
Macroadenomas were found in 19% of cases, and a negative MRI in another 19%. The
cure rate was 70% overall and 80% when only microadenomas were considered. There
were no major perioperative complications. Four out of 8 surgical failures were
re-operated, and three achieved cure. After a mean follow-up period of 5.9
years, there was only one recurrence.
CONCLUSION: Our results are in accordance with those reported by others and
confirm that in the hands of an experienced neurosurgeon, pituitary surgery
constitutes an effective treatment for Cushing disease. Cushing's disease (CD) is a rare disabling condition caused by
Adrenocorticotropic hormone (ACTH)-secreting adenomas of the pituitary. The
majority of corticotropic adenomas are monoclonal and occur sporadically. Only
rarely does CD arise in the context of genetic familial syndromes. Targeted
sequencing of oncogenes and tumour suppressor genes commonly mutated in other
tumours did not identify recurrent mutations. In contrast, next generation
sequencing allowed us recently to clarify the genetic basis of CD: we identified
somatic driver mutations in the ubiquitin-specific protease 8 (USP8) gene in a
significant portion of corticotropinomas. These mutations represent a novel and
unique mechanism leading to ACTH excess. Inhibition of USP8 or its downstream
signalling pathways could represent a new therapeutic approach for the
management of CD. In this review, we will focus on this new evidence and its
implication for clinical care of affected patients. BACKGROUND: Cushing's disease (CD) is a rare endocrine disorder associated with
increased serum levels of cortisol secreted due to an underlying tumour in
pituitary. Psychiatric disturbances like depression, psychosis, mania along with
body image disturbances are seen in patients of CD. Hence, we undertook this
research to find the prevalence and type of psychiatric disorders, body image
disturbances, and self-esteem in patients of CD.
MATERIALS AND METHODS: Thirty-five patients diagnosed as CD as per the standard
criteria by the endocrinologist were recruited after informed consent and ethics
approval. Proforma with demographic details, Structured Clinical Interview for
DSM-IV, Beck Depression Inventory (BDI), Rosenberg Self-Esteem Scale, and Body
Image Concern Inventory were used for assessment of the aims.
RESULTS: 65% patients had psychopathology with 21% patients having major
depressive disorder, 62% patients had mild, and 28% had moderate depression on
BDI. 50% patients had body image disturbances and 60% had low self-esteem.
Depression was found to have a negative correlation with self-esteem and
positive correlation with body image disturbances.
CONCLUSION: A high prevalence of psychopathology is seen in patients of CD which
may often go undetected. Liaison with the endocrinologist would also work
towards improving the issues of body image disturbances and self-esteem for
better prognosis for the patient. Cushing's disease is primarily caused by autonomic hypersecretion of
adrenocorticotropic hormone (ACTH) from a pituitary adenoma. In Cushing's
disease, mutations in the ubiquitin-specific protease 8 (USP8) have been
detected. These mutations are associated with hyperactivation of USP8 that
prevent epidermal growth factor receptor (EGFR) degradation. This leads to
increased EGFR stability and results in the maintece of EGFR signaling in
Cushing's disease. USP8 inhibitors can suppress the growth of various tumors. In
this study, the effects of a potent USP8 inhibitor, DUBs-IN-2, on ACTH
production and cell proliferation were examined in mouse corticotroph tumor
(AtT-20) cells. Proopiomelanocortin (Pomc) mRNA levels and ACTH levels were
decreased in AtT-20 cells by DUBs-IN-2. Further, cell proliferation was
inhibited, and apoptosis was induced by DUBs-IN-2. Transcript levels of
pituitary tumor-transforming gene 1 (Pttg1), a pituitary tumor growth marker,
were increased; and transcript levels of stress response growth arrest and DNA
damage-inducible 45 (Gadd45β) and Cdk5 and ABL enzyme substrate 1 (Cables1) mRNA
levels were increased in response to the drug. Gadd45β or Cables1 knockdown
partially inhibited the DUBs-IN-2-induced decrease in cell proliferation, but
not Pomc mRNA levels. Both GADD45β and CABLES1 may be responsible, at least in
part, for the USP8-induced suppression of corticotroph tumor cell proliferation.
USP-8 may be a new treatment target in Cushing's disease. |
Which was the first genetically modified organism (GMO) to be used as vaccine? | The first genetically modified organism to be used as vaccine was the live oral cholera vaccine CVD 103-HgR or vaxchora. | Effective and easy to administer cholera vaccines are in need more than ever,
for at risk populations and travellers alike. In many parts of the world cholera
is still endemic, causing outbreaks and constituting repeatedly serious public
health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol),
the first genetically modified organism (GMO) used as vaccine, was in its time
(launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective
efficacy of 80-100% against moderate to severe cholera, acting within 8 days and
exhibiting excellent safety, indiscernible from placebo. However, there were
strong headwinds: In the 1990s the indication for cholera vaccines was generally
downplayed by experts and in 1997 the European Commission called for a
moratorium of GMOs which blocked the registration in the European Union. Thus,
demand for this vaccine remained low and in 2003 it was taken off the market for
economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced
again, now produced in the U.S. and equipped with a U.S. FDA license (June 10,
2016). What had happened? This commentary gives a critical account of an almost
unbelievable string of misadventures, emerging adverse circumstances and
man-made failures which nearly killed this single-dose live oral cholera
vaccine. The good news is that patience and persistence lead to success in the
end, allowing good science to prevail for the benefit of those in need. |
How does PRDM9 recognize the specific DNA motifs for meiotic recombination? | The PRDM9 gene encodes a protein with a highly variable tandem-repeat zinc finger (ZF) DNA-binding domain that plays a key role in determining sequence-specific hotspots of meiotic recombination genome wide. The long zinc finger domain of PRDM9 forms a highly stable and long-lived complex with its DNA recognition sequence. | Meiotic recombination generates reciprocal exchanges between homologous
chromosomes (also called crossovers, COs) that are essential for proper
chromosome segregation during meiosis and are a major source of genome diversity
by generating new allele combinations. COs have two striking properties: they
occur at specific sites, called hotspots, and these sites evolve rapidly. In
mammals, the Prdm9 gene, which encodes a meiosis-specific histone H3
methyltransferase, has recently been identified as a determit of CO hotspots.
Here, using transgenic mice, we show that the sole modification of PRDM9 zinc
fingers leads to changes in hotspot activity, histone H3 lysine 4 trimethylation
(H3K4me3) levels, and chromosome-wide distribution of COs. We further
demonstrate by an in vitro assay that the PRDM9 variant associated with hotspot
activity binds specifically to DNA sequences located at the center of the three
hotspots tested. Remarkably, we show that mutations in cis located at hotspot
centers and associated with a decrease of hotspot activity affect PRDM9 binding.
Taken together, these results provide the direct demonstration that Prdm9 is a
master regulator of hotspot localization through the DNA binding specificity of
its zinc finger array and that binding of PRDM9 at hotspots promotes local
H3K4me3 enrichment. During mammalian meiosis, double-strand breaks are deliberately made throughout
the genome and then repaired, leading to the exchange of genetic material
between copies of chromosomes. How the locations of breaks are specified was
largely unknown until a fortuitous confluence of statistical genetics and
molecular biology uncovered the role of PRDM9, a DNA binding protein. Many
properties of this protein remain mysterious, however, including how it binds to
DNA, how it contributes to male infertility-both in humans, and in hybrid
mice-and why, in spite of its fundamental function in meiosis, its binding
domain varies extensively among humans and across mammals. We present a brief
summary of what has recently been learned about PRDM9 in different fields,
focusing on the puzzles yet to be resolved. BACKGROUND: Meiotic recombination ensures proper segregation of homologous
chromosomes and creates genetic variation. In many organisms, recombination
occurs at limited sites, termed 'hotspots', whose positions in mammals are
determined by PR domain member 9 (PRDM9), a long-array zinc-finger and
chromatin-modifier protein. Determining the rules governing the DNA binding of
PRDM9 is a major issue in understanding how it functions.
RESULTS: Mouse PRDM9 protein variants bind to hotspot DNA sequences in a manner
that is specific for both PRDM9 and DNA haplotypes, and that in vitro binding
parallels its in vivo biological activity. Examining four hotspots, three
activated by Prdm9Cst and one activated by Prdm9Dom2, we found that all binding
sites required the full array of 11 or 12 contiguous fingers, depending on the
allele, and that there was little sequence similarity between the binding sites
of the three Prdm9Cst activated hotspots. The binding specificity of each
position in the Hlx1 binding site, activated by Prdm9Cst, was tested by mutating
each nucleotide to its three alternatives. The 31 positions along the binding
site varied considerably in the ability of alternative bases to support binding,
which also implicates a role for additional binding to the DNA phosphate
backbone.
CONCLUSIONS: These results, which provide the first detailed mapping of PRDM9
binding to DNA and, to our knowledge, the most detailed analysis yet of DNA
binding by a long zinc-finger array, make clear that the binding specificities
of PRDM9, and possibly other long-array zinc-finger proteins, are unusually
complex. A recent study investigates the in vitro DNA binding behavior of PRDM9, a zinc
finger protein involved in the localization of recombination hotspots in
mammals. BACKGROUND: Genetic recombination plays an important role in evolution,
facilitating the creation of new, favorable combinations of alleles and the
removal of deleterious mutations by unlinking them from surrounding sequences.
In most mammals, the placement of genetic crossovers is determined by the
binding of PRDM9, a highly polymorphic protein with a long zinc finger array, to
its cognate binding sites. It is one of over 800 genes encoding proteins with
zinc finger domains in the human genome.
RESULTS: We report a novel technique, Affinity-seq, that for the first time
identifies both the genome-wide binding sites of DNA-binding proteins and
quantitates their relative affinities. We have applied this in vitro technique
to PRDM9, the zinc-finger protein that activates genetic recombination,
obtaining new information on the regulation of hotspots, whose locations and
activities determine the recombination landscape. We identified 31,770 binding
sites in the mouse genome for the PRDM9(Dom2) variant. Comparing these results
with hotspot usage in vivo, we find that less than half of potential PRDM9
binding sites are utilized in vivo. We show that hotspot usage is increased in
actively transcribed genes and decreased in genomic regions containing H3K9me2/3
histone marks or bound to the nuclear lamina.
CONCLUSIONS: These results show that a major factor determining whether a
binding site will become an active hotspot and what its activity will be are
constraints imposed by prior chromatin modifications on the ability of PRDM9 to
bind to DNA in vivo. These constraints lead to the presence of long genomic
regions depleted of recombination. In mammals, meiotic recombination occurs at 1- to 2-kb genomic regions termed
hotspots, whose positions and activities are determined by PRDM9, a DNA-binding
histone methyltransferase. We show that the KRAB domain of PRDM9 forms complexes
with additional proteins to allow hotspots to proceed into the next phase of
recombination. By a combination of yeast-two hybrid assay, in vitro binding, and
coimmunoprecipitation from mouse spermatocytes, we identified four proteins that
directly interact with PRDM9's KRAB domain, namely CXXC1, EWSR1, EHMT2, and
CDYL. These proteins are coexpressed in spermatocytes at the early stages of
meiotic prophase I, the limited period when PRDM9 is expressed. We also detected
association of PRDM9-bound complexes with the meiotic cohesin REC8 and the
synaptonemal complex proteins SYCP3 and SYCP1. Our results suggest a model in
which PRDM9-bound hotspot DNA is brought to the chromosomal axis by the action
of these proteins, ensuring the proper chromatin and spatial environment for
subsequent recombination events. Homologous recombination is required for proper segregation of homologous
chromosomes during meiosis. It occurs predomitly at recombination hotspots
that are defined by the DNA binding specificity of the PRDM9 protein. PRDM9
contains three conserved domains typically involved in regulation of
transcription; yet, the role of PRDM9 in gene expression control is not clear.
Here, we analyze the germline transcriptome of Prdm9-/- male mice in comparison
to Prdm9+/+ males and find no apparent differences in the mRNA and miRNA
profiles. We further explore the role of PRDM9 in meiosis by analyzing the
effect of the KRAB, SSXRD, and post-SET zinc finger deletions in a cell culture
expression system and the KRAB domain deletion in mice. We found that although
the post-SET zinc finger and the KRAB domains are not essential for the
methyltransferase activity of PRDM9 in cell culture, the KRAB domain mutant mice
show only residual PRDM9 methyltransferase activity and undergo meiotic arrest.
In aggregate, our data indicate that domains typically involved in regulation of
gene expression do not serve that role in PRDM9, but are likely involved in
setting the proper chromatin environment for initiation and completion of
homologous recombination. |
Which micro-RNAs (miR) are associated with the human cycloxygenase-2 (COX-2) gene promoter? | MicroRNA-16, miRNA-128, miR-26b, icroRNA-26a, MicroRNA-146b-3p, microRNA-137, mi R-146a, mir-143-5p,microRNA-101, microRNAs-142-3 p, mi r-146p, mir-128 and miR -128 were found to be associated with the human cycloxygenase-2 (COX-2) gene promoter. | Commonly observed in colorectal cancer is the elevated expression of the
prostaglandin (PG) synthase COX-2. In normal intestinal epithelium, the COX-2
mRNA is targeted for rapid decay through the 3'-untranslated region (3'-UTR)
adenylate- and uridylate (AU)-rich element (ARE), whereas in tumors ARE-mediated
decay is compromised. Here we show that the COX-2 ARE can mediate degradation
through microRNA (miRNA)-mediated regulation. We identified miR-16 to bind the
COX-2 3'-UTR and inhibit COX-2 expression by promoting rapid mRNA decay. In
colorectal cancer cells and tumors, miR-16 levels were decreased approximately
twofold and miR-16 expression in cancer cells attenuated COX-2 expression and PG
synthesis. The COX-2 ARE is also bound by the RNA-binding protein HuR. In
colorectal cancer tumors, HuR is overexpressed and localized within the
cytoplasm, where it promotes ARE-mRNA stabilization. Under conditions of HuR
overexpression, miR-16 was unable to promote rapid mRNA decay through the COX-2
ARE. Ribonucleoprotein immunoprecipitation of HuR showed direct association with
miR-16 that was reversed when cytoplasmic trafficking of HuR was inhibited.
Furthermore, this interaction between HuR and miR-16 promoted the downregulation
of miR-16. These new results identify miR-16 as a central posttranscriptional
regulator of COX-2 and show the ability of elevated levels of HuR to antagonize
miR-16 function. Along with insight into altered ARE-mediated mRNA decay
observed in colorectal cancer, these findings provide a new explanation for
tumor-derived loss of miR-16. Cyclooxgenase-2 (COX-2) knock-out mouse experiments showed that COX-2 was
necessary for in vivo allergic inflammation, such as passive cutaneous
anaphylaxis, passive systemic anaphylaxis, and triphasic cutaneous allergic
reaction. TargetScan analysis predicted COX-2 as a target of miR-26a and
miR-26b. miR-26a/-26b decreased luciferase activity associated with
COX-2-3'-UTR. miR-26a/-26b exerted negative effects on the features of in vitro
and in vivo allergic inflammation by targeting COX-2. ChIP assays showed the
binding of HDAC3 and SNAIL, but not COX-2, to the promoter sequences of miR-26a
and miR-26b. Cytokine array analysis showed that the induction of chemokines,
such as MIP-2, in the mouse passive systemic anaphylaxis model occurred in a
COX-2-dependent manner. ChIP assays showed the binding of HDAC3 and COX-2 to the
promoter sequences of MIP-2. In vitro and in vivo allergic inflammation was
accompanied by the increased expression of MIP-2. miR-26a/-26b negatively
regulated the expression of MIP-2. Allergic inflammation enhanced the
tumorigenic and metastatic potential of cancer cells and induced positive
feedback involving cancer cells and stromal cells, such as mast cells,
macrophages, and endothelial cells. miR-26a mimic and miR-26b mimic negatively
regulated the positive feedback between cancer cells and stromal cells and the
positive feedback among stromal cells. miR-26a/-26b negatively regulated the
enhanced tumorigenic potential by allergic inflammation. COX-2 was necessary for
the enhanced metastatic potential of cancer cells by allergic inflammation.
Taken together, our results indicate that the miR26a/-26b-COX-2-MIP-2 loop
regulates allergic inflammation and the feedback relationship between allergic
inflammation and the enhanced tumorigenic and metastatic potential. Mammalian folliculogenesis is a complex process in which primordial follicles
develop into pre-ovulatory follicles, followed by ovulation to release mature
oocytes. In this study, we explored the role of miR-144 in ovulation. miR-144
was one of the differentially expressed microRNAs, which showed 5.59-fold
changes, in pre-ovulatory ovarian follicles between Large White and Chinese
Taihu sows detected by Solexa deep sequencing. We demonstrated that
overexpression of miR-144 significantly decreased the luciferase reporter
activity under the control of the cyclooxygenase-2 (COX-2) or mothers against
decapentaplegic homologue 4 (Smad4) 3'-untranslated region (3'-UTR) and
suppressed COX-2 and Smad4 expression. In contrast, a miR-144 inhibitor
increased COX-2 and Smad4 expression in mouse granulosa cells (mGCs). Meanwhile,
Smad4 upregulated COX-2 expression, but this effect was abolished when the mGCs
were treated with the transforming growth factor beta signalling pathway
inhibitor SB431542. Moreover, luciferase reporter, chromatin immunoprecipitation
and electrophoretic mobility shift assay results showed that the transcription
factor CP2 upregulated miR-144 expression, which partially contributed to the
suppression of COX-2 in mGCs. Both CP2 and miR-144 alter prostaglandin E2 (PGE2)
production by regulating COX-2 expression. In addition, miR-144 regulated mGC
apoptosis and affected follicular atresia, but these activities did not appear
to be through COX-2 and Smad4. Taken together, we revealed an important
CP2/miR-144/COX-2/PGE2/ovulation pathway in mGCs. Abnormal angiogenesis is critically involved in tumor progression and metastasis
including endometrial cancer and is regulated by microRNAs such as microRNA-101
(miR-101). We hypothesize that miR-101 expression is disrupted in endometrial
cancer and modulation of miR-101 levels is sufficient to regulate tumor growth
through angiogenesis. We examined the expression levels of miR-101 and factors
involved in angiogenesis in the patients with endometrial cancer. We also
overexpressed or inhibited miR-101 in RL-95-2 cells and examined their effects
on cell toxicity and tumor growth. Finally, we determined if miR-101 regulated
tumorigenesis through cyclooxygenase-2 (COX-2). We found that miR-101 levels
were significantly reduced. Factors involved in angiogenesis included vascular
endothelial growth factor-A (VEGF-A), thrombospondin-1 (TSP-1), cyclooxygenase-2
(COX-2), prostaglandin E2 (PGE2), and aromatase (P450arom), which were increased
in endometrial carcinoma. Modulation of miR-101 level was sufficient to affect
tumor growth. Finally, we found that the effects of miR-101 inhibition on tumor
growth were suppressed by COX-2 inhibition. Our results suggest that modulating
miR-101 and COX-2 levels or their activity may be a potential therapeutic
strategy for endometrial cancer. Diabetes has been considered as an independent risk factor for cerebral
infarction. However, the pathological mechanism of cerebral infarction with
diabetes (DMCI) is still rarely known. In this study, we try to explore the
relationship between microRNA-146b-3p (miR-146b-3p) and DMCI patients. The
peripheral blood mononuclear cells were separated after the patients were
selected from our hospital. Firstly, the content of IL-6 and COX-2 was detected
by ELISA. Then, the total RNAs were extracted and analyzed by microRNA (miRNA)
microarray. Moreover, the target genes of miR-146b-3p were predicted by online
miRNA target prediction algorithms. Meanwhile, luciferase reporter system was
used for assaying the target gene for miRNA-146b-3p. Simultaneously, RT-PCR
assay was used for the miRNA expression detection. Furthermore, western blot was
applied to determine the expression of the signal pathway involved proteins. Our
results demonstrated that expression of IL-6 and COX-2 were remarkably
up-regulated in peripheral blood of DMCI patients compared with that in normal
control group. In addition, miRNA microarray data suggested that miR-146b-3p
expression was significantly down-regulated in DMCI patients, with v-raf-1
expression negatively regulated. Moreover, miR-146b-3p regulated RAF1 expression
was found to mediate P38MAPK signaling activation in thrombosis patients. The
following research indicated that activation of RAF1 trough miR-146b-3p
down-regulation contributed to activation of RAF/P38MAPK/COX-2 signaling pathway
in vascular infarction. Our data have implied that altered expression of
miR-146b-3p is closely related to the progression and development of DCMI
mediating the RAF/P38MAPK/COX-2 signal transduction pathway. MicroRNAs (miRNA), a class of small noncoding RNAs, regulates message RNA (mRNA)
by targeting the 3'-untranslated region (3'-UTR) resulting in suppression of
gene expression. In this study, we identified the expression and function of
miR-128, which was found to be downregulated in glioma tissues and glioma cells
by real time PCR. Overexpression of miR-128 mimics into LN229 and U251 cells
could inhibit proliferation and invasion of glioma cells. However, the
inhibitory effects of miR-128 mimics on the invasion and proliferation of glioma
cells were reversed by overexpression of cyclooxygenase-2 (COX-2). Our data
showed that COX-2 was a candidate target of miR-128. Luciferase activity of
3'-UTR of COX-2 was reduced in the presence of miR-128. Additionally, miR-128
obviously decreased COX-2 mRNA stability determined by real time PCR.
Contrarily, we found that miR-128 inhibitor significantly increased the COX-2
mRNA expression, and elevated the protein expression of MMP9 and ki67, and
promoted the proliferation of glioma cells. Furthermore, luciferase activity of
the 3'-UTR was upregulated by miR-128 inhibitor. All of these results supported
that miR-128 was a direct regulator of COX-2. Further studies proved that COX-2
was elevated in glioma tissues and its expression was negatively correlated with
the levels of miR-128. These findings may establish miR-128 as a new potential
target for the treatment of patients with gliomas. MicroRNA-137 (miR-137) plays an important role in the development and
progression of many types of human cancers; however, the role of miR-137 in
retinoblastoma (RB) remains unclear. In this study, we aimed to investigate the
functional significance and molecular mechanisms of miR-137 in RB. We reported
that miR-137 was frequently down-regulated in RB tissues and cell lines. The
overexpression of miR-137 inhibited RB cell proliferation and invasion, while
the suppression of miR-137 promoted RB cell proliferation and invasion.
Bioinformatic analysis predicted that cyclooxygenase-2 (COX-2) was a potential
target gene of miR-137, which was validated by a dual-luciferase reporter assay.
Moreover, our results showed that miR-137 negatively regulated the expression of
COX-2 and the production of prostaglandin E2 (PGE2) in RB cells. The knockdown
of COX-2 suppressed the proliferation and invasion of RB cells as well as the
production of PGE2. The overexpression of COX-2 significantly reversed the
inhibitory effect of miR-137 overexpression on RB cell proliferation and
invasion. Taken together, these results suggest that miR-137 suppresses the
proliferation and invasion of RB cells by targeting COX-2/PGE2. Our study
reveals a tumor suppressive role of miR-137 in the progression of RB and
suggests miR-137 as a potentially effective therapeutic target for the treatment
of RB. |
What percentage of patients of nasopharyngeal carcinoma (NPC) develop recurrent disease? | 1.04% of patients with nasopharyngeal carcinoma develop recurrent disease. The overall recurrence rate is 75%. | An important challenge in nasopharyngeal carcinoma (NPC) research is to develop
effective predictors of tumor recurrence following treatment to determine
whether immediate adjuvant therapy is necessary. We retrospectively analyzed
archived specimens collected from 45 patients with paired samples of primary NPC
(pNPC) and recurrent NPC (rNPC). Clinical samples were collected from the Cancer
Center Databases of the First People's Hospital of Foshan and Shantou Central
Hospital (affiliates of Sun Yat-Sen University) between 2001 and 2012.
Expression levels of phosphor-Stat3 (p-Stat3), signalosome complex subunit 5
(Jab1/Csn5), Akt1, C/EBP homologous protein (CHOP), Ki-67, and apoptosis were
determined by immunohistochemistry in pNPC and rNPC samples from the same
patients. Differences in these markers between the short-term interval to
recurrence (ITR) group (ITR <18 months) and long-term ITR group (ITR ≥18 months)
were further analyzed. In Cox's regression analysis, the ITR was significantly
associated as an independent‑negative prognostic factor for overall survival
(hazard ratio, 0.211; 95% confidence interval, 0.053-0.841; P=0.027). p-Stat3
was increased in the short-term ITR group (ITR <18 months) and tended to be
lower in the long-term ITR group (ITR ≥18 months). In the short-term ITR group,
nuclear Akt expression was significantly increased in paired rNPC (P=0.028). In
the long-term ITR group, the expression of nuclear Jab1/Csn5 (P=0.047) and
assessment of apoptosis measured with TdT-mediated dUTP nick end‑labeling
(TUNEL) (P=0.003) was significantly increased in paired rNPC. The results
suggest that differences between short- and long-term ITR may predict outcome in
rNPC. Furthermore, the overexpression of Jab1/Csn5 and Akt may contribute to the
carcinogenesis of rNPC, and Akt seems to promote the progression of short-term
ITR. Intra-individual changes of Jab1/Csn5, Akt, and TUNEL may help to identify
short-term ITR. To date, there are no serum biomarkers available for the prediction of recurrent
nasopharyngeal carcinoma (rNPC). The diagnosis of rNPC mostly depends on imaging
and biopsy of diseased tissue; however, both of these methods work mostly if the
target tumor is at an advanced stage. Therefore, the identificaqtion of
recurrent biomarkers is urgently required. In the present study, we used tandem
mass tag (TMT) labeling and high performance liquid chromatography (HPLC)
fractionation followed by liquid chromatography-tandem mass
spectrometry (LC‑MS/MS) to identify differentially expressed proteins. Serum was
collected from 40 patients with NPC [recurrence (n=20) and no
recurrence (n=20)]. Compared to non‑recurrent NPC (nrNPC), we found 59 proteins
to be significantly dysregulated in rNPC; most of these have been previously
reported to play a role in carcinogenesis. The dysregulation of
calmodulin (CALM) was confirmed in 74 new patients [recurrence (n=32) and
no recurrence (n=42)] by ELISA. Moreover, we performed a preliminary pathway
analysis which revealed that oxidative phosphorylation was altered in the
patients with rNPC compared to those with nrNPC. Taken together, these data
identify a potential diagnostic biomarker for rNPC and elucidate the potential
molecular mechanisms that are dysregulated and contribute to the pathogenesis of
rNPC. Background: The aim of this study was to build nomograms to predict local
recurrence (LR) and regional recurrence (RR) in patients with nasopharyngeal
carcinoma (NPC) underwent intensity-modulated radiation therapy (IMRT). Patients
and Methods : A total of 1811 patients with non-metastatic NPC treated with IMRT
(with or without chemotherapy) between October 2009 and February 2012 at our
center were involved for building the nomograms. Nomograms for LR-free rate and
RR-free rate at 3- and 5- year were generated as visualizations of Cox
proportional hazards regression models, and validated using bootstrap
resampling, estimating discrimination and calibration. Results: With a median
follow up of 49.50 months, the 3- and 5- year LR-free rate were 95.43% and
94.30% respectively; the 3- and 5- year RR-free rate were 95.94% and 95.41%
respectively. The final predictive model for LR included age, the
neutrophil/leukocyte ratio (NWR), pathological type, primary gross tumor volume,
maxillary sinus invasion, ethmoidal sinus invasion and lacerated foramen
invasion; the model for RR involved NWR, plasma Epstein-Barr virus (EBV) DNA
copy number, cervical lymph node volume and N category. The models showed fairly
good discriminatory ability with concordance indices (c-indices) of 0.76 and
0.74 for predicting LR and RR, respectively, as well as good calibration. The
proposed stratification of risk groups based on the nomograms allowed
significant distinction between Kaplan-Meier curves for LR and RR. Conclusions:
The proposed nomograms resulted in more-accurate prognostic prediction for LR
and RR with a high concordance, hence to inform patients with high risk of
recurrence on more aggressive therapy. The prognostic nomograms could better
stratify patients into different risk groups. OBJECTIVE: The study was designed to appraise the locoregional recurrence
patterns using conventional two-dimensional radiotherapy (2D-RT) and intensity
modulated radiation therapy (IMRT) in nasopharyngeal carcinoma (NPC) in order to
better establish the scenario of the modern radiotherapy and the duration of
surveillance.
MATERIALS AND METHODS: We reviewed the institutional database to identify
patients with pathologically confirmed, non-metastatic NPC who completed radical
2D-RT or IMRT at our center from 2000 to 2011. We collected data on
clinicopathologic features, treatments and outcomes. Statistical analyses were
performed using SPSS 20.0 or STATASE 14.0.
RESULTS: The median follow-up was 60.1 months. Of 2315 patients, 1289 (53%) were
treated with 2D-RT and 1026 (47%) with IMRT. IMRT group achieved better
locoregional control rate, with the 5-year locoregional relapse-free survival
(LRRFS) were 84.9% and 87.7% among patients received 2D-RT and IMRT,
respectively (P = 0.050). IMRT was superior to 2D technique in terms of local
relapse-free survival (LRFS) (88.4% vs 91.1%, P = 0.047) and the advantage was
only significant in T3-4 subgroup (81.6% vs 90.2%, P = 0.000). Similar neck
control rates were observed using different RT techniques. And the recurrence
time appeared to be postponed by IMRT, with peaks accounting for the year 1.5
and year 3-4 compared to which was predomit at the first two years using
2D-RT in nature.
CONCLUSIONS: IMRT provided an improved LRRFS in overall stage and LRFS in
advanced T stage for NPC compared with 2D-RT. Annual hazard of recurrence also
changed with RT techniques. |
What classes of drugs does Retapamulin belong to? | Retapamulin is a member of the pleuromutilin family of antibiotics. | Retapamulin is a semisynthetic pleuromutilin derivative being developed as a
topical antibiotic for treating bacterial infections of the skin. It is potent
in vitro against susceptible and multidrug-resistant organisms commonly
associated with bacterial skin infections. We report detailed mode of action
studies demonstrating that retapamulin binds to the bacterial ribosome with high
affinity, inhibits ribosomal peptidyl transferase activity, and partially
inhibits the binding of the initiator tRNA substrate to the ribosomal P-site.
Taken together, these data distinguish the mode of action of retapamulin from
that of other classes of antibiotics. This unique mode of action may explain the
lack of clinically relevant, target-specific cross-resistance of retapamulin
with antibacterials in current use. OBJECTIVES: Retapamulin is the first agent of the pleuromutilin class formulated
as a topical antibacterial for treating skin infections. The aim of this study
was to determine the antimicrobial activity of retapamulin by determining the
minimal inhibitory concentration (MIC) values of this new drug and comparators
against a wide range of anaerobic bacteria of human origin.
METHODS: The in vitro activity of retapamulin and six comparators (amoxicillin,
amoxicillin/clavulanic acid, ceftriaxone, imipenem, clindamycin and
metronidazole) was evaluated against 232 anaerobic clinical isolates. MICs were
determined by the CLSI reference agar dilution method (M11-A6).
RESULTS: Ceftriaxone, clindamycin and amoxicillin/clavulanic acid resistance
rates were 54%, 42% and 9.6%, respectively, within the Bacteroides fragilis
group. Despite high resistance rates to various antibiotics, retapamulin
inhibited 37/52 (71%) strains of the B. fragilis group and 85/87 (98%) of the
other Gram-negative bacilli at a concentration of 2 mg/L or less. All the
investigated strains of Clostridium perfringens were inhibited by 1 mg/L
retapamulin. Three strains of C. difficile and one strain of C. clostridioforme
demonstrated decreased susceptibility to retapamulin. Based on inhibitory
concentrations, retapamulin was more active than clindamycin, metronidazole and
ceftriaxone against Propionibacterium acnes and anaerobic Gram-positive cocci,
as all isolates were inhibited by <or=2 mg/L.
CONCLUSIONS: At <or=2 mg/L, retapamulin inhibited 90% of all 232 anaerobes
tested, whereas overall resistance rates for the comparators were as follows:
co-amoxiclav, 2%; metronidazole, 12%; clindamycin, 15% and ceftriaxone, 20%. The
broad anaerobic spectrum demonstrated by retapamulin in vitro is attractive.
Pending further clinical investigation, retapamulin may offer an alternative
treatment for anaerobic skin infections in this era of increasing resistance. Retapamulin is a semisynthetic pleuromutilin compound with in vitroactivity
against Gram-positive bacteria, no cross-resistance to other classes of
antimicrobial agents in current use and a low potential for development of
resistance. A 1% ointment formulation has been developed for clinical use, and a
placebo-controlled trial of impetigo in 210 patients produced significantly
higher rates of clinical and microbiological success compared with placebo -
85.6 versus 52.1% and 91.2 versus 50.9%, respectively. Additional comparative
studies in over 1900 patients showed noninferiority to topical fusidic acid and
oral cephalexin and a low frequency of adverse events. In 2007, retapamulin was
approved in the USA for topical treatment of impetigo caused by Streptococcus
pyogenes and methicillin-susceptible Staphylococcus aureus, and in the EU for
topical treatment of impetigo and infected wounds caused by S. pyogenes and S.
aureus, with approvals including adults and children over 9 months of age. Retapamulin is the first agent in the new pleuromutilin class of antibacterials
to become commercially available for clinical use in humans. Retapamulin acts as
a potent inhibitor of bacterial protein synthesis and has a unique mode of
antibiotic action. To date, retapamulin has not demonstrated any clinically
relevant, target-specific crossresistance with other antibiotic classes, and has
shown a low potential for resistance selection in vitro. In preclinical studies,
retapamulin demonstrated pronounced in vitro activity against staphylococcal,
streptococcal and anaerobic Gram-positive clinical isolates associated with skin
and skin structure infections. Clinical pharmacology studies showed low systemic
exposure with topical use of retapamulin, and a favorable tolerability profile.
In clinical efficacy trials involving pediatric and adult patients who received
retapamulin twice daily for five days, retapamulin was highly effective in the
treatment of impetigo, secondarily infected traumatic lesions and secondarily
infected dermatitis. Further, the clinical efficacy and safety profile of
retapamulin was comparable to that of commonly used oral and topical
antibiotics. Retapamulin was also clinically effective against isolates
resistant to existing therapies. As a 1% ointment, retapamulin has been approved
in the United States for the treatment of impetigo and in Europe for the
shortterm treatment of impetigo and infected small lacerations, abrasions and
sutured wounds. Retapamulin is a novel semisynthetic pleuromutilin antibiotic specifically
designed for use as a topical agent. The unique mode of action by which
retapamulin selectively inhibits bacterial protein synthesis differentiates it
from other nonpleuromutilin antibacterial agents that target the ribosome or
ribosomal factors, minimizing the potential for target-specific cross-resistance
with other antibacterial classes in current use. In vitro studies show that
retapamulin has high potency against the Gram-positive bacteria (Staphylococcus
aureus, Streptococcus pyogenes, and coagulase-negative staphylococci) commonly
found in skin and skin-structure infections (SSSIs), including S. aureus strains
with resistance to agents such as macrolides, fusidic acid, or mupirocin, and
other less common organisms associated with SSSIs, anaerobes, and common
respiratory tract pathogens. Clinical studies have shown that twice-daily
topical retapamulin for 5 days is comparable to 10 days of oral cephalexin in
the treatment of secondarily infected traumatic lesions. A 1% concentration of
retapamulin ointment has been approved for clinical use as an easily applied
treatment with a short, convenient dosing regimen for impetigo. Given the novel
mode of action, low potential for cross-resistance with established
antibacterial agents, and high in vitro potency against many bacterial pathogens
commonly recovered from SSSIs, retapamulin is a valuable enhancement over
existing therapeutic options. Impetigo is a common childhood skin infection. There are reports of increasing
drug resistance to the currently used topical antibiotics including fusidic acid
and mupirocin. Retapamulin is a newer topical agent of pleuromutilin class
approved by the Food and Drug Administration for treatment of impetigo in
children and has been recently made available in the Indian market. It has been
demonstrated to have low potential for the development of antibacterial
resistance and a high degree of potency against poly drug resistant
Gram-positive bacteria found in skin infections including Staphylococcus aureus
strains. The drug is safe owing to low systemic absorption and has only minimal
side-effect of local irritation at the site of application. Novel approaches for the treatment of multidrug-resistant Gram-negative
bacterial infections are urgently required. One approach is to potentiate the
efficacy of existing antibiotics whose spectrum of activity is limited by the
permeability barrier presented by the Gram-negative outer membrane. Cationic
peptides derived from polymyxin B have been used to permeabilize the outer
membrane, granting antibiotics that would otherwise be excluded access to their
targets. We assessed the in vitro efficacies of combinations of SPR741 with
conventional antibiotics against Escherichia coli, Klebsiella pneumoniae, and
Acinetobacter baumannii Of 35 antibiotics tested, the MICs of 8 of them were
reduced 32- to 8,000-fold against E. coli and K. pneumoniae in the presence of
SPR741. The eight antibiotics, azithromycin, clarithromycin, erythromycin,
fusidic acid, mupirocin, retapamulin, rifampin, and telithromycin, had diverse
targets and mechanisms of action. Against A. baumannii, similar potentiation was
achieved with clarithromycin, erythromycin, fusidic acid, retapamulin, and
rifampin. Susceptibility testing of the most effective antibiotic-SPR741
combinations was extended to 25 additional multidrug-resistant or clinical
isolates of E. coli and K. pneumoniae and 17 additional A. baumannii isolates in
order to rank the potentiated antibiotics. SPR741 was also able to potentiate
antibiotics that are substrates of the AcrAB-TolC efflux pump in E. coli,
effectively circumventing the contribution of this pump to intrinsic antibiotic
resistance. These studies support the further development of SPR741 in
combination with conventional antibiotics for the treatment of Gram-negative
bacterial infections. Invasive infections due to Staphylococcus aureus, including
methicillin-resistant S. aureus are prevalent and life-threatening. Combinations
of antibiotic therapy have been employed in many clinical settings for improving
therapeutic efficacy, reducing side effects of drugs, and development of
antibiotic resistance. Pleuromutilins have a potential to be developed as a new
class of antibiotics for systemic use in humans. In the current study, we
investigated the relationship between pleuromutilins, including valnemulin,
tiamulin, and retapamulin, and 13 other antibiotics representing different
mechanisms of action, against methicillin-susceptible and -resistant S. aureus
both in vitro and in an experimental Galleria mellonella model. In vitro
synergistic effects were observed in combination of all three study
pleuromutilins with tetracycline (TET) by standard checkerboard and/or time-kill
assays. In addition, the combination of pleuromutilins with ciprofloxacin or
enrofloxacin showed antagonistic effects, while the rest combinations presented
indifferent effects. Importantly, all study pleuromutilins in combination with
TET significantly enhanced survival rates as compared to the single drug
treatment in the G. mellonella model caused by S. aureus strains. Taken
together, these results demonstrated synergy effects between pleuromutilins and
TET against S. aureus both in vitro and in vivo. |
What is the mechanism of action of ozanimod? | Ozanimod is a specific and potent small molecule modulator of the sphingosine 1-phosphate receptor 1 (S1PR1) and receptor 5 (S1PR5), which has shown therapeutic benefit in clinical trials of relapsing multiple sclerosis and ulcerative colitis. | Sphingosine 1-phosphate (S1P) receptor modulators possess a unique mechanism of
action as disease-modifying therapy for multiple sclerosis (MS). Subtype 1 S1P
receptors are expressed on the surfaces of lymphocytes and are important in
regulating egression from lymph nodes. The S1P receptor modulators indirectly
antagonize the receptor's function and sequester lymphocytes in lymph nodes.
Fingolimod was the first S1P agent approved in the USA in 2010 for relapsing MS
after two phase III trials (FREEDOMS and TRANSFORMS) demonstrated potent
efficacy, and good safety and tolerability. Post-marketing experience, as well
as a third phase III trial (FREEDOMS II), also showed favorable results. More
selective S1P receptor agents-ponesimod (ACT128800), siponimod (BAF312),
ozanimod (RPC1063), ceralifimod (ONO-4641), GSK2018682, and MT-1303-are still in
relatively early stages of development, but phase I and II trials showed
promising efficacy and safety. However, these observations have yet to be
reproduced in phase III clinical trials. The sphingosine-1-phosphate receptor-1 (S1P1) agonist ozanimod ameliorates
ulcerative colitis, yet its mechanism of action is unknown. Here, we examine the
cell subsets that express S1P1 in intestine using S1P1-eGFP mice, the regulation
of S1P1 expression in lymphocytes after administration of dextran sulfate sodium
(DSS), after colitis induced by transfer of CD4+CD45RBhi cells, and by crossing
a mouse with TNF-driven ileitis with S1P1-eGFP mice. We then assayed the
expression of enzymes that regulate intestinal S1P levels, and the effect of
FTY720 on lymphocyte behavior and S1P1 expression. We found that not only T and
B cells express S1P1, but also dendritic (DC) and endothelial cells.
Furthermore, chronic but not acute inflammatory signals increased S1P1
expression, while the enzymes that control tissue S1P levels in mice and humans
with inflammatory bowel disease (IBD) were uniformly dysregulated, favoring
synthesis over degradation. Finally, we observed that FTY720 reduced T-cell
velocity and induced S1P1 degradation and retention of Naïve but not effector T
cells. Our data demonstrate that chronic inflammation modulates S1P1 expression
and tissue S1P levels and suggests that the anti-inflammatory properties of S1PR
agonists might not be solely due to their lymphopenic effects, but also due to
potential effects on DC migration and vascular barrier function. BACKGROUND: Ozanimod (RPC1063) is an oral agonist of the sphingosine-1-phosphate
receptor subtypes 1 and 5 that induces peripheral lymphocyte sequestration,
potentially decreasing the number of activated lymphocytes circulating to the
gastrointestinal tract.
METHODS: We conducted a double-blind, placebo-controlled phase 2 trial of
ozanimod in 197 adults with moderate-to-severe ulcerative colitis. Patients were
randomly assigned, in a 1:1:1 ratio, to receive ozanimod at a dose of 0.5 mg or
1 mg or placebo daily for up to 32 weeks. The Mayo Clinic score was used to
measure disease activity on a scale from 0 to 12, with higher scores indicating
more severe disease; subscores range from 0 to 3, with higher scores indicating
more severe disease. The primary outcome was clinical remission (Mayo Clinic
score ≤2, with no subscore >1) at 8 weeks.
RESULTS: The primary outcome occurred in 16% of the patients who received 1 mg
of ozanimod and in 14% of those who received 0.5 mg of ozanimod, as compared
with 6% of those who received placebo (P=0.048 and P=0.14, respectively, for the
comparison of the two doses of ozanimod with placebo). Differences in the
primary outcome between the group that received 0.5 mg of ozanimod and the
placebo group were not significant; therefore, the hierarchical testing plan
deemed the analyses of secondary outcomes exploratory. Clinical response
(decrease in Mayo Clinic score of ≥3 points and ≥30% and decrease in
rectal-bleeding subscore of ≥1 point or a subscore ≤1) at 8 weeks occurred in
57% of those receiving 1 mg of ozanimod and 54% of those receiving 0.5 mg, as
compared with 37% of those receiving placebo. At week 32, the rate of clinical
remission was 21% in the group that received 1 mg of ozanimod, 26% in the group
that received 0.5 mg of ozanimod, and 6% in the group that received placebo; the
rate of clinical response was 51%, 35%, and 20%, respectively. At week 8,
absolute lymphocyte counts declined 49% from baseline in the group that received
1 mg of ozanimod and 32% from baseline in the group that received 0.5 mg. The
most common adverse events overall were anemia and headache.
CONCLUSIONS: In this preliminary trial, ozanimod at a daily dose of 1 mg
resulted in a slightly higher rate of clinical remission of ulcerative colitis
than placebo. The trial was not large enough or of sufficiently long duration to
establish clinical efficacy or assess safety. (Funded by Receptos; TOUCHSTONE
ClinicalTrials.gov number, NCT01647516.). The sphingosine-1-phosphate 1 receptor (S1P1R ) is expressed by lymphocytes,
dendritic cells, and vascular endothelial cells and plays a role in the
regulation of chronic inflammation and lymphocyte egress from peripheral
lymphoid organs. Ozanimod is an oral selective modulator of S1P1R and S1P5R
receptors in clinical development for the treatment of chronic immune-mediated,
inflammatory diseases. This first-in-human study characterized the safety,
pharmacokinetics (PK), and pharmacodynamics (PD) of ozanimod in 88 healthy
volunteers using a range of single and multiple doses (7 and 28 days) and a
dose-escalation regimen. Ozanimod was generally well tolerated up to a maximum
single dose of 3 mg and multiple doses of 2 mg/d, with no severe adverse events
(AEs) and no dose-limiting toxicities. The most common ozanimod-related AEs
included headache, somnolence, dizziness, nausea, and fatigue. Ozanimod
exhibited linear PK, high steady-state volume of distribution (73-101 L/kg),
moderate oral clearance (204-227 L/h), and an elimination half-life of
approximately 17 to 21 hours. Ozanimod produced a robust dose-dependent
reduction in total peripheral lymphocytes, with a median decrease of 65% to 68%
observed after 28 days of dosing at 1 and 1.5 mg/d, respectively. Ozanimod
selectivity affected lymphocyte subtypes, causing marked decreases in cells
expressing CCR7 and variable decreases in subsets lacking CCR7. A dose-dependent
negative chronotropic effect was observed following the first dose, with the
dose-escalation regimen attenuating the first-dose negative chronotropic effect.
Ozanimod safety, PK, and PD properties support the once-daily regimens under
clinical investigation. The past three decades have witnessed remarkable advances in our ability to
target specific elements of the immune and inflammatory response, fuelled by
advances in both biotechnology and disease knowledge. As well as providing
superior treatments for immune-mediated inflammatory diseases (IMIDs), such
therapies also offer unrivalled opportunities to study the underlying
immunopathological basis of these conditions.In this review, we explore recent
approaches to the treatment of IMIDs and the insights to pathobiology that they
provide. We review novel biologic agents targeting the T-helper 17 axis,
including therapies directed towards interleukin (IL)-17 (secukinumab,
ixekizumab, bimekizumab), IL-17R (brodalumab), IL-12/23p40 (ustekinumab,
briakinumab) and IL-23p19 (guselkumab, tildrakizumab, brazikumab, risankizumab,
mirikizumab). We also present an overview of biologics active against type I and
II interferons, including sifalumumab, rontalizumab, anifrolumab and
fontolizumab. Emerging strategies to interfere with cellular adhesion processes
involved in lymphocyte recruitment are discussed, including both integrin
blockade (natalizumab, vedolizumab, etrolizumab) and sphingosine-1-phosphate
receptor inhibition (fingolimod, ozanimod). We summarise the development and
recent application of Janus kinase (JAK) inhibitors in the treatment of IMIDs,
including first-generation pan-JAK inhibitors (tofacitinib, baricitinib,
ruxolitinib, peficitinib) and second-generation selective JAK inhibitors
(decernotinib, filgotinib, upadacitinib). New biologics targeting B-cells
(including ocrelizumab, veltuzumab, tabalumab and atacicept) and the development
of novel strategies for regulatory T-cell modulation (including low-dose IL-2
therapy and Tregitopes) are also discussed. Finally, we explore recent
biotechnological advances such as the development of bispecific antibodies
(ABT-122, COVA322), and their application to the treatment of IMIDs. Ozanimod is a novel, selective, oral sphingosine-1-phosphate (1 and 5) receptor
modulator in development for multiple sclerosis and inflammatory bowel disease.
This randomized, double-blind, placebo-controlled, positive-controlled,
parallel-group thorough QT study characterized the effects of ozanimod on
cardiac repolarization in healthy subjects. Eligible subjects were randomized to
1 of 2 groups: ozanimod (escalated from 0.25 to 2 mg over 14 days) or placebo
(for 14 days). A single dose of moxifloxacin 400 mg or placebo was administered
on days 2 and 17. The primary end point was the time-matched, placebo-corrected,
baseline-adjusted mean QTcF (ΔΔQTcF). A total of 113/124 (91.1%) subjects
completed the study. The upper limits of the 2-sided 90% confidence intervals
for ΔΔQTcF for both ozanimod 1 and 2 mg were below the 10-millisecond regulatory
threshold. No QTcF >480 milliseconds or postdose change in QTcF of
>60 milliseconds was observed. There was no evidence of a positive relationship
between concentrations of ozanimod and its active metabolites and ΔΔQTcF.
Although ozanimod blunted the observed diurnal increase in heart rate,
excursions below predose heart rates were no greater than with placebo. Results
demonstrate that ozanimod does not prolong the QTc interval or cause clinically
significant bradycardia, supporting ozanimod's evolving favorable cardiac safety
profile. Ozanimod (RPC1063) is an oral selective modulator of the sphingosine-1-phosphate
1 and 5 receptors under development for the treatment of relapsing multiple
sclerosis and inflammatory bowel disease. The effects of high-fat and low-fat
meals on the pharmacokinetics (PK) of a single oral dose of ozanimod were
evaluated in 24 healthy volunteers in a randomized, open-label crossover trial.
Each subject received a 1-mg dose of ozanimod hydrochloride under 3 meal
conditions (fasted, high-fat, and low-fat), each separated by 7 days. Mean
plasma concentration-time profiles for ozanimod and its active metabolites
(RP101988 [major], RP101075 [minor]) were similar under all 3 conditions.
Moreover, all PK parameters for ozanimod, RP101988, and RP101075 were similar
under the 3 meal conditions. The 90% confidence intervals (CIs) for the ratios
of geometric least-squares mean (fed/fasted) were within the equivalence limits
of 0.80 to 1.25 for area under the concentration-time curve from time 0 to
infinity (AUC0-∞ ) and maximum plasma concentration (Cmax ) for ozanimod,
RP101988, and RP101075, except for the high-fat effect on RP101075 Cmax (90%CI,
0.76-0.88). Given this lack of a food effect on the exposure of ozanimod and its
active metabolites, ozanimod can be taken without regard to meals. Multiple sclerosis treatment faces tremendous changes owing to the approval of
new medications, some of which are available as oral formulations. Until now,
the four orally available medications, fingolimod, dimethylfumarate (BG-12),
teriflunomide, and cladribine have received market authorization, whereas
laquinimod is still under development. Fingolimod is a sphingosine-1-phosphate
inhibitor, which is typically used as escalation therapy and leads to up to 60%
reduction of the annualized relapse rate, but might also have neuroprotective
properties. In addition, there are three more specific S1P agonists in late
stages of development: siponimod, ponesimod, and ozanimod. Dimethylfumarate has
immunomodulatory and cytoprotective functions and is used as baseline therapy.
Teriflunomide, the active metabolite of the rheumatoid arthritis medication
leflunomide, targets the dihydroorotate dehydrogenase, thus inhibiting the
proliferation of lymphocytes by depletion of pyrimidines. Here we will review
the mechanisms of action, clinical trial data, as well as data about safety and
tolerability of the compounds. Conflict of interest statement: Declaration of conflicting interests: The
author(s) declared the following potential conflicts of interest with respect to
the research, authorship, and/or publication of this article: J.A.C. received
personal compensation for consulting for Adamas, Celgene Corporation, Novartis,
and PendoPharm and as a co-editor of Multiple Sclerosis Journal – Experimental,
Translational and Clinical. G.C. received compensation for consulting services
and/or speaking activities from Almirall, Biogen, Celgene Corporation, EXCEMED
Forward Pharma, Medday, Merck, Novartis, Roche, Sanofi, Sanofi Genzyme, and
Teva. D.L.A. received personal fees for consulting from Acorda Therapeutics,
Biogen, Genzyme, the Immune Tolerance Network, Novartis, and Sanofi-Aventis;
grants from Biogen and Novartis; and holds an equity interest in NeuroRx
Research. A.B.-O. received personal compensation for consulting from Biogen,
Celgene Corporation, EMD Serono, Medimmune, Novartis, Roche, and Sanofi Genzyme.
K.W.S. served as a consultant for Biogen Idec, Celgene Corporation, Genzyme,
Merck, Novartis, Ono Pharma, Roche, Synthon, and Teva. L.S. served as a
consultant for Abbvie, Atreca, Celgene Corporation, Coherus, EMD Serono,
Novartis, Teva, and Tolerion; and received research support from Atara, Biogen,
Celgene Corporation, and Coherus. E.K.H. received personal compensation for
consulting and speaking for Actelion, Biogen, Celgene Corporation, Merck,
Novartis, Sanofi, Roche, and Teva and was supported by Czech Ministry of
Education, project PROGRES Q27/LF1. B.A.C.C. received personal compensation for
consulting from Abbvie, Biogen, EMD Serono, GeNeuro, Novartis, and Sanofi
Genzyme. X.M. received speaking honoraria and travel expenses for scientific
meetings or participated in steering committees or in advisory boards for
clinical trials with Almirall, Bayer, Schering Pharma, Biogen, Genentech,
Genzyme, GSK, Merck Serono, MS International Federation, National Multiple
Sclerosis Society, Novartis, Roche, Sanofi-Aventis, and Teva; for serving as an
editor for Clinical Cases for MSJ. H.-P.H. received fees for consulting, serving
on steering committees, and speaking from Bayer HealthCare, Biogen, GeNeuro,
Genzyme, Merck, Medimmune, Novartis, Octapharma, Opexa, Roche, Sanofi, and Teva.
V.H. is a current employee of Celgene Corporation and is a stockholder in
Celgene Corporation. P.F. is a former employee of Celgene Corporation (at the
time of the study and analysis) and is currently employed by Bioniz
Therapeutics, Inc. B.E.S. is a current employee of Celgene Corporation and is
also a stockholder in Celgene Corporation. L.K.’s institution (University
Hospital Basel) has received in the last 3 years and used exclusively for
research support: steering committee, advisory board, and consultancy fees
(Actelion, Addex, Bayer HealthCare, Biogen Idec, Biotica, Celgene Corporation,
Genzyme, Lilly, Merck, Mitsubishi, Novartis, Ono Pharma, Pfizer, Sanofi,
Santhera, Siemens, Teva, UCB, and Xenoport); speaker fees (Bayer HealthCare,
Biogen Idec, Merck, Novartis, Sanofi, and Teva); support for educational
activities (Bayer HealthCare, Biogen, CSL Behring, Genzyme, Merck, Novartis,
Sanofi, and Teva); license fees for Neurostatus products; and grants (Bayer
HealthCare, Biogen Idec, European Union, Merck, Novartis, Roche Research
Foundation, Swiss MS Society, and Swiss National Research Foundation). BACKGROUND: Ozanimod, a sphingosine 1-phosphate receptor modulator, selectively
binds to receptor subtypes 1 and 5 with high affinity. The RADIANCE phase 2
study showed that ozanimod had better efficacy than placebo on MRI measures,
with a favourable safety profile, in participants with relapsing multiple
sclerosis. The SUNBEAM study aimed to assess the safety and efficacy of ozanimod
versus intramuscular interferon beta-1a in participants with relapsing multiple
sclerosis.
METHODS: SUNBEAM was a randomised, double-blind, double-dummy, active-controlled
phase 3 trial done at 152 academic medical centres and clinical practices in 20
countries. We enrolled participants aged 18-55 years with relapsing multiple
sclerosis, baseline expanded disability status scale (EDSS) score of 0·0-5·0,
and either at least one relapse within the 12 months before screening or at
least one relapse within 24 months plus at least one gadolinium-enhancing lesion
within 12 months before screening. Participants were randomly assigned 1:1:1 by
a blocked algorithm stratified by country and baseline EDSS score to at least 12
months treatment of either once-daily oral ozanimod 1·0 mg or 0·5 mg or weekly
intramuscular interferon beta-1a 30 μg. Participants, investigators, and study
staff were masked to treatment assignment. The primary endpoint was annualised
relapse rate (ARR) during the treatment period and was assessed in the
intention-to-treat population. Safety was assessed in all participants according
to the highest dose of ozanimod received. This trial is registered at
ClinicalTrials.gov, number NCT02294058 and EudraCT, number 2014-002320-27.
FINDINGS: Between Dec 18, 2014, and Nov 12, 2015, 1346 participants were
enrolled and randomly assigned to ozanimod 1·0 mg (n=447), ozanimod 0·5 mg
(n=451), or interferon beta-1a (n=448). 91 (6·8%) participants discontinued the
study drug (29 in the ozanimod 1·0 mg group; 26 in the ozanimod 0·5 mg group;
and 36 in the interferon beta-1a group). Adjusted ARRs were 0·35 (0·28-0·44) for
interferon beta-1a, 0·18 (95% CI 0·14-0·24) for ozanimod 1·0 mg (rate ratio [RR]
of 0·52 [0·41-0·66] vs interferon beta-1a; p<0·0001), and 0·24 (0·19-0·31) for
ozanimod 0·5 mg (RR 0·69 [0·55-0·86] vs interferon beta-1a; p=0·0013). Few
ozanimod-treated participants discontinued treatment because of adverse events
(13 [2·9%] who received ozanimod 1·0 mg; seven [1·5%] who received ozanimod 0·5
mg; and 16 [3·6%] who received interferon beta-1a). No first-dose, clinically
significant bradycardia or second-degree or third-degree atrioventricular block
was reported. The incidence of serious adverse events was low and similar across
treatment groups (13 [2·9%] participants who received ozanimod 1·0 mg; 16 [3·5%]
who received ozanimod 0·5 mg; and 11 [2·5%] who received interferon beta-1a). No
serious opportunistic infections occurred in ozanimod-treated participants.
INTERPRETATION: In participants with relapsing multiple sclerosis treated for at
least 12 months, ozanimod was well tolerated and demonstrated a significantly
lower relapse rate than interferon beta-1a. These findings provide support for
ozanimod as an oral therapy for individuals with relapsing multiple sclerosis.
FUNDING: Celgene International II. BACKGROUND: Ozanimod is a sphingosine 1-phosphate receptor modulator, which
selectively binds to sphingosine 1-phosphate receptor subtypes 1 and 5 with high
affinity. In the RADIANCE phase 2 study in participants with relapsing multiple
sclerosis, ozanimod was associated with better efficacy than placebo on MRI
measures and was well tolerated. The RADIANCE phase 3 study aimed to confirm the
safety and efficacy of ozanimod versus interferon beta-1a in individuals with
relapsing multiple sclerosis.
METHODS: We did a 24-month, multicentre, double-blind, double-dummy phase 3
trial in participants with relapsing multiple sclerosis at 147 medical centres
and clinical practices in 21 countries. Participants were aged 18-55 years, had
multiple sclerosis according to 2010 McDonald criteria, a relapsing clinical
course, brain MRI lesions consistent with multiple sclerosis, an expanded
disability status scale score of 0·0-5·0, and either at least one relapse within
12 months before screening or at least one relapse within 24 months before
screening plus at least one gadolinium-enhancing lesion within the 12 months
before randomisation. Participants were randomly assigned (1:1:1) via an
interactive voice response system to daily oral ozanimod 1·0 mg or 0·5 mg or
weekly intramuscular interferon beta-1a 30 μg. Participants, investigators, and
study staff were masked to treatment allocation. The primary endpoint was
annualised relapse rate (ARR) over 24 months. The primary analysis was done in
the intention-to-treat population of all participants who received study drug
and safety was assessed in all randomly assigned participants who received study
drug, grouped by highest dose of ozanimod received. This trial is registered at
ClinicalTrials.gov, NCT02047734, and EudraCT, 2012-002714-40.
FINDINGS: Between Dec 27, 2013, and March 31, 2015, we screened 1695
participants, of which 375 did not meet inclusion criteria. 1320 participants
were enrolled and randomly assigned to a group, of whom 1313 received study drug
(433 assigned to ozanimod 1·0 mg, 439 assigned to ozanimod 0·5 mg, and 441
assigned to interferon beta-1a) and 1138 (86·7%) completed 24 months of
treatment. Adjusted ARRs were 0·17 (95% CI 0·14-0·21) with ozanimod 1·0 mg, 0·22
(0·18-0·26) with ozanimod 0·5 mg, and 0·28 (0·23-0·32) with interferon beta-1a,
with rate ratios versus interferon beta-1a of 0·62 (95% CI 0·51-0·77; p<0·0001)
for ozanimod 1·0 mg and 0·79 (0·65 to 0·96; p=0·0167) for ozanimod 0·5 mg. The
incidence of treatment-emergent adverse events was higher in the interferon
beta-1a group (365 [83·0%] of 440 participants) than in the ozanimod 1·0 mg
group (324 [74·7%] of 434) or the ozanimod 0·5 mg group (326 [74·3%] of 439).
More participants in the interferon beta-1a group had treatment-emergent adverse
events leading to treatment discontinuation than in the ozanimod groups.
Incidences of infections and serious treatment-emergent adverse events were
similar across treatment groups. No cases of ozanimod-related symptomatic
reduction in heart rate and no second-degree or third-degree cases of
atrioventricular block were reported.
INTERPRETATION: In this 24-month phase 3 study in participants with relapsing
multiple sclerosis, ozanimod was well tolerated and associated with a
significantly lower rate of clinical relapses than intramuscular interferon
beta-1a. These findings show the potential of ozanimod as an effective oral
therapy for individuals with relapsing multiple sclerosis.
FUNDING: Celgene International II. |
What are Syndecans? | Syndecans are transmembrane proteoglycans with heparan and chondroitin sulfate chains attached to their extracellular domain. Like many proteoglycans, they interact with a large number of ligands, such as growth factors, adhesion receptors, soluble small molecules, proteinases, and other extracellular matrix proteins to initiate downstream signaling pathways. Syndecans play a major role in inflammation, mainly by regulating leukocyte extravasation and cytokine function. | Syndecans are cell surface heparan sulfate proteoglycans that serve as
co-receptors and modulate the actions of a number of extracellular ligands.
Syndecans thereby regulate cell adhesion, proliferation, and differentiation.
Studies in cancer cells suggest that syndecans may also modulate cell viability.
We previously showed that syndecan-2 controls the growth of normal human
osteoblastic cells. In this study, we examined the role of syndecan-2 in
osteosarcoma cell proliferation and apoptosis. To this goal, MG63 osteosarcoma
cells which express low syndecan-2 levels were transfected to overexpress
full-length syndecan-2 or truncated syndecan-2 lacking its cytoplasmic domain.
Determination of cell growth by cell counting and 3H-thymidine incorporation
showed that truncated syndecan-2 inhibited MG63 cell proliferation. Flow
cytometry analysis of DNA content and colony forming test revealed that
syndecan-2, but not truncated syndecan-2, induced MG63 cell death. We show that
characteristic features of apoptosis such as caspase activation, PARP cleavage,
cytochrome c release, increased Bax expression, and DNA fragmentation were
associated with syndecan-2-induced cell death. We further show that expression
of full-length or truncated syndecan-2 induced differential activation of MAPK
phosphorylation in MG63 cells. Notably, syndecan-2 but not truncated syndecan-2
overexpression increased JNK phosphorylation. Moreover, SP600125, a specific
inhibitor of JNK, suppressed Bax expression induced by syndecan-2
overexpression, indicating that JNK activation mediates syndecan-2-induced
apoptosis. The results show that syndecan-2 induces osteoblastic cell apoptosis
through the JNK/Bax apoptotic pathway and that the cytoplasmic domain of
syndecan-2 is required for this action. This supports a role for syndecan-2 in
the regulation of osteosarcoma cell fate and identifies one signaling pathway by
which syndecan-2 induces apoptosis in osteosarcoma cells. Syndecans are transmembrane heparan sulfate proteoglycans with roles in cell
proliferation, differentiation, adhesion, and migration. They have been
associated with multiple functions in tumour progression, through their ability
to interact with a wide range of ligands as well as other receptors, which makes
them key effectors in the pericellular microenvironment. Extracellular shedding
of syndecans by tumour-associated matrix metalloproteinases (MMPs) may have an
important role in tumour progression. Such ectodomain shedding generates soluble
ectodomains that may function as paracrine or autocrine effectors, or as
competitive inhibitors of the intact proteoglycan. Tumour-associated MMPs are
shown here to cleave the ectodomains of human syndecan-1 and syndecan-4. Two
membrane proximal regions of both syndecan-1 and syndecan-4 are favoured MMP
cleavage sites, six and 15 residues from the transmembrane domain. Other sites
are 35-40 residues C-terminal from the heparan sulfate chain substitution sites
in both syndecans. The MT1-MMP cleavage sites in syndecan-1 and syndecan-4 were
confirmed by site-directed mutagenesis. These findings provide insights into the
characteristics of syndecan shedding. The syndecans are a type of cell surface adhesion receptor that initiates
intracellular signaling events through receptor clustering mediated by their
highly conserved transmembrane domains (TMDs). However, the exact function of
the syndecan TMD is not yet fully understood. Here, we investigated the specific
regulatory role of the syndecan-2 TMD. We found that syndecan-2 mutants in which
the TMD had been replaced with that of syndecan-4 were defective in
syndecan-2-mediated functions, suggesting that the TMD of syndecan-2 plays one
or more specific roles. Interestingly, syndecan-2 has a stronger tendency to
form sodium dodecyl sulfate (SDS)-resistant homodimers than syndecan-4. Our
structural studies showed that a unique phenylalanine residue (Phe(167)) enables
an additional molecular interaction between the TMDs of the syndecan-2
homodimer. The presence of Phe(167) was correlated with a higher tendency toward
oligomerization, and its replacement with isoleucine significantly reduced the
SDS-resistant dimer formation and cellular functions of syndecan-2 (e.g. cell
migration). Conversely, replacement of isoleucine with phenylalanine at this
position in the syndecan-4 TMD rescued the defects observed in a mutant
syndecan-2 harboring the syndecan-4 TMD. Taken together, these data suggest that
Phe(167) in the TMD of syndecan-2 endows the protein with specific functions.
Our work offers new insights into the signaling mediated by the TMD of syndecan
family members. Syndecans are transmembrane heparan sulfate proteoglycans involved in the
regulation of cell growth, differentiation, adhesion, neuronal development, and
lipid metabolism. Syndecans are expressed in a tissue-specific manner to
facilitate diverse cellular processes. As receptors and co-receptors, syndecans
provide promising therapeutic targets that bind to a variety of physiologically
important ligands. Negatively charged glycosaminoglycan chains of syndecans,
located in the extracellular compartment, are critical for such binding.
Functions of syndecans are as diverse as their ligands. For example, hepatic
syndecan-1 mediates clearance of triglyceride-rich lipoproteins. Syndecan-2
promotes localization of Alzheimer's amyloid Aβ peptide to the cell surface,
which is proposed to contribute to amyloid plaque formation. Syndecan-3 helps
co-localize the appetite-regulating melanocortin-4 receptor with its agonist,
leading to an increased appetite. Finally, syndecan-4 initiates the capture of
modified low-density lipoproteins by macrophages and thereby promotes the
atheroma formation. We hypothesize that syndecan modifications such as
desulfation of glycosaminoglycan chains may contribute to a wide range of
diseases, from atherosclerosis to type 2 diabetes. At the same time, desulfated
syndecans may have beneficial effects, as they can inhibit amyloid plaque
formation or decrease the appetite. Despite considerable progress in
understanding diverse functions of syndecans, the complex physiological roles of
this intriguing family of proteoglycans are far from clear. Additional studies
of syndecans may potentially help develop novel therapeutic approaches and
diagnostic tools to alleviate complex human diseases such as cardiovascular and
Alzheimer's diseases. Syndecans are transmembrane proteoglycans that, together with integrins, control
cell interactions with extracellular matrix components. Despite structural
similarities between all members of the syndecan family, their specific
attachment to extracellular matrix proteins is defined by heparan and
chondroitin chains. We postulate various unbinding kinetics for each type of
single syndecan complex. Force spectroscopy data, recorded by atomic force
microscope, were analyzed using two theoretical approaches describing
force-induced unbinding, authored by Bell-Evans and Dudko-Hummer-Szabo. Our
results reveal distinct unbinding pathways dependent on the syndecan family
member. Syndecan-1 unbinds by passing over two energy barriers, inner and outer.
Syndecan-4 unbinds by crossing over only one energy barrier. It has already been
reported that both syndecans bear heparan chains that are structurally
indistinguishable. Our finding reveals that unbinding of single syndecan
complexes is family-member-dependent. Distinct unbinding pathways can be
attributed to structural differences of heparan and chondroitin chains. Syndecans are important mediators of signalling by transmitting external stimuli
into the cells. This role in signal transduction has been attributed mainly to
the membrane-bound syndecans. In the last years, however, the soluble ectodomain
of syndecans generated by shedding has come into the focus of research as this
process has been show to modulate the syndecan-dependent signalling pathways, as
well as other pathways. This review summarizes the current knowledge about the
induction of syndecan shedding and the different pathways modulated by shed
syndecan proteins. This review summarizes the known and putative sheddases for
each syndecan and describes the exemplary conditions of sheddase activity for
some syndecans. This review summarizes the proposed use of shed syndecans as
biomarkers for various diseases, as the shedding process of syndecans depends
crucially on tissue- and disease-specific activation of the sheddases.
Furthermore, the potential use of soluble syndecans as a therapeutic option is
discussed, on the basis of the current literature. LINKED ARTICLES: This article
is part of a themed section on Translating the Matrix. To view the other
articles in this section visit
http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.1/issuetoc. |
What is chemokinesis? | Chemokinesis is chemically prompted kinesis, a motile response of unicellular prokaryotic or eukaryotic organisms to chemicals that cause the cell to make some kind of change in their migratory/swimming behaviour. | Eosinophils play an important role in the pathogenesis of allergic diseases such
as allergic asthma. Eosinophil migration in vitro can be divided into directed
migration, or chemotaxis, and random migration, or chemokinesis. Here, we
studied intracellular signals involved in eosinophil migration in vitro induced
by platelet-activating factor (PAF) and interleukin-5 (IL-5), applying a Boyden
chamber assay. Migration induced by PAF (10(-11)-10(-6) M) largely consisted of
chemotaxis with some chemokinesis, whereas IL-5 (10(-12)-10(-8) M) induced
chemokinesis only. Eosinophils were depleted from intracellular and
extracellular Ca2+ to study the role of Ca2+ as a second messenger. Ca2+
depletion did not change PAF-induced chemotaxis, however, IL-5-induced
chemokinesis was inhibited. Interestingly, PAF, but not IL-5, induced changes in
[Ca2+]i. This rise originated mainly from internal stores. Inhibition of protein
kinase A by H-89 and protein kinase C by GF 109203X had no effect on both forms
of eosinophil migration. Addition of the protein kinase inhibitor staurosporine
significantly inhibited IL-5-induced chemokinesis. Inhibition of tyrosine
kinases by herbimycin A completely blocked IL-5-induced chemokinesis. PAF and
IL-5-induced actin polymerization was studied to compare migratory responses
with a migration-associated intracellular response. Ca2+ depletion significantly
enhanced PAF-induced (10(-8) M) actin polymerization, whereas IL-5-induced actin
polymerization was not influenced. Addition of staurosporine led to an increase
in F-actin. Subsequent addition of PAF or IL-5 resulted in an additive increase
in F-actin content. In summary, both forms of eosinophil migration are protein
kinase A and protein kinase C independent. In contrast to PAF-induced
chemotaxis, Il-5-induced chemokinesis was found to be completely Ca2+ and
tyrosine kinase dependent. BACKGROUND: Chemotaxis is defined as directional cell movement of cells towards
concentration gradients of solubilized attractants, whereas chemokinesis is
defined as random cell movement in the absence of chemoattractant gradients.
Since tumor cell motility plays an important role in the process of tumor
invasion and metastasis, we investigated these two distinct motile behaviors in
highly invasive tumor, maligt mesothelioma.
MATERIALS AND METHODS: Chemotaxis and chemokinesis of mesothelioma cells were
assayed using Boyden chambers fitted with filters coated with collagen type IV
and different growth factors and cytokines were used as chemoattractants.
RESULTS: We found that growth factors such as epidermal growth factor,
transforming growth factor-alpha, amphiregulin, heparin-binding epidermal growth
factor-like growth factor, beta-cellulin, insulin-like growth factor-I,
insulin-like growth factor-II and stem cell factor stimulated directional
(chemotactic) and/or random (chemokinetic) motility in all mesothelioma cell
lines tested, whereas none of acidic fibroblast growth factor, basic fibroblast
growth factor, granulocyte-macrophage colony-stimulating factor or interleukin-6
induced migration in the same mesothelioma cells.
CONCLUSION: These findings provide evidence that: (i) multiple growth factors
can induce chemotaxis and chemokinesis in maligt mesothelioma cell lines, and
(ii) may contribute to our understanding of the highly invasive behavior of
maligt mesotheliomas in vivo. Movements of D. discoideum vegetative amoebae responding to pteridine
chemoattractants, folate acid and pterin, were recorded. A vector analysis of
these images was performed to partition the speed and orientation components of
these motility patterns. This study demonstrates that in addition to orientation
(chemotaxis), stimulated speed (chemokinesis) is an important component of the
directed migration of these amoebae. Furthermore, the primary difference in
their response to folate versus pterin is in speed rather than orientation. The
data support a model of directed migration of these cells in which there are (1)
separate signal translation pathways consequent from folate versus pterin
reception and (2) specific pathways leading to increase in orientation versus
speed. BACKGROUND: Biologics containing growth factors are frequently used to enhance
healing after musculoskeletal injuries. One mechanism of action is thought to be
though the ability of biologics to induce homing and migration of endogenous
mesenchymal stromal cells (MSCs) to a target tissue. However, the ability of
biologics to stimulate chemotaxis (directed migration of cells) and chemokinesis
(increase rate of cell migration) of MSCs is unknown.
HYPOTHESIS/PURPOSE: The aim of this study was to directly compare the ability of
biologics including platelet rich plasma (PRP) and bone marrow concentrate (BMC)
to induce MSC migration. The hypothesis was that leukocyte-low platelet rich
plasma (Llo PRP) would induce migration to a greater extent than leukocyte-high
platelet rich plasma (Lhi PRP) or BMC.
METHODS: Bone marrow-derived MSCs were isolated from 8 horses. Migration of MSCs
toward a biologic (BMC, Llo PRP, and Lhi PRP) or the positive control platelet
derived growth factor (PDGF) was continuously traced and measured for 24hrs
using time-lapse microscopy and a microfluidics device. Cell migration,
chemotaxis and chemokinesis were determined by measurements of displacement,
number of cells migrated, and cell flux.
RESULTS: All biologics resulted in a significantly greater percentage of MSCs
migrated compared to the positive control (PDGF). MSCs migrated further toward
BMC compared to Llo PRP. Cell migration, measured as cell flux, was greater
toward BMC and Lhi PRP than Llo PRP.
CONCLUSION: The biologics BMC and Lhi PRP elicit greater chemotaxis and
chemokinesis of MSCs than Llo PRP. However, all biologics recruited the same
number of MSCs suggesting that differences in other regenerative effects, such
as growth factor concentration, between biologics should be strongly considered
when choosing a biologic for treatment of musculoskeletal injuries. The results
of this study have the potential to reduce the need, risks, and costs associated
with MSC culture and delivery. |
What cellular process is JAK/STAT involved in? | The Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signaling pathway is utilized by numerous cytokines and interferons, and is essential for the development and function of both innate and adaptive immunity. | The JAK/STAT pathway was originally identified in mammals. Studies of this
pathway in the mouse have revealed that JAK/STAT signaling plays a central role
during hematopoeisis and other developmental processes. The role of JAK/STAT
signaling in blood appears to be conserved throughout evolution, as it is also
required during fly hematopoeisis. Studies in Dictyostelium, Drosophila, and
zebrafish have shown that the JAK/STAT pathway is also required in an unusually
broad set of developmental decisions, including cell proliferation, cell fate
determination, cell migration, planar polarity, convergent extension, and
immunity. There is increasing evidence that the versatility of this pathway
relies on its cooperation with other signal transduction pathways. In this
review, we discuss the components of the JAK/STAT pathway in model organisms and
what is known about its requirement in cellular and developmental processes. In
particular, we emphasize recent insights into the role that this pathway plays
in the control of cell movement. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT)
pathway is involved in many cellular processes, including cell growth and
differentiation, immune functions and cancer. It is activated by various
cytokines, growth factors, and protein tyrosine kinases (PTKs) and regulates the
transcription of many genes. Of the four JAK isoforms and seven STAT isoforms
known, JAK2 and STAT3 are highly expressed in the brain where they are present
in the postsynaptic density (PSD). Here, we demonstrate a new neuronal function
for the JAK/STAT pathway. Using a variety of complementary approaches, we show
that the JAK/STAT pathway plays an essential role in the induction of
NMDA-receptor dependent long-term depression (NMDAR-LTD) in the hippocampus.
Therefore, in addition to established roles in cytokine signaling, the JAK/STAT
pathway is involved in synaptic plasticity in the brain. Gastric carcinoma remains one of the most prevalent forms of cancer worldwide,
despite the decline in incidence rates, increased awareness of the disease and
advancement in treatment strategies. Helicobacter pylori infection, dietary
factors, lifestyle influences and various genetic aberrations have been shown to
contribute to the development and progression of gastric cancer. Recent studies
on the genomic landscape of gastric adenocarcinoma have identified several key
signaling molecules, including epidermal growth factor receptor family (ErbB)
members, vascular endothelial growth factor receptor family (VEGFR) members and
PI3K/Akt/mTOR pathway components, that have been implicated in the molecular
pathogenesis of gastric cancers. However, clinical trials with compounds that
target these molecules have failed to show a significant improvement in overall
survival rates when supplemented with conventional therapies. Therefore, it is
essential to identify effective prognostic and/or diagnostic biomarkers and
develop molecular targeted therapies. The JAK/STAT cascade is a principal signal
transduction pathway in cytokine and growth factor signaling, regulating various
cellular processes such as cell proliferation, differentiation, migration and
survival. Numerous in vivo and in vitro studies have shown that dysregulated
JAK/STAT signaling is a driving force in the pathogenesis of various solid
cancers as well as hematopoietic maligcies. Hence, a large number of
preclinical and clinical studies of drugs targeting this pathway are currently
underway. Notably, aberrant JAK/STAT signaling has also been implicated in
gastric cancers. In this review, we focus on the ongoing research on the
JAK/STAT cascade in gastric carcinoma and discuss the therapeutic potential of
targeting JAK/STAT signaling for the treatment of gastric cancer. Cytokines are believed to be crucial mediators of chronic intestinal
inflammation in inflammatory bowel diseases (IBD) such as Crohn's disease (CD)
and ulcerative colitis (UC). Many of these cytokines trigger cellular effects
and functions through signaling via janus kinase (JAK) and signal transducer and
activator of transcription (STAT) molecules. In this way, JAK/STAT signaling
controls important events like cell differentiation, secretion of cytokines or
proliferation and apoptosis in IBD in both adaptive and innate immune cells.
Moreover, JAK/STAT signaling, especially via the IL-6/STAT3 axis, is believed to
be involved in the transition of inflammatory lesions to tumors leading to
colitis-associated cancer (CAC). In this review, we will introduce the main
cellular players and cytokines that contribute to pathogenesis of IBD by
JAK/STAT signaling, and will highlight the integrative function that JAK/STATs
exert in this context as well as their divergent role in different cells and
processes. Moreover, we will explain current concepts of the implication of
JAK/STAT signaling in CAC and finally discuss present and future therapies for
IBD that interfere with JAK/STAT signaling. The Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT)
signaling pathway is utilized by numerous cytokines and interferons, and is
essential for the development and function of both innate and adaptive immunity.
Aberrant activation of the JAK/STAT pathway is evident in neuroinflammatory
diseases such as Multiple Sclerosis and Parkinson's Disease. Innate immunity is
the front line defender of the immune system and is composed of various cell
types, including microglia, macrophages and neutrophils. Innate immune responses
have both pathogenic and protective roles in neuroinflammation, depending on
disease context and the microenvironment in the central nervous system. In this
review, we discuss the role of innate immunity in the pathogenesis of
neuroinflammatory diseases, how the JAK/STAT signaling pathway regulates the
innate immune response, and finally, the potential for ameliorating
neuroinflammation by utilization of JAK/STAT inhibitors. BACKGROUND: JAK/STAT signal pathway, a requisite part in the signaling process
of growth factors and cytokines, has become attractive targets for numerous
immune, inflammatory and hematopoietic diseases.
OBJECTIVE: Herein, we present a review of the JAK/STAT signal pathway, the
structure, biological function, mechanism of the JAKs and STATs along with a
summary of the up-to-date clinical or approved JAK inhibitors which are involved
in the treatment of various kinds of tumors and other immunity indications.
Moreover, kinds of recently discovered JAKs inhibitors with potent activity or
promising selectivity are also briefly discussed.
CONCLUSION: Research and development of isoform selective JAK inhibitors has
become a hot topic in this field. With the assistance of high throughput
screening and rational drug design, more and more JAK inhibitors with improved
selective profiles will be discovered as biological probes and even therapeutic
agents. Cytokines are key modulators of immunity. Most cytokines use the Janus kinase
and signal transducers and activators of transcription (JAK-STAT) pathway to
promote gene transcriptional regulation, but their signals must be attenuated by
multiple mechanisms. These include the suppressors of cytokine signaling (SOCS)
family of proteins, which represent a main negative regulation mechanism for the
JAK-STAT pathway. Cytokine-inducible Src homology 2 (SH2)-containing protein
(CIS), SOCS1, and SOCS3 proteins regulate cytokine signals that control the
polarization of CD4+ T cells and the maturation of CD8+ T cells. SOCS proteins
also regulate innate immune cells and are involved in tumorigenesis. This review
summarizes recent progress on CIS, SOCS1, and SOCS3 in T cells and tumor
immunity. Stimulation of the cholinergic inflammatory pathway can attenuate
collagen-induced arthritis (CIA) and inhibit synovitis by Janus kinase (JAK) 2
and signal transducer and activator of transcription (STAT) 3 signaling.
Suppressor of cytokine signaling (SOCS) protein can also regulate the
inflammatory processes and activate JAK/STAT signal transduction, but its
involvement in rheumatoid arthritis (RA) has not been demonstrated. This study
investigated the effect of SOCS on cholinergic pathway regulation of synovitis
in the fibroblast-like synoviocytes (FLSs) of RA and CIA mice. The effects of
nicotine on SOCS1 and SOCS3 protein expression in FLSs were assayed by western
blotting before and after transfection with a small interfering RNA
oligonucleotide (SOCS3-siRNA or control-siRNA). Interleukin-6 was measured by
enzyme-linked immunosorbent assay of SOCS3-siRNA and control-siRNA transfected
FLS culture supernatants. Histopathological evaluation and immunohistochemical
staining of SOCS3 were performed in joint tissue sections of control, CIA model,
vagotomy, and nicotine-treated DBA/1 mice. Nicotine increased SOCS3 expression
in the FLSs of RA. The inhibitory effect of nicotine on inflammatory factors was
abolished by siRNA knockdown of SOCS3 protein expression. Nicotine increased the
expression of SOCS3 protein in the synovium and reduced synovitis and bone
erosion in CIA mice. |
What is the link between dental x-ray and brain tumor risk? | There is data to suggest that dental x-ray can be associated with significantly increased risk of meningiomas and gliomas. However, some studies failed to demonstrate an association between dental x-rays and brain tumor risk. | This investigation of a brain cancer cluster in Missouri used two approaches to
investigate associations with potential risk factors. In a case-control study in
a rural town, we interviewed surrogates of cases and controls about potential
risk factors. We found a statistically significant positive association of brain
cancer with reported exposure to dental X-rays. Occupation was not associated
with the cluster in the rural town. In a standardized proportional mortality
study for the state of Missouri, we calculated the observed and expected
proportion of brain cancers by occupation and industry in Missouri decedents. We
found that motor vehicle manufacturers, beauty shop workers, managers and
administrators, elementary school teachers, and hairdressers and cosmetologists
had significantly elevated proportions of brain cancer. Brain tumors are
inconsistently associated with occupation in the literature. Further study of
brain cancer etiology with respect to dental X-ray exposures seems warranted. Detailed job histories and information about other suspected risk factors were
obtained during interviews with 272 men aged 25-69 with a primary brain tumor
first diagnosed during 1980-1984 and with 272 individually matched neighbor
controls. Separate analyses were conducted for the 202 glioma pairs and the 70
meningioma pairs. Meningioma, but not glioma, was related to having a serious
head injury 20 or more years before diagnosis [odds ratio (OR) = 2.3; 95%
confidence interval (CI) = 1.1-5.4], and a clear dose-response effect was
observed relating meningioma risk to number of serious head injuries (P for
trend = 0.01; OR for greater than or equal to 3 injuries = 6.2; CI = 1.2-31.7).
Frequency of full-mouth dental X-ray examinations after age 25 related to both
glioma (P for trend = 0.04) and meningioma risk (P for trend = 0.06). Glioma,
but not meningioma risk, related to duration of prior employment in jobs likely
to involve high exposure to electric and magnetic fields (P for trend = 0.05).
This risk was greatest for astrocytoma (OR for employment in such jobs for
greater than 5 years = 4.3; CI = 1.2-15.6). More glioma cases had worked in the
rubber industry (discordant pairs 6/1) and more worked in hot processes using
plastics (9/1). More meningioma cases had jobs that involved exposure to metal
dusts and fumes (discordant pairs 13/5), and six of these cases and two controls
worked as machinists. Finally, there was a protective effect among glioma pairs
relating to frequency of use of vitamin C and other vitamin supplements (P for
trend = 0.004); the OR for use at least twice a day was 0.4 (CI = 0.2-0.8). BACKGROUND: Ionizing radiation is a consistently identified and potentially
modifiable risk factor for meningioma, which is the most frequently reported
primary brain tumor in the United States. The objective of this study was to
examine the association between dental x-rays-the most common artificial source
of ionizing radiation-and the risk of intracranial meningioma.
METHODS: This population-based case-control study included 1433 patients who had
intracranial meningioma diagnosed at ages 20 to 79 years and were residents of
the states of Connecticut, Massachusetts, North Carolina, the San Francisco Bay
Area, and 8 counties in Houston, Texas between May 1, 2006 and April 28, 2011
(cases). A control group of 1350 individuals was frequency matched on age, sex,
and geography (controls). The main outcome measure for the study was the
association between a diagnosis of intracranial meningioma and self-reported
bitewing, full-mouth, and panorex dental x-rays.
RESULTS: Over a lifetime, cases were more than twice as likely as controls (odds
ratio [OR], 2.0; 95% confidence interval [CI], 1.4-2.9) to report having ever
had a bitewing examination. Regardless of the age at which the films were
obtained, individuals who reported receiving bitewing films on a yearly basis or
with greater frequency had an elevated risk for ages <10 years (OR, 1.4; 95% CI,
1.0-1.8), ages 10 to 19 years (OR, 1.6; 95% CI, 1.2-2.0), ages 20 to 49 years
(OR, 1.9; 95% CI, 1.4-2.6), and ages ≥40 years (OR, 1.5; 95% CI, 1.1-2.0). An
increased risk of meningioma also was associated with panorex films taken at a
young age or on a yearly basis or with greater frequency, and individuals who
reported receiving such films at ages <10 years had a 4.9 times increased risk
(95% CI, 1.8-13.2) of meningioma. No association was appreciated for tumor
location above or below the tentorium.
CONCLUSIONS: Exposure to some dental x-rays performed in the past, when
radiation exposure was greater than in the current era, appears to be associated
with an increased risk of intracranial meningioma. As with all sources of
artificial ionizing radiation, considered use of this modifiable risk factor may
be of benefit to patients. BACKGROUND: This study evaluates the risk of benign brain tumors (BBTs) and
maligt brain tumors (MBTs) associated with dental diagnostic X-ray, using a
large population-based case-control study.
MATERIALS AND METHODS: We identified 4123 BBT cases and 16 492 controls without
BBT (study 1) and 197 MBT cases and 788 controls without MBT (study 2) from
Taiwan National Health Insurance claim data. The risks of both types of tumor
were estimated in association with the frequency of received dental diagnostic
X-ray.
RESULTS: The mean ages were ~44.2 years in study 1 and 40.6 years in study 2.
Multivariable unconditional logistic regression analysis showed that the risk of
BBT increases as the frequency of received dental diagnostic X-ray increases.
The BBT odds ratio increased from 1.33 [95% confidence interval (CI) 1.22-1.44]
for those with annual mean X-ray examination of less than one to 1.65 (95% CI
1.37-1.98) for those with three or more X-ray examinations, after controlling
for comorbidities. No significant association was found between MBTs and dental
diagnostic X-ray exposure.
CONCLUSIONS: Exposure to dental diagnostic X-rays in oral and maxillofacial care
increases the risk of BBTs, but not MBTs. Case control studies implicating dental X-rays in the genesis of intracranial
meningiomas have yielded conflicting results. To further evaluate what risk, if
any, that intracranial meningioma might be associated with dental X-rays, we
examined the association of benign brain tumor incidence with the number of
dentists and other correlates of oral health in U.S. states and the District of
Columbia. We compared these correlations to the association of the same markers
of oral health with Alzheimer's death rates. Poor oral health, especially
periodontal disease, is a well-established risk factor for dementia.
RESULTS: Pearson correlations, number of cases (49, no data from Kansas or
Maryland) and significance (2 tailed p values) of benign brain tumor incidence
and parameters of oral health are presented. None of the correlations approached
statistical significance. In contrast, Alzheimer's deaths by state were
negatively correlated with number of dentists and other markers of oral health.
CONCLUSION: Our finding of a total lack of correlation between benign brain
tumors and markers of oral health and, by implication, dental X-rays, suggests
there may be no relationship between dental X-rays and meningioma or other
benign brain tumors. This conclusion is strengthened by our demonstration of the
known negative correlation between Alzheimer's and dental care. Background: Exposure to moderate-to-high doses of ionizing radiation is the only
established environmental risk factor for thyroid cancer and brain and central
nervous system tumors. Considering the high lifetime prevalence and frequency of
exposure to dental X-rays, the most common source of diagnostic radiation
exposure in the general population, even a small associated increase in cancer
risk would be of considerable public health importance. With the objective to
inform clinical practice and guidelines, we synthesized the current
epidemiological evidence on the association between dental X-rays and the risk
of thyroid cancer, meningioma, and other cancers of the head and neck region.
Methods: The Medline, Embase, and Web of Science databases were searched to
identify eligible studies. Summary odds ratio/relative risk estimates and
confidence intervals were extracted, and pooled risk ratios (RRs) for each
cancer were calculated using random effects meta-analysis. Results: The
literature search identified 5537 publications; of these, 26 studies including
10,868 cancer patients were included in the synthesis. The random effects
meta-analyses, based on seven studies of thyroid cancer (six case/control, one
cohort) and eight studies of meningioma (all case/control), showed that multiple
(or repeated) exposures to dental X-rays were significantly associated with an
increased risk of thyroid cancer (pooled RR = 1.87 [95% confidence interval, CI
1.11-3.15]) and meningioma (pooled RR = 1.53 [CI 1.26-1.85]). There was no
association with glioma, and there were too few studies of other cancers of the
head and neck region to conduct a meaningful meta-analysis. Conclusions: Based
on a meta-analysis of retrospective case/control studies, these findings provide
some support to the hypothesis that multiple (or repeated) exposures to dental
X-rays may be associated with an increased risk of thyroid cancer and
meningioma. These studies did not include individual organ doses and ages at
exposure, and are subject to recall bias and other limitations. Furthermore, the
thyroid exposure has decreased dramatically over time from the use of thyroid
shields and improved technology/equipment. Prospective studies, based on dental
X-ray records and patient follow-up, are needed to test the hypothesis further
and clarify the possible cancer risk associated with dental radiography, as
although the risk at the individual level, particularly with improved
technology/equipment, is likely to be very low, the proportion of the population
exposed is high. Considering that about one-third of the general population in
developed countries is routinely exposed to one or more dental X-rays per year,
these findings manifest the need to reduce diagnostic radiation exposure as much
as possible. |
Is there a vaccine for rotavirus? | yes, rotavirus pentavalent vaccine (RotaTeq(r)) as a sole vaccine | In a four cell trial, a single 10(4) plaque-forming unit dose of rhesus
rotavirus (RRV) vaccine (serotype G3), a human rotavirus-rhesus rotavirus
reassortant vaccine with serotype G1 specificity, a similar vaccine with
serotype G2 specificity, or a placebo was administered with buffer orally at 2
months of age to 800 Peruvian infants. Only the RRV vaccine was associated with
a febrile response (< 38 degrees C) that occurred in 9% of the infants on day 4
after vaccination. Diarrhea or other side-effects were not associated with
administration of vaccine. Vaccine strains were shed by only 12-18% of the
infants as determined by examination of a single stool specimen obtained on days
4 or 5 after vaccination. Fifty per cent of vaccines developed an IgA ELISA
seroresponse; however, a serotype-specific seroresponse by plaque reduction
neutralization was demonstrated in < 20% of the participants against each of the
three candidate vaccine strains. Vaccine efficacy was evaluated by twice-weekly
home surveillance for diarrheal diseases during 24 months post-immunization.
Rotavirus diarrheal episodes were identified by ELISA. Only the RRV vaccine had
a significant protective efficacy (29%, p = 0.03, chi-square test) against
rotavirus diarrhea. Analysis of vaccine efficacy against rotavirus episodes of
any severity in which no other enteropathogen was isolated showed a trend
towards higher vaccine efficacy. In addition, a similar trend was observed in
rotavirus-only episodes in which there was some degree of dehydration or when
health services were utilized. Serotype G1 or G2 rotavirus strains were most
prevalent during surveillance. Neither serotype G1 or serotype G2 vaccines were
protective against serotype 1 or 2 rotavirus diarrhea, respectively. The
serotype G2 vaccine was 84% protective against serotype 1 and 2 dehydrating
rotavirus diarrhea in the small numbers of individuals evaluated. We conclude
that one dose of 10(4) p.f.u. of the RRV, serotype G1, or serotype G2 rotavirus
vaccine failed to induce either an adequate serotype-specific seroresponse or
serotype-specific protection in children immunized at 2 months of age. Only the
RRV vaccine induced a low level of protection against rotavirus diarrhea mainly
of serotype G1 specificity. Future studies need to explore whether higher
vaccine dose and/or more than one dose would increase the immunogenicity and
efficacy of the rotavirus vaccine, especially in developing countries with a
high level of baseline rotavirus antibodies. The need for safe and effective vaccines to reduce morbidity and mortality
caused by rotavirus gastroenteritis in children is well-known. A live attenuated
monovalent rotavirus vaccine (Rotarix) containing human rotavirus strain RIX4414
of G1P1A P[8] specificity is being developed to meet the global need. An
overview of RIX4414 trials in developed and developing settings is presented for
3 selected trials conducted in Finland (pilot study), Latin America (Brazil,
Mexico and Venezuela) and Singapore involving 5024 infants. The vaccine was
well-tolerated, with no increase in any solicited symptoms as compared with the
placebo. After 2 doses, 61-91% of vaccinated infants developed
rotavirus-specific IgA antibodies. There was no interference with immunogenicity
of coadministered routine pediatric vaccines. Rotarix significantly reduced
rotavirus gastroenteritis episodes and rotavirus-related hospitalizations in
vaccinated infants compared with placebo recipients (P < 0.05). Vaccine efficacy
was observed against severe rotavirus gastroenteritis caused by G1 and non-G1
types including the emerging G9 type (P < 0.05) in Latin America. These results
show prospects for widespread use of Rotarix to reduce rotavirus disease burden
and warrant continued worldwide evaluation. Two new rotavirus vaccines are expected to be introduced in the European Union
(EU) in coming years. A human rotavirus vaccine has already been licensed in
several countries worldwide, and a pentavalent bovine vaccine has been submitted
for licensure in the United States and the EU. Few data exist on the burden of
rotavirus disease and its associated costs within the EU. To estimate the burden
of rotavirus disease in the EU, we adapted a model based on the approach
developed by the Centers for Disease Control and Prevention to the European
situation and applied it to recent population and mortality data from European
countries. Country-specific estimates were added to obtain a global estimate of
rotavirus episodes treated at home, clinic visits, hospitalization and death. We
estimate that 3.6 million episodes of rotavirus disease occur annually among the
23.6 million children younger than 5 years of age in the EU. Every year,
rotavirus accounts for 231 deaths, >87,000 hospitalizations and almost 700,000
outpatient visits. Rotavirus disease constitutes a large public health burden in
the EU. Except for deaths, the burden of disease is not dissimilar to that in
the developing world. Country-specific studies are required to more accurately
understand the burden of disease caused by rotavirus. With the introduction of
new rotavirus vaccines in sight, rotavirus gastroenteritis may be regarded as
the single most frequent vaccine-preventable disease among children in the EU. Evidence generated through years of research has built a solid scientific
foundation on the safety and efficacy of rotavirus vaccines, and has served to
raise awareness of global rotavirus disease burden and the potential impact of
vaccination. In this commentary, we explore the role that researchers can play
in closing key gaps of knowledge, demand, and ficing to support
decision-making on introduction of new vaccines in developing countries. With
safe and efficacious rotavirus vaccines now on the verge of widespread adoption,
researchers can be vital advocates for their uptake into routine immunization
programs. Temporal and spatial fluctuations in the genotype distribution of human
rotaviruses are continuously observed in surveillance studies. New genotypes,
such as G9 and G12, have emerged and spread worldwide in a very short time span.
In addition, reassortment events have the potential to contribute substantially
to genetic diversity among human and animal rotaviruses. With the recent
introduction of the two rotavirus vaccines, RotaTeq and Rotarix, in many
countries, it appears that the total number of hospitalizations due to rotavirus
infections is being reduced, at least in developed countries that implemented a
universal immunization program. However, continued surveillance is warranted,
especially regarding the long-term effects of the vaccines. No data analyses are
available to clarify whether rotavirus vaccine introduction would allow other
rotavirus P and G genotypes, which are not covered by the current vaccines, to
emerge into the human population and fill the apparent gap. This kind of data
analysis is essential, but its interpretation is hampered by natural and
cyclical genotype fluctuations. Retrospective analysis done at a children's hospital showed significant decrease
in infections and hospitalizations caused by rotavirus in northeast Florida
after the introduction of rotavirus vaccines in 2006. The rotavirus season was
delayed in onset by 8 months and duration prolonged by 2-3 months in 2008, and
no definite season occurred in 2009. The most common cause of severe diarrhoea in infants and young children is
rotavirus gastroenteritis (RVGE), which is associated with significant
morbidity, healthcare resource use and direct and indirect costs in
industrialized nations. The monovalent rotavirus vaccine RIX4414 (Rotarix™) is
administered as a two-dose oral series in infants and has demonstrated
protective efficacy against RVGE in clinical trials conducted in developed
countries. In addition, various naturalistic studies have demonstrated
'real-world' effectiveness after the introduction of widespread rotavirus
vaccination programmes in the community setting. Numerous cost-effectiveness
analyses have been conducted in developed countries in which a universal
rotavirus vaccination programme using RIX4414 was compared with no universal
rotavirus vaccination programme. There was a high degree of variability in
base-case results across studies even when conducted in the same country, often
reflecting differences in the selection of data sources or assumptions used to
populate the models. In addition, results were sensitive to plausible changes in
a number of key input parameters. As such, it is not possible to definitively
state whether a universal rotavirus vaccination programme with RIX4414 is cost
effective in developed countries, although results of some analyses in some
countries suggest this is the case. In addition, international guidelines
advocate universal vaccination of infants and children against rotavirus. It is
also difficult to draw conclusions regarding the cost effectiveness of rotavirus
vaccine RIX4414 relative to that of the pentavalent rotavirus vaccine, which is
administered as a three-dose oral series. Although indirect comparisons in
cost-effectiveness analyses indicate that RIX4414 provided more favourable
incremental cost-effectiveness ratios when each vaccine was compared with no
universal rotavirus vaccination programme, results were generally sensitive to
vaccine costs. Actual tender prices of a full vaccination course for each
vaccine were not known at the time of the analyses and therefore had to be
estimated. Question Les vaccins contre le rotavirus sont progressivement inclus dans les
programmes d’immunisation planifiés au Canada et de plus en plus d’enfants de
moins de 1 an dans ma pratique reçoivent ces vaccins. Y a-t-il des données
scientifiques confirmantt que les vaccins contre le rotavirus sont efficaces
pour prévenir les complications de la gastro-entérite aiguë, comme la
déshydratation et l’hospitalisation? Réponse Pour réduire le fardeau de la
gastro-entérite causée par le rotavirus, 2 vaccins administrés par voie orale
ont été homologués récemment. Des études de grande envergure ont documenté les
profils de sécurité de ces vaccins et plusieurs provinces ont inclus un vaccin
contre le rotavirus dans le contexte de leur programme d’immunisation. De
récentes données provet de pays développés et en développement font valoir
que le vaccin contre le rotavirus diminue considérablement la morbidité et la
mortalité chez les enfants. Les études cliniques initiales sont maintet
corroborées par des données sur l’efficacité tirées d’études sur le terrain
démontrant une réduction de 70 % à 100 % des visites à l’urgence et de
l’hospitalisation des enfants souffrant de gastro-entérite aiguë due au
rotavirus. BACKGROUND: With the recent postlicensure identification of an increased risk of
intussusception with rotavirus vaccine, the 14 Latin American countries
currently using rotavirus vaccine must now weigh the health benefits versus
risks to assess whether to continue vaccination. To inform policy
considerations, we estimated excess intussusception cases and mortality
potentially caused by rotavirus vaccine for each of the 14 countries and
compared these estimates to hospitalizations and deaths expected to be averted
through vaccination.
METHODS: We used regional rotavirus disease burden and rotavirus vaccine
efficacy data, global natural intussusception and regional rotavirus
vaccine-related risk estimates, and country-specific diphtheria, tetanus, and
pertussus vaccination coverage rates to estimate rotavirus vaccine coverage
rates. We performed a probabilistic sensitivity analysis to account for
uncertainty in these parameters.
RESULTS: For an aggregate hypothetical birth cohort of 9.5 million infants in
these 14 countries, rotavirus vaccine would annually prevent 144 746 (90%
confidence interval [CI], 128 821-156 707) hospitalizations and 4124 deaths (90%
CI, 3740-4239) due to rotavirus in their first 5 years of life but could cause
an additional 172 hospitalizations (90% CI, 126-293) and 10 deaths (90% CI,
6-17) due to intussusception, yielding benefit-risk ratios for hospitalization
and death of 841:1 (90% CI, 479:1 to 1142:1) and 395:1 (90% CI, 207:1 to 526:1),
respectively. In an uncertainty analysis using 10 000 simulations of our
probabilistic parameters, in comparing rotavirus disease averted to
intussusception events caused, the hospitalization ratio was never below 100:1,
and our death ratio fell below 100:1 only once.
CONCLUSIONS: The health benefits of vaccination far outweigh the short-term
risks and support continued rotavirus vaccination in Latin America. Rotaviruses are the most common cause of acute gastroenteritis in young children
worldwide. Both licensed rotavirus vaccines (Rotarix™ [RV1] and RotaTeq™ [RV5])
are effective and safe. Studies from countries that have included RV1 or RV5 in
the national immunization programs have demonstrated their safety and sustained
efficacy under real-life circumstances. A significant decline in acute
gastroenteritis-related deaths among Latin American children was observed after
the introduction of RV1 and RV5 vaccines. Both vaccines were able to decrease
the number of cases of rotavirus acute gastroenteritis and of severe rotavirus
diseases. Vaccination was also associated with a dramatic reduction in
hospitalizations and outpatient visits for all-cause acute gastroenteritis.
Indirect protection after infant mass vaccination has been strongly suggested.
Moreover, postlicensure safety studies assessed rare adverse events (rates <1 in
50,000), such as intussusception. BACKGROUND: Although current rotavirus vaccines were not associated with an
increased risk of intussusception in large trials before licensure, recent
postlicensure data from international settings suggest the possibility of a
small increase in risk of intussusception after monovalent rotavirus
vaccination. We examined this risk in a population in the United States.
METHODS: Participants were infants between the ages of 4 and 34 weeks who were
enrolled in six integrated health care organizations in the Vaccine Safety
Datalink (VSD) project. We reviewed medical records and visits for
intussusception within 7 days after monovalent rotavirus vaccination from April
2008 through March 2013. Using sequential analyses, we then compared the risk of
intussusception among children receiving monovalent rotavirus vaccine with
historical background rates. We further compared the risk after monovalent
rotavirus vaccination with the risk in a concurrent cohort of infants who
received the pentavalent rotavirus vaccine.
RESULTS: During the study period, 207,955 doses of monovalent rotavirus vaccine
(including 115,908 first doses and 92,047 second doses) were administered in the
VSD population. We identified 6 cases of intussusception within 7 days after the
administration of either dose of vaccine. For the two doses combined, the
expected number of intussusception cases was 0.72, resulting in a significant
relative risk of 8.4. For the pentavalent rotavirus vaccine, 1,301,810 doses
were administered during the study period, with 8 observed intussusception cases
(7.11 expected), for a nonsignificant relative risk of 1.1. The relative risk of
chart-confirmed intussusception within 7 days after monovalent rotavirus
vaccination, as compared with the risk after pentavalent rotavirus vaccination,
was 9.4 (95% confidence interval, 1.4 to 103.8). The attributable risk of
intussusception after the administration of two doses of monovalent rotavirus
vaccine was estimated to be 5.3 per 100,000 infants vaccinated.
CONCLUSIONS: In this prospective postlicensure study of more than 200,000 doses
of monovalent rotavirus vaccine, we observed a significant increase in the rate
of intussusception after vaccination, a risk that must be weighed against the
benefits of preventing rotavirus-associated illness. (Funded by the Centers for
Disease Control and Prevention.). Rotavirus vaccine was introduced in El Salvador in 2006 and is recommended to be
given concomitantly with DTP-HepB-Haemophilus influenzae type b (pentavalent)
vaccine at ages 2 months (upper age limit 15 weeks) and 4 months (upper age
limit 8 months) of age. However, rotavirus vaccination coverage continues to lag
behind that of pentavalent vaccine, even in years when national rotavirus
vaccine stock-outs have not occurred. We analyzed factors associated with
receipt of oral rotavirus vaccine among children who received at least 2 doses
of pentavalent vaccine in a stratified cluster survey of children aged 24-59
months conducted in El Salvador in 2011. Vaccine doses included were documented
on vaccination cards (94.4%) or in health facility records (5.6%). Logistic
regression and survival analysis were used to assess factors associated with
vaccination status and age at vaccination. Receipt of pentavalent vaccine by age
15 weeks was associated with rotavirus vaccination (OR: 5.1; 95% CI 2.7, 9.4),
and receipt of the second pentavalent dose by age 32 weeks was associated with
receipt of two rotavirus vaccine doses (OR: 5.0; 95% CI 2.1-12.3). Timely
coverage with the first pentavalent vaccine dose was 88.2% in the 2007 cohort
and 91.1% in the 2008 cohort (p=0.04). Children born in 2009, when a four-month
national rotavirus vaccine stock-out occurred, had an older median age of
receipt of rotavirus vaccine and were less likely to receive rotavirus on the
same date as the same dose of pentavalent vaccine than children born in 2007 and
2008. Upper age limit recommendations for rotavirus vaccine administration
contributed to suboptimal vaccination coverage. Survey data suggest that late
rotavirus vaccination and co-administration with later doses of pentavalent
vaccine among children born in 2009 helped increase rotavirus vaccine coverage
following shortages. Widespread introduction of rotavirus vaccines has led to major reductions in the
burden of rotavirus gastroenteritis worldwide. Vaccine effectiveness is
diminished, however, in low income countries, that harbour the greatest burden
of rotavirus attributed morbidity and mortality. Indirect effects of rotavirus
vaccine (herd immunity and herd protection) could increase population level
impact and improve vaccine cost effectiveness in such settings. While rotavirus
vaccine indirect effects have been demonstrated in high and middle income
countries, there are very little data from low income countries where force of
infection, population structures and vaccine schedules differ. Targeted efforts
to evaluate indirect effects of rotavirus vaccine in low income countries are
required to understand the total impact of rotavirus vaccine on the global
burden of rotavirus disease. Author information:
(1)Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke
Clinical Vaccine Unit, Duke University School of Medicine, Durham, North
Carolina.
(2)Department of Pediatrics, Durham, North Carolina.
(3)Duke Clinical Vaccine Unit, Duke University Medical Center, Durham, North
Carolina.
(4)Department of Pediatrics, Division of Infectious Diseases, Cincinnati
Children's Hospital Medical Center, Ohio.
(5)Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke
Global Health Institute, Duke Clinical Vaccine Unit, Duke University School of
Medicine, Durham, North Carolina. BACKGROUND: Previous studies have found a strong correlation between internet
search and public health surveillance data. Less is known about how search data
respond to public health interventions, such as vaccination, and the consistency
of responses in different countries. In this study, we aimed to study the
correlation between internet searches for "rotavirus" and rotavirus disease
activity in the United States, United Kingdom, and Mexico before and after
introduction of rotavirus vaccine.
METHODS: We compared time series of internet searches for "rotavirus" from
Google Trends with rotavirus laboratory reports from the United States and
United Kingdom and with hospitalizations for acute gastroenteritis in the United
States and Mexico. Using time and location parameters, Google quantifies an
internet query share (IQS) to measure the relative search volume for specific
terms. We analyzed the correlation between IQS and laboratory and
hospitalization data before and after national vaccine introductions.
RESULTS: There was a strong positive correlation between the rotavirus IQS and
laboratory reports in the United States (R2 = 0.79) and United Kingdom (R2 =
0.60) and between the rotavirus IQS and acute gastroenteritis hospitalizations
in the United States (R2 = 0.87) and Mexico (R2 = 0.69) (P < .0001 for all
correlations). The correlations were stronger in the prevaccine period than in
the postvaccine period. After vaccine introduction, the mean rotavirus IQS
decreased by 40% (95% confidence interval [CI], 25%-55%) in the United States
and by 70% (95% CI, 55%-86%) in Mexico. In the United Kingdom, there was a loss
of seasonal variation after vaccine introduction.
CONCLUSIONS: Rotavirus internet search data trends mirrored national rotavirus
laboratory trends in the United States and United Kingdom and
gastroenteritis-hospitalization data in the United States and Mexico; lower
correlations were found after rotavirus vaccine introduction. BACKGROUND: Established in 2006 with four countries conducting hospital-based
rotavirus surveillance, the African rotavirus surveillance network has expanded
over subsequent years. By 2015, 14 countries in the World Health Organization
(WHO) East and Southern Africa sub-region (Eritrea, Ethiopia, Kenya, Lesotho,
Madagascar, Mauritius, Namibia, Rwanda, Seychelles, Swaziland, Tanzania, Uganda,
Zambia and Zimbabwe) were participating in the rotavirus surveillance network
coordinated by WHO. We monitored the proportion of rotavirus diarrhoea among
children under five years of age who were hospitalized for diarrhoea in the
sentinel hospitals from 2010 to 2015 among countries that introduced rotavirus
vaccine during or before 2013 (Rwanda, Tanzania, Zambia and Ethiopia) and
compared with the other countries in the network.
METHODS: Children under the age of five years hospitalized due to acute
diarrhoea were enrolled into the sentinel surveillance system and had stool
samples collected and tested for rotavirus antigens by enzyme immunoassay. We
described trends in rotavirus positivity among tested stool samples before and
after rotavirus vaccine introduction.
RESULTS: In countries that introduced rotavirus vaccine by 2013 (Rwanda,
Tanzania, Zambia and Ethiopia), average rotavirus vaccine coverage from 2010 to
2015 improved from 0% in 2010 and 2011, 13% in 2012, 46% in 2013, 83% in 2014 to
90% in 2015. Annual average rotavirus positivity from 2010 to 2015 was 35%, 33%,
38%, 28%, 27%, and 19%, respectively. In countries that introduced rotavirus
vaccine after 2013 or had not introduced by 2015, average rotavirus vaccine
coverage was 0% in 2010-2013, 13% in 2014 and 51% in 2015. In these countries,
rotavirus positivity was 44% in 2010, 32% in 2011, 33% in 2012, 41% in 2013, 40%
in 2014 and 25% in 2015.
CONCLUSION: Countries that introduced rotavirus vaccine by 2013 had a lower
proportion of rotavirus positive hospitalizations in 2013-2015 as compared to
those that had not introduced rotavirus vaccine by 2013. The decrease in
rotavirus positivity was inversely related to increase in rotavirus vaccine
coverage showing impact of rotavirus vaccines. In 2012, Fiji introduced rotavirus vaccine (Rotarix, GSK) into the national
immunisation schedule. We describe the intussusception epidemiology prior to
rotavirus vaccine, temporal association of intussusception cases to
administration of rotavirus vaccine, and estimate the additional number of
intussusception cases that may be associated with rotavirus vaccine. A
retrospective review of intussusception cases for children aged <24 months old
was undertaken between January 2007 and October 2012 pre-vaccine. All admissions
and deaths with a discharge diagnosis of intussusception, bowel obstruction,
paralytic ileus, or intussusception ICD10-AM codes were extracted from national
databases and hospital records. Nationwide active intussusception surveillance
was established for three years post-vaccine (2013-2015). There were 24 definite
intussusception cases in the pre-rotavirus vaccine period, 96% were confirmed by
surgery. The median age was 6.5 months. The incidence rate was 22.2 (95% CI:
13.9-33.7) per 100,000 infants. There were no deaths. Active surveillance
identified 25 definite intussusception cases, 96% of which were among children
who were age-eligible for rotavirus vaccine. None were potentially vaccine
related. We estimated one to five additional cases of intussusception every
five years. The incidence of intussusception pre-rotavirus vaccine in Fiji is
low. Intussusception associated with rotavirus vaccine is likely a rare event in
Fiji. BACKGROUND: Rotavirus remains an important cause of gastroenteritis and has been
associated with the hospitalization of 34 to 53 per 10 000 children <5 years of
age in the United States annually from 2008 to 2012. Rotavirus vaccines are
underused compared with other routine vaccines. We describe rotavirus vaccine
coverage and missed opportunities for rotavirus vaccination.
METHODS: The National Immunization Survey is a random-digit-dial,
population-based survey including US children 19 to 35 months of age. Children
fully vaccinated for rotavirus were those who received 3 doses of the
pentavalent rotavirus vaccine, 2 doses of the monovalent rotavirus vaccine, or
≥3 doses of either vaccine type. Doses of the diphtheria-tetanus-acellular
pertussis vaccine received from 6 weeks through 8 months and 0 days of age when
the rotavirus vaccine was not received were considered missed opportunities for
rotavirus vaccination according to Advisory Committee on Immunization Practices
(ACIP) guidelines, and doses of the diphtheria-tetanus-acellular pertussis
vaccine or measles-mumps-rubella vaccine from 6 weeks through 24 months and 0
days of age were considered missed opportunities according to World Health
Organization recommendations.
RESULTS: Of the 14 571 children included in the 2014 National Immunization
Survey, 71% were fully vaccinated for rotavirus. Lower socioeconomic status
increased the likelihood of being unvaccinated for rotavirus. Among the 14% of
children who received no doses of the rotavirus vaccine, 72% had ≥1 ACIP-defined
missed opportunities, and 83% had ≥1 World Health Organization-defined missed
opportunities. Higher socioeconomic status increased the likelihood of having
missed opportunities. Complete rotavirus vaccine coverage could be improved to
81% if all missed opportunities within the ACIP-recommended schedule were
addressed.
CONCLUSIONS: Addressing missed opportunities for rotavirus vaccination is
essential to achieving the 80% rotavirus vaccine coverage target outlined by
Healthy People 2020. |
Which T-UCR has been implicated in prostate cancer? | Transcribed ultraconserved region Uc.63+ promotes resistance to docetaxel through regulation of androgen receptor signaling in prostate cancer. Docetaxel is the standard chemotherapy for metastatic castration-resistant prostate cancer ( CRPC). However, nearly all patients ultimately become refractory due to the development of docetaxel resistance. | |
Is BNN20 involved in Parkinson's disease? | Yes. Neurotrophic factors are among the most promising treatments aiming at slowing or stopping and even reversing Parkinson's disease (PD). BNN-20 has been suggested as an important neuroprotective agent acting through the TrkB neurotrophin receptor pathway, mimicking the action of the endogenous neurotrophin BDNF. Thus BNN-20 could be proposed for treatment of PD. | Neurotrophic factors are among the most promising treatments aiming at slowing
or stopping and even reversing Parkinson's disease (PD). However, in most cases,
they cannot readily cross the human blood-brain-barrier (BBB). Herein, we
propose as a therapeutic for PD the small molecule
17-beta-spiro-[5-androsten-17,2'-oxiran]-3beta-ol (BNN-20), a synthetic analogue
of DHEA, which crosses the BBB and is deprived of endocrine side-effects. Using
the "weaver" mouse, a genetic model of PD, which exhibits progressive
dopaminergic neurodegeneration in the Substantia Nigra (SN), we have shown that
long-term administration (P1-P21) of BNN-20 almost fully protected the
dopaminergic neurons and their terminals, via i) a strong anti-apoptotic effect,
probably mediated through the Tropomyosin receptor kinase B (TrkB) neurotrophin
receptor's PI3K-Akt-NF-κB signaling pathway, ii) by exerting an efficient
antioxidant effect, iii) by inducing significant anti-inflammatory activity and
iv) by restoring Brain-Derived Neurotrophic Factor (BDNF) levels. By
intercrossing "weaver" with NGL mice (dual GFP/luciferase-NF-κΒ reporter mice,
NF-κΒ.GFP.Luc), we obtained Weaver/NGL mice that express the NF-κB reporter in
all somatic cells. Acute BNN-20 administration to Weaver/NGL mice induced a
strong NF-κB-dependent transcriptional response in the brain as detected by
bioluminescence imaging, which was abolished by co-administration of the TrkB
inhibitor ANA-12. This indicates that BNN-20 exerts its beneficial action (at
least in part) through the TrkB-PI3K-Akt-NF-κB signaling pathway. These results
could be of clinical relevance, as they suggest BNN-20 as an important
neuroprotective agent acting through the TrkB neurotrophin receptor pathway,
mimicking the action of the endogenous neurotrophin BDNF. Thus BNN-20 could be
proposed for treatment of PD. |
Which domain of the MOZ/MYST3 protein complex associates with histone H3? | The double PHD finger domain of MOZ/MYST3 induces a-helical structure of the histone H3 tail | Histone tail modifications control many nuclear processes by dictating the
dynamic exchange of regulatory proteins on chromatin. Here we report novel
insights into histone H3 tail structure in complex with the double PHD finger
(DPF) of the lysine acetyltransferase MOZ/MYST3/KAT6A. In addition to sampling
H3 and H4 modification status, we show that the DPF cooperates with the MYST
domain to promote H3K9 and H3K14 acetylation, although not if H3K4 is
trimethylated. Four crystal structures of an extended DPF alone and in complex
with unmodified or acetylated forms of the H3 tail reveal the molecular basis of
crosstalk between H3K4me3 and H3K14ac. We show for the first time that MOZ DPF
induces α-helical conformation of H3K4-T11, revealing a unique mode of H3
recognition. The helical structure facilitates sampling of H3K4 methylation
status, and proffers H3K9 and other residues for modification. Additionally, we
show that a conserved double glycine hinge flanking the H3 tail helix is
required for a conformational change enabling docking of H3K14ac with the DPF.
In summary, our data provide the first observations of extensive helical
structure in a histone tail, revealing the inherent ability of the H3 tail to
adopt alternate conformations in complex with chromatin regulators. |
Which company sells the drug Afrezza since 2015? | Afrezza has been marketed by Sanofi since February 2015. | The current review was designed to compare between the insulin inhalation
systems Exubera and Afrezza and to investigate the reasons why Exubera was
unsuccessful, when Afrezza maker is expecting their product to be felicitous. In
January 2006, Pfizer secured FDA and EC approval for the first of its kind,
regular insulin through Exubera inhaler device for the management of types 1 and
2 diabetes mellitus (DM) in adults. The product was no longer available to the
market after less than two years from its approval triggering a setback for
competitive new inhalable insulins that were already in various clinical
development phases. In contrary, MannKind Corporation started developing its
ultra-rapid-acting insulin Afrezza in a bold bid, probably by managing the
issues in which Exubera was not successful. Afrezza has been marketed since
February, 2015 by Sanofi after getting FDA approval in June 2014. The results
from this systematic review indicate the effectiveness of insulin inhalation
products, particularly for patients initiating insulin therapy. Pharmaceutical
companies should capitalize on the information available from insulin inhalation
to produce competitive products that are able to match the bioavailability of
subcutaneous (SC) insulin injection and to deal with the single insulin unit
increments and basal insulin requirements in some diabetic patients or extending
the horizon to inhalable drug products with completely different drug entities
for other indications. |
Is there a role for MRPL53 in cancer? | No. MRPL53 is a new candidate gene for orofacial clefting identified using an eQTL approach. | A valuable approach to understand how individual and population genetic
differences can predispose to disease is to assess the impact of genetic
variants on cellular functions (e.g., gene expression) of cell and tissue types
related to pathological states. To understand the genetic basis of nonsyndromic
cleft lip with or without cleft palate (NSCL/P) susceptibility, a complex and
highly prevalent congenital malformation, we searched for genetic variants with
a regulatory role in a disease-related tissue, the lip muscle (orbicularis oris
muscle [OOM]), of affected individuals. From 46 OOM samples, which are
frequently discarded during routine corrective surgeries on patients with
orofacial clefts, we derived mesenchymal stem cells and correlated the
individual genetic variants with gene expression from these cultured cells.
Through this strategy, we detected significant cis-eQTLs (i.e., DNA variants
affecting gene expression) and selected a few candidates to conduct an
association study in a large Brazilian cohort (624 patients and 668 controls).
This resulted in the discovery of a novel susceptibility locus for NSCL/P,
rs1063588, the best eQTL for the MRPL53 gene, where evidence for association was
mostly driven by the Native American ancestry component of our Brazilian sample.
MRPL53 (2p13.1) encodes a 39S protein subunit of mitochondrial ribosomes and
interacts with MYC, a transcription factor required for normal facial
morphogenesis. Our study illustrates not only the importance of sampling admixed
populations but also the relevance of measuring the functional effects of
genetic variants over gene expression to dissect the complexity of disease
phenotypes. |
Does Uc.63+ promote sensitivity to treatment in prostate cancer? | No. Overexpression of Uc.63+ increases the expression of AR and its downstream molecule PSA and promotes resistance to docetaxel through AR regulation. In patients treated with docetaxel, the expression of serum Uc.63+ in the docetaxel-resistant patients is higher than that in the docetaxel-sensitive patients (P = 0.011). Moreover, Kaplan-Meier analysis indicates that the high expression of serum Uc.63+ correlated with a worse prognosis (P = 0.020). | |
What is the gene PTENP? | PTEN pseudogene (PTENp) acts as an endogenous RNA, which regulates its parental gene by competitively binding to the 3' UTR of PTEN gene in the human. | Phosphatase and tensin homolog (PTEN) is a tumor-suppressor gene. PTEN
pseudogene (PTENp) acts as an endogenous RNA, which regulates its parental gene
by competitively binding to the 3' UTR of PTEN gene in the human. Despite the
importance of this pseudogene, little is known about the molecular evolution of
PTENp in mammals. In this study, we identified 37 pseudogenes from 65 mammalian
genomes. Among them, 32 were from rodents or primates. Phylogenetic analyse
showed a complex evolutionary history of this gene family. Some PTENps were
shared both in primates and rodents. However, some PTENps were shown to be
species-specific, such as the tasmanian devil PTENp1, nine banded armadillo
PTENp1 and gibbon PTENp1. Most interestingly, the naked mole rat (NMR), an
anticancer model organism, possessed 17 copies of PTENps, which were classified
into four clades based on the phylogenetic analyses. Furthermore, we found that
all the 3'UTR of PTEN and PTENps shared common microRNA (MicroRNA) binding sites
in NMR, based on our prediction of specific MicroRNA binding sites. Our findings
suggested that multiple gene duplications have occurred in the formation of
PTEN/PTENp gene family during the evolution of mammals. Some PTENps were
relatively ancient and were shared by primates and rodents; others were newly
originated through species- specific gene duplications. PTENps in NMR may
function as competitive endogenous RNAs (ceRNAs) to regulate their counterpart
genes by competing for common MicroRNAs, which may be one of the interpretations
for the cancer resistance in NMR. |
Rachmilewitz Index is used for which diseases? | Rachmilewitz Index is used for assessment of endoscopic disease activity of patients with ulcerative colitis. | 82 consecutive outpatients with Crohn's disease (n = 52) and ulcerative colitis
(n = 30) were examined ambulatory. Rheumatic complaints, objective results and
diagnosis were correlated to the activity of the underlying illness and the
extent of the bowel affected. 61% of the examined patients complaint about
rheumatic pains. In two thirds this could be attributed to noninflammatory
causes (30% insertion tendinitis. 16% degenerative arthritis, 16% wrong
carriage), which appeared to be independent of the activity and severity of the
underlying disease. One fourth of the rheumatic complaints was caused by
inflammation (21% arthritis, 5% sacroileitis). In these cases a dependency on
the disease activity and the extent of the colon involvement could be found. No
cause was found for 12% of the rheumatic complaints. In patients with ulcerative
colitis suffering from arthritis a significant increase of disease activity
(Rachmilewitz index) could be shown as compared to ulcerative colitis patients
without arthritis (p < 0.02). For patients with Crohn's disease no significant
correlation between arthritis and disease activity could be established. In
these cases the occurrence of arthritis was associated with the colon
involvement (Chi2 = 8.48). The data indicate the high frequency of rheumatic
complaints in inflammatory bowel diseases due to noninflammatory causes. Ulcerative colitis (UC) and Crohn's disease (CD) are the nonspecific
inflammatory bowel diseases with unknown etiology. Existing diagnostic methods
are in many cases insufficient for proper diagnosis and choice of treatment
method. In 10% cases of inflammatory bowel disease indeterminate colitis (IC) is
described. It includes cases with diverse clinical manifestations, range and
histopathological picture. New methods to distinguish inflammatory bowel
diseases, chose proper treatment and monitor their activity are searched.
Anti-Saccharomyces cerevisiae antibodies (ASCA) and antineutrophil cytoplasmatic
antibodies (pANCA) seem to be a new markers used in this end.
OBJECTIVE: Comparison of ASCA and pANCA appearance in CD and UC searching of
correlation between serum levels of antibodies, activity and clinical picture of
disease and appearance of ASCA and pANCA in IC.
MATERIAL AND METHODS: We examined 63 patients with UC aged 24 to 74 (30 men and
33 women), 14 patients with CD aged 27 to 64 (10 men and 4 women) and 11
patients with IC aged 21 to 53 (4 men and 7 women). Mean duration time of
diseases respectively for UC, CD and IC was 7.9 (from 1.0 to 32), 9 (from 1 to
20) and 3.04 (0.5 to 7) years. Diagnosis in specific clinical picture was
established with endoscopic and histopathologic examination. Disease activity
was described according to Rachmilewitz scale in UC and in CD according to
Crohn's disease activity index (CDAI). Control group consisted of 24 healthy
men. Examination of pANCA, IgA and IgG ACSA was performed with ELISA kits
respectively by Congent Diagnostics and Genesis Diagnostic.
RESULTS: There were 39 of UC patients and of CD patients with active disease
according to Rachmilewitz scale (above 3 points) and CDAI. We observed
statistically more often pANCA in patients with UC (58%; n=31) than in patients
with CD (28%; n=4) (p<0.05). Both IgA and IgG ACSCA occurred more often in
patients with CD (57%; n=8) than in patients with UC (24%; n=15) (p<0.05). There
were no significant differences between antibodies according to duration time,
activity, location and treatment method of diseases. Obtained results besides
the help with understanding of pathologic mechanisms, indicate for use of
antibodies as an diagnostic tool in inflammatory bowel diseases. BACKGROUND: The accuracy of noninvasive markers for the detection of
endoscopically active ulcerative colitis (UC) according the Rachmilewitz Score
is so far unknown. The aim was to evaluate the correlation between endoscopic
disease activity and fecal calprotectin, Clinical Activity Index, C-reactive
protein (CRP), and blood leukocytes.
METHODS: UC patients undergoing colonoscopy were prospectively enrolled and
scored independently according the endoscopic and clinical part of the
Rachmilewitz Index. Patients and controls provided fecal and blood samples for
measuring calprotectin, CRP, and leukocytes.
RESULTS: Values in UC patients (n = 134) compared to controls (n = 48):
calprotectin: 396 ± 351 versus 18.1 ± 5 μg/g, CRP 16 ± 13 versus 3 ± 2 mg/L,
blood leukocytes 9.9 ± 3.5 versus 5.4 ± 1.9 g/L (all P < 0.001). Endoscopic
disease activity correlated closest with calprotectin (Spearman's rank
correlation coefficient r = 0.834), followed by Clinical Activity Index (r =
0.672), CRP (r = 0.503), and leukocytes (r = 0.461). Calprotectin levels were
significantly lower in UC patients with inactive disease (endoscopic score 0-3,
calprotectin 42 ± 38 μg/g), compared to patients with mild (score 4-6,
calprotectin 210 ± 121 μg/g, P < 0.001), moderate (score 7-9, calprotectin 392 ±
246 μg/g, P = 0.002), and severe disease (score 10-12, calprotectin 730 ± 291
μg/g, P < 0.001). The overall accuracy for the detection of endoscopically
active disease (score ≥4) was 89% for calprotectin, 73% for Clinical Activity
Index, 62% for elevated CRP, and 60% for leukocytosis.
CONCLUSIONS: Fecal calprotectin correlated closest with endoscopic disease
activity, followed by Clinical Activity Index, CRP, and blood leukocytes.
Furthermore, fecal calprotectin was the only marker that reliably discriminated
inactive from mild, moderate, and highly active disease, which emphasizes its
usefulness for activity monitoring. BACKGROUND/AIMS: The aim of this study was to evaluate plasma transforming
growth factor-B1 concentration in patients with inflammatory bowel disease at
different stages of disease activation and to compare these values with those of
healthy controls.
METHODS: A total of 70 patients (31 women) evaluated in the Inflammatory Bowel
Disease Clinics of TUrkiye YUksek Ihtisas Hospital, Gastroenterology Department,
and 20 healthy controls (10 women) were enrolled in the study. Serum samples
were obtained from 40 patients with ulcerative colitis (female/male: 18/22, mean
age: 41.5+/-12), 30 patients with Crohn's disease (female/male: 17/13, mean age:
36.9+/-1.9) and 20 healthy controls (female/ male: 10/10, mean age: 32.1+/-1.7).
The control group included normal blood donors without gastrointestinal
complaints or a familial history of inflammatory bowel disease. Clinical
activity in Chron's disease was measured by Crohn disease activity index and in
ulcerative colitis patients by Rachmilewitz endoscopic index. Chron's disease
patients with a Chron's disease activity index >150 and ulcerative colitis
patients with a Rachmilewitz index > or =4 were accepted to have active disease.
Determination of transforming growth factor-B1 level was performed with the
enzyme- linked immunosorbent assay.
RESULTS: Serum transforming growth factor-B1 levels were measured as: Chron's
disease 1133.3+/-766.5 pg/ml, ulcerative colitis 1362.5+/-880.6 pg/ml and
control group 1230.0+/-572.7 pg/ml. There were no significant differences
between the three groups. In patients with active disease in ulcerative colitis,
transforming growth factor-B1 level was measured as 1952.5+/-543.7, while this
value was 772.5+/-750.5 in patientsin remission in ulcerative colitis. There was
a significant difference between patients with active ulcerative colitis and
remission ulcerative colitis.
CONCLUSIONS: In inflammatory bowel disease, transforming growth factor-B1 can be
used as a marker for differential diagnosis of active ulcerative colitis
patients and remission ulcerative colitis patients. Nevertheless, more studies
with larger patient groups are necessary. AIM: To elaborate optimal cell culture administration regimens to enhance the
efficiency of anti-inflammatory therapy for inflammatory bowel diseases.
SUBJECTS AND METHODS: Three groups of patients with chronic continuous or
chronic recurrent ulcerative colitis (UC) were formed according to the treatment
option: 1) 15 patients with UC, in whom mesenchymal stromal cells (MSC) were
thrice administered for a month at a one-week interval; 2) 20 patients with UC
who received MSC once; 3) 20 patients with UC who had standard anti-inflammatory
therapy with 5-aminosalycilic acid (5-ASA) preparations and glucocorticosteroids
(GCS). The clinical activity of UC was evaluated using the Rachmilewitz index;
its endoscopic pattern was assessed with the Mayo index. UC histological
specimens were scored using the Gebs scale. To ascertain the duration of
remission, the authors used the Kaplan-Maier survival curve method and
calculated relative risk (RR) and odds ratio with 95% confidence intervals.
RESULTS: Following 12 months, allogeneic bone marrow (BM) MSC transplantation
performed thrice during a month caused the greatest reduction in the
Rachmilewitz clinical activity index, Mayo endoscopic activity index, and Gebs
pathohistological index in patients with UC as compared to those who had
underwent one transplantation or received 5-ASA preparations and GCS (p < 0.05).
The duration of remission also depended on the chosen therapy option for UC and
the frequency of cell culture administration: the longer duration was recorded
in patients who were infused thrice with allogeneic BM MSC.
CONCLUSION: In the patients who had undergone one MSC administration, the risk
of recurrent UC was higher than in those who had received MSC thrice during a
month (a 2-year follow-up) and comparable with the RR of recurrent UC in the
patient receiving only 5-ASA preparations, GCS, and/or immunosuppressants. BACKGROUND: Fecal biomarkers have emerged as an important tool for assessing and
monitoring disease activity in patients with inflammatory bowel diseases (IBDs).
We performed a prospective head-to-head comparison of the diagnostic accuracy of
both fecal calprotectin (fCal) and neopterin (fNeo), and serum C-reactive
protein in predicting endoscopic disease severity in patients with IBD.
METHODS: A total of 133 consecutive patients with IBD (78 Crohn's disease [CD]
and 55 ulcerative colitis [UC]) undergoing a colonoscopy provided fecal samples
for the measurement of fCal and fNeo concentrations and a blood sample for the
serum C-reactive protein measurement. Endoscopic disease activities were scored
independently according to the Simple Endoscopic Score for CD in patients with
CD and to the Rachmilewitz Index in patients with UC. The respective
performances of the fecal markers with respect to endoscopic disease severity
were assessed by computing correlations, sensitivities, specificities, and
overall accuracies at adjusted cutoffs and also test operating characteristics.
RESULTS: The fCal and fNeo concentrations differed significantly in clinically
and endoscopically active IBD when compared with those in patients with inactive
disease. Both fCal and fNeo concentrations correlated closer with endoscopic
scores in UC (r = 0.75 and r = 0.72, respectively; P < 0.0001 for both) than in
CD (r = 0.53 and r = 0.47, respectively; P < 0.0001 for both). Using cutoffs of
250 μg/g for fCal and 200 pmol/g for fNeo, both fecal markers had similar
overall accuracies to predict endoscopic activity in patients with CD (74%) and
also a higher and similar accuracies (88% and 90%, respectively) in patients
with UC, whereas accuracies of C-reactive protein were slightly lower in
patients with CD and UC.
CONCLUSIONS: The fNeo is a novel reliable surrogate biomarker with the potential
to identify patients with IBD with active mucosal lesions and represents an
alternative marker as accurate as fCal to predict and monitor the severity of
mucosal damages in patients with IBD. Granulocyte-monocyte apheresis (GMA) is an emerging therapeutic option in active
course of ulcerative colitis (UC). Appropriate GMA dose, including total number,
frequency, and duration of the individual GMA session, is a matter of debate. It
was the aim of the present study to evaluate the efficacy of a dose-intensified
GMA regimen in patients with moderately to severely active UC. A prospective
open-label, single-center study was performed in 10 patients with active UC
(Rachmilewitz Clinical Activity Index [CAI] ≥ 8 points; Rachmilewitz Endoscopic
Index ≥ 7 points). Patients had failed to improve after treatment with steroids
and/or immunomodulators. GMA was performed twice weekly for 2 h to a maximum of
10 sessions. In each GMA session, the adsorber was changed after 1 h of
treatment time. Four patients achieved remission with a CAI ≤ 4 points. Three
patients had a response with an improvement of CAI of ≥3 points. Three patients
showed no benefit from GMA. The quality of life score determined by the
inflammatory bowel disease questionnaire-Deutschland increased by 26 points in
median. First and second filters had similar efficiency in granulocyte and
monocyte adsorption. No major adverse effects were observed. Dose-intensified
GMA as reported in this study provided an encouraging short-term response rate
of 70% in patients with moderately to severely active UC not responding to
standard steroid or immunomodulator therapy. Although all patients relapsed not
later than 16 weeks, GMA might be useful to reduce steroid and immunomodulator
usage, or to delay surgery in this patient group. BACKGROUND: Improving health-related quality of life is a primary target of
therapy for patients with inflammatory bowel disease. Physical activity has been
demonstrated to improve health-related quality of life in several patient
populations with chronic disease. There are very few studies investigating the
effects of physical activity on health-related quality of life in inflammatory
bowel disease. The primary purpose of this study is to investigate the effects
of 10 weeks of moderate physical activity on health-related quality of life in
patients with inflammatory bowel disease.
METHODS: Thirty patients with mild to moderate IBD (Crohn's Disease Activity
Index (CDAI) <220 or Rachmilewitz Index (RI) <11) were randomized 1:1 to either
supervised moderate-intensity running thrice a week for 10 weeks or a control
group who were not prescribed any exercise. Health-related quality of life,
symptoms, and inflammation were assessed at baseline and after 10 weeks.
RESULTS: Participants were 41 ± 14 years (73% female), had a body mass index of
22.8 ± 4.1 kg/m(2), and an average CDAI or RI of 66.8 ± 42.4 and 3.6 ± 3.1. No
adverse events occurred during the 10-week training period. Health-related
quality of life, reported as IBDQ total score, improved 19% in the intervention
group and 8% in the control group. Scores for the IBDQ social sub-scale were
significantly improved in the intervention group compared with controls
(ΔIBDQsocial = 6.27 ± 5.46 vs. 1.87 ± 4.76, p = 0.023).
CONCLUSION: Patients suffering from moderately active IBD are capable of
performing symptom-free regular endurance exercise. Our data support the
assumption that PA is feasible in IBD patients. PA may furthermore improve
quality of life through improvements in social well-being, and may, therefore,
be a useful adjunct to IBD therapy. BACKGROUND AND AIM: We aimed to identify ischemia-modified albumin (IMA) levels
in inflammatory bowel disease (IBD) and IBD subgroups, and to examine its
relation with disease activity index.
METHODS: Sixty-eight patients with IBD (35 ulcerative colitis [UC] and 33 crohn
disease [CD]) and 65 healthy volunteers were included in the study. Rachmilewitz
scoring system (endoscopic activity index [EAI]) was used to determine UC
activity, and as for CD activity, CD activity index (CDAI) scoring was used. IMA
measurement was performed with ELISA kit.
RESULTS: Ischemia-modified albumin levels in IBD, UC, and CD groups were
comparably higher than the control group (37.7 ng/mL vs 42.4 ng/mL vs 36.4 ng/mL
vs 21.8 ng/mL, respectively; P < 0.05). In IBD group, a positive correlation was
identified between IMA level and CRP (r = 0.325, P = 0.011), EAI(r = 0.302,
P = 0.020), and CDAI (r = 0.311, P = 0.013). In stepwise regression model; it
was identified that IMA(OR = 1.496; P = 0.016) and CRP(OR = 3.457; P = 0.015)
are predictors of IBD in comparison with the control group. In linear regression
model, it was identified that risk factors such as log(IMA) and log(CRP) were
independent predictors of log(CDAI) and log(EAI) levels.
CONCLUSION: This is the first study showing that IMA levels in IBD were
determined higher in comparison with the control group. Moreover, IMA being a
predictor for IBD and being positively correlated with disease activity indexes
were determined for the first time in the study. In accordance with these
results, it is possible to say that IMA in IBD might be related with the
pathogenesis of disease and correlated with the severity of the disease. OBJECTIVE: The combination of clinical remission and mucosal healing represents
a major goal of different treatment strategies for ulcerative colitis (UC). This
study aimed to assess which of the endoscopic indices used to evaluate mucosal
changes in UC are correlated with clinical indices currently used to determine
disease activity, as well as which of the endoscopic indices are correlated with
the Geboes Index used for histological evaluation. It also aimed to find
correlations between the currently used clinical activity indices and the
histological Geboes Index.
METHODS: A group of 49 patients with a confirmed diagnosis of UC and a group of
52 individuals without a diagnosis of gastrointestinal disease, who constituted
the control group, were investigated. All patients were evaluated by
colonoscopy, and the severity of mucosal changes was scored in terms of nine
different endoscopic indices commonly used in both pharmacological trials and
clinical practice. Evaluation was also carried out using clinical and
histological indices. Endoscopic indices used for UC were then correlated with
different clinical and histological indices to find the strongest correlations.
RESULTS AND CONCLUSION: A high correlation was demonstrated between three of the
11 evaluated clinical indices - Improvement Based on Individual Symptom Scores,
Ulcerative Colitis Disease Activity Index, and Schroeder Index - and all nine
endoscopic indices - Ulcerative Colitis Endoscopic Index of Severity, Baron
Score, Schroeder Index, Feagan Index, Powell-Tuck Index, Rachmilewitz Index,
Sutherland Index, Lofberg Index, and Lemman Index. Improvement Based on
Individual Symptom Scores was the index with the highest correlation with all
the endoscopic indices used for UC. The above indices are recommended for
clinical evaluation of UC activity. The Ulcerative Colitis Endoscopic Index of
Severity was moderately correlated with a histological index, and it is
therefore recommended for routine endoscopic mucosal evaluation in patients with
UC. OBJECTIVE: Calcineurin inhibitors are highly effective in patients with
corticosteroid-refractory ulcerative colitis (UC). When therapy with calcineurin
inhibitors fails, adalimumab can be considered to avoid colectomy. The efficacy
and safety of this sequential alternative salvage therapy remain unknown.
Therefore, the present study was performed to investigate the short- and
long-term efficacy and safety of adalimumab after failure of calcineurin
inhibitors in corticosteroid-refractory UC.
MATERIALS AND METHODS: Patients with a corticosteroid-refractory flare of UC who
did not respond to calcineurin inhibitors and received continuing salvage
therapy with adalimumab were included in this retrospective, observational,
single-centre study. The cumulative rates of colectomy were calculated using the
Kaplan-Meier method. Clinical remission and response were evaluated based on the
Rachmilewitz index. The cumulative rates of colectomy were calculated.
Predictive factors for clinical remission and colectomy were identified. In the
safety evaluation, any adverse event occurring after the administration of
adalimumab was considered.
RESULTS: Forty-one patients were enrolled; 78% had extensive colitis and 87% had
moderate to severe colitis. Seventeen patients (41%) underwent colectomy during
the follow-up period. At week 8, 26, and 52 after adalimumab injection, 27%,
39%, and 32% of patients achieved clinical remission, respectively. The adverse
event rate was 17%, including one case of tuberculosis.
CONCLUSIONS: The efficacy of adalimumab for calcineurin inhibitor-refractory UC
was examined for the first time. Treatment with adalimumab avoided the need for
colectomy in two-thirds of patients with corticosteroid-refractory UC in whom
calcineurin inhibitors had failed. However, attention is needed to avoid adverse
events, especially infection. |
List angiotensin-converting-enzyme inhibitors. | captopril
enalapril
lisinopril
ramipril | AIMS: Angiotensin-converting enzyme inhibitors (ACEIs) are recommended as
first-line therapy in patients with heart failure with reduced ejection fraction
(HFrEF). The comparative effectiveness of different ACEIs is not known.
METHODS AND RESULTS: A total of 4723 outpatients with stable HFrEF prescribed
enalapril, lisinopril, or ramipril were identified from three registries in
Norway, England, and Germany. In three separate matching procedures, patients
were individually matched with respect to both dose equivalents and their
respective propensity scores for ACEI treatment. During a follow-up of 21 939
patient-years, 360 (49.5%), 337 (52.4%), and 1119 (33.4%) patients died among
those prescribed enalapril, lisinopril, and ramipril, respectively. In
univariable analysis of the general sample, enalapril and lisinopril were both
associated with higher mortality when compared with ramipril treatment [hazard
ratio (HR) 1.46, 95% confidence interval (CI) 1.30-1.65, P < 0.001 and HR 1.38,
95% CI 1.22-1.56, P < 0.001, respectively). Patients prescribed enalapril or
lisinopril had similar mortality (HR 1.06, 95% CI 0.92-1.24, P = 0.41). However,
there was no significant association between ACEI choice and all-cause mortality
in any of the matched samples (HR 1.07, 95% CI 0.91-1.25, P = 0.40; HR 1.12, 95%
CI 0.96-1.32, P = 0.16; and HR 1.10, 95% CI 0.93-1.31, P = 0.25 for enalapril
vs. ramipril, lisinopril vs. ramipril, and enalapril vs. lisinopril,
respectively). Results were confirmed in subgroup analyses with respect to age,
sex, left ventricular ejection fraction, New York Class Association functional
class, cause of HFrEF, rhythm, and systolic blood pressure.
CONCLUSION: Our results suggest that enalapril, lisinopril, and ramipril are
equally effective in the treatment of patients with HFrEF when given at
equivalent doses. |
How does androgen deprivation therapy affect pain perception? | There were no significant changes in pain thresholds, ratings, or other response to quantitative sensory tests over the 6-month course of the study. Clinical pain did not differ between test and control groups, and no changes from baseline were observed in their group. | |
What is OAC CHV? | The Open Access and Collaborative Consumer Health Vocabulary (OAC CHV), which contains health-related terms used by lay consumers, | The widely known vocabulary gap between health consumers and healthcare
professionals hinders information seeking and health dialogue of consumers on
end-user health applications. The Open Access and Collaborative Consumer Health
Vocabulary (OAC CHV), which contains health-related terms used by lay consumers,
has been created to bridge such a gap. Specifically, the OAC CHV facilitates
consumers' health information retrieval by enabling consumer-facing health
applications to translate between professional language and consumer friendly
language. To keep up with the constantly evolving medical knowledge and language
use, new terms need to be identified and added to the OAC CHV. User-generated
content on social media, including social question and answer (social Q&A)
sites, afford us an enormous opportunity in mining consumer health terms.
Existing methods of identifying new consumer terms from text typically use
ad-hoc lexical syntactic patterns and human review. Our study extends an
existing method by extracting n-grams from a social Q&A textual corpus and
representing them with a rich set of contextual and syntactic features. Using
K-means clustering, our method, simiTerm, was able to identify terms that are
both contextually and syntactically similar to the existing OAC CHV terms. We
tested our method on social Q&A corpora on two disease domains: diabetes and
cancer. Our method outperformed three baseline ranking methods. A post-hoc
qualitative evaluation by human experts further validated that our method can
effectively identify meaningful new consumer terms on social Q&A. |
What is known about autosomal dominant Alzheimer’s disease? | The first autosomal dominant mutation in the amyloid precursor protein (APP) gene was described in 1991. Later, AD was also associated with mutated early-onset (presenilin 1/2, PSEN1/2 and APP) and late-onset (apolipoprotein E, ApoE) genes. Genome-wide association and linkage analysis studies with identified multiple genomic areas have implications for the treatment of AD.
The Dominantly Inherited Alzheimer Network, an international family-clustered registry to study autosomal dominant Alzheimer disease which is a rare form of Alzheimer disease caused by mutations in any of the three genes including the amyloid precursor protein, presenilin 1 and presenilin 2. | Many medical diagnostic studies involve three ordinal diagnostic populations in
which the diagnostic accuracy can be summarized by the volume or partial volume
under the receiver operating characteristic surface for a diagnostic marker.
When the diagnostic populations are clustered, e.g. by families, we propose to
model the diagnostic marker by a general linear mixed model that takes into
account of the correlation on the diagnostic marker from members of the same
clusters. This model then facilitates the maximum likelihood estimation and
statistical inferences of the diagnostic accuracy for the diagnostic marker.
This approach naturally allows the incorporation of covariates as well as
missing data when some clusters do not have subjects on all diagnostic groups in
the estimation of, and the subsequent inferences on the diagnostic accuracy. We
further study the performance of the proposed methods in a large simulation
study with clustered data. Finally, we apply the proposed methodology to the
data of several biomarkers collected by the Domitly Inherited Alzheimer
Network, an international family-clustered registry to study autosomal domit
Alzheimer disease which is a rare form of Alzheimer disease caused by mutations
in any of the three genes including the amyloid precursor protein, presenilin 1
and presenilin 2. We estimate the accuracy of several cerebrospinal fluid and
neuroimaging biomarkers in differentiating three diagnostic and genetic
populations: normal non-mutation carriers, asymptomatic mutation carriers, and
symptomatic mutation carriers. |
List characteristic features of the Revesz syndrome. | Revesz syndrome is characterized by retinopathy, aplastic anemia, nail dystrophy, and cerebellar hypoplasia. | Revesz syndrome is a variant of dyskeratosis congenita characterized by aplastic
anemia, retinopathy, and central nervous system abnormalities. We describe a
3-year-old boy in whom the spectrum of neuroimaging findings, including
intracranial calcifications, cerebellar hypoplasia and unusual brain lesions
were found by biopsy to be gliosis despite their enhancement and progression. In
patients with dyskeratosis-related syndromes, non-neoplastic parenchymal brain
lesions occur and gliosis should be considered in the differential diagnosis for
progressive enhancing brain lesions. Should this finding be confirmed
consistently in additional cases, brain biopsy could potentially be avoided. A 5-year-old girl was admitted with pallor, hypopigmented sparse hair, tongue
ulcers, atrophic nail changes, hypoplastic anemia and bilateral exudative
retinopathy. A diagnosis of Revesz syndrome was made. She had the additional
features of retinal detachment and retinitis pigmentosa, which are hitherto
unreported in this syndrome. We report a case of a 12-year-old boy with history of myelofibrosis and
retinopathy who developed sudden neurological deficits associated with
coagulopathy, multiorgan failure, and death. A fluorescent in situ hybridization
study revealed monosomy of chromosome 7 in 21% of the bone marrow cells in
support of his diagnosis of myelofibrosis. Postmortem neuropathology examination
revealed multiple coarse and microcalcifications and cerebral hemorrhages,
explaining the patient's neurological deterioration. The findings of
myelofibrosis, retinopathy, and cerebral calcifications indicate that this could
be a case of a rare condition known as Revesz syndrome. Dyskeratosis congenita is a group of rare genetic bone marrow failure syndromes.
Revesz syndrome, a variant disorder, is characterized by retinopathy, aplastic
anemia, nail dystrophy, and cerebellar hypoplasia. We report the case of an
11-month-old boy with bilateral cicatricial retinal detachments associated with
fibrovascular proliferation. Genetic testing ultimately confirmed a diagnosis of
Revesz syndrome, which can mimic cicatricial retinopathy of prematurity. Prompt
referral to a hematologist expedites diagnosis and treatment. Two siblings presenting with exudative retinopathy, thrombocytopenia, and
macrocytosis were found to have markedly shortened telomeres and a previously
unreported inherited mutation in TERT, c.2603A>G. Revesz syndrome, a subtype of
dyskeratosis congenita (DC) caused by TINF2 mutation, combines marrow failure
with exudative retinopathy, intracranial calcifications, and neurocognitive
impairment. As our patients manifested neither intracranial calcification nor
significant neurocognitive impairment, we conclude that the c.2603A>G TERT
mutation may define a subtype of DC manifesting first as exudative retinopathy
without other signs of DC. Children with exudative retinopathy should be
periodically screened for macrocytosis and cytopenias to evaluate for underlying
DC. Dyskeratosis congenita (DC) is the prototypical member of a family of diseases
caused by defective telomere maintece. These "telomeropathies" also include
Hoyeraal-Hreidarsson syndrome (HH) and Revesz syndrome, which are severe forms
of dyskeratosis congenita, as well as a subset of idiopathic pulmonary fibrosis,
aplastic anemia, and Coats' plus syndrome. Retinopathy has only rarely been
reported in DC and HH, but is universally present in Coats' plus and Revesz
syndromes. The care of these patients is typically a multidisciplinary effort,
and this should include monitoring by an ophthalmologist. BACKGROUND: Revesz syndrome is a telomere disorder in the dyskeratosis congenita
(DKC) spectrum characterized by exudative retinopathy, bone marrow failure,
neuroradiographic abnormalities, and integumentary findings.
MATERIALS/METHODS: We report the ophthalmologic findings, documented by
examinations under anesthesia with clinical photography and fluorescein
angiography, as well as the systemic manifestations and genetic and molecular
testing, in identical twins with Revesz syndrome, and compare and contrast these
features to those of other pediatric retinal vasculopathies.
RESULTS: Both twins exhibited widespread avascularity and anomalous vasculature
of the retinal periphery, retinal telangiectasias, and exudation. One twin
developed a combination exudative/tractional/rhegmatogenous retinal detachment,
while the other exhibited a focal collection of buds of retinal
neovascularization. Both twins developed bone marrow failure and were found to
have cerebellar hypoplasia and widespread cerebral calcifications. Telomere
testing in lymphocytes and granulocytes revealed telomere length less than the
1st percentile for age, and gene sequencing revealed a novel mutation in the
TINF2 gene, resulting in the T284P TIN2 protein variant.
CONCLUSIONS: We report ophthalmic findings in twins with Revesz syndrome due to
a previously unreported mutation in TINF2 and propose that phenotypic and
molecular overlaps between DKC spectrum disorders and pediatric retinal
vasculopathies may reflect a shared pathophysiologic basis. A 13-month-old boy with mild hemophilia A presented for strabismus evaluation
and was found to have retinal hemorrhages in the right eye, left exotropia, and
left total retinal detachment. These findings were attributed to trauma and
hemophilia A. Routine blood work for hemophilia A subsequently showed
pancytopenia. A bone marrow aspirate showed marked hypocellularity consistent
with severe aplastic anemia, and telomere testing revealed very short telomeres.
The patient was found to have a TINF2 mutation consistent with a diagnosis of
Revesz syndrome, a variant of dyskeratosis congenita. He underwent successful
bone marrow transplantation, and on subsequent evaluation was found to have
retinal hemorrhages, vessel sclerosis, and cotton wool spots in the right eye
associated with peripheral retinal nonperfusion. He underwent retinal laser
treatment to the areas of retinal nonperfusion which resulted in stable visual
function. |
Does BNN27 promote memory loss? | No. The novel dehydroepiandrosterone (DHEA) derivative BNN27 counteracts delay-dependent and scopolamine-induced recognition memory deficits in rats. | |
Are genomic regulatory blocks (GRBs) any different than TADs? | No, clusters of CNEs (GRBs) strongly coincide with topological organisation, predicting the boundaries of hundreds of topologically associating domains (TADs) in human and Drosophila. The set of TADs that are associated with high levels of noncoding conservation exhibit distinct properties compared to TADs devoid of extreme noncoding conservation. The close correspondence between extreme noncoding conservation and TADs suggests that these TADs are ancient, revealing a regulatory architecture conserved over hundreds of millions of years. | Developmental genes in metazoan genomes are surrounded by dense clusters of
conserved noncoding elements (CNEs). CNEs exhibit unexplained extreme levels of
sequence conservation, with many acting as developmental long-range enhancers.
Clusters of CNEs define the span of regulatory inputs for many important
developmental regulators and have been described previously as genomic
regulatory blocks (GRBs). Their function and distribution around important
regulatory genes raises the question of how they relate to 3D conformation of
these loci. Here, we show that clusters of CNEs strongly coincide with
topological organisation, predicting the boundaries of hundreds of topologically
associating domains (TADs) in human and Drosophila. The set of TADs that are
associated with high levels of noncoding conservation exhibit distinct
properties compared to TADs devoid of extreme noncoding conservation. The close
correspondence between extreme noncoding conservation and TADs suggests that
these TADs are ancient, revealing a regulatory architecture conserved over
hundreds of millions of years.Metazoan genomes contain many clusters of
conserved noncoding elements. Here, the authors provide evidence that these
clusters coincide with distinct topologically associating domains in humans and
Drosophila, revealing a conserved regulatory genomic architecture. |
Are Spinal Intradural Primary Malignant Peripheral Nerve Sheath Tumors(MPNST) rare in neurofibromatosis patients? | Spinal intradural primary malignant peripheral nerve sheath tumors (MPNST) are rare in patients without neurofibromatosis. | Primary maligt peripheral nerve sheath tumors (MPNSTs) are extremely rare in
patients without a history of neurofibromatosis; only 18 cases have been
reported in the English-language literature to this point. The authors report
their experience with 1 new case of a primary MPNST. A 33-year-old woman
presented with low-back pain radiating to the right calf that progressed over 1
year. Magnetic resoce imaging of the spine revealed an intradural
extramedullary lesion at the T12-L1 level. The patient was diagnosed with
primary MPNST, underwent two surgical excisions and radiation therapy, and
developed leptomeningeal metastases as well as brain metastases. The patient
revisited the emergency room with sudden loss of consciousness. A brain CT scan
displayed bilateral lateral ventricle enlargement, for which a
ventriculoperitoneal shunt was inserted. These symptoms have not been described
in any previous report. Primary spinal MPNST is an exceedingly rare entity, and
the overall prognosis is very poor. To the authors' knowledge, no standard of
care for primary spinal MPNSTs has yet been established. All 19 cases of primary
spinal MPNSTs are reviewed, and the authors discuss their clinical,
radiological, and therapeutic features and outcomes. Spinal intradural primary maligt peripheral nerve sheath tumors (MPNST) are
rare in patients without neurofibromatosis. Here we represent a 3-year-old girl
of primary intradural spinal maligt peripheral nerve sheath tumor. The tumor
was removed partially and MPNST was diagnosed in the histopathological
examination. Her condition deteriorated due to acute hydrocephalus in the
following days. In this article, we discuss the clinical presentation, imaging,
treatment, and prognosis of our patient and the other 22 patients of primary
intradural MPNST, found in the literature. The Kaplan?Meier method was applied
for univariate analysis and Cox proportional hazards model for multivariate
analysis. This analysis showed that age, was an important factor predicting
short-term survival of patients with MPNST. |
What does MVA85A stand for? | MVA85A is the Modified Vaccinia virus Ankara expressing Antigen 85A. | |
Can MVA85A confer immunity against smallpox? | No MVA85A is a candidate tuberculosis vaccine. | BACKGROUND: HIV-1 infection is associated with increased risk of tuberculosis
and a safe and effective vaccine would assist control measures. We assessed the
safety, immunogenicity, and efficacy of a candidate tuberculosis vaccine,
modified vaccinia virus Ankara expressing antigen 85A (MVA85A), in adults
infected with HIV-1.
METHODS: We did a randomised, double-blind, placebo-controlled, phase 2 trial of
MVA85A in adults infected with HIV-1, at two clinical sites, in Cape Town, South
Africa and Dakar, Senegal. Eligible participants were aged 18-50 years, had no
evidence of active tuberculosis, and had baseline CD4 counts greater than 350
cells per μL if they had never received antiretroviral therapy or greater than
300 cells per μL (and with undetectable viral load before randomisation) if they
were receiving antiretroviral therapy; participants with latent tuberculosis
infection were eligible if they had completed at least 5 months of isoniazid
preventive therapy, unless they had completed treatment for tuberculosis disease
within 3 years before randomisation. Participants were randomly assigned (1:1)
in blocks of four by randomly generated sequence to receive two intradermal
injections of either MVA85A or placebo. Randomisation was stratified by
antiretroviral therapy status and study site. Participants, nurses,
investigators, and laboratory staff were masked to group allocation. The second
(booster) injection of MVA85A or placebo was given 6-12 months after the first
vaccination. The primary study outcome was safety in all vaccinated participants
(the safety analysis population). Safety was assessed throughout the trial as
defined in the protocol. Secondary outcomes were immunogenicity and vaccine
efficacy against Mycobacterium tuberculosis infection and disease, assessed in
the per-protocol population. Immunogenicity was assessed in a subset of
participants at day 7 and day 28 after the first and second vaccination, and M
tuberculosis infection and disease were assessed at the end of the study. The
trial is registered with ClinicalTrials.gov, number NCT01151189.
FINDINGS: Between Aug 4, 2011, and April 24, 2013, 650 participants were
enrolled and randomly assigned; 649 were included in the safety analysis (324 in
the MVA85A group and 325 in the placebo group) and 645 in the per-protocol
analysis (320 and 325). 513 (71%) participants had CD4 counts greater than 300
cells per μL and were receiving antiretroviral therapy; 136 (21%) had CD4 counts
above 350 cells per μL and had never received antiretroviral therapy. 277 (43%)
had received isoniazid prophylaxis before enrolment. Solicited adverse events
were more frequent in participants who received MVA85A (288 [89%]) than in those
given placebo (235 [72%]). 34 serious adverse events were reported, 17 (5%) in
each group. MVA85A induced a significant increase in antigen 85A-specific T-cell
response, which peaked 7 days after both vaccinations and was primarily
monofunctional. The number of participants with negative QuantiFERON-TB Gold
In-Tube findings at baseline who converted to positive by the end of the study
was 38 (20%) of 186 in the MVA85A group and 40 (23%) of 173 in the placebo
group, for a vaccine efficacy of 11·7% (95% CI -41·3 to 44·9). In the
per-protocol population, six (2%) cases of tuberculosis disease occurred in the
MVA85A group and nine (3%) occurred in the placebo group, for a vaccine efficacy
of 32·8% (95% CI -111·5 to 80·3).
INTERPRETATION: MVA85A was well tolerated and immunogenic in adults infected
with HIV-1. However, we detected no efficacy against M tuberculosis infection or
disease, although the study was underpowered to detect an effect against
disease. Potential reasons for the absence of detectable efficacy in this trial
include insufficient induction of a vaccine-induced immune response or the wrong
type of vaccine-induced immune response, or both.
FUNDING: European & Developing Countries Clinical Trials Partnership
(IP.2007.32080.002), Aeras, Bill & Melinda Gates Foundation, Wellcome Trust, and
Oxford-Emergent Tuberculosis Consortium. |
Is MLL3 part of the ASCOM complex? | Yes | |
What are the effects of CAMK4 inhibition? | Here, we present evidence that the calcium/calmodulin-dependent protein kinase IV (CaMK4) is increased and required during Th17 cell differentiation. Inhibition of CaMK4 reduced Il17 transcription through decreased activation of the cAMP response element modulator a (CREM-a) and reduced activation of the AKT/mTOR pathway, which is known to enhance Th17 differentiation. CAMK4 knockdown and kinase-dead mutant inhibited crocin-mediated HO-1 expression, Nrf2 activation, and phosphorylation of Akt, indicating that HO-1 expression is mediated by CAMK4 and that Akt is a downstream mediator of CAMK4 in crocin signaling | Tissue inflammation in several autoimmune diseases, including SLE and MS, has
been linked to an imbalance of IL-17-producing Th (Th17) cells and Tregs;
however, the factors that promote Th17-driven autoimmunity are unclear. Here, we
present evidence that the calcium/calmodulin-dependent protein kinase IV (CaMK4)
is increased and required during Th17 cell differentiation. Isolation of naive T
cells from a murine model of lupus revealed increased levels of CaMK4 following
stimulation with Th17-inducing cytokines but not following Treg, Th1, or Th2
induction. Furthermore, naive T cells from mice lacking CaMK4 did not produce
IL-17. Genetic or pharmacologic inhibition of CaMK4 decreased the frequency of
IL-17-producing T cells and ameliorated EAE and lupus-like disease in murine
models. Inhibition of CaMK4 reduced Il17 transcription through decreased
activation of the cAMP response element modulator α (CREM-α) and reduced
activation of the AKT/mTOR pathway, which is known to enhance Th17
differentiation. Importantly, silencing CaMK4 in T cells from patients with SLE
and healthy individuals inhibited Th17 differentiation through reduction of
IL17A and IL17F mRNA. Collectively, our results suggest that CaMK4 inhibition
has potential as a therapeutic strategy for Th17-driven autoimmune diseases. Crocin is a water-soluble carotenoid pigment that is primarily used in various
cuisines as a seasoning and coloring agent, as well as in traditional medicines
for the treatment of edema, fever, and hepatic disorder. In this study, we
demonstrated that crocin markedly induces the expression of heme oxygenase-1
(HO-1) which leads to an anti-inflammatory response. Crocin inhibited inducible
nitric oxide synthase (iNOS) expression and nitric oxide production via
downregulation of nuclear factor kappa B activity in lipopolysaccharide- (LPS-)
stimulated RAW 264.7 macrophages. These effects were abrogated by blocking of
HO-1 expression or activity. Crocin also induced Ca(2+) mobilization from
intracellular pools and phosphorylation of Ca(2+)/calmodulin-dependent protein
kinase 4 (CAMK4). CAMK4 knockdown and kinase-dead mutant inhibited
crocin-mediated HO-1 expression, Nrf2 activation, and phosphorylation of Akt,
indicating that HO-1 expression is mediated by CAMK4 and that Akt is a
downstream mediator of CAMK4 in crocin signaling. Moreover, crocin-mediated
suppression of iNOS expression was blocked by CAMK4 inhibition. Overall, these
results suggest that crocin suppresses LPS-stimulated expression of iNOS by
inducing HO-1 expression via Ca(2+)/calmodulin-CAMK4-PI3K/Akt-Nrf2 signaling
cascades. Our findings provide a novel molecular mechanism for the inhibitory
effects of crocin against endotoxin-mediated inflammation. OBJECTIVE: To clarify the significance of immunometabolism in systemic lupus
erythematosus (SLE), and to determine the effect of calcium/calmodulin-dependent
protein kinase 4 (CaMK4) on T cell metabolism.
METHODS: Metabolomic profiling was performed using capillary electrophoresis
mass spectrometry in naive T cells from MRL/lpr mice treated with anti-CD3/CD28
antibodies in the absence or presence of a CaMK4 inhibitor (KN-93). The
expression of GLUT1 and CaMK4 in CD4+ T cells from healthy controls (n = 16),
patients with inactive SLE (n = 13), and patients with active SLE (n = 14) was
examined by flow cytometry and quantitative polymerase chain reaction. In vitro
experiments were performed to determine the effect of KN-93 on the expression of
GLUT1 during Th17 cell differentiation in T cells from patients with SLE.
RESULTS: CaMK4 inhibition significantly decreased the levels of glycolytic
intermediates such as glucose-6-phosphate, fructose-6-phosphate,
fructose-1,6-diphosphate, pyruvate, and lactate (P < 0.05), whereas it did not
affect the levels of the pentose phosphate pathway intermediates such as
6-phospho-d-gluconate, ribulose-5-phosphate, ribose-5-phosphate, and
phosphoribosyl pyrophosphate. The expression levels of GLUT1 and CaMK4 in
effector memory CD4+ T cells were significantly higher in patients with active
SLE compared to healthy controls (P < 0.01 and P < 0.05, respectively) and
patients with inactive SLE (P < 0.05 and P < 0.01, respectively). A functional
analysis revealed that CaMK4 inhibition decreased the expression of GLUT1 during
Th17 cell differentiation (P < 0.01), followed by a reduction of interleukin-17
(IL-17) production (P < 0.05).
CONCLUSION: The results of the study indicate that the activity of CaMK4 could
be responsible for glycolysis, which contributes to the production of IL-17, and
CaMK4 may contribute to aberrant expression of GLUT1 in T cells from patients
with active SLE. |
List cohesinopathies | Roberts syndrome (RBS), Cornelia de Lange Syndrome (CdLS), Warsaw Breakage Syndrome (WABS) and Chronic Atrial and Intestinal Dysrhythmia (CAID) syndrome. | A new study identifies homozygous missense mutations in SGOL1, which encodes a
component of the cohesin complex, in a newly described disorder termed Chronic
Atrial and Intestinal Dysrhythmia (CAID) syndrome. These findings implicate
cohesin in the regulation of intrinsic cardiac and intestinal rhythm and further
expand the growing group of disorders termed the cohesinopathies. |
Which protein is mutated in Erythropoietic Protoporphyria? | Erythropoietic protoporphyria (EPP) is a rare inherited disorder of the heme biosynthesis pathway resulting in the accumulation of protoporphyrins in the blood, erythrocytes, and other tissues. Because of a gene mutation in the FECH gene, ferrochelatase, the enzyme involved in the final step of heme synthesis, is deficient in these patients. | Erythropoietic protoporphyria (EPP) is a rare inherited disorder of the heme
biosynthesis pathway resulting in the accumulation of protoporphyrins in the
blood, erythrocytes, and other tissues. Because of a gene mutation in the FECH
gene, ferrochelatase, the enzyme involved in the final step of heme synthesis,
is deficient in these patients. Although the major symptom of this disorder is
photosensitivity, rarely, it can cause progressive liver disease requiring liver
transplantation (LT). However, LT is not curative and only bone marrow
transplantation (BMT) can correct the underlying enzymatic defect. Because liver
disease results from accumulation of protoporphyrin in the liver, LT without
hematopoietic stem cell transplantation leaves the new liver at risk for similar
EPP-related damage. A handful of pediatric patients undergoing sequential LT and
stem cell transplantation have been described in the literature; however, to
date none has been described in detail in adults. We report a case of an adult
male with EPP and liver failure who successfully underwent a sequential liver
and hematopoietic stem cell transplantation (HSCT). A 27-year-old man bearing an erythropoietic protoporphyria (EPP)-associated
ferrochelatase (FECH) mutation was admitted to our hospital for general malaise
and marked elevation of the serum levels of hepatobiliary enzymes and bilirubin.
Initial treatment with plasma exchange did not reduce the blood protoporphyrin
or serum liver enzyme levels, so phlebotomy was started. Surprisingly, weekly
phlebotomy normalized the serum levels of liver enzymes, accompanied by a marked
reduction in the blood protoporphyrin levels. The clinical course of this case
strongly suggests that phlebotomy may be a suitable treatment option for
EPP-related hepatopathy. |
Is marimastat effective for small-cell lung cancer? | No. Marimastat is not effective for small-cell lung cancer. | Marimastat [BB 2516, TA 2516] is a second-generation anticancer drug originally
developed with British Biotech in Europe and North America. It is an orally
active metalloprotease inhibitor of the same class as batimastat, and is the
first compound in this class to have completed a pivotal clinical trial.
Marimastat also has collagenase- and angiogenesis-inhibiting properties. British
Biotech and Schering-Plough have signed an agreement enabling the latter to
develop and market marimastat in North America and Europe. Under the terms of
the agreement, British Biotech will receive an up-front license fee of 4 million
US dollars and a 4 million US dollars equity investment in British Biotech by
Schering-Plough. Schering-Plough holds rights to marimastat in all countries
other than the Far East and Japan. The two companies are considering asking the
FDA for accelerated approval in gastric cancer based on the secondary endpoint
of progression-free survival. Marimastat is licensed to Tanabe Seiyaku in Japan,
where phase II clinical trials are underway for the treatment of advanced
gastric cancer and lung cancer. Further phase II trials in other tumour types
are planned. The commencement of phase II trials in Japan resulted in a
milestone payment of 5 million US dollars to British Biotech from Tanabe
Seiyaku. Tanabe Seiyaku also holds rights to marimastat in the Far East.
Marimastat has been in pivotal phase III trials in glioblastoma, breast, ovarian
and small and non-small cell lung cancer, but these trials have all been
discontinued because marimastat failed to show superior efficacy over either
standard chemotherapy or placebo. Results from the marimastat 131 trial in
patients with glioblastoma, for example, indicated that marimastat was no better
than placebo at prolonging survival in these cancer patients. In June 2000, when
the results of this study were released, shares in British Biotech fell 21.6% to
just 19 pence per share. The phase III trial in small cell lung cancer was
discontinued when the results of study 140 were released in February 2001
showing that marimastat was not significantly more effective than placebo in
prolonging the survival of small cell lung cancer patients. The results of this
study were consistent with those reported in study 117. British Biotech has also
conducted a phase III placebo-controlled study of marimastat as monotherapy in
patients with inoperable gastric cancer at 37 centres throughout Europe. Results
from this trial indicated that it did not achieve its primary endpoint of a
statistically significant survival benefit over placebo. However, data collected
during the follow-up period have shown increases in survival benefit in the
treatment group in addition to a significant improvement in disease-free
progression, the secondary endpoint of the trial. Development of marimastat for
this indication is ongoing. In May 2001, British Biotech reported data from an
interim analysis of results from the remaining phase III study in pancreatic
cancer (study 183) that showed no patient benefit for marimastat recipients
compared with gemcitabine. However, these results did not meet stopping criteria
and the study continues under the guidance of Schering-Plough. The multicentre
trials are being conducted in the US, Canada and the European Union. The phase
III trial of marimastat in combination with carboplatin that was being conducted
in patients with ovarian cancer was discontinued because British Biotech
realised that the design of the trial was insufficient for registration in the
US or Europe. Altogether, seven phase III studies have failed to meet their
primary end-points, but the company has stated that the effectiveness of
marimastat is more likely to be seen in patients with less advanced disease.
Phase II trials in prostate and head and neck cancer are still underway in the
US. |
Which part of the TNFR2 gene is genetically associated with Systemic Lupus Erythematosus? | There is a TNFR2 3' flanking region polymorphism in systemic lupus erythematosus. | Multiple genetic as well as environmental factors are considered to be involved
in the development of systemic lupus erythematosus (SLE). A number of previous
studies have suggested a possible role for tumor necrosis factor (TNF) in the
pathogenesis of SLE. In addition, one of the candidate loci suggested by the
genome-wide linkage analysis corresponds to the chromosomal position
encompassing the TNF receptor 2 gene (TNFR2). The purpose of this study was to
analyze the polymorphism of TNFR2 and its possible association with the
susceptibility to SLE, using the case-control association analysis. Polymorphism
screening of the exons containing previously reported nonsynonymous base
substitutions was carried out by the polymerase chain reaction (PCR)-single
strand conformation polymorphism (SSCP) method, using genomic DNA from 81
Japanese patients with SLE and 207 healthy individuals. Two alleles were present
in exon 6, coding for methionine (196M) and arginine (196R) at position 196. 30
of 81 patients (37.0%) with SLE were positive for the 196R allele, which was
significantly more frequent compared with 39 of 207 healthy individuals (18.8%)
(chi2=10.6, df=l, P=0.001, odds ratio=2.53, 95% CI: 1.45-4.43). Genotype
analysis revealed that the presence of one 196R allele was sufficient for
rendering susceptibility. The association of 196R allele with SLE was
independent from that of HLA-DRB1*1501. In conclusion, the TNFR2 196R allele was
found to be significantly associated with the susceptibility to SLE in the
Japanese population. Further population and functional studies will be of
particular importance to establish TNFR2 as one of the susceptibility genes to
SLE. A polymorphism in high-affinity receptor of TNF (TNFR2) gene, Met196Arg, was
reported to be associated with systemic lupus erythematosus (SLE) in Japanese,
whereas the association could not be found in Europeans at all and this
represents an apparent discrepancy. The association, then, should be tested in
other populations to clarify the possible involvement, if any, of the TNFR2
polymorphism in SLE or other related autoimmune diseases. The purposes of this
study were to examine the TNFR2 polymorphism in Japanese patients with SLE and
to investigate its association with other autoimmune diseases accompanied by
vasculitis, mixed connective tissue disease, Buerger's disease, and Takayasu's
arteritis. We found no association at all between the TNFR2 polymorphism and any
autoimmune diseases including SLE in Japanese. The role of pro-inflammatory cytokines in systemic lupus erythematosus (SLE)
remains somewhat controversial. Several studies have shown increased production
of TNF alpha and IL-6 in patients with SLE. Increased production of IL-6, TNF
alpha, and IL-1 soluble receptors have also been reported. This finding is
provocative because the soluble receptors have the capacity to act as
antagonists. Several other inflammatory disorders are also associated with
increased production of soluble TNF alpha receptors suggesting that this may be
a general compensatory mechanism designed to down-regulate inflammation. The
recent identification of an SLE disease susceptibility locus near the TNFR2
locus (TNFR p75) suggested the hypothesis that genetically driven differences in
soluble TNFR2 production could play a role in the genetic susceptibility to SLE.
We therefore characterized the frequency of a genetic polymorphism in the 3'
untranslated region of the TNFR2 gene in Caucasoid SLE patients and
geographically matched controls. No difference in the gene frequency of the two
base-pair polymorphism in SLE patients compared to controls was found, nor was
there any association with any particular clinical phenotype. We recently reported the association of the allele coding for Arg at the
position 196 (196R: nucleotide [nt] 587G) of tumor necrosis factor receptor 2
(TNFR2, TNF-R75) with systemic lupus erythematosus (SLE) in Japanese. In the
present study, we completed the variation screening of the entire coding region
of TNFR2. Three new single nucleotide polymorphisms within the coding sequence
(cSNPs), as well as several variations within the promoter, introns and
3'-untranslated region (3' UTR), were identified. Among the new SNPs, nt168G, a
synonymous substitution (K56K), was in tight linkage disequilibrium with nt587G.
Two other cSNPs, nt543 (C-->T) (P181P) and nt694 (G-->A) (E232K), were not
significantly associated with SLE. Thus, among the non-synonymous cSNPs, only
nt587 (T-->G) (M196R) was found to be significantly associated with SLE in
Japanese. A number of studies reported associations of HLA-DRB1, TNFalpha (TNF) promoter
and TNF receptor II (TNFR2, TNFRSF1B) polymorphisms with systemic lupus
erythematosus (SLE), however, the results have often been inconsistent. Such
lack of consistency could partly derive from the population admixture involved
in the case-control study. To avoid such a problem, polymorphisms in these genes
were analyzed using transmission disequilibrium test (TDT) in Caucasian SLE
families. Ninety-one Caucasian SLE family samples recruited in southern
California were analyzed for the association with HLA-DRB1, TNF promoter
positions at -1031, -863, -857 and -308, and TNFR2-196M/R polymorphisms.
Significant transmission was observed for HLA-DRB1*1501, but not for
HLA-DRB1*0301, nor for TNF haplotype that codes for -308A. Interestingly, TNF
haplotype coding for -1031C, -863A, -857C showed a tendency of preferential
nontransmission in the patients without lupus nephritis and in those with malar
rash. No transmission distortion was observed for TNFR2-196R allele. These
findings confirmed the association of HLA-DRB1*1501, but did not replicate that
of the HLA-DRB1*0301, TNFA-308A and TNFR2-196R with SLE in this population. In
addition, a possible disease-protective role for TNF haplotype coding for
-1031C, -863A, -857C was suggested. |
What is VISMapper? | VISMapper is a vector integration site analysis web server to analyze next-generation sequencing data for retroviral vector integration sites. VISMapper can be found at: http://vismapper.babelomics.org. | |
What is Taupathy? | Tauopathies are a group of neurodegenerative disorders with accumulation of three-repeat (3R) or four-repeat (4R) Tau protein. | BACKGROUND: Chronic traumatic encephalopathy (CTE) is the term coined for the
neurodegenerative disease often suspected in athletes with histories of repeated
concussion and progressive dementia. Histologically, CTE is defined as a
tauopathy with a distribution of tau-positive neurofibrillary tangles (NFTs)
that is distinct from other tauopathies, and usually shows an absence of
beta-amyloid deposits, in contrast to Alzheimer's disease (AD). Although the
connection between repeated concussions and CTE-type neurodegeneration has been
recently proposed, this causal relationship has not yet been firmly established.
Also, the prevalence of CTE among athletes with multiple concussions is unknown.
METHODS: We performed a consecutive case series brain autopsy study on six
retired professional football players from the Canadian Football League (CFL)
with histories of multiple concussions and significant neurological decline.
RESULTS: All participants had progressive neurocognitive decline prior to death;
however, only 3 cases had post-mortem neuropathological findings consistent with
CTE. The other 3 participants had pathological diagnoses of AD, amyotrophic
lateral sclerosis (ALS), and Parkinson's disease (PD). Moreover, the CTE cases
showed co-morbid pathology of cancer, vascular disease, and AD.
DISCUSSION: Our case studies highlight that not all athletes with history of
repeated concussions and neurological symptomology present neuropathological
changes of CTE. These preliminary findings support the need for further research
into the link between concussion and CTE as well as the need to expand the
research to other possible causes of taupathy in athletes. They point to a
critical need for prospective studies with good sampling methods to allow us to
understand the relationship between multiple concussions and the development of
CTE. BACKGROUND: Tauopathies are a group of neurodegenerative disorders with
accumulation of three-repeat (3R) or four-repeat (4R) Tau. While 3R tau is found
in Pick's disease and Alzheimer's disease (AD), 4R tau is more abundant in
corticobasal degeneration, progressive supranuclear palsy, and AD. We have
previously shown that Cerebrolysin™ (CBL), a neuropeptide mixture with
neurotrophic effects, ameliorates the pathology in amyloid precursor protein
transgenic (tg) mouse model of AD and 4R tau, however it is unclear if CBL
ameliorates the deficits and neuropathology in the mouse model of Pick's disease
over expressing 3R tau.
RESULTS: Mice expressing 3R tau (L266V and G272V mutations) under the mThy-1
promoter were treated with CBL in two separate groups, the first was 3 months
old (treated for 3 months, IP) and the second was 6 months old (treated for
3 months, IP) at the start of the treatment. We found that although the levels
of total 3R tau were unchanged, CBL reduced the levels of hyper-phosphorylated
tau in both groups of mice. This was accompanied by reduced neurodegenerative
pathology in the neocortex and hippocampus in both groups and by improvements in
the behavioral deficits in the nest-building test and water maze in the
3-6 month group.
CONCLUSION: Taken together these results support the notion that CBL may be
beneficial in other taupathy models by reducing the levels of aberrantly
phosphorylated tau. |
Is Figitumumab effective for non-small cell lung cancer? | No. Phase III trials of the anti-insulin-like growth factor-1 receptor (IGF1R) antibody figitumumab in non-small cell lung cancer (NSCLC) patients have been discontinued owing to lack of survival benefit. Adding figitumumab to standard chemotherapy also failed to increase overall survival in patients with advanced nonadenocarcinoma NSCLC. | Insulin-like growth factor 1 (IGF-1)-directed therapy is currently at a
crossroads. After decades of research, several agents targeting the IGF pathway
are now in clinical trials. One recent phase III trial of the IGF-1R inhibitor
figitumumab in patients with non-small-cell lung cancer was discontinued after
an interim analysis showed no survival improvement. Clinical trials for patients
with sarcoma have demonstrated impressive anti-tumor activity in cases where the
IGF-1 pathway is activated, such as in Ewing sarcoma; however, acquired
resistance has been common. Recently, randomized phase II trials combining IGF-1
R with epidermal grown factor receptor (EGFR) inhibition in colorectal cancer
have been completed. Preclinical studies have indicated that several biomarkers
may have potential predictive value. Studies of IGF-1R inhibitors in
gastrointestinal cancers are currently ongoing in pancreatic, gastroesophageal,
hepatocellular, and colorectal cancers. A critical analysis of prior work in
this field and a rational strategy for maximizing success on the basis of
biomarker use are necessary. The type 1 insulin-like growth factor receptor (IGF-1R) and its downstream
signaling components have become increasingly recognized as having a driving
role in the development of maligcy, and consequently IGF-1R has become a
potential target for cancer therapy. Several inhibitors of IGF-1R are in
clinical development for the treatment of solid tumors, including non-small cell
lung cancer (NSCLC). These IGF-1R-targeted agents include monoclonal antibodies
such as cixutumumab (IMC-A12), AMG-479, AVE1642, BIIB022, dalotuzumab (MK-0646),
and robatumumab (Sch717454), the ligand neutralizing antibody Medi-573, and the
small molecule inhibitors BMS-754807, linsitinib (OSI-906), XL228, and AXL1717.
Two phase III trials of the anti-IGF-1R monoclonal antibody, figitumumab
(CP-751,871), were discontinued in 2010 as it was considered unlikely either
trial would meet their primary endpoints. In light of disappointing clinical
data with figitumumab and other targeted agents, it is likely that the use of
molecular markers will become important in predicting response to treatment.
This review outlines the role of IGF-1R signaling in solid tumors with a
particular focus on NSCLC, and provides an overview of clinical data. The insulin-like growth factor-1 receptor (IGF-1R) is a central component of
lung cancer signal transduction pathways. A phase III study failed for
carboplatin, paclitaxel, with or without figitumumab in first-line treating
metastatic non-small cell lung cancer (NSCLC). There is an urgent need for a
better understanding of signaling in IGF system. Insulin-like growth
factor-binding proteins (IGFBPs) function as modulators for IGF signaling
through sequestration of IGFs in serum and the extracellular fluid. IGFBPs can
also act as transporters or modulators for IGF action and insulin action. IGFBPs
have attracted increased attention for their lung cancer-related role in recent
years. Recent studies have demonstrated the critical role of IGFBPs in risk
assessment, early detection, prognosis evaluation, and drug resistance appraisal
for lung cancer. These observations suggest a potential new approach to
understand the pathogenesis of lung cancer, have important clinical
implications, while additional investigations are necessary. |
The LINCS L1000 data set contains gene expression data for drug treated human cells, yes or no? | The Library of Integrated Network-based Cellular Signatures (LINCS) L1000 dataset measures changes in GE before and after treatment of human cells with over 20 000 small-molecule compounds including most of the FDA-approved drugs. | The Library of Integrated Network-based Cellular Signatures (LINCS) L1000 big
data provide gene expression profiles induced by over 10 000 compounds, shRNAs,
and kinase inhibitors using the L1000 platform. We developed csNMF, a systematic
compound signature discovery pipeline covering from raw L1000 data processing to
drug screening and mechanism generation. The csNMF pipeline demonstrated better
performance than the original L1000 pipeline. The discovered compound signatures
of breast cancer were consistent with the LINCS KINOMEscan data and were
clinically relevant. The csNMF pipeline provided a novel and complete tool to
expedite signature-based drug discovery leveraging the LINCS L1000 resources. MOTIVATION: Adverse drug reactions (ADRs) are a central consideration during
drug development. Here we present a machine learning classifier to prioritize
ADRs for approved drugs and pre-clinical small-molecule compounds by combining
chemical structure (CS) and gene expression (GE) features. The GE data is from
the Library of Integrated Network-based Cellular Signatures (LINCS) L1000
dataset that measured changes in GE before and after treatment of human cells
with over 20 000 small-molecule compounds including most of the FDA-approved
drugs. Using various benchmarking methods, we show that the integration of GE
data with the CS of the drugs can significantly improve the predictability of
ADRs. Moreover, transforming GE features to enrichment vectors of biological
terms further improves the predictive capability of the classifiers. The most
predictive biological-term features can assist in understanding the drug
mechanisms of action. Finally, we applied the classifier to all >20 000
small-molecules profiled, and developed a web portal for browsing and searching
predictive small-molecule/ADR connections.
AVAILABILITY AND IMPLEMENTATION: The interface for the adverse event predictions
for the >20 000 LINCS compounds is available at http://maayanlab.net/SEP-L1000/
CONTACT: [email protected]
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. The Library of Integrated Cellular Signatures (LINCS) project provides
comprehensive transcriptome profiling of human cell lines before and after
chemical and genetic perturbations. Its L1000 platform utilizes 978 landmark
genes to infer the transcript levels of 14,292 genes computationally. Here we
conducted the L1000 data quality control analysis by using MCF7, PC3, and A375
cell lines as representative examples. Before perturbations, a promising 80%
correlation in transcriptome was observed between L1000- and Affymetrix
HU133A-platforms. After library-based shRNA perturbations, a moderate 30% of
differentially expressed genes overlapped between any two selected controls
viral vectors using the L1000 platform. The mitogen-activated protein kinase,
vascular endothelial growth factor, and T-cell receptor pathways were identified
as the most significantly shared pathways between chemical and genetic
perturbations in cancer cells. In conclusion, L1000 platform is reliable in
assessing transcriptome before perturbation. Its response to perturbagens needs
to be interpreted with caution. A quality control analysis pipeline of L1000 is
recommended before addressing biological questions. The LINCS L1000 data repository contains almost two million gene expression
profiles for thousands of small molecules and drugs. However, due to the
complexity and the size of the data repository and a lack of an interoperable
interface, the creation of pharmacologically meaningful workflows utilizing
these data is severely hampered. In order to overcome this limitation, we
developed the L1000 Viewer, a search engine and graphical web interface for the
LINCS data repository. The web interface serves as an interactive platform
allowing the user to select different forms of perturbation profiles, e.g., for
specific cell lines, drugs, dosages, time points and combinations thereof. At
its core, our method has a database we created from inferring and utilizing the
intricate dependency graph structure among the data files. The L1000 Viewer is
accessible via http://L1000viewer.bio-complexity.com/. |
What is a cytokine storm? | A cytokine storm is an undesirable elevation of cytokine levels, as may occur in response to a drug or a device, may lead to severe side effects such as systemic inflammatory response syndrome. | Cytokine storm is an immune reaction to an acute or chronic injury and may be
caused by a disease itself or by treatment directed at an underlying disease.
The result is an overwhelming release of cytokines which can cause a sepsis-like
response and may lead to multi-system organ failure and even death. Because it
occurs in various settings, oncology nurses need to be aware of this process
when assessing the pediatric oncology patient. Early recognition and treatment
initiation is imperative and may lead to better outcomes for the patient. The cytokine storm is an aggressive immune response characterized by the
recruitment of inflammatory leukocytes and exaggerated levels of cytokines and
chemokines at the site of infection. Here we review evidence that cytokine storm
directly contributes to the morbidity and mortality resulting from influenza
virus infection and that sphingosine-1-phosphate (S1P) receptor agonists can
abort cytokine storms providing significant protection against pathogenic human
influenza viral infections. In experiments using murine models and the human
pathogenic 2009 influenza viruses, S1P1 receptor agonist alone reduced deaths
from influenza virus by over 80% as compared to lesser protection (50%) offered
by the antiviral neuraminidase inhibitor oseltamivir. Optimal protection of 96%
was achieved by combined therapy with the S1P1 receptor agonist and oseltamivir.
The functional mechanism of S1P receptor agonist(s) action and the predomit
role played by pulmonary endothelial cells as amplifiers of cytokine storm
during influenza infection are described. The cytokine storm is an intensified, dysregulated, tissue-injurious
inflammatory response driven by cytokine and immune cell components. The
cytokine storm during influenza virus infection, whereby the amplified innate
immune response is primarily responsible for pulmonary damage, has been well
characterized. Now we describe a novel event where virus-specific T cells induce
a cytokine storm. The paramyxovirus pneumonia virus of mice (PVM) is a model of
human respiratory syncytial virus (hRSV). Unexpectedly, when C57BL/6 mice were
infected with PVM, the innate inflammatory response was undetectable until day 5
postinfection, at which time CD8(+) T cells infiltrated into the lung,
initiating a cytokine storm by their production of gamma interferon (IFN-γ) and
tumor necrosis factor alpha (TNF-α). Administration of an immunomodulatory
sphingosine-1-phosphate (S1P) receptor 1 (S1P1R) agonist significantly inhibited
PVM-elicited cytokine storm by blunting the PVM-specific CD8(+) T cell response,
resulting in diminished pulmonary disease and enhanced survival.
IMPORTANCE: A dysregulated overly exuberant immune response, termed a "cytokine
storm," accompanies virus-induced acute respiratory diseases (VARV), is
primarily responsible for the accompanying high morbidity and mortality, and can
be controlled therapeutically in influenza virus infection of mice and ferrets
by administration of sphingosine-1-phosphate 1 receptor (S1P1R) agonists. Here,
two novel findings are recorded. First, in contrast to influenza infection,
where the cytokine storm is initiated early by the innate immune system, for
pneumonia virus of mice (PVM), a model of RSV, the cytokine storm is initiated
late in infection by the adaptive immune response: specifically, by
virus-specific CD8 T cells via their release of IFN-γ and TNF-α. Blockading
these cytokines with neutralizing antibodies blunts the cytokine storm and
protects the host. Second, PVM infection is controlled by administration of an
S1P1R agonist. Cytokine storm defines a dysregulation of and an excessively exaggerated immune
response most often accompanying selected viral infections and several
autoimmune diseases. Newly emerging and re-emerging infections of the
respiratory tract, especially influenza, SARS, and hantavirus post considerable
medical problems. Their morbidities and mortalities are often a direct result of
cytokine storm. This chapter visits primarily influenza virus infection and
resultant cytokine storm. It provides the compelling evidence that illuminates
cytokine storm in influenza pathogenesis and the clear findings that cytokine
storm is chemically tractable by therapy directed toward sphingosine-1-phosphate
receptor (S1PR) modulation, specifically S1P1R agonist therapy. The mechanism(s)
of how S1P1R signaling works and the pathways involved are subjects of this
review. Cytokines, chemokines, and interferons are released by the immune cells in
response to cellular stress, damage and/or pathogens, and are widely used as
biomarkers of inflammation. Certain levels of cytokines are needed to stimulate
an immune response in applications such as vaccines or immunotherapy where
immune stimulation is desired. However, undesirable elevation of cytokine
levels, as may occur in response to a drug or a device, may lead to severe side
effects such as systemic inflammatory response syndrome or cytokine storm.
Therefore, preclinical evaluation of a test material's propensity to cause
cytokine secretion by healthy immune cells is an important parameter for
establishing its safety profile. Herein, we describe in vitro methods for
analysis of cytokines, chemokines, and type II interferon in whole blood
cultures derived from healthy donor volunteers. First, whole blood is incubated
with controls and tested omaterials for 24 h. Then, culture supernatants are
analyzed by ELISA to detect IL-1β, TNFα, IL-8, and IFNγ. The culture
supernatants can also be analyzed for the presence of other biomarkers secreted
by the immune cells. Such testing would require additional assays not covered in
this chapter and/or optimization of the test procedure to include relevant
positive controls and/or cell types. Endotoxins and exotoxins are among the most potent bacterial inducers of
cytokines. During infectious processes, the production of inflammatory cytokines
including tumor necrosis factor (TNF), interleukin-1β (IL-1β), gamma interferon
(IFNγ) and chemokines orchestrates the anti-infectious innate immune response.
However, an overzealous production, leading up to a cytokine storm, can be
deleterious and contributes to mortality consecutive to sepsis or toxic shock
syndrome. Endotoxins of Gram-negative bacteria (lipopolysaccharide, LPS) are
particularly inflammatory because they generate auto-amplificatory loops after
activation of monocytes/macrophages. LPS and numerous pore-forming exotoxins
also activate the inflammasome, the molecular platform that allows the release
of mature IL-1β and IL-18. Among exotoxins, some behave as superantigens, and as
such activate the release of cytokines by T-lymphocytes. In most cases,
pre-exposure to exotoxins enhances the cytokine production induced by LPS and
its lethality, whereas pre-exposure to endotoxin usually results in tolerance.
In this review we recall the various steps, which, from the very early discovery
of pyrogenicity induced by bacterial products, ended to the discovery of the
endogenous pyrogen. Furthermore, we compare the specific characteristics of
endotoxins and exotoxins in their capacity to induce inflammatory cytokines. Cytokine storm is a poorly explained clinical entity caused by an undesired and
aggrandized immune system response leading to unregulated activation of the
proinflammatory cascade, often contributing to multisystem organ failure and
even death. Its potentially diverse etiologies and sepsis-like presentation have
made it even more challenging to diagnose, and so far, no well-established
treatment protocol has been proposed. Its association with certain medications,
especially with monoclonal antibodies, has well been reported in literature. To
the best of our knowledge, so far, no previous case of cytokine storm associated
with imatinib has been reported. We herein present a case report of a
77-year-old male with a past medical history of hypereosinophilic syndrome who
developed acute fatal cytokine storm following treatment with imatinib. This
study highlights a life-threatening complication of the medication that may be
underrecognized. |
Which database exists that contains regulatory SNPs which affect predicted transcription factor binding site affinity? | SNP2TFBS is a computational resource intended to support researchers investigating the molecular mechanisms underlying regulatory variation in the human genome. The database essentially consists of a collection of text files providing specific annotations for human single nucleotide polymorphisms (SNPs), namely whether they are predicted to abolish, create or change the affinity of one or several transcription factor (TF) binding sites. A SNP's effect on TF binding is estimated based on a position weight matrix (PWM) model for the binding specificity of the corresponding factor. | |
Which R package has been developed for MS-based label-free phosphoproteomics? | Phosphonormalizer is an R package for normalization of MS-based label-free phosphoproteomics. | MOTIVATION: Global centering-based normalization is a commonly used
normalization approach in mass spectrometry-based label-free proteomics. It
scales the peptide abundances to have the same median intensities, based on an
assumption that the majority of abundances remain the same across the samples.
However, especially in phosphoproteomics, this assumption can introduce bias, as
the samples are enriched during sample preparation which can mask the underlying
biological changes. To address this possible bias, phosphopeptides quantified in
both enriched and non-enriched samples can be used to calculate factors that
mitigate the bias.
RESULTS: We present an R package phosphonormalizer for normalizing enriched
samples in label-free mass spectrometry-based phosphoproteomics.
AVAILABILITY AND IMPLEMENTATION: The phosphonormalizer package is freely
available under GPL ( > =2) license from Bioconductor
(https://bioconductor.org/packages/phosphonormalizer).
CONTACT: [email protected] or [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
Is there a vaccine for peanut allergy? | Yes, there is a vaccine for peanut allergy. | This article presents an overview of potential treatments of food allergy, with
an emphasis on various forms of immunotherapy (including oral immunotherapy,
sublingual immunotherapy, epicutaneous immunotherapy, immunotherapy with
modified food antigens, and immunotherapy with a recombit peanut vaccine).
Allergen nonspecific treatments, such as Chinese herbal formulas,
probiotics/prebiotics, helminths, monoclonal antibodies, and toll-like receptor
agonists, are also summarized. Peanut allergy is a common problem and can be the cause of severe,
life-threatening allergic reactions. It rarely resolves, with the majority of
patients carrying the disease onto adulthood. Peanut allergy poses a significant
burden on the quality of life of sufferers and their families, which results
mainly from the fear of accidental peanut ingestion, but is also due to dietary
and social restrictions. Current standard management involves avoidance, patient
education and provision of emergency medication, for use in allergic reactions,
when they occur. Efforts have been made to develop a vaccine for peanut allergy.
Recent developments have also highlighted the use of immunotherapy, which has
shown promise as an active form of treatment and may present a disease-modifying
therapy for peanut allergy. So far, results, especially from oral immunotherapy
studies, have shown good efficacy in achieving desensitization to peanut with a
good safety profile. However, the capacity to induce long-term tolerance has not
been demonstrated conclusively yet and larger, phase III studies are required to
further investigate safety and efficacy of this intervention. Peanut
immunotherapy is not currently recommended for routine clinical use or outside
specialist allergy units. Food allergies are a growing public health concern with an estimated 8% of US
children affected. Peanut allergies are also on the rise and often do not
spontaneously resolve, leaving individuals at-risk for potentially
life-threatening anaphylaxis throughout their lifetime. Currently, two forms of
peanut immunotherapy, oral immunotherapy (OIT) and epicutaneous immunotherapy
(EPIT), are in Phase III clinical trials and have shown promise to induce
desensitization in many subjects. However, there are several limitations with
OIT and EPIT, such as allergic side effects, daily dosing requirements, and the
infrequent outcome of long-term tolerance. Next-generation therapies for peanut
allergy should aim to overcome these limitations, which may be achievable with
adjuvanted immunotherapy. An adjuvant can be defined as anything that enhances,
accelerates, or modifies an immune response to a particular antigen. Adjuvants
may allow for lower doses of antigen to be given leading to decreased side
effects; may only need to be administered every few weeks or months rather than
daily exposures; and may induce a long-lasting protective effect. In this review
article, we highlight examples of adjuvants and formulations that have shown
pre-clinical efficacy in treating peanut allergy. |
The virus that causes FIP, Feline Infectious Peritonitis belongs to what family? | The virus that causes FIP, Feline Infectious Peritonitis belongs to the family coronavirus. | The feline infectious peritonitis virus (FIPV) is a member of the feline
coronavirus family that causes FIP, which is incurable and fatal in cats.
Cyclosporin A (CsA), an immunosuppressive agent that targets the nuclear factor
pathway of activated T-cells (NF-AT) to bind cellular cyclophilins (CyP),
dose-dependently inhibited FIPV replication in vitro. FK506 (an immunosuppressor
of the pathway that binds cellular FK506-binding protein (FKBP) but not CyP) did
not affect FIPV replication. Neither cell growth nor viability changed in the
presence of either CsA or FK506, and these factors did not affect the NF-AT
pathway in fcwf-4 cells. Therefore, CsA does not seem to exert inhibitory
effects via the NF-AT pathway. In conclusion, CsA inhibited FIPV replication in
vitro and further studies are needed to verify the practical value of CsA as an
anti-FIPV treatment in vivo. Feline coronaviruses (FCoV) exist as 2 biotypes: feline enteric coronavirus
(FECV) and feline infectious peritonitis virus (FIPV). FECV causes subclinical
infections; FIPV causes feline infectious peritonitis (FIP), a systemic and
fatal disease. It is thought that mutations in FECV enable infection of
macrophages, causing FIP. However, the molecular basis for this biotype switch
is unknown. We examined a furin cleavage site in the region between
receptor-binding (S1) and fusion (S2) domains of the spike of serotype 1 FCoV.
FECV sequences were compared with FIPV sequences. All FECVs had a conserved
furin cleavage motif. For FIPV, there was a correlation with the disease and >1
substitution in the S1/S2 motif. Fluorogenic peptide assays confirmed that the
substitutions modulate furin cleavage. We document a functionally relevant S1/S2
mutation that arises when FIP develops in a cat. These insights into FIP
pathogenesis may be useful in development of diagnostic, prevention, and
treatment measures against coronaviruses. Feline infectious peritonitis (FIP) is a fatal disease caused by feline
coronavirus (FCoV) infection. FCoV can be divided into serotypes I and II. The
virus that causes FIP (FIPV) is believed to occur sporadically and spread
infrequently from cat to cat. Recently, an FIP outbreak from an animal shelter
was confirmed in Taiwan. FCoV from all the cats in this shelter were analyzed to
determine the epidemiology of this outbreak. Thirteen of 46 (28.2%) cats with
typical signs of FIP were identified. Among them, seven cats were confirmed by
necropsy and/or histopathological examinations. Despite the fact that more than
one FCoV was identified in this multi-cat environment, the eight FIP cats were
invariably found to be infected with a type II FCoV. Sequence analysis revealed
that the type II FIPV detected from fecal samples, body effusions and
granulomatous tissue homogenates from the cats that succumbed to FIP all
harbored an identical recombination site in their S gene. Two of the cats that
succumbed to FIP were found to harbor an identical nonsense mutation in the 3c
gene. Fecal shedding of this type II virus in the effusive form of FIP can be
detected up to six days before death. Taken together, our data demonstrate that
horizontal transmission of FIPV is possible and that FIP cats can pose a
potential risk to other cats living in the same environment. Feline infectious peritonitis virus (FIP virus: FIPV), a feline coronavirus of
the family Coronaviridae, causes a fatal disease called FIP in wild and domestic
cat species. The genome of coronaviruses encodes a hydrophobic transmembrane
protein, the envelope (E) protein. The E protein possesses ion channel activity.
Viral proteins with ion channel activity are collectively termed "viroporins".
Hexamethylene amiloride (HMA), a viroporin inhibitor, can inhibit the ion
channel activity of the E protein and replication of several coronaviruses.
However, it is not clear whether HMA and other viroporin inhibitors affect
replication of FIPV. We examined the effect of HMA and other viroporin
inhibitors (DIDS [4,4'-disothiocyano-2,2'-stilbenedisulphonic acid] and
amantadine) on infection by FIPV serotypes I and II. HMA treatment drastically
decreased the titers of FIPV serotype I strains Black and KU-2 in a
dose-dependent manner, but it only slightly decreased the titer of FIPV serotype
II strain 79-1146. In contrast, DIDS treatment decreased the titer of FIPV
serotype II strain 79-1146 in dose-dependent manner, but it only slightly
decreased the titers of FIPV serotype I strains Black and KU-2. We investigated
whether there is a difference in ion channel activity of the E protein between
viral serotypes using E. coli cells expressing the E protein of FIPV serotypes I
and II. No difference was observed, suggesting that a viroporin other than the E
protein influences the differences in the actions of HMA and DIDS on FIPV
serotypes I and II. Coronaviruses (CoVs) can cause highly prevalent diseases in humans and animals.
Feline infectious peritonitis virus (FIPV) belongs to the genus
Alphacoronavirus, resulting in a lethal systemic granulomatous disease called
feline infectious peritonitis (FIP), which is one of the most important fatal
infectious diseases of cats worldwide. No specific vaccines or drugs have been
approved to treat FIP. CoV main proteases (M(pro)s) play a pivotal role in viral
transcription and replication, making them an ideal target for drug development.
Here, we report the crystal structure of FIPV M(pro) in complex with dual
inhibitors, a zinc ion and a Michael acceptor. The complex structure elaborates
a unique mechanism of two distinct inhibitors synergizing to inactivate the
protease, providing a structural basis to design novel antivirals and suggesting
the potential to take advantage of zinc as an adjunct therapy against
CoV-associated diseases.
IMPORTANCE: Coronaviruses (CoVs) have the largest genome size among all RNA
viruses. CoV infection causes various diseases in humans and animals, including
severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome
(MERS). No approved specific drugs or vaccinations are available to treat their
infections. Here, we report a novel dual inhibition mechanism targeting CoV main
protease (M(pro)) from feline infectious peritonitis virus (FIPV), which leads
to lethal systemic granulomatous disease in cats. M(pro), conserved across all
CoV genomes, is essential for viral replication and transcription. We
demonstrated that zinc ion and a Michael acceptor-based peptidomimetic inhibitor
synergistically inactivate FIPV M(pro). We also solved the structure of FIPV
M(pro) complexed with two inhibitors, delineating the structural view of a dual
inhibition mechanism. Our study provides new insight into the pharmaceutical
strategy against CoV M(pro) through using zinc as an adjuvant therapy to enhance
the efficacy of an irreversible peptidomimetic inhibitor. Feline infectious peritonitis (FIP) belongs to the few animal virus diseases in
which, in the course of a generally harmless persistent infection, a virus
acquires a small number of mutations that fundamentally change its
pathogenicity, invariably resulting in a fatal outcome. The causative agent of
this deadly disease, feline infectious peritonitis virus (FIPV), arises from
feline enteric coronavirus (FECV). The review summarizes our current knowledge
of the genome and proteome of feline coronaviruses (FCoVs), focusing on the
viral surface (spike) protein S and the five accessory proteins. We also review
the current classification of FCoVs into distinct serotypes and biotypes,
cellular receptors of FCoVs and their presumed role in viral virulence, and
discuss other aspects of FIPV-induced pathogenesis. Our current knowledge of
genetic differences between FECVs and FIPVs has been mainly based on comparative
sequence analyses that revealed "discriminatory" mutations that are present in
FIPVs but not in FECVs. Most of these mutations result in amino acid
substitutions in the S protein and these may have a critical role in the switch
from FECV to FIPV. In most cases, the precise roles of these mutations in the
molecular pathogenesis of FIP have not been tested experimentally in the natural
host, mainly due to the lack of suitable experimental tools including
genetically engineered virus mutants. We discuss the recent progress in the
development of FCoV reverse genetics systems suitable to generate recombit
field viruses containing appropriate mutations for in vivo studies. Feline infectious peritonitis (FIP) is a common and highly lethal coronavirus
disease of domestic cats. Recent studies of diseases caused by several RNA
viruses in people and other species indicate that antiviral therapy may be
effective against FIP in cats. The small molecule nucleoside analog GS-441524 is
a molecular precursor to a pharmacologically active nucleoside triphosphate
molecule. These analogs act as an alternative substrate and RNA-chain terminator
of viral RNA dependent RNA polymerase. We determined that GS-441524 was
non-toxic in feline cells at concentrations as high as 100 uM and effectively
inhibited FIPV replication in cultured CRFK cells and in naturally infected
feline peritoneal macrophages at concentrations as low as 1 uM. We determined
the pharmacokinetics of GS-441524 in cats in vivo and established a dosage that
would sustain effective blood levels for 24 h. In an experimental FIPV infection
of cats, GS-441524 treatment caused a rapid reversal of disease signs and return
to normality with as little as two weeks of treatment in 10/10 cats and with no
apparent toxicity. Feline infectious peritonitis (FIP), one of the most important lethal infections
of cats, is caused by feline infectious peritonitis virus (FIPV), the
high-virulence biotype of feline coronaviruses (FCoVs). FIPVs are suggested to
emerge from feline enteric coronaviruses (FECVs) by acquiring mutations in
specific genes in the course of persistent infections. Although numerous studies
identified mutations predicted to be responsible for the FECV-FIPV biotype
switch, the presumed roles of specific genetic changes in FIP pathogenesis have
not been confirmed experimentally. Reverse genetics systems established
previously for serotype I and the less common serotype II FCoVs were based on
cell culture-adapted FIPV strains which, however, were shown to be unsuitable
for FIP pathogenesis studies in vivo To date, systems to produce and manipulate
recombit serotype I field viruses have not been developed, mainly because
these viruses cannot be grown in vitro Here, we report the first reverse
genetics system based on a serotype I FECV field isolate that is suitable to
produce high-titer stocks of recombit FECVs. We demonstrate that these
recombit viruses cause productive persistent infections in cats that are
similar to what is observed in natural infections. The system provides an
excellent tool for studying FCoVs that do not grow in standard cell culture
systems and will greatly facilitate studies into the molecular pathogenesis of
FIP. Importantly, the system could also be adapted for studies of other RNA
viruses with large genomes whose production and characterization in vivo are
currently hampered by the lack of in vitro propagation systems.IMPORTANCE The
availability of recombit serotype I FCoV field isolates that are amenable to
genetic manipulation is key to studying the molecular pathogenesis of FIP,
especially since previous studies using cell culture-adapted FIPVs had proven
unsuccessful. To our knowledge, we report the first serotype I FECV field
isolate-based reverse genetics system that allows the production of high-titer
recombit virus stocks that can be used for subsequent in vivo studies in
cats. The system represents a milestone in FCoV research. It provides an
essential tool for studying the molecular pathogenesis of FIP and, more
specifically, the functions of specific gene products in causing a fundamentally
different progression of disease following acquisition of specific mutations.
The system developed in this study will also be useful for studying other
coronaviruses or more distantly related RNA viruses with large genomes for which
suitable in vitro culture systems are not available. Feline infectious peritonitis (FIP) is one of the most important infectious
diseases in cats and is caused by feline coronavirus (FCoV). Tissue
culture-adapted type I FCoV shows reduced FIP induction in experimental
infections, which complicates the understanding of FIP pathogenesis caused by
type I FCoV. We previously found that the type I FCoV strain C3663 efficiently
induces FIP in specific-pathogen-free cats through the naturally infectious
route. In this study, we employed a bacterial artificial chromosome-based
reverse genetics system to gain more insights into FIP caused by the C3633
strain. We successfully generated recombit virus (rC3663) from Fcwf-4 cells
transfected with infectious cDNA that showed growth kinetics similar to those
shown by the parental virus. Next, we constructed a reporter C3663 virus
carrying the oluciferase (Nluc) gene to measure viral replication with high
sensitivity. The inhibitory effects of different compounds against rC3663-Nluc
could be measured within 24 h postinfection. Furthermore, we found that A72
cells derived from canine fibroblasts permitted FCoV replication without
apparent cytopathic effects. Thus, our reporter virus is useful for uncovering
the infectivity of type I FCoV in different cell lines, including canine-derived
cells. Surprisingly, we uncovered aberrant viral RNA transcription of rC3663 in
A72 cells. Overall, we succeeded in obtaining infectious cDNA clones derived
from type I FCoV that retained its virulence. Our recombit FCoVs are powerful
tools for increasing our understanding of the viral life cycle and pathogenesis
of FIP-inducing type I FCoV.IMPORTANCE Feline coronavirus (FCoV) is one of the
most significant coronaviruses, because this virus induces feline infectious
peritonitis (FIP), which is a lethal disease in cats. Tissue culture-adapted
type I FCoV often loses pathogenicity, which complicates research on type I
FCoV-induced feline infectious peritonitis (FIP). Since we previously found that
type I FCoV strain C3663 efficiently induces FIP in specific-pathogen-free cats,
we established a reverse genetics system for the C3663 strain to obtain
recombit viruses in the present study. By using a reporter C3663 virus, we
were able to examine the inhibitory effect of 68 compounds on C3663 replication
in Fcwf-4 cells and infectivity in a canine-derived cell line. Interestingly,
one canine cell line, A72, permitted FCoV replication but with low efficiency
and aberrant viral gene expression. |
What is a "cytokine storm"? | During infectious processes, the production of inflammatory cytokines including tumor necrosis factor (TNF), interleukin-1b (IL-1b), gamma interferon (IFNg) and chemokines orchestrates the anti-infectious innate immune response. However, an overzealous production, leading up to a cytokine storm, can be deleterious and contributes to mortality consecutive to sepsis or toxic shock syndrome. | INTRODUCTION: Macrophage activation syndrome (MAS) is a life-threatening
hyperinflammatory state mediated by uncontrolled cytokine storm and
haemophagocytosis. Although rarely reported, MAS might occur in systemic lupus
erythematosus (SLE), notably as an inaugural manifestation. Glucocorticoids
(GCs) are the cornerstone of SLE therapy. However, in some cases high doses of
GCs are required to achieve remission (i.e. glucocorticoid-resistance), leading
to significant side effects.
CASE REPORT: A 28-year-old Romani male was admitted to our hospital for
polyarthralgia, polyserositis and fatigability. The patient had high-grade
fever, jaundice and generalized lymphadenopathy. Laboratory tests revealed
severe mixed hemolytic autoimmune anemia, leukopenia, hepatocytolysis,
coagulation abnormalities, hypertriglyceridemia, biological inflammatory
syndrome, hyperferritinemia and persistent proteinuria of nephritic pattern.
Imaging studies showed pleuropericardial effusion, hepatosplenomegaly and
polysynovitis. Additional blood tests revealed hypocomplementemia and positive
ANA, anti-dsDNA and anti-Sm antibodies. Haemophagocytosis was not identified
either on bone marrow or axillary lymph node biopsy specimens. However,
SLE-associated MAS seemed to fit this set-up. High-dose corticotherapy (6.5 g
methylprednisolone followed by prednisone, 1.5 mg/kg/day after discharge) and
intravenous cyclophosphamide were necessary to induce and sustain remission.
CONCLUSION: MAS is a potentially severe manifestation that should be considered
at SLE onset whenever high fever and elevated serum levels of aspartate
aminotransferase, lactate dehydrogenase, C-reactive protein, ferritin and
procalcitonin are noted. Early diagnosis and prompt treatment lead to remission
in two thirds of cases. Glucocorticoid-resistance leads to the use of high-dose
corticotherapy or immunosuppressive agents that could elicit serious side
effects. New insights into the molecular mechanisms of glucocorticoid-resistance
are needed in order to conceive more adequate GC-therapies. Endotoxins and exotoxins are among the most potent bacterial inducers of
cytokines. During infectious processes, the production of inflammatory cytokines
including tumor necrosis factor (TNF), interleukin-1β (IL-1β), gamma interferon
(IFNγ) and chemokines orchestrates the anti-infectious innate immune response.
However, an overzealous production, leading up to a cytokine storm, can be
deleterious and contributes to mortality consecutive to sepsis or toxic shock
syndrome. Endotoxins of Gram-negative bacteria (lipopolysaccharide, LPS) are
particularly inflammatory because they generate auto-amplificatory loops after
activation of monocytes/macrophages. LPS and numerous pore-forming exotoxins
also activate the inflammasome, the molecular platform that allows the release
of mature IL-1β and IL-18. Among exotoxins, some behave as superantigens, and as
such activate the release of cytokines by T-lymphocytes. In most cases,
pre-exposure to exotoxins enhances the cytokine production induced by LPS and
its lethality, whereas pre-exposure to endotoxin usually results in tolerance.
In this review we recall the various steps, which, from the very early discovery
of pyrogenicity induced by bacterial products, ended to the discovery of the
endogenous pyrogen. Furthermore, we compare the specific characteristics of
endotoxins and exotoxins in their capacity to induce inflammatory cytokines. BACKGROUND Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening
condition that has a poor prognosis due to the ensuing cytokine storm leading to
severe organ damage. Current treatment guidelines suggest using a combination of
steroid- and etoposide-based chemotherapy. CASE REPORT The authors present a
case of a 41-year-old African-American female who presented with symptoms of
foodborne illness and who developed multi-organ dysfunction. HLH was suspected
because of poor response to broad-spectrum antibiotics with a constellation of
findings, including cytopenia, hypofibrinogenemia, hypertriglyceridemia, and
hyperferritinemia. Clinical improvement was noted after administration of
intravenous immunoglobulin and dexamethasone while waiting for the soluble
interleukin-2 receptor levels; therefore, chemotherapy was not administered.
CONCLUSIONS Despite the variable and poor prognosis of HLH, early treatment with
steroids and immunosuppressive therapy is crucial to improving the survival
rate. The inclusion of immunoglobulin therapy should be considered a treatment
option for HLH. |
Is golimumab effective for sarcoidosis? | No, golimumab is not effective for treatment of sarcoidosis. | |
Is SARS virus interacting with ACE2 encoded protein? | Yes,
The infection of target cells by the SARS CoV is mediated through the interaction of the viral Spike (S) protein (1255 amino acids) and its cellular receptor, angiotensin-converting enzyme 2 (ACE2). | The severe acute respiratory syndrome (SARS) coronavirus (CoV) identified in
2003 has infected ∼8000 people worldwide, killing nearly 10% of them. The
infection of target cells by the SARS CoV is mediated through the interaction of
the viral Spike (S) protein (1255 amino acids) and its cellular receptor,
angiotensin-converting enzyme 2 (ACE2). The SARS CoV receptor-binding domain
(amino acids N318-T509 of S protein) harbors an extended excursion along its
periphery that contacts ACE2 and is designated the receptor-binding motif (RBM,
amino acids S432-T486). In addition, the RBM is a major antigenic determit,
able to elicit production of neutralizing antibodies. Hence, the role of the RBM
is a bi-functional bioactive surface that can be demonstrated by antibodies such
as the neutralizing human anti-SARS monoclonal antibody (mAb) 80R which targets
the RBM and competes with the ACE2 receptor for binding. Here, we employ
phage-display peptide-libraries to reconstitute a functional RBM. This is
achieved by generating a vast collection of candidate RBM peptides that present
a diversity of conformations. Screening such 'Conformer Libraries' with
corresponding ligands has produced short RBM constructs (ca. 40 amino acids)
that can bind both the ACE2 receptor and the neutralizing mAb 80R. In response to infectious and, in some instances, noninfectious insults, the
affected tissues/cells of the host undergo inflammation. However, uncontrolled
inflammation could be detrimental to the host, resulting in inflammatory
disease, such as inflammatory lung disease. Although the etiology of the disease
is well defined, the underling pathogenesis is still incompletely understood.
The renin-angiotensin system (RAS), one of the primary cardiovascular regulatory
systems, has been proposed to be involved in the pathogenesis of inflammatory
lung disease. In particular, the RAS has been implicated as advances in the
understanding of the multifunctionality of individual components of the system
have been made, and by the fact that the RAS acts not only systemically, but
also locally in a variety of tissues, including the lung. Angiotensin-converting
enzyme 2 (ACE2), a relatively new member of the RAS, has drawn extensive
attention since 2003, because of the findings that ACE2 is the receptor for SARS
Corona virus and that maintece of normal ACE2 levels in the lung is
beneficial for the host to combat inflammatory lung disease. Nevertheless, the
mechanism through which ACE2 plays a role in inflammatory lung disease has not
been clearly identified. In an attempt to summarize current literature findings
and progress made in uncovering the role of ACE2 in inflammatory lung disease,
this review will focus on recent studies examining pulmonary ACE2 biology, its
roles in inflammatory lung disease pathogenesis and possible underlying
mechanisms. Finally, we will discuss pulmonary ACE2 as a potential therapeutic
target for inflammatory lung disease. The trimeric SARS coronavirus (SARS-CoV) surface spike (S) glycoprotein
consisting of three S1-S2 heterodimers binds the cellular receptor
angiotensin-converting enzyme 2 (ACE2) and mediates fusion of the viral and
cellular membranes through a pre- to postfusion conformation transition. Here,
we report the structure of the SARS-CoV S glycoprotein in complex with its host
cell receptor ACE2 revealed by cryo-electron microscopy (cryo-EM). The complex
structure shows that only one receptor-binding domain of the trimeric S
glycoprotein binds ACE2 and adopts a protruding "up" conformation. In addition,
we studied the structures of the SARS-CoV S glycoprotein and its complexes with
ACE2 in different in vitro conditions, which may mimic different conformational
states of the S glycoprotein during virus entry. Disassociation of the S1-ACE2
complex from some of the prefusion spikes was observed and characterized. We
also characterized the rosette-like structures of the clustered SARS-CoV S2
trimers in the postfusion state observed on electron micrographs. Structural
comparisons suggested that the SARS-CoV S glycoprotein retains a prefusion
architecture after trypsin cleavage into the S1 and S2 subunits and acidic pH
treatment. However, binding to the receptor opens up the receptor-binding domain
of S1, which could promote the release of the S1-ACE2 complex and S1 monomers
from the prefusion spike and trigger the pre- to postfusion conformational
transition. Severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in 2002 as a
highly transmissible pathogenic human betacoronavirus. The viral spike
glycoprotein (S) utilizes angiotensin-converting enzyme 2 (ACE2) as a host
protein receptor and mediates fusion of the viral and host membranes, making S
essential to viral entry into host cells and host species tropism. As SARS-CoV
enters host cells, the viral S is believed to undergo a number of conformational
transitions as it is cleaved by host proteases and binds to host receptors. We
recently developed stabilizing mutations for coronavirus spikes that prevent the
transition from the pre-fusion to post-fusion states. Here, we present cryo-EM
analyses of a stabilized trimeric SARS-CoV S, as well as the trypsin-cleaved,
stabilized S, and its interactions with ACE2. Neither binding to ACE2 nor
cleavage by trypsin at the S1/S2 cleavage site impart large conformational
changes within stabilized SARS-CoV S or expose the secondary cleavage site, S2'. |
What is Soluvia? | Soluvia(tm) by Becton Dickinson is a microinjection system for intradermal delivery of vaccines. | |
Is the FIP virus thought to be a mutated strain for the Feline enteric Coronavirus? | yes, Feline infectious peritonitis (FIP) results from mutations in the viral genome during a common feline enteric coronavirus (FECV) infection. | Feline Infectious Peritonitis (FIP) is a severe fatal immune-augmented disease
in cat population. It is caused by FIP virus (FIPV), a virulent mutant strain of
Feline Enteric Coronavirus (FECV). Current treatments and prophylactics are not
effective. The in vitro antiviral properties of five circular Triple-Helix
Forming Oligonucleotide (TFO) RNAs (TFO1 to TFO5), which target the different
regions of virulent feline coronavirus (FCoV) strain FIPV WSU 79-1146 genome,
were tested in FIPV-infected Crandell-Rees Feline Kidney (CRFK) cells. RT-qPCR
results showed that the circular TFO RNAs, except TFO2, inhibit FIPV
replication, where the viral genome copy numbers decreased significantly by
5-fold log10 from 10(14) in the virus-inoculated cells to 10(9) in the circular
TFO RNAs-transfected cells. Furthermore, the binding of the circular TFO RNA
with the targeted viral genome segment was also confirmed using electrophoretic
mobility shift assay. The strength of binding kinetics between the TFO RNAs and
their target regions was demonstrated by NanoITC assay. In conclusion, the
circular TFOs have the potential to be further developed as antiviral agents
against FIPV infection. Feline infectious peritonitis (FIP) results from mutations in the viral genome
during a common feline enteric coronavirus (FECV) infection. Since many
virological and immunological data on FECV infections are lacking, the present
study investigated these missing links during experimental infection of three
SPF cats with FECV strain UCD. Two cats showed mild clinical signs, faecal
shedding of infectious virus from 4 dpi, a cell-associated viraemia at
inconsistent time points from 5 dpi, a highly neutralising antibody response
from 9 dpi, and no major abnormalities in leukocyte numbers. Faecal shedding
lasted for 28-56 days, but virus shed during this stage was less infectious in
enterocyte cultures and affected by mutations. Remarkably, in the other cat
neither clinical signs nor acute shedding were seen, but virus was detected in
blood cells from 3 dpi, and shedding of non-enterotropic, mutated viruses
suddenly occurred from 14 dpi onwards. Neutralising antibodies arose from 21
dpi. Leukocyte numbers were not different compared to the other cats, except for
the CD8(+) regulatory T cells. These data indicate that FECV can infect immune
cells even in the absence of intestinal replication and raise the hypothesis
that the gradual adaptation to these cells can allow non-enterotropic mutants to
arise. Coronaviruses infect animals and humans causing a wide range of diseases. The
diversity of coronaviruses in many mammalian species is contributed by
relatively high mutation and recombination rates during replication. This
dynamic nature of coronaviruses may facilitate cross-species transmission and
shifts in tissue or cell tropism in a host, resulting in substantial change in
virulence. Feline enteric coronavirus (FECV) causes inapparent or mild enteritis
in cats, but a highly fatal disease, called feline infectious peritonitis (FIP),
can arise through mutation of FECV to FIP virus (FIPV). The pathogenesis of FIP
is intimately associated with immune responses and involves depletion of T
cells, features shared by some other coronaviruses like Severe Acute Respiratory
Syndrome Coronavirus. The increasing risks of highly virulent coronavirus
infections in humans or animals call for effective antiviral drugs, but no such
measures are yet available. Previously, we have reported the inhibitors that
target 3C-like protease (3CLpro) with broad-spectrum activity against important
human and animal coronaviruses. Here, we evaluated the therapeutic efficacy of
our 3CLpro inhibitor in laboratory cats with FIP. Experimental FIP is 100% fatal
once certain clinical and laboratory signs become apparent. We found that
antiviral treatment led to full recovery of cats when treatment was started at a
stage of disease that would be otherwise fatal if left untreated. Antiviral
treatment was associated with a rapid improvement in fever, ascites, lymphopenia
and gross signs of illness and cats returned to normal health within 20 days or
less of treatment. Significant reduction in viral titers was also observed in
cats. These results indicate that continuous virus replication is required for
progression of immune-mediated inflammatory disease of FIP. These findings may
provide important insights into devising therapeutic strategies and selection of
antiviral compounds for further development for important coronaviruses in
animals and humans. Feline infectious peritonitis (FIP) is an almost invariably fatal feline
coronavirus (FCoV)-induced disease thought to arise from a combination of viral
mutations and an overexuberant immune response. Natural initial enteric FCoV
infection may remain subclinical, or result in mild enteric signs or the
development of FIP; cats may also carry the virus systemically with no adverse
effect. This study screened mesenteric lymph nodes (MLNs), the presumed first
site of FCoV spread from the intestine regardless of viraemia, for changes in
the transcription of a panel of innate immune response mediators in response to
systemic FCoV infection and with FIP, aiming to identify key pathways triggered
by FCoV. Cats with and without FIP, the latter with and without FCoV infection
in the MLN, were compared. Higher expression levels in FIP were found for
toll-like receptors (TLRs) 2, 4 and 8. These are part of the first line of
defence and suggest a response to both viral structural proteins and viral
nucleic acid. Expression of genes encoding inflammatory cytokines and
chemokines, including interleukin (IL)-1β, IL-6, IL-15, tumour necrosis factor
(TNF)-α, CXCL10, CCL8, interferon (IFN)-α, IFN-β and IFN-γ, was higher in cats
with FIP, consistent with inflammatory pathway activation. Expression of genes
encoding transcription factors STAT1 and 2, regulating signalling pathways,
particularly of the interferons, was also higher. Among cats without FIP, there
were few differences between virus-positive and virus-negative MLNs; however,
TLR9 and STAT2 expression were higher with infection, suggesting a direct viral
effect. The study provides evidence for TLR involvement in the response to FCoV.
This could open up new avenues for therapeutic approaches. |
Does SATB1 regulate the RAG1 and RAG2 genes? | SATB1 binds to the ASE and Rag promoters, facilitating inclusion of Rag2 in the chromatin hub and the loading of RNA polymerase II to both the Rag1 and Rag2 promoters. | The X-linked lymphocyte-regulated (Xlr) protein is a 30,000 Mr nuclear protein
bearing homology with meiosis-specific proteins and expressed in late stage B
lymphoid cell lines. In the present study we investigated its expression in the
T lymphoid lineage. In adults, a high level of expression was detected in
CD4-CD8- thymocytes. Most remarkably, the peak of Xlr expression occurred early
during thymus cell ontogeny, precisely on days 14-15 of gestation, and was
associated with the first wave of pre-T cell differentiation. Its onset preceded
the rearrangement of TCR genes, as Xlr expression was conserved in thymus cells
from RAG1(0/0) mice. The lower expression of Xlr on day 13 of fetal development,
the bright Thy1+ phenotype of Xlr-positive cells, their large size, and their
absence from subcapsular areas suggest that Xlr expression must be turned on
within the thymus and not in prethymic precursors. From day 16 of gestation, Xlr
expression decreased markedly. At birth and later, Xlr(high) cells were mostly
large cells scattered throughout the cortical area. As shown by confocal
microscopy, expression of Xlr closely overlapped that of SATB1, which binds
special AT-rich DNA sequences associated with the nuclear matrix and plays an
important regulatory role for many genes. The remarkably regulated expression of
Xlr in the lymphoid cell lineage and of its homologue Xmr in the germ cell
lineage suggests that they might play an important role in chromatin metabolism
at critical stages of differentiation during which the genome undergoes
irreversible rearrangements. Rag1 and Rag2 gene expression in CD4(+)CD8(+) double-positive (DP) thymocytes
depends on the activity of a distant anti-silencer element (ASE) that
counteracts the activity of an intergenic silencer. However, the mechanistic
basis for ASE activity is unknown. Here, we show that the ASE physically
interacts with the distant Rag1 and Rag2 gene promoters in DP thymocytes,
bringing the two promoters together to form an active chromatin hub. Moreover,
we show that the ASE functions as a classical enhancer that can potently
activate these promoters in the absence of the silencer or other locus elements.
In thymocytes lacking the chromatin organizer SATB1, we identified a partial
defect in Tcra gene rearrangement that was associated with reduced expression of
Rag1 and Rag2 at the DP stage. SATB1 binds to the ASE and Rag promoters,
facilitating inclusion of Rag2 in the chromatin hub and the loading of RNA
polymerase II to both the Rag1 and Rag2 promoters. Our results provide a novel
framework for understanding ASE function and demonstrate a novel role for SATB1
as a regulator of Rag locus organization and gene expression in DP thymocytes. |
What is the main difference between nascent and mature chromatin? | Nascent chromatin is created after transcription and is mostly lacking histone modifications and H1, which makes it more prone to digestion by DNaseI. | During chromatin replication and nucleosome assembly, newly synthesized histone
H4 is acetylated before it is deposited onto DNA, then deacetylated as assembly
proceeds. In a previous study (Perry and Annunziato, Nucleic Acids Res. 17, 4275
[1989]) it was shown that when replication occurs in the presence of sodium
butyrate (thereby inhibiting histone deacetylation), nascent chromatin fails to
mature fully and instead remains preferentially sensitive to DNaseI, more
soluble in magnesium, and depleted of histone H1 (relative to mature chromatin).
In the following report the relationships between chromatin replication, histone
acetylation, and H1-mediated nucleosome aggregation were further investigated.
Chromatin was replicated in the presence or absence of sodium butyrate; isolated
nucleosomes were stripped of linker histone, reconstituted with H1, and treated
to produce Mg(2+)-soluble and Mg(2+)-insoluble chromatin fractions. Following
the removal of H1, all solubility differences between chromatin replicated in
sodium butyrate for 30 min (bu-chromatin) and control chromatin were lost.
Reconstitution with H1 completely restored the preferential Mg(2+)-solubility of
bu-chromatin, demonstrating that a reduced capacity for aggregation/condensation
is an inherent feature of acetylated nascent nucleosomes; however, titration
with excess H1 caused the solubility differences to be lost again. Moreover,
when the core histone N-terminal "tails" (the sites of acetylation) were removed
by trypsinization prior to reconstitution, H1 was unable to reestablish the
altered solubility of chromatin replicated in butyrate. Thus, the core histone
"tails," and the acetylation thereof, not only modulate H1-mediated nucleosome
interactions in vitro, but also strongly influence the ability of H1 to
differentiate between new and old nucleosomes. The data suggest a possible
mechanism for the control of H1 deposition and/or chromatin folding during
nucleosome assembly. The effects of inhibiting histone deacetylation on the maturation of newly
replicated chromatin have been examined. HeLa cells were labeled with
[3H]thymidine in the presence or absence of sodium butyrate; control experiments
demonstrated that butyrate did not significantly inhibit DNA replication for at
least 70 min. Like normal nascent chromatin, chromatin labeled for brief periods
(0.5-1 min) in the presence of butyrate was more sensitive to digestion with
DNase I and micrococcal nuclease than control bulk chromatin. However, chromatin
replicated in butyrate did not mature as in normal replication, but instead
retained approximately 50% of its heightened sensitivity to DNase I. Incubation
of mature chromatin in butyrate for 1 h did not induce DNase I sensitivity:
therefore, the presence of sodium butyrate was required during replication to
preserve the increased digestibility of nascent chromatin DNA. In contrast,
sodium butyrate did not inhibit or retard the maturation of newly replicated
chromatin when assayed by micrococcal nuclease digestion, as determined by the
following criteria: 1) digestion to acid solubility, 2) rate of conversion to
mononucleosomes, 3) repeat length, and 4) presence of non-nucleosomal DNA.
Consistent with the properties of chromatin replicated in butyrate, micrococcal
nuclease also did not preferentially attack the internucleosomal linkers of
chromatin regions acetylated in vivo. The observation of a novel chromatin
replication intermediate, which is highly sensitive to DNase I but possesses
normal resistance to micrococcal nuclease, suggests that nucleosome assembly and
histone deacetylation are not obligatorily coordinated. Thus, while
deacetylation is required for chromatin maturation, histone acetylation
apparently affects chromatin organization at a level distinct from that of core
particle or linker, possibly by altering higher order structure. |
Is CTCF bound at nucleosome free regions? | yes, robust inter-nucleosomal interactions exist around transcription start site (TSS), transcription termination sites (TTS) or around CTCF binding sites | The application of deep sequencing to map 5' capped transcripts has confirmed
the existence of at least two distinct promoter classes in metazoans: "focused"
promoters with transcription start sites (TSSs) that occur in a narrowly defined
genomic span and "dispersed" promoters with TSSs that are spread over a larger
window. Previous studies have explored the presence of genomic features, such as
CpG islands and sequence motifs, in these promoter classes, but virtually no
studies have directly investigated the relationship with chromatin features.
Here, we show that promoter classes are significantly differentiated by
nucleosome organization and chromatin structure. Dispersed promoters display
higher associations with well-positioned nucleosomes downstream of the TSS and a
more clearly defined nucleosome free region upstream, while focused promoters
have a less organized nucleosome structure, yet higher presence of RNA
polymerase II. These differences extend to histone variants (H2A.Z) and marks
(H3K4 methylation), as well as insulator binding (such as CTCF), independent of
the expression levels of affected genes. Notably, differences are conserved
across mammals and flies, and they provide for a clearer separation of promoter
architectures than the presence and absence of CpG islands or the occurrence of
stalled RNA polymerase. Computational models support the stronger contribution
of chromatin features to the definition of dispersed promoters compared to
focused start sites. Our results show that promoter classes defined from 5'
capped transcripts not only reflect differences in the initiation process at the
core promoter but also are indicative of divergent transcriptional programs
established within gene-proximal nucleosome organization. Gene expression frequently requires chromatin-remodeling complexes, and it is
assumed that these complexes have common gene targets across cell types.
Contrary to this belief, we show by genome-wide expression profiling that Bptf,
an essential and unique subunit of the nucleosome-remodeling factor (NURF),
predomitly regulates the expression of a unique set of genes between diverse
cell types. Coincident with its functions in gene expression, we observed that
Bptf is also important for regulating nucleosome occupancy at nucleosome-free
regions (NFRs), many of which are located at sites occupied by the multivalent
factors Ctcf and cohesin. NURF function at Ctcf binding sites could be direct,
because Bptf occupies Ctcf binding sites in vivo and has physical interactions
with CTCF and the cohesin subunit SA2. Assays of several Ctcf binding sites
using reporter assays showed that their regulatory activity requires Bptf in two
different cell types. Focused studies at H2-K1 showed that Bptf regulates the
ability of Klf4 to bind near an upstream Ctcf site, possibly influencing gene
expression. In combination, these studies demonstrate that gene expression as
regulated by NURF occurs partly through physical and functional interactions
with the ubiquitous and multivalent factors Ctcf and cohesin. Combinatorial effects of epigenetic modifications on transcription activity have
been proposed as "histone codes". However, it is unclear whether there also
exist inter-nucleosomal communications among epigenetic modifications at single
nucleosome level, and if so, what functional roles they play. Meanwhile, how
clear nucleosome patterns, such as nucleosome phasing and depletion, are formed
at functional regions remains an intriguing enigma. To address these questions,
we developed a Bayesian network model for interactions among different histone
modifications across neighboring nucleosomes, based on the framework of dynamic
Bayesian network (DBN). From this model, we found that robust inter-nucleosomal
interactions exist around transcription start site (TSS), transcription
termination sites (TTS) or around CTCF binding sites; and these
inter-nucleosomal interactions are often involved in transcription regulation.
In addition to these general principles, DBN also uncovered a novel specific
epigenetic interaction between H2A.Z and H4K20me1 on neighboring nucleosomes,
involved in nucleosome free region (NFR) and nucleosome phasing establishment or
maintece. The level of negative correlation between neighboring H2A.Z and
H4K20me1 strongly correlate with the size of NFR and the strength of nucleosome
phasing around TSS. Our study revealed inter-nucleosomal communications as
important players in signal propagation, chromatin remodeling and transcription
regulation. Author information:
(1)European Molecular Biology Laboratory (EMBL), Genome Biology Unit,
Meyerhofstrasse 1, Heidelberg 69117, Germany. Electronic address:
[email protected].
(2)European Molecular Biology Laboratory (EMBL), Genome Biology Unit,
Meyerhofstrasse 1, Heidelberg 69117, Germany.
(3)European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics
Unit, Meyerhofstrasse 1, Heidelberg 69117, Germany.
(4)Genomics & Immunity, National Institute of Arthritis and Musculoskeletal and
Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
(5)Genomics & Immunity, National Institute of Arthritis and Musculoskeletal and
Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Center
for Cancer Research, NCI, National Institutes of Health, Bethesda, MD 20892,
USA.
(6)European Molecular Biology Laboratory (EMBL), Genome Biology Unit,
Meyerhofstrasse 1, Heidelberg 69117, Germany; Stanford Genome Technology Center,
855 California Ave, Palo Alto, CA 94305, USA; Department of Genetics, Stanford
University School of Medicine, Stanford, CA 94305, USA.
(7)European Molecular Biology Laboratory (EMBL), Genome Biology Unit,
Meyerhofstrasse 1, Heidelberg 69117, Germany; European Molecular Biology
Laboratory (EMBL), European Bioinformatics Institute, Wellcome Trust Genome
Campus, Cambridge CB10 1SD, UK; Wellcome Trust - Medical Research Council Stem
Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR,
UK. Electronic address: [email protected].
(8)European Molecular Biology Laboratory (EMBL), Genome Biology Unit,
Meyerhofstrasse 1, Heidelberg 69117, Germany. Electronic address:
[email protected]. |
Is bortezomib a Proteasome inhibitor? | The proteasome inhibitor bortezomib is effective for a variety of tumors, but not for GBM. Proteasome inhibitor bortezomib | The proteasome inhibitor bortezomib is emerging as a potent anti-cancer agent.
Still, recent clinical trials have revealed a significant secondary toxicity of
bortezomib. Consequently, there is much interest in dissecting the mechanism of
action of this compound to rationally improve its therapeutic index. The
cytotoxic effect of bortezomib is frequently characterized by interfering with
downstream events derived from the accumulation of proteasomal targets. Here we
identify the first chemical agent able to act upstream of the proteasome to
prevent cell killing by bortezomib. Specifically, we show that the polyhydroxyl
compound Tiron can function as a competitive inhibitor of bortezomib. This
effect of Tiron was surprising, since it is a classical radical spin trap and
was expected to scavenge reactive oxygen species produced as a consequence of
bortezomib action. The inhibitory effect of Tiron against bortezomib was
selective, since it was not shared by other antioxidants, such as vitamin E,
MnTBAP, L-N-acetyl-cysteine, and FK-506. Comparative analyses with nonboronated
proteasome inhibitors (i.e. MG132) revealed a specificity of Tiron for
bortezomib. We exploited this novel feature of Tiron to define the "point of no
return" of proteasome inhibition in melanoma cells and to block cell death in a
three-dimensional model of human skin. Cells from T-cell lymphoma, breast
carcinoma, and non-small cell lung cancer were also responsive to Tiron,
suggesting a broad impact of this agent as a bortezomib blocker. These results
may have important implications for the analysis of bortezomib in vivo and for
the design of drug mixtures containing proteasome inhibitors. Targeting the ubiquitin-proteasome pathway has emerged as a rational approach in
the treatment of human cancer. Based on positive preclinical and clinical
studies, bortezomib was subsequently approved for the clinical use as a
front-line treatment for newly diagnosed multiple myeloma patients and for the
treatment of relapsed/refractory multiple myeloma and mantle cell lymphoma, for
which this drug has become the staple of treatment. The approval of bortezomib
by the US Food and Drug Administration (FDA) represented a significant milestone
as the first proteasome inhibitor to be implemented in the treatment of
maligt disease. Bortezomib has shown a positive clinical benefit either alone
or as a part of combination therapy to induce chemo-/radio-sensitization or
overcome drug resistance. One of the major mechanisms of bortezomib associated
with its anticancer activity is through upregulation of NOXA, which is a
proapoptotic protein, and NOXA may interact with the anti-apoptotic proteins of
Bcl-2 subfamily Bcl-X(L) and Bcl-2, and result in apoptotic cell death in
maligt cells. Another important mechanism of bortezomib is through
suppression of the NF-κB signaling pathway resulting in the down-regulation of
its anti-apoptotic target genes. Although the majority of success achieved with
bortezomib has been in hematological maligcies, its effect toward solid
tumors has been less than encouraging. Additionally, the widespread clinical use
of bortezomib continues to be hampered by the appearance of dose-limiting
toxicities, drug-resistance and interference by some natural compounds. These
findings could help guide physicians in refining the clinical use of bortezomib,
and encourage basic scientists to generate next generation proteasome inhibitors
that broaden the spectrum of efficacy and produce a more durable clinical
response in cancer patients. Other desirable applications for the use of
proteasome inhibitors include the development of inhibitors against specific E3
ligases, which act at an early step in the ubiquitin-proteasome pathway, and the
discovery of less toxic and novel proteasome inhibitors from natural products
and traditional medicines, which may provide more viable drug candidates for
cancer chemoprevention and the treatment of cancer patients in the future. The proteasome inhibitor bortezomib, registered for Multiple Myeloma treatment,
is currently explored for activity in solid tumors including non-small cell lung
cancer (NSCLC). Here we studied the proteasome-based mechanisms underlying
intrinsic and acquired bortezomib resistance in NSCLC cells. Various NSCLC cell
lines displayed differential intrinsic sensitivities to bortezomib. High basal
chymotrypsin- and caspase-like proteasome activities correlated with bortezomib
resistance in these cells. Next, via stepwise selection, acquired bortezomib
resistant cells were obtained with 8-70-fold increased resistance.
Cross-resistance was found to proteasome inhibitors specifically targeting
β-subunits, but not to the novel α-subunit-specific proteasome inhibitor (5AHQ).
Consistently, bortezomib-resistant cells required higher bortezomib
concentrations to induce G2/M arrest and apoptosis. Interestingly, bortezomib
concentration-dependent caspase cleavage, Mcl-1 and NOXA accumulation remained
intact in resistant H460 and SW1573 cells, while A549 resistant cells displayed
different expression profiles suggesting additional and more protein specific
adaptations. Furthermore, bortezomib-resistant cells exhibited increased levels
of both constitutive and immuno-β-subunits. Sequence analysis of the
bortezomib-binding pocket in the β5-subunit revealed Ala49Thr, Met45Val and
Cys52Phe substitutions that were not previously described in solid tumors.
Bortezomib-resistant cells displayed reduced catalytic proteasome activities and
required higher bortezomib concentrations to achieve comparable inhibition of
proteasome activity. Taken together, these findings establish that high basal
levels of proteasome activity correlate with intrinsic bortezomib resistance.
Furthermore, acquired bortezomib resistance in NSCLC is associated with
proteasome subunit overexpression and emergence of mutant β5-subunits that
likely compromise bortezomib binding. α-Subunit-specific proteasome inhibitors,
however, can efficiently bypass this resistance modality. Bortezomib (Velcade™) is a reversible proteasome inhibitor that is approved for
the treatment of multiple myeloma (MM). Despite its demonstrated clinical
success, some patients are deprived of treatment due to primary refractoriness
or development of resistance during therapy. To investigate the role of the
duration of proteasome inhibition in the anti-tumor response of bortezomib, we
established clonal isolates of HT-29 adenocarcinoma cells adapted to continuous
exposure of bortezomib. These cells were ~30-fold resistant to bortezomib. Two
novel and distinct mutations in the β5 subunit, Cys63Phe, located distal to the
binding site in a helix critical for drug binding, and Arg24Cys, found in the
propeptide region were found in all resistant clones. The latter mutation is a
natural variant found to be elevated in frequency in patients with MM.
Proteasome activity and levels of both the constitutive and immunoproteasome
were increased in resistant cells, which correlated to an increase in subunit
gene expression. These changes correlated with a more rapid recovery of
proteasome activity following brief exposure to bortezomib. Increased recovery
rate was not due to increased proteasome turnover as similar findings were seen
in cells co-treated with cycloheximide. When we exposed resistant cells to the
irreversible proteasome inhibitor carfilzomib we noted a slower rate of recovery
of proteasome activity as compared to bortezomib in both parental and resistant
cells. Importantly, carfilzomib maintained its cytotoxic potential in the
bortezomib resistant cell lines. Therefore, resistance to bortezomib, can be
overcome with irreversible inhibitors, suggesting prolonged proteasome
inhibition induces a more potent anti-tumor response. In eukaryotic cells, degradation of most intracellular proteins is carried out
by the ubiquitin-proteasome pathway. Recent investigations suggest that bone
metabolism is also regulated by this pathway. The clinical efficacy of
bortezomib, a 26S proteasome inhibitor used as an anticancer drug, has been
linked to an increase in bone formation. In this study, we show that proteasome
inhibitors induce expression of osteoblastic differentiation-related genes such
as osteocalcin and alkaline phosphatase in C2C12 cells. In contrast, myogenic
differentiation is inhibited. Among the proteasome inhibitors tested, bortezomib
induced the greatest increase in osteocalcin expression. Although these effects
were similar to that of bone morphogenetic protein (BMP) 2, proteasome
inhibitors did not induce transcriptional activity of Smad1/4-dependent reporter
or BMP2 signaling target gene expression. Transient transfection of osteocalcin
promoter-luciferase constructs with bortezomib resulted in an increase in
luciferase activity. Mutation of OSE2, but not OSE1, sites of the osteocalcin
promoter diminished the bortezomib-induced activity. Also, Runx2 binding
activity and protein levels were induced by bortezomib treatment. These results
suggest that the bortezomib induces osteoblastic differentiation by modifying
the activity of Runx2 and that the function of the proteasome in controlling
degradation of differentiation-related transcription factors plays an important
role in osteoblast differentiation. The proteasome inhibitor Bortezomib is used to treat multiple myeloma (MM).
Bortezomib inhibits protein degradation by inactivating proteasomes'
active-sites. MM cells are exquisitely sensitive to Bortezomib - exhibiting a
low-omolar IC(50) - suggesting that minimal inhibition of degradation
suffices to kill MM cells. Instead, we report, a low Bortezomib concentration,
contrary to expectation, achieves severe inhibition of proteasome activity in MM
cells: the degree of inhibition exceeds what one would expect from the small
proportion of active-sites that Bortezomib inhibits. Our data indicate that
Bortezomib achieves this severe inhibition by triggering secondary changes in
proteasome structure that further inhibit proteasome activity. Comparing MM
cells to other, Bortezomib-resistant, cancer cells shows that the degree of
proteasome inhibition is the greatest in MM cells and only there leads to
proteasome stress, providing an explanation for why Bortezomib is effective
against MM but not other cancers. The proteasome-inhibitor bortezomib was introduced into the treatment of
multiple myeloma more than a decade ago. It is clinically beneficial, but
peripheral neuropathy (PNP) is a side effect that may limit its use in some
patients. To examine the possible genetic predisposing factors to PNP, we
performed a genome-wide association study on 646 bortezomib-treated German
multiple myeloma patients. Our aim was to identify genetic risk variants
associated with the development of PNP as a serious side effect of the
treatment. We identified 4 new promising loci for bortezomib-induced PNP at
4q34.3 (rs6552496), 5q14.1 (rs12521798), 16q23.3 (rs8060632), and 18q21.2
(rs17748074). Even though the results did not reach genome-wide significance
level, they support the idea of previous studies, suggesting a genetic basis for
neurotoxicity. The identified single nucleotide polymorphisms map to genes or
next to genes involved in the development and function of the nervous system
(CDH13, DCC, and TENM3). As possible functional clues, 2 of the variants,
rs12521798 and rs17748074, affect enhancer histone marks in the brain. The
rs12521798 may also impact expression of THBS4, which affects specific signal
trasduction pathways in the nervous system. Further research is needed to
clarify the mechanism of action of the identified single nucleotide
polymorphisms in the development of drug-induced PNP and to functionally
validate our in silico predictions. Bone atrophy and its related fragility fractures are frequent, late side effects
of radiotherapy in cancer survivors and have a detrimental impact on their
quality of life. In another study, we showed that parathyroid hormone 1-34 and
anti-sclerostin antibody attenuates radiation-induced bone damage by
accelerating DNA repair in osteoblasts. DNA damage responses are partially
regulated by the ubiquitin proteasome pathway. In the current study, we examined
whether proteasome inhibitors have similar bone-protective effects against
radiation damage. MG132 treatment greatly reduced radiation-induced apoptosis in
cultured osteoblastic cells. This survival effect was owing to accelerated DNA
repair as revealed by γH2AX foci and comet assays and to the up-regulation of
Ku70 and DNA-dependent protein kinase, catalytic subunit, essential DNA repair
proteins in the nonhomologous end-joining pathway. Administration of bortezomib
(Bzb) reversed the loss of trabecular bone structure and strength in mice at 4
wk after focal radiation. Histomorphometry revealed that Bzb significantly
increased the number of osteoblasts and activity in the irradiated area and
suppressed the number and activity of osteoclasts, regardless of irradiation.
Two weeks of Bzb treatment accelerated DNA repair in bone-lining osteoblasts and
thus promoted their survival. Meanwhile, it also inhibited bone marrow
adiposity. Taken together, we demonstrate a novel role of proteasome inhibitors
in treating radiation-induced osteoporosis.-Chandra, A., Wang, L., Young, T.,
Zhong, L., Tseng, W.-J., Levine, M. A., Cengel, K., Liu, X. S., Zhang, Y.,
Pignolo, R. J., Qin, L. Proteasome inhibitor bortezomib is a novel therapeutic
agent for focal radiation-induced osteoporosis. Viruses commandeer host cell 26S proteasome activity to promote viral entry,
gene expression, replication, assembly, and egress. Proteasomal degradation
activity is critical for herpes simplex virus (HSV) infection. The proteasome
inhibitor bortezomib (also known as Velcade and PS-341) is a clinically
effective antineoplastic drug that is FDA approved for treatment of hematologic
maligcies such as multiple myeloma and mantle cell lymphoma. Low omolar
concentrations of bortezomib inhibited infection by HSV-1, HSV-2, and
acyclovir-resistant strains. Inhibition coincided with minimal cytotoxicity.
Bortezomib did not affect attachment of HSV to cells or inactivate the virus
directly. Bortezomib acted early in HSV infection by perturbing two distinct
proteasome-dependent steps that occur within the initial hours of infection: the
transport of incoming viral nucleocapsids to the nucleus and the virus-induced
disruption of host nuclear domain 10 (ND10) structures. The combination of
bortezomib with acyclovir demonstrated synergistic inhibitory effects on HSV
infection. Thus, bortezomib is a novel potential therapeutic for HSV with a
defined mechanism of action.IMPORTANCE Viruses usurp host cell functions to
advance their replicative agenda. HSV relies on cellular proteasome activity for
successful infection. Proteasome inhibitors, such as MG132, block HSV infection
at multiple stages of the infectious cycle. Targeting host cell processes for
antiviral intervention is an unconventional approach that might limit antiviral
resistance. Here we demonstrated that the proteasome inhibitor bortezomib, which
is a clinically effective cancer drug, has the in vitro features of a promising
anti-HSV therapeutic. Bortezomib inhibited HSV infection during the first hours
of infection at omolar concentrations that were minimally cytotoxic. The
mechanism of bortezomib's inhibition of early HSV infection was to halt
nucleocapsid transport to the nucleus and to stabilize the ND10 cellular defense
complex. Bortezomib and acyclovir acted synergistically to inhibit HSV
infection. Overall, we present evidence for the repurposing of bortezomib as a
novel antiherpesviral agent and describe specific mechanisms of action. |
Is PRDM9 essential for meiosis? | PRDM9 is essential for the progression through early meiotic prophase, including double strand break repair, homologous chromosome pairing, and sex body formation during spermatogenesis. | The onset of prezygotic and postzygotic barriers to gene flow between
populations is a hallmark of speciation. One of the earliest postzygotic
isolating barriers to arise between incipient species is the sterility of the
heterogametic sex in interspecies' hybrids. Four genes that underlie hybrid
sterility have been identified in animals: Odysseus, JYalpha, and Overdrive in
Drosophila and Prdm9 (Meisetz) in mice. Mouse Prdm9 encodes a protein with a
KRAB motif, a histone methyltransferase domain and several zinc fingers. The
difference of a single zinc finger distinguishes Prdm9 alleles that cause hybrid
sterility from those that do not. We find that concerted evolution and positive
selection have rapidly altered the number and sequence of Prdm9 zinc fingers
across 13 rodent genomes. The patterns of positive selection in Prdm9 zinc
fingers imply that rapid evolution has acted on the interface between the Prdm9
protein and the DNA sequences to which it binds. Similar patterns are apparent
for Prdm9 zinc fingers for diverse metazoans, including primates. Indeed,
allelic variation at the DNA-binding positions of human PRDM9 zinc fingers show
significant association with decreased risk of infertility. Prdm9 thus plays a
role in determining male sterility both between species (mouse) and within
species (human). The recurrent episodes of positive selection acting on Prdm9
suggest that the DNA sequences to which it binds must also be evolving rapidly.
Our findings do not identify the nature of the underlying DNA sequences, but
argue against the proposed role of Prdm9 as an essential transcription factor in
mouse meiosis. We propose a hypothetical model in which incompatibilities
between Prdm9-binding specificity and satellite DNAs provide the molecular basis
for Prdm9-mediated hybrid sterility. We suggest that Prdm9 should be
investigated as a candidate gene in other instances of hybrid sterility in
metazoans. Homologous recombination is required for proper segregation of homologous
chromosomes during meiosis. It occurs predomitly at recombination hotspots
that are defined by the DNA binding specificity of the PRDM9 protein. PRDM9
contains three conserved domains typically involved in regulation of
transcription; yet, the role of PRDM9 in gene expression control is not clear.
Here, we analyze the germline transcriptome of Prdm9-/- male mice in comparison
to Prdm9+/+ males and find no apparent differences in the mRNA and miRNA
profiles. We further explore the role of PRDM9 in meiosis by analyzing the
effect of the KRAB, SSXRD, and post-SET zinc finger deletions in a cell culture
expression system and the KRAB domain deletion in mice. We found that although
the post-SET zinc finger and the KRAB domains are not essential for the
methyltransferase activity of PRDM9 in cell culture, the KRAB domain mutant mice
show only residual PRDM9 methyltransferase activity and undergo meiotic arrest.
In aggregate, our data indicate that domains typically involved in regulation of
gene expression do not serve that role in PRDM9, but are likely involved in
setting the proper chromatin environment for initiation and completion of
homologous recombination. During meiosis, maternal and paternal chromosomes undergo exchanges by
homologous recombination. This is essential for fertility and contributes to
genome evolution. In many eukaryotes, sites of meiotic recombination, also
called hotspots, are regions of accessible chromatin, but in many vertebrates,
their location follows a distinct pattern and is specified by PR
domain-containing protein 9 (PRDM9). The specification of meiotic recombination
hotspots is achieved by the different activities of PRDM9: DNA binding, histone
methyltransferase, and interaction with other proteins. Remarkably, PRDM9
activity leads to the erosion of its own binding sites and the rapid evolution
of its DNA-binding domain. PRDM9 may also contribute to reproductive isolation,
as it is involved in hybrid sterility potentially due to a reduction of its
activity in specific heterozygous contexts. |
What is particular about the mouse Fxy gene's chromosomal position? | We have previously described a gene, Fxy , that spans the pseudoautosomal boundary in mice such that the first three exons of the gene are located on the X chromosome, but the remainder of the gene is located on both X and Y chromosomes. The Fxy gene in mice is also located on the X chromosome but spans the pseudoautosomal boundary in this species. | Genes evolve at different rates depending on the strength of selective pressure
to maintain their function. Chromosomal position can also have an influence [1]
[2]. The pseudoautosomal region (PAR) of mammalian sex chromosomes is a small
region of sequence identity that is the site of an obligatory pairing and
recombination event between the X and Y chromosomes during male meiosis [3] [4]
[5] [6]. During female meiosis, X chromosomes can pair and recombine along their
entire length. Recombination in the PAR is therefore approximately 10 times
greater in male meiosis compared with female meiosis [4] [5] [6]. The gene Fxy
(also known as MID1 [7]) spans the pseudoautosomal boundary (PAB) in the
laboratory mouse (Mus musculus domesticus, C57BL/6) such that the 5' three exons
of the gene are located on the X chromosome but the seven exons encoding the
carboxy-terminal two-thirds of the protein are located within the PAR and are
therefore present on both the X and Y chromosomes [8]. In humans [7] [9], the
rat, and the wild mouse species Mus spretus, the gene is entirely X-unique.
Here, we report that the rate of sequence divergence of the 3' end of the Fxy
gene is much higher (estimated at 170-fold higher for synonymous sites) when
pseudoautosomal (present on both the X and Y chromosomes) than when X-unique.
Thus, chromosomal position can directly affect the rate of evolution of a gene.
This finding also provides support for the suggestion that regions of the genome
with a high recombination frequency, such as the PAR, may have an intrinsically
elevated rate of sequence divergence. Opitz G/BBB syndrome (OS) is a genetically heterogeneous disorder with an
X-linked locus and an autosomal locus linked to 22q11.2. OS affects multiple
organ systems with often variable severity even between siblings. The clinical
features, which include hypertelorism, cleft lip and palate, defects of cardiac
septation, hypospadias, and anorectal anomalies, indicate an underlying
disturbance of the developing ventral midline of the embryo. The gene
responsible for X-linked OS, FXY/MID1, is located on the short arm of the human
X chromosome within Xp22.3 and encodes a protein with both an RBCC (RING finger,
B-box, coiled coil) and a B30.2 domain. The Fxy gene in mice is also located on
the X chromosome but spans the pseudoautosomal boundary in this species. Here we
describe a gene closely related to FXY/MID1, called FXY2, which also maps to the
X chromosome within Xq22. The mouse Fxy2 gene is located on the distal part of
the mouse X chromosome within a region syntenic to Xq22. Analysis of genes
flanking both FXY/MID1 and FXY2 (as well as their counterparts in mouse)
suggests that these regions may have arisen as a result of an intrachromosomal
duplication on an ancestral X chromosome. We have also identified in both FXY2
and FXY/MID1 proteins a conserved fibronectin type III domain located between
the RBCC and B30.2 domains that has implications for understanding protein
function. The FXY/MID1 protein has previously been shown to colocalize with
microtubules, and here we show that the FXY2 protein similarly associates with
microtubules in a manner that is dependent on the carboxy-terminal B30.2 domain. |
Should Pentoxifylline be used for treatment of amyotrophic lateral sclerosis? | No. Pentoxifylline is not beneficial in amyotrophic lateral sclerosis and should be avoided in patients treated with riluzole. | OBJECTIVE: To assess the efficacy and safety of pentoxifylline, a US Food and
Drug Administration-approved drug, in patients with ALS treated with riluzole.
METHODS: The authors conducted a double-blind, randomized, placebo-controlled,
multicenter trial. Four hundred patients with probable or definite ALS and vital
capacity less than 100% were randomly assigned to treatment with placebo or 1.2
g pentoxifylline daily. The primary outcome was death. Secondary outcomes were
rates of deterioration of ALS Functional Rating Scale-Respiratory and muscle
strength. The primary intention-to-treat analysis was the survival comparison of
drug vs placebo, assessed before (log-rank test) and after adjustment (Cox
model) for predefined prognostic factors.
RESULTS: At the end of the study, after 547 days of follow-up, 103 patients
(51.7%) in the pentoxifylline group and 120 (59.7%) in the placebo group were
alive (unadjusted risk 1.28, p = 0.107; adjusted risk 1.43, p = 0.02). In
contrast, analysis of secondary outcome functional variables did not show the
same negative effect of the drug. The most common adverse reactions were nausea,
dysphagia, and flushing, all reversible after stopping the drug.
CONCLUSIONS: Pentoxifylline is not beneficial in ALS and should be avoided in
patients treated with riluzole. The discrepancy between survival and measures of
functional changes urges caution in equating these end points in phase III
trials, and suggests that both survival and function should be used in phase III
trials. |
What does a PET (Positron Excitation Tomography) measure? | Positron Excitation Tomography (PET) is a simple, reliable, and valid method of assessing brain activity in patients with Parkinson's disease (PD). | We used positron emission tomography to measure hippocampal and medial temporal
lobe metabolism in brains of patients intoxicated by domoic acid from Prince
Edward Island mussels. This analog of kainic acid specifically excites certain
neurons in the hippocampus, and the study revealed a severe reduction of glucose
metabolism in this part of the brain which paralleled the absence of long-,
medium-, or short-term memory in these patients. Positron emission tomography (PET) allows the quantitative measurement of
regional cerebral flow (rCBF) in humans in quantitative terms. Gross changes in
rCBF are due to variation in vessel diameter. Changes of rCBF also reflect
synaptic activity (inhibition and excitation). Therefore, PET was used to
monitor changes in blood flow during the aura and headache phase of a migraine
attack and to investigate focal areas of increased or decreased blood flow,
e.g., in the brain stem and midbrain. Hemispheric rCBF was unchanged in
spontaneous migraine attacks without aura. This was true for the headache side
as well as for the nonheadache side. Sumatriptan had no effects on cerebral
blood flow. Regional cerebral blood flow was increased in midline brain stem
structures during the headache phase, but also when the headache had been
treated with sumatriptan. This persisting increased activity might reflect
activity of a presumed migraine center in the brain stem. These changes are
specific for migraine attacks and are not seen during attacks of cluster
headache. Positron emission tomography measurements in the early phase of a
migraine attack in a single subject showed flow reductions in the occipital
cortex spreading forwards; an observation which would be compatible with the
existence of spreading depression in humans. Our attempts to study the aura
phase with PET have, to date, been unsuccessful. |
Is the CADM2 gene associated with differences in information processing speed? | Yes, genetic variation in the CADM2 gene is associated with individual differences in information processing speed. | Author information:
(1)Genetic Epidemiology Unit, Department of Epidemiology, Erasmus University
Medical Center, Rotterdam, The Netherlands.
(2)Department of Neurology, Erasmus University Medical Center, Rotterdam, The
Netherlands.
(3)Geriatric Unit, Azienda Sanitaria Firenze (ASF), Florence, Italy.
(4)Human Genetics Center, School of Public Health, University of Texas Health
Science Center at Houston, Houston, TX, USA.
(5)Department of Neurology, Boston University School of Medicine, Boston, MA,
USA.
(6)Institut National de la Santé et de la Recherche Médicale (INSERM), U897,
Epidemiology and Biostatistics, University of Bordeaux, Bordeaux, France.
(7)Department of Neurology, Bordeaux University Hospital, Bordeaux, France.
(8)Icelandic Heart Association, Kopavogur, Iceland.
(9)Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
(10)Cardiovascular Health Research Unit, Department of Medicine, University of
Washington, Seattle, WA, USA.
(11)Centre for Cognitive Ageing and Cognitive Epidemiology, The University of
Edinburgh, Edinburgh, UK.
(12)Department of Cardiology, Leiden University Medical Center, Leiden, The
Netherlands.
(13)Department of Gerontology and Geriatrics, Leiden University Medical Center,
Leiden, The Netherlands.
(14)Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA.
(15)RG Statistical Genetics, Max Planck Institute of Psychiatry, Munich,
Germany.
(16)Program in Translational Neuropsychiatric Genomics, Department of Neurology,
Brigham and Women's Hospital, Boston, MA, USA.
(17)Department of Epidemiology, Wake Forest School of Medicine, Winston-Salem,
NC, USA.
(18)MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, UK.
(19)Centre for Population Health Sciences, University of Edinburgh, Edinburgh,
UK.
(20)Department of Neurology, Medical University and General Hospital of Graz,
Graz, Austria.
(21)Department of Public Health, University of Split, Split, Croatia.
(22)Department of Public Health and Primary Care, Trinity College Dublin,
Dublin, Ireland.
(23)Institute of Neuroscience and Medicine (INM -1), Research Center Juelich,
Juelich, Germany.
(24)Division of Medical Genetics, Department of Biomedicine, University of
Basel, Basel, Switzerland.
(25)Department of Genomics, Life and Brain Research Center, Institute of Human
Genetics, University of Bonn, Bonn, Germany.
(26)Department of Genetics, University Medical Centre Groningen, University of
Groningen, Groningen, The Netherlands.
(27)Institute of Behavioural Sciences, University of Helsinki, Helsinki,
Finland.
(28)Folkhälsan Research Centre, Helsinki, Finland.
(29)Institute of Biomedical and Clinical Sciences, University of Exeter Medical
School, Exeter, UK.
(30)Institute for Community Medicine, University Medicine Greifswald,
Greifswald, Germany.
(31)Centre for Healthy Brain Ageing, School of Psychiatry, UNSW Medicine,
University of New South Wales, Sydney, Australia.
(32)Inserm, U1167, Institut Pasteur de Lille, Université Lille-Nord de France,
Lille, France.
(33)Channing Division of Network Medicine, Department of Medicine, Brigham and
Women's Hospital and Harvard Medical School, Boston, MA, USA.
(34)Laboratory of Behavioral Neuroscience, National Institute on Aging, NIH,
Baltimore, MD, USA.
(35)Division of Preventive Medicine, Brigham and Women's Hospital, Boston, MA,
USA.
(36)Hunter Medical Research Institute and Faculty of Health, University of
Newcastle, Newcastle, NSW, Australia.
(37)Medical Research Institute, University of Dundee, Dundee, UK.
(38)The National Heart Lung and Blood Institute's Framingham Heart Study,
Framingham, MA, USA.
(39)Department of Biostatistics, Boston University School of Public Health,
Boston, MA, USA.
(40)Department of Epidemiology, Erasmus University Medical Center, Rotterdam,
The Netherlands.
(41)Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands.
(42)Laboratory of Epidemiology and Population Sciences, National Institute on
Aging, Bethesda, MD, USA.
(43)Department of Psychology, University of Edinburgh, Edinburgh, UK.
(44)Division of Public Health Sciences and Neurology, Wake Forest School of
Medicine, Winston-Salem, NC, USA.
(45)Max Planck Institute for Developmental Biology, Max Planck Institute for
Intelligent Systems, Tübingen, Germany.
(46)Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
(47)Interfaculty Institute for Genetics and Functional Genomics, University
Medicine Greifswald, Greifswald, Germany.
(48)Robertson Center for biostatistics, University of Glasgow, Glasgow, UK.
(49)Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
(50)Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
(51)Landspitali Hospital, Reykjavik, Iceland.
(52)Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD, USA.
(53)Division of Nephrology and Hypertension, Department of Internal Medicine,
Mayo Clinic, Rochester, MN, USA.
(54)Departments of Psychiatry, Neurology and Epidemiology, University of
California, San Francisco and San Francisco VA Medical Center, San Francisco,
CA, USA.
(55)Department of Neurology, Mayo Clinic, Rochester, MN, USA.
(56)Department of Medicine, Division of Geriatrics, University of Mississippi
Medical Center, Jackson, MS, USA.
(57)Department of Epidemiology, Gillings School of Global Public Health,
University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
(58)School of Medicine and Public Health, Faculty of Health, University of
Newcastle, Newcastle, SW, Australia.
(59)Translational Gerontology Branch, National Institute on Aging, Baltimore,
MD, USA.
(60)Department of Cardiovascular and Medical Sciences, University of Glasgow,
Glasgow, UK.
(61)Alzheimer Scotland Research Centre, Edinburgh, UK.
(62)Division of Applied Medicine, University of Aberdeen, Aberdeen, UK.
(63)Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW,
Australia.
(64)School of Mathematics & Statistics and Prince of Wales Clinical School,
University of New South Wales, Sydney, NSW, Australia.
(65)Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
(66)Department of Molecular and Human Genetics, The Jan and Dan Duncan
Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
(67)Epidemiology and Public Health Group, University of Exeter Medical School,
Exeter, UK.
(68)Neuropsychiatric Institute, The Prince of Wales Hospital, Sydney, NSW,
Australia.
(69)Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge,
UK.
(70)Institute for Molecular Medicine Finland (FIMM), University of Helsinki,
Helsinki, Finland.
(71)Department of Medical Genetics, University of Helsinki and University
Central Hospital, Helsinki, Finland.
(72)School of Public Health, Taipei Medical University, Taipei, Taiwan.
(73)Department of General Practice and Primary Health Care, University of
Helsinki, Helsinki, Finland.
(74)National Institute for Health and Welfare, Helsinki, Finland.
(75)Helsinki University Central Hospital, Unit of General Practice, Helsinki,
Finland.
(76)Vasa Central Hospital, Vasa, Finland.
(77)Center of Biostatistics and Bioinformatics, University of Mississippi
Medical Center, Jackson, MS, USA.
(78)Department of Neurology, Johns Hopkins University School of Medicine,
Baltimore, MD, USA.
(79)Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago,
IL, USA.
(80)Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA,
USA.
(81)Institute for Translational Genomics and Population Sciences, Los Angeles
BioMedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
(82)Division of Genetic Outcomes, Department of Pediatrics, Harbor-UCLA Medical
Center, Torrance, CA, USA.
(83)German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
(84)Department of Molecular Epidemiology, Leiden University Medical Center,
Leiden, The Netherlands.
(85)Leiden Academy of Vitality and Ageing, Leiden, The Netherlands.
(86)Department of Pharmacology and Therapeutics, University College Cork, Cork,
Ireland.
(87)Department of Internal Medicine, Erasmus University Medical Center,
Rotterdam, The Netherlands.
(88)Department of Epidemiology, University of Washington, Seattle, WA, USA.
(89)Department of Health Services, University of Washington, Seattle, WA, USA.
(90)Group Health Research Institute, Group Health, Seattle, WA, USA.
(91)Department of Psychiatry and Psychotherapy, University Medicine Greifswald,
HELIOS-Hospital Stralsund, Stralsund, Germany.
(92)Centre for Genomic and Experimental Medicine, Institute of Genetics and
Molecular Medicine, University of Edinburgh, Edinburgh, UK.
(93)Institute of Neuroscience and Medicine (INM-1), Research Center Juelich,
Juelich, Germany.
(94)Department of Internal Medicine, Wake Forest University School of Medicine,
Winston-Salem, NC, USA.
(95)Institute for Molecular Medicine and Human Genetics Center, University of
Texas Health Science Center at Houston, Houston, TX, USA.
(96)Department of Radiology, Erasmus University Medical Center, Rotterdam, The
Netherlands.
(97)Department of Medicine and Neurology, University of Mississippi Medical
Center, Jackson, MS, USA.
(#)Contributed equally |
What is GeneCodeq? | The exponential reduction in cost of genome sequencing has resulted in a rapid growth of genomic data. Most of the entropy of short read data lies not in the sequence of read bases themselves but in their Quality Scores-the confidence measurement that each base has been sequenced correctly. Lossless compression methods are now close to their theoretical limits and hence there is a need for lossy methods that further reduce the complexity of these data without impacting downstream analyses. GeneCodeq is a Bayesian method inspired by coding theory for adjusting quality scores to improve the compressibility of quality scores without adversely impacting genotyping accuracy. | |
Is Nivolumab (Opdivo) a PD-L1 inhibitor? | No, Nivolumab (Opdivo) is a PD-1 inhibitor. | Nivolumab (Opdivo(®); Nivolumab BMS™) was the first programmed death (PD)-1
immune checkpoint inhibitor to be approved for use in advanced, squamous
non-small cell lung cancer (NSCLC) following prior chemotherapy. In the pivotal
CheckMate 017 trial, intravenous nivolumab 3 mg/kg every 2 weeks was associated
with significantly better overall survival and progression-free survival and a
significantly higher overall response rate than intravenous docetaxel in the
second-line treatment of advanced, squamous NSCLC. Nivolumab was also better
tolerated than docetaxel in CheckMate 017, and its adverse event profile (which
included immune-mediated adverse events) was manageable. In conclusion,
nivolumab represents an important advance in previously-treated, advanced,
squamous NSCLC. Until recently, the prognosis and treatment of patients with advanced-stage
squamous cell lung cancers have been limited. An improvement in the
understanding of the role of the immune system in tumor immunosurveillance has
led to the development of the programmed death-1 (PD-1) immune checkpoint
inhibitor nivolumab (Opdivo). Nivolumab is the first PD-1 inhibitor approved for
the treatment of advanced-stage squamous cell non-small-cell lung cancer
following platinum-based chemotherapy. In the key Phase III trial CHECKMATE 017,
a better overall survival and progression-free survival were seen in patients
treated with second-line nivolumab compared with docetaxel. Programmed death
ligand-1 (PD-L1) expression did not predict for outcome. In addition, nivolumab
had better safety and tolerability, and led to better patient reported outcomes.
Further research on the role of PD-L1 expression as a predictive biomarker
should be performed, and other biomarkers that can predict the efficacy of
PD-1/PD-L1 inhibitors should also be pursued. Further studies on the combination
treatment are ongoing to determine the optimal role of nivolumab as monotherapy
or nivolumab with other agents in non-small-cell lung cancer. OBJECTIVE: To investigate the question of whether salvage therapy with the
programmed cell death protein 1 (PD-1)-blocking antibodies nivolumab or
pembrolizumab with or without bevacizumab offers clinical or survival benefit in
patients with recurrent high-grade gliomas (HGGs).
METHODS: This was a single-institution retrospective observational study in 31
adult patients who received pembrolizumab (Keytruda) or nivolumab (Opdivo) with
or without concurrent bevacizumab for recurrent high-grade glioma.
RESULTS: Median progression-free survival (mPFS) from first anti-PD-1 dose was
3.2 months (95% confidence interval [CI] 2.2-4.2), and there was no difference
in patients receiving nivolumab (mPFS 3.8 months, 95% CI 1.7-5.8) compared to
patients receiving pembrolizumab (mPFS 2.3 months, 95% CI 1.7-2.8, log rank 3.1,
p = 0.08). There was also no difference in mPFS if patients had previously
received bevacizumab (mPFS 3.2 months, 95% CI 2-4.3) or were bevacizumab naive
(mPFS 3.7, 95% CI 0-7.9, log rank 1.3, p = 0.3). The median survival from date
of first anti-PD-1 dose was 6.6 months (95% CI 4.2-9.1).
CONCLUSION: Salvage therapy with nivolumab or pembrolizumab with or without
bevacizumab does not confer a survival benefit in this heavily pretreated
unselected patient population. Until the results of the currently ongoing
clinical trials become available, the use of PD-1-blocking antibodies should be
considered in selected individuals only.
CLASSIFICATION OF EVIDENCE: This retrospective observational study provides
Class IV evidence that for patients with recurrent HGGs, salvage therapy with
nivolumab or pembrolizumab does not significantly improve survival. |
Does clinical trial data support the use of minocycline for amyotrophic lateral sclerosis? | No. Available clinical trial data suggest that minocycline does not improve prognosis and functional status, and has a harmful effect on patients with amyotrophic lateral sclerosis. | Two double-blind, randomized, placebo-controlled feasibility trials of
minocycline in ALS were conducted. In Trial 1, 19 subjects received 200 mg/day
or placebo for 6 months; there were no significant differences in adverse events
(AE). In Trial 2, 23 subjects received up to 400 mg/day in an 8-month crossover
trial. The mean tolerated dose was 387 mg/day, there was a trend toward more
gastrointestinal AE (p = 0.057), and blood urea nitrogen and liver enzymes
became elevated (p < 0.05). Using these data, the authors have designed and
launched a phase III trial. Recent studies indicate that minocycline exerts neuroprotective effects in vitro
and in vivo, and suggest that the drug may represent a novel therapeutic
approach to amyotrophic lateral sclerosis (ALS). In this study we investigated
the safety of combined treatment with minocycline and riluzole in ALS. Twenty
ALS patients were randomised into two groups and administered either riluzole
(50 mg b.i.d.) or riluzole and minocycline (100 mg i.d.) for 6 months. Disease
progression was measured by means of the ALS-Functional Rating Scale score at
monthly intervals. Respiratory function was measured at the beginning of the
study and repeated after 3 and 6 months of treatment. Combined treatment with
minocycline and riluzole was not followed by significant side effects. This
pilot study shows that minocycline and riluzole can be taken safely together.
Further trials are needed to assess efficacy of such treatment. BACKGROUND: Minocycline has anti-apoptotic and anti-inflammatory effects in
vitro, and extends survival in mouse models of some neurological conditions.
Several trials are planned or are in progress to assess whether minocycline
slows human neurodegeneration. We aimed to test the efficacy of minocycline as a
treatment for amyotrophic lateral sclerosis (ALS).
METHODS: We did a multicentre, randomised placebo-controlled phase III trial.
After a 4-month lead-in phase, 412 patients were randomly assigned to receive
placebo or minocycline in escalating doses of up to 400 mg/day for 9 months. The
primary outcome measure was the difference in rate of change in the revised ALS
functional rating scale (ALSFRS-R). Secondary outcome measures were forced vital
capacity (FVC), manual muscle testing (MMT), quality of life, survival, and
safety. Analysis was by intention to treat. This trial is registered with
ClinicalTrials.gov, number NCT00047723.
FINDINGS: ALSFRS-R score deterioration was faster in the minocycline group than
in the placebo group (-1.30 vs -1.04 units/month, 95% CI for difference -0.44 to
-0.08; p=0.005). Patients on minocycline also had non-significant tendencies
towards faster decline in FVC (-3.48 vs -3.01, -1.03 to 0.11; p=0.11) and MMT
score (-0.30 vs -0.26, -0.08 to 0.01; p=0.11), and greater mortality during the
9-month treatment phase (hazard ratio=1.32, 95% CI 0.83 to 2.10; p=0.23) than
did patients on placebo. Quality-of-life scores did not differ between the
treatment groups. Non-serious gastrointestinal and neurological adverse events
were more common in the minocycline group than in the placebo group, but these
events were not significantly related to the decline in ALSFRS-R score.
INTERPRETATION: Our finding that minocycline has a harmful effect on patients
with ALS has implications for trials of minocycline in patients with other
neurological disorders, and for how potential neuroprotective agents are
screened for use in patients with ALS. A recent publication of the results of a clinical trial of minocycline in 412
ALS patient has aroused considerable controversy in the ALS scientific
community. As on previous occasions, the results obtained in the laboratory are
not reproduced in clinical practice. The reasons for this new disappointment in
translational medicine are analysed by applying the successes obtained in the
experimental animal model for ALS to humans. The most frequently suggested
causes for explaining these continuous failures are unawareness of the correct
dosage to be used, the ideal duration of the clinical trial in phase III, sample
size, the search for a primary outcome for measurement other than survival, the
need for biomarkers giving information on the progression of the disease and
whether this is modified by the introduction of the drug for study. Debate
focuses on whether the transgenic mouse model of ALS which expresses SOD1
mutations which we have been using for more than a decade is an exact reflection
of the clinical profile and the physiopathogenic mechanisms present in patients
with spo- radic ALS. There is the possibility that depending on the dose
administered, minocycline can be a neuroprotector or a neurotoxin. In other
words, at a dose of 200 mg/day, this drug behaves like <<Dr. Jekyll>> and like
<<Mr. Hyde>> at doses of 400 mg. For the authors of the trial, this possibility
does not seem to be the cause of the disappointing results obtained. However,
they acknowledge that one of the limitations of their study was that it was
impossible to compare the effects of minocycline in the patient after receiving
200 or 400 mg. For many other researchers running ongoing clinical trials in
both ALS and other neurological diseases, the dose of 200 mg/day is chosen as
ideal for testing the effectiveness of minocycline in patients. The strategy of
administering the maximum dose of a drug to be tested may give rise to
misleading results. We agree with the opinion of other authors, who say that
minocycline should be given a second chance. |
What are apoptotic bodies? | Extracellular vesicles (EVs) are membrane-bound vesicles released into the extracellular space by almost all types of cells. EVs can cross the physiological barriers, and a variety of biological fluids are enriched in them. EVs are a heterogeneous population of vesicles, including exosomes, microvesicles, and apoptotic bodies.
Apoptotic bodies are generated on apoptotic cell shrinkage and death. | A novel guaiane sesquiterpene derivative, guai-2-en-10α-ol, from Ulva fasciata
Delile exhibits antimicrobial property. U. fasciata extract was reported to
exhibit cytotoxicity against cancer. In the present study, we have studied the
anticancer potential of the compound, guai-2-en-10α-ol, from U. fasciata. The
compound showed selective cytotoxicity toward triple-negative breast cancer
(TNBC) cell line (MDA MB-231) in a dose-dependent manner. In treated cells, the
apoptotic hallmarks such as formation of apoptotic bodies, cell shrinkage, and
nuclear condensation were observed. Many small molecules affect the function of
cellular signaling pathways. As EGFR/PI3K/Akt pathway proteins are frequently
altered in TNBC, we have studied the gene expression of key proteins of this
pathway. The semiquantitative PCR results demonstrated the down-regulated
expression of PDPK1 (positive regulator) and Akt (key activator) as well as
up-regulated expression of PTEN (negative regulator), which suggested the
interaction of guai-2-en-10α-ol with upstream protein. Further investigation
showed the down-regulation of both PI3K and EGFR. As EGFR is the most upstream
protein of the pathway, its protein level expression was investigated. Western
blotting analysis confirmed the down-regulation of p-EGFR expression and
activation of apoptosis upon compound treatment. Cell cycle analysis also
evidenced the G1 phase arrest, which can be due to the inhibition of cell
survival pathway. Computational studies showed the interaction of
guai-2-en-10α-ol with Asp855 residue of EGFR kinase domain in active
conformation. All these results demonstrate the anticancer potential of
guai-2-en-10α-ol through EGFR/PI3K/Akt pathway. Extracellular vesicles are cell-derived membrane particles ranging from 30 to
5,000 nm in size, including exosomes, microvesicles, and apoptotic bodies. They
are released under physiological conditions, but also upon cellular activation,
senescence, and apoptosis. They play an important role in intercellular
communication. Their release may also maintain cellular integrity by ridding the
cell of damaging substances. This review describes the biogenesis, uptake, and
detection of extracellular vesicles in addition to the impact that they have on
recipient cells, focusing on mechanisms important in the pathophysiology of
kidney diseases, such as thrombosis, angiogenesis, tissue regeneration, immune
modulation, and inflammation. In kidney diseases, extracellular vesicles may be
utilized as biomarkers, as they are detected in both blood and urine.
Furthermore, they may contribute to the pathophysiology of renal disease while
also having beneficial effects associated with tissue repair. Because of their
role in the promotion of thrombosis, inflammation, and immune-mediated disease,
they could be the target of drug therapy, whereas their favorable effects could
be utilized therapeutically in acute and chronic kidney injury. Polyphenols are found in plant-derived foods and beverages and display numerous
protective effects against cancers, cardiovascular, metabolic and
neurodegenerative diseases. Extracellular vesicles (EVs), microparticles,
exosomes, and apoptotic bodies, originated by different cell types are emerging
as a novel mean of cell-to-cell communication in physiology and pathology and
represent a new way to convey fundamental information between cells. Polyphenols
can act on signaling pathways that interfere with the biogenesis of EVs. Thus,
they are able to control EV release from cells and their content and therefore
their functional properties. Both EVs and polyphenols are therapeutic tools that
can be used against several diseases. In this context, the combination of both
tools can increase their therapeutic potential. Three types of strategies can be
used: (i) plants are able to produce EVs that encapsulate natural components
from vegetables, polyphenols for instance, (ii) mammalian cells can be treated
with polyphenols and the subsequent EVs produced are enriched in these
components, and (iii) EVs from mammalian cells can be uploaded with polyphenols.
We review the novel aspects of the interplay between polyphenols and EVs that
could trigger and improve the health benefits in cancer, cardiovascular,
metabolic and neurodegenerative diseases. |
Is the drug Exubera currently (March 2020) available? | No, Exubera has been discontinued due to suboptimal market acceptance. | INTRODUCTION: Delivery of therapeutic insulin via the pulmonary route has been
the most investigated non-invasive alternative to the commonly used subcutaneous
(SC) route for diabetes management. Despite discontinuation of the first
inhalable insulin, Exubera®, due to suboptimal market acceptance, development of
orally inhaled insulin delivery systems has been galvanized by the recent
approval of Afrezza® and several others awaiting approval.
AREAS COVERED: The scope of this review article includes the prospects for and
the challenges faced in developing inhaled insulin delivery systems; discussion
of orally inhaled therapeutic insulin delivery systems that were discontinued,
recently approved or are currently under active investigation; and formulation
approaches that have the potential to deliver insulin via the pulmonary route.
EXPERT OPINION: The pulmonary route is the most advantageous route for
non-invasive insulin delivery. Inhalable insulin therapeutics have the potential
to be successful, provided that the formulations can be made with modified
release patterns to substitute for both prandial and basal insulin injections,
the delivery devices are convenient and easy to use, and the long-term safety of
inhaled insulin is documented through extensive studies. |
What is the function of the ISW1 and CHD1 remodellers in yeast chromatin? | eviction of h1 | |
Are breaks in double stranded DNA associated with ionizing radiation? | Yes, double-strand breaks in double stranded DNA may be associated with ionizing radiation risk. | Gamma-ray irradiation introduces single and/or double strand breaks into the DNA
molecule of the cells. In the case of mammalian cells, these breaks are being
repaired in general during the first hr following exposure to ionizing
radiation. The article reports on the results obtained from testing the ability
of cultured lymphocytes from patients with Down's syndrome to repair
radiation-induced DNA single-strand breaks. The ability to repair was deduced
from the study of the DNA sedimentation profiles in alkaline sucrose gradients.
It was found that lymphocytes from Down's syndrome patients are less efficient
in repairing single-strand DNA breaks than are lymphocytes from normal
individuals. This significantly increased fraction of unrepaired DNA strand
breaks might be associated with the unusually high level of radiation-induced
chromosome aberrations as compared with normals. DNA double-strand breaks are considered to be the most deleterious lesion
induced by ionizing radiation. However, the mechanism of rejoining of these
lesions has not been extensively studied at the molecular level. We have used a
shuttle vector, pHAZE, to analyze the mechanism of rejoining of DNA
double-strand breaks in human cells. The advantage of this vector system is
that, unlike many previously described shuttle vectors, it has a large target
gene for the detection of deletions and it is maintained as a freely replicating
episome with chromatin conformation in the nucleus of human cells. In this study
we compare data obtained on the spectrum of mutations induced in pHAZE by
ionizing radiation (alpha-particles) and restriction enzymes (PvuII, ClaI, and
PvuI). Unlike ionizing radiation, restriction enzymes induce double-strand
breaks in DNA with known end structures at defined locations and therefore
provide a model system for analyzing cellular responses to DNA double-strand
breaks. Exposure of human cells containing the vector to alpha-particle
irradiation produced both point mutations and large deletions in pHAZE. When the
junction regions of the deletions were sequenced it was found that 65% were
rejoined with up to 6 bp of homology at the junction region. Analysis of
restriction-enzyme-induced mutations suggests that double-strand break ends are
modified to facilitate rejoining and that the type of modification is
characteristic for different end structures. Double-strand breaks with cohesive
ends appear to have fewer modifications introduced at the break points before
rejoining than breaks with blunt ends. When considered in relation to the data
obtained with ionizing radiation this suggests that the presence of cohesive
sequences either at, or in proximity to, the ends enhances rejoining of DNA
double-strand breaks. Ionizing radiation and radiomimetic drugs such as bleomycin, calichieamycin,
neocarzinostatin chromophore, and other synthetic agents can produce both single
and double strand breaks in DNA. The ability to study the structure-activity
relationships of single and double-strand break repair, lethality, and
mutagenesis in vivo is complicated by the numerous types and sites of DNA
cleavage products that can be induced by such agents. The ability to "cage" such
breaks in DNA might help to further such studies and additionally afford a
mechanism for activating and deactivating nucleic acid based drugs and probes.
The major type of single strand break induced by ionizing radiation is a 3'- and
5'-phosphate terminated single nucleotide gap. Previously, a caged strand break
of this type had been developed that was designed to produce the 5'-phosphate
directly upon irradiation with 366 nm light, and the 3'-phosphate by a
subsequent beta-elimination reaction [Ordoukhanian, P., and Taylor, J.-S. (1995)
J. Am. Chem. Soc. 117, 9570]. Unfortunately, the release of the 3'-phosphate
group was quite slow at pH 7. To circumvent this problem, a second caged strand
break has been developed that produces the 3'-phosphate directly upon
irradiation, and the 5'-phosphate by a subsequent beta-elimination reaction.
When this caged strand break was used in tandem with the previous caged strand
break, 5'- and 3'-phosphate terminated gaps could be directly produced by
irradiation with 366 nm light. These caged single strand breaks were also
incorporated in tandem into hairpin substrates to demonstrate that they could be
used to cage double strand breaks. These caged single strand breaks should be
generally useful for generating site-specific DNA single and double strand
breaks and gaps, using wavelengths and doses of light that are nondetrimental to
biological systems. Because the position of the single strand break can be
varied, it should now be possible to examine the effect of the sequence context
and cleavage pattern of single and double strand breaks on the lethality and
mutagenicity of this important class of DNA damage. BACKGROUND: Induction of DNA double strand breaks and alterations in the repair
of these breaks is implicated in breast carcinogenesis. Prior studies have
demonstrated that peripheral blood mononuclear cells (PBMC) from breast cancer
patients exhibit increased numbers of DNA strand breaks after exposure to
ionizing radiation, but these studies did not specifically measure DNA double
strand breaks and it is not known whether chemical carcinogens produce similar
effects.
MATERIALS AND METHODS: PBMC from 32 women undergoing breast surgery were
genotyped at nine loci of seven DNA repair genes. DNA double strand break repair
was measured using the neutral comet assay after exposure to ionizing radiation
(0.5 Gy) or bioactivated benzo[a]pyrene (B[a]P, 5 microM.
RESULTS: PBMC from breast cancer patients showed higher levels of residual DNA
double strand breaks 30 min after exposure to radiation than PBMC from patients
with benign breast disease (1.40 times baseline [95% confidence intervals [CI]
1.29-1.51] versus 1.24 times baseline [95% CI 1.15-1.33], respectively, P =
0.04). The response to B[a]P trended in the same direction, but did not reach
statistical significance. The MGMT K178R variant genotype was associated with
improved DNA double strand break repair in PBMC exposed to B[a]P.
CONCLUSIONS: Reduced repair of radiation-induced DNA double strand breaks in
PBMC is a robust biomarker of breast cancer risk. Reduced DNA repair capacity
may have a genetic component even in sporadic breast cancer. The induction of DNA interstrand cross-links by ionizing radiation has been
largely ignored in favour of studies on double-strand break formation and
repair. At least part of the problem is technical; it is difficult to detect and
quantify interstrand cross-links when the same agent forms both cross-links and
single strand breaks because the detection of interstrand cross-links generally
involves a denaturation step. Our group has studied the induction of interstrand
cross-links following irradiation of DNA containing bromouracil at specific
sites. We found that the formation of interstrand cross-links requires the
presence of a few (3-5) mismatched bases, comprising the bromouracil. In the
absence of mismatched bases, no radiation-induced cross-linking was observed;
however, even in the absence of bromouracil, cross-linking still occurred,
albeit at a lower efficiency. Our molecular modelling studies demonstrate that
the mobility of the bases in the mismatched region is essential for the
cross-linking process. Thus, our hypothesis is that ionizing radiation induces
DNA interstrand cross-links in non-hybridized regions of DNA. Some obvious
examples of such DNA regions are replication forks, transcription bubbles and
the D-loop of telomeres. However, an abundance of studies have made it clear
that there must be many single-stranded regions in the genome, such as hairpins
and cruciforms. For example, alpha satellite DNA, in centromere regions of human
chromosomes, forms hairpins. Thus, a variety of non-B DNA structures (hairpins,
slipped DNA and tetrahelical structures) exist in the genome and should be
susceptible to the formation of radiation-induced interstrand cross-links.
Although interstrand cross-links have thus far been virtually ignored in
radiation biology, it will be worthwhile to develop methods to detect their
presence following exposure of cells to biologically relevant levels of ionizing
radiation, since, on a per lesions basis, they are probably more toxic than
double-strand breaks. Double-stranded breaks (DSBs) are cytotoxic DNA lesions caused by oxygen
radicals, ionizing radiation, and radiomimetic chemicals. Increasing
understanding of DNA damage signaling has provided an ever-expanding list of
modulators reported to orchestrate DNA damage repair and ataxia telangiectasia
mutated (ATM) is the master regulator and main transducer of the DSB response.
Increasingly, it is being realized that DNA damage response is a synchronized
and branched network that functionalizes different molecular cascades to
activate special checkpoints, thus temporarily arresting progression of the cell
cycle while damage is being assessed and processed. It is noteworthy that both
nutrigenetics and nutrigenomics have revolutionized the field of molecular
biology and rapidly accumulating experimental evidence has started to shed light
on biological activities of a wide range of phytochemicals reported to modulate
cell cycle, DNA repair, cell growth, differentiation and apoptosis as evidenced
by cell-based studies. In this review, we have attempted to provide an overview
of DNA damage signaling, how ATM signaling regulates tumor necrosis
factors-related apoptosis inducing ligand (TRAIL)-induced intracellular network.
We also illuminate on how resveratrol, epigallocatechin gallate, curcumin,
jaceosidin, cucurbitacin, apigenin, genistein, and others trigger activation of
ATM in different cancer cells as well as agents for ATM inactivation.
Understanding the interplay of TRAIL-induced intracellular signaling and ATM
modulation of downstream effectors is very important. This holds particularly
for a reconceptualization of the apparently paradoxical roles and
therapeutically targetable for enhancing the response to DNA damage-inducing
therapy. DNA double-strand breaks (DSBs) are major DNA lesions that are constantly formed
during physiological processes such as DNA replication, transcription, and
recombination, or as a result of exogenous agents such as ionizing radiation,
radiomimetic drugs, and genome editing nucleases. Unrepaired DSBs threaten
genomic stability by leading to the formation of potentially oncogenic
rearrangements such as translocations. In past few years, several methods based
on next-generation sequencing (NGS) have been developed to study the genome-wide
distribution of DSBs or their conversion to translocation events. We developed
Breaks Labeling, Enrichment on Streptavidin, and Sequencing (BLESS), which was
the first method for direct labeling of DSBs in situ followed by their
genome-wide mapping at nucleotide resolution (Crosetto et al., Nat Methods
10:361-365, 2013). Recently, we have further expanded the quantitative nature,
applicability, and scalability of BLESS by developing Breaks Labeling In Situ
and Sequencing (BLISS) (Yan et al., Nat Commun 8:15058, 2017). Here, we first
present an overview of existing methods for genome-wide localization of DSBs,
and then focus on the BLESS and BLISS methods, discussing different assay design
options depending on the sample type and application. Exposure of cells to ionizing radiation induces DNA double-strand breaks. To
repair double-strand breaks correctly, cells must distinguish between the ends
of chromosomes (telomeres) and DNA double-strand breaks within chromosomes.
Double-strand breaks in telomeric DNA may lead to telomere shortening and
mutagenesis. Eukaryotic cells repair double-strand breaks primarily by two
mechanisms: error-free homologous recombination and error-prone nonhomologous
end joining, of which homologous recombination is used in early meiotic prophase
I to create recombined haploid gametes by two meiotic cell divisions lacking an
intervening S-phase. Genotoxic exposures put meiosis at risk to transmit
mutations, and ionizing radiation is known to induce large double-strand
break-marking phospho (gamma)-H2AX foci along the cores and ends of mouse
meiotic chromosomes. However, it remained unclear through which repair pathway
the ionizing radiation-induced telomeric double-strand breaks are repaired in
late prophase I spermatocytes. Using male wild-type and nonhomologous end
joining-deficient (severe combined immunodeficient) mice, this study
investigated the kinetics of in vivo double-strand break formation and repair at
telomeres of late prophase I chromosomes up to 12 h after 0.5 Gy of whole-body
gamma irradiation. Late pachytene and diplotene spermatocytes revealed
overlapping gamma-H2AX and telomere repeat signal foci, indicating telomeric DNA
damage. The comparison of double-strand break repair rates at telomeres and
internal prophase chromosome sites revealed a more rapid double-strand break
repair at wild-type telomeres during the first hour after irradiation. Increased
double-strand break foci numbers at nonhomologous end joining-deficient
telomeres and chromosomes and a slowed repair rate in this DNA-dependent protein
kinase catalytic subunit mutant suggest that the fast repair of double-strand
breaks in telomeric DNA repeats during late prophase I is largely mediated by
canonical nonhomologous end joining. Whereas most endogenous and exogenous DNA damaging agents typically generate
lesions that are relatively isolated and can be repaired easily, ionizing
radiation (IR) also induces clustered lesions causing DNA double strand breaks
(DSBs). Moreover, forms of IR characterized by high linear energy transfer (LET)
induce not only isolated DSBs but also DSB clusters - multiple DSBs in close
proximity -that pose increased risks for the cell. DSB clusters can destabilize
chromatin locally and compromise processing of individual DSBs within the
cluster. Since the discovery of chromothripsis, a phenomenon whereby multiple
DSBs locally generated by a catastrophic event causes genomic rearrangements
that feed carcinogenesis, DSB clusters receive increased attention also in the
field of cancer. While formation of DSB clusters after exposure to high LET is a
direct and inherent consequence of the spatial distribution of the constituting
energy deposition events, also called track structure, the sources of local
genomic shattering underpinning chromothripsis are under investigation. Notably,
many consequences of DSB clusters in the affected genome reflect processing by
pathways that have evolved to repair DSBs, but which operate with widely
different degrees of fidelity. The molecular underpinnings and the basis of the
underlying repair pathway choices that ultimately lead to the observed
consequences from DSB clusters remain unknown. We developed a tractable model of
DSB clustering that allows direct analysis in cells of the consequences of
certain configurations of DSB clusters. We outline the rationale for the
development of this model and describe its key characteristics. We summarize
results suggesting that DSB clusters compromise the first-line DSB-processing
pathways of c-NHEJ and HRR, increasing as a consequence the contribution of
alt-EJ, which has high propensity of generating chromosomal rearrangements. The
results suggest a mechanism for the increased toxicity of high LET radiation and
the extensive genomic rearrangements associated with chromothripsis. Author information:
(1)Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center
(CI-IPOP), Portuguese Institute of Oncology of Porto, 4200-072 Porto, Portugal.
[email protected].
(2)Faculty of Medicine of University of Porto (FMUP), 4200-319 Porto, Portugal.
[email protected].
(3)Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center
(CI-IPOP), Portuguese Institute of Oncology of Porto, 4200-072 Porto, Portugal.
[email protected].
(4)Faculty of Medicine of University of Porto (FMUP), 4200-319 Porto, Portugal.
[email protected].
(5)Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center
(CI-IPOP), Portuguese Institute of Oncology of Porto, 4200-072 Porto, Portugal.
[email protected].
(6)Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center
(CI-IPOP), Portuguese Institute of Oncology of Porto, 4200-072 Porto, Portugal.
[email protected].
(7)Faculty of Medicine of University of Porto (FMUP), 4200-319 Porto, Portugal.
[email protected].
(8)Biomedical Research Center (CEBIMED), Faculty of Health Sciences of Ferdo
Pessoa University, 4249-004 Porto, Portugal. [email protected].
(9)Research Department, Portuguese League against Cancer (NRNorte), 4200-172
Porto, Portugal. [email protected]. |
As of 2019, what type of cancer is commonly associated with ionizing radiation | Ionizing radiation is commonly associated with lung cancer, prostate cancer, breast cancer, cervical intraepithelial neoplasia and oral squamous cell carcinoma. | Marked dissimilarities in the epidemiology of osteosarcoma, Ewing's tumor, and
rhabdomyosarcoma indicate differences in their origins. A major clue to the
genesis of Ewing's tumor comes not from defining persons at high risk but from
the observation that blacks are at unusually low risk. The neoplasm does not
aggregate in families and is not part of any known syndrome. No environmental
causes have been identified. By contrast, osteosarcoma may be caused by external
or internal ionizing radiation, and it aggregated in families with the same
tumor or with dissimilar tumors and in certain genetic disorders of bone. In man
and in dogs, the frequency of the neoplasm is related to bone mass and growth.
Rhabdomyosarcoma of the upper versus the lower limbs seems related to muscle
mass. Age peaks in the occurrence of the tumor elsewhere vary with the anatomic
site; head and neck tumors develop in early childhood and urogenital tumors both
in early years and in adolescence. The sex ratio (male to female) also varies
with the site affected. Rhabdomyosarcoma aggregates with certain other tumors in
families and overlaps with osteosarcoma in some of these relationships but is
distinguished from that tumor by its excessive occurrence in neurofibromatosis. All human beings are exposed to the influence of ionizing radiation from
natural, medical and other artificial sources. Therefore, the influence of
radiation as a risk factor for cancer development has been among the most
studied external factors over the last 6 decades, particularly with respect to
radiosensitive tissues and organs. It has been known that female breast tissue
is highly sensitive to the carcinogenic effects of radiation, particularly when
exposure takes place at younger age. All women are exposed to low doses of
radiation for several common reasons (kind of occupation, medical diagnostic
procedures, residence background radiation) whose effects on breast cancer
development cannot be documented, and thus it is believed that ionizing
radiation is not primary or major risk factor leading to development of breast
cancer. Radiobiological studies revealed a specific event caused by radiation
through recognition of the critical target in radiation-induced carcinogenesis.
Accordingly, mutagenic and carcinogenic effects of ionizing radiation are
evidenced both in vitro and in vivo, although the incidence of radiation-induced
cancers is low. The highest risk of radiation- induced breast cancer is
evidenced in the sub-population of female patients who have undergone
radiotherapy for either maligt or non-maligt diseases, including benign
breast diseases in their childhood or young age. Therefore, as a means of
prevention in this group of population, indications for application of ionizing
radiation, both diagnostic and therapeutic, should be highly selective, meaning
that radiation should be applied only if the possible benefit outweighs the
risk. Understanding of the role of radiation as a cause of kidney cancer remains
limited. The most common types of kidney cancer are renal cell carcinoma and
renal pelvis carcinoma. It has been posited that these entities differ in their
degree of radiogenicity. Recent analyses of cancer incidence and mortality in
the Life Span Study (LSS) of Japanese atomic bomb survivors have examined
associations between ionizing radiation and renal cell carcinoma, but these
analyses have not reported results for cancer of the renal pelvis and ureters.
This paper reports the results of analyses of kidney cancer incidence during the
period 1958-1998 among 105,427 atomic bomb survivors. Poisson regression methods
were used to derive estimates of associations between radiation dose (in
sievert, Sv) and cancer of the renal parenchyma (n = 167), and cancer of the
renal pelvis and ureter (n = 80). Heterogeneity by cancer site was tested by
joint modeling of cancer risks. Radiation dose was positively associated with
cancers of the renal pelvis and ureter [excess relative rate (ERR)/Sv = 1.65;
90% confidence interval (CI): 0.37, 3.78]. The magnitude of this association was
larger than the estimated association between radiation dose and cancer of the
renal parenchyma (ERR/Sv = 0.27; 90% CI = -0.19, 0.98). While the association
between radiation and cancer of the renal parenchyma was of greater magnitude at
ages <55 years (ERR/Sv = 2.82; 90% CI = 0.45, 8.89) than at older attained ages
(ERR/Sv = -0.11; 90% CI = nd, 0.53), the association between radiation and
cancers of the renal pelvis and ureter varied minimally across these categories
of attained age. A test of heterogeneity of type-specific risks provides modest
support for the conclusion that risks vary by kidney cancer site (LRT = 2.34, 1
d.f., P = 0.13). Since some studies of radiation-exposed populations examine
these sites in aggregate, results were also derived for the combined category of
cancer of the renal parenchyma, renal pelvis and ureters. Overall, there was a
positive association between radiation and the combined category of cancer of
the renal parenchyma, renal pelvis and ureters (ERR/Sv = 0.60, 90% CI: 0.09,
1.30). Updated follow-up of the LSS cohort provides substantial additional
information on the association between radiation and cancer of the renal pelvis
and ureter, a site not examined in recent reports on analyses of these data. The
results are suggestive of differences between the different regions of the
kidney in sensitivity to the carcinogenic effects of ionizing radiation. Breast cancer (BC) is the most common type of maligcy in female patients and
radio-treatment is the conventional therapy even if a great number of studies
reported that enhanced sensitivity to ionizing radiation as measured as
chromosome effects is present in a significant proportion of cancer patients,
including breast cancer ones. In this study we analysed whether peripheral blood
lymphocytes from sporadic BC patients and healthy subjects showed a different
sensitivity to ionizing radiation and whether cytogenetic radiosensitivity may
serve as a breast cancer risk biomarker. To test this hypothesis, the in vitro
radiation sensitivity was measured by using both G(0) and G(2) chromosome
radiosensitivity assays, on 46 subjects (23 BC patients and 23 healthy
subjects). Results show that cancer patients are more radiosensitive than
healthy controls and that G(2) assay could be more appropriate to define the
individual radiosensitivity if compared to G(0) assay. Esophageal cancer is the sixth leading cause of cancer death worldwide and the
seventh leading cause of cancer death in the U.S. male population. Ionizing
radiation exposure is a risk factor for development of esophageal squamous cell
carcinoma, a histological subtype of esophageal cancer that is highly aggressive
and is associated with poor patient prognosis. This study investigated the
effects of ionizing radiation on the microenvironment and intercellular
communication as it relates to esophageal carcinogenesis. We demonstrate that
normal esophageal epithelial cells exhibited increased migration and invasion
when cultured in the presence of irradiated stromal fibroblasts or with
conditioned medium derived from irradiated stromal fibroblasts. Cytokine
antibody arrays and ELISAs were used to identify hepatocyte growth factor (HGF)
as an abundant protein that is secreted by esophageal fibroblasts at twofold
increased levels in culture medium after γ irradiation. Reverse transcription
qPCR analysis confirmed an approximately 50% increase in mRNA levels for HGF at
1 h in irradiated fibroblasts compared to unirradiated controls. Recombit HGF
stimulated increased wound healing, migration and invasion of esophageal
epithelial cells, while blocking antibodies against HGF significantly decreased
migration and invasion of epithelial cells in coculture with irradiated
fibroblasts. Since HGF is known to direct cell migration, invasion and
metastasis in a variety of tissues, including the esophagus, its modulation by
ionizing radiation may have important implications for nontargeted pathways that
influence radiation carcinogenesis in the esophagus. AIMS: The central issue of resistance to radiation remains a significant
challenge in the treatment of cancer despite improvements in treatment modality
and emergence of new therapies. To facilitate the identification of molecular
factors that elicit protection against ionizing radiation, we developed a
matched model of radiation resistance for head and neck squamous cell cancer
(HNSCC) and characterized its properties using quantitative mass spectrometry
and complementary assays.
RESULTS: Functional network analysis of proteomics data identified DNA
replication and base excision repair, extracellular matrix-receptor interaction,
cell cycle, focal adhesion, and regulation of actin cytoskeleton as
significantly up- or downregulated networks in resistant (rSCC-61) HNSCC cells.
Upregulated proteins in rSCC-61 included a number of cytokeratins, fatty acid
synthase, and antioxidant proteins. In addition, the rSCC-61 cells displayed two
unexpected features compared with parental radiation-sensitive SCC-61 cells: (i)
rSCC-61 had increased sensitivity to Erlotinib, a small-molecule inhibitor of
epidermal growth factor receptor; and (ii) there was evidence of
mesenchymal-to-epithelial transition in rSCC-61, confirmed by the expression of
protein markers and functional assays (e.g., Vimentin, migration).
INNOVATION: The matched model of radiation resistance presented here shows that
multiple signaling and metabolic pathways converge to produce the rSCC-61
phenotype, and this points to the function of the antioxidant system as a major
regulator of resistance to ionizing radiation in rSCC-61, a phenomenon further
confirmed by analysis of HNSCC tumor samples.
CONCLUSION: The rSCC-61/SCC-61 model provides the opportunity for future
investigations of the redox-regulated mechanisms of response to combined
radiation and Erlotinib in a preclinical setting. BACKGROUND: There is much uncertainty about the risks of leukaemia and lymphoma
after repeated or protracted low-dose radiation exposure typical of
occupational, environmental, and diagnostic medical settings. We quantified
associations between protracted low-dose radiation exposures and leukaemia,
lymphoma, and multiple myeloma mortality among radiation-monitored adults
employed in France, the UK, and the USA.
METHODS: We assembled a cohort of 308,297 radiation-monitored workers employed
for at least 1 year by the Atomic Energy Commission, AREVA Nuclear Cycle, or the
National Electricity Company in France, the Departments of Energy and Defence in
the USA, and nuclear industry employers included in the National Registry for
Radiation Workers in the UK. The cohort was followed up for a total of 8.22
million person-years. We ascertained deaths caused by leukaemia, lymphoma, and
multiple myeloma. We used Poisson regression to quantify associations between
estimated red bone marrow absorbed dose and leukaemia and lymphoma mortality.
FINDINGS: Doses were accrued at very low rates (mean 1.1 mGy per year, SD 2.6).
The excess relative risk of leukaemia mortality (excluding chronic lymphocytic
leukaemia) was 2.96 per Gy (90% CI 1.17-5.21; lagged 2 years), most notably
because of an association between radiation dose and mortality from chronic
myeloid leukaemia (excess relative risk per Gy 10.45, 90% CI 4.48-19.65).
INTERPRETATION: This study provides strong evidence of positive associations
between protracted low-dose radiation exposure and leukaemia.
FUNDING: Centers for Disease Control and Prevention, Ministry of Health, Labour
and Welfare of Japan, Institut de Radioprotection et de Sûreté Nucléaire, AREVA,
Electricité de France, National Institute for Occupational Safety and Health, US
Department of Energy, US Department of Health and Human Services, University of
North Carolina, Public Health England. |
Is KAT2A involved in Acute myeloid leukemia (AML)? | Yes. The KAT2A gene encodes a receptor tyrosine kinase that is frequently mutated in human acute myeloid leukemia (AML). Activating mutations in Kat2A in response to aberrations in TRAIL can lead to TRAIL-1 activation, resulting in the up-regulation of key AML genes, such as TGFb1, NF-kB, Akt, IKK-1, FOXO1, ERK1/2 and c-Myc. | |
What is Idiopathic toe walking? | Idiopathic toe walking is a pathological gait pattern in which children older than 3 years walk on their tip toes with no contact between the heels and the ground. | Idiopathic toe-walking is defined as persistent toe-walking in a normal child in
the absence of developmental, neurological or neuromuscular conditions. True
idiopathic toe-walking is a rare referral, representing approximately 1:100 new
patients seen in the Paediatric Orthopaedic Clinic. A prospective study of
idiopathic toe-walking (ITW) was organised between 1999 and 2003. Patients
underwent full history, neurological examination and assessment of ankle
dorsiflexion, followed by below-knee weight-bearing casting. Forty four
developmentally normal children with no delay in walking age were in this study.
There was an age range on presentation from 2 years to 14 years 4 months, with
median 60.5 months. Sixty eight percent were male. Thirty four percent had a
family history of the condition. Following casting, 66% of patients had improved
gait on patient and clinician determined outcomes, with the majority of children
ceasing to toe-walk. Ankle dorsiflexion significantly improved in those children
who were successfully treated (p = 0.001). Idiopathic toe-walking is a diagnosis of exclusion when a child presents with
bilateral toe-to-toe gait. Although toe-walking is considered part of the normal
gait spectrum in development, it is abnormal when persisting past the age of
two. Toe-walking may be caused by cerebral palsy, congenital contracture of the
Achilles tendon or paralytic muscular disorders such as Duchenne Muscular
Dystrophy. Idiopathic toe-walking may be associated with developmental disorders
such as autism or other myopathic or neuropathic disorders. The majority of
disorders causing toe-walking can be ruled out through the history and physical
examination, resulting in a diagnosis of idiopathic toe-walking. However, it may
be difficult to differentiate mild forms of cerebral palsy, specifically mild
spastic diplegia, and idiopathic toe-walking. The treatment options for
idiopathic toe-walking include observation, conservative methods and surgical
methods. Most children can be treated in the primary care setting with either
observation or conservative treatment. Patients with severe contracture of the
Achilles tendon, or persistent toe-walking, may need surgical intervention. The
prognosis of idiopathic toe-walking is favorable with both conservative and
surgical treatment allowing children to attain normal function and range of
plantarflexion. The following article provides an overview of the background
information, differential diagnosis and treatment options for idiopathic
toe-walking. INTRODUCTION: Idiopathic toe-walking (ITW) is described as a gait pattern with
no contact between the heels and the ground in children older than 3years. The
diagnosis is clinical, making it necessary to rule out other neurological and
orthopaedic conditions. A relationship between ITW and vestibular dysfunction
and/or proprioceptive sensibility has been proposed. Children with
neurodevelopmental disorders (autism, language and cognitive disorders) often
have ITW.
OBJECTIVES: To determine the frequency of ITW in children with attention deficit
disorder and hyperactivity (ADHD).
PATIENTS AND METHOD: A study was conducted on children diagnosed with ADHD, with
normal neurological examination, with no alterations in MRI scan, cognitive
disorder or autism. A complete clinical anamnesis was performed and Achilles
shortening was measured with a goniometer.
RESULTS: The study included 312 children with a mean age of 11 years (73.7%
boys). The ADHD combined subtype was the most frequent (53.8%), followed by the
inattentive (44.9%), and hyperactive (1.3%). ITW was observed in 20.8% of
patients, particularly in the combined subtype (P=.054). Only 32 of them (49.2%)
had Achilles shortening. ITW was associated with sociability disorders (P=.01),
absence of pain in legs (P=.022), and family history of ITW (P=.004). Only 11%
had previously visited a doctor for this reason.
CONCLUSIONS: As in other neurodevelopmental disorders, children with ADHD have
frequently more ITW and Achilles shortening than controls, especially if they
presented with a social communication disorder or a family history of ITW. An
early diagnosis is essential to establish effective treatments. Toe walking refers to the lack of heel strike during the stance phase of the
gait cycle. It is a common variation of normal gait development in children.
Persistent toe walking past 2-3 years of age warrants further evaluation as toe
walking can be associated with cerebral palsy, muscular dystrophy, and autism
spectrum disorders. The diagnosis of idiopathic toe walking is a diagnosis of
exclusion used for children with persistent toe walking and no associated
medical condition. Despite variable pathophysiology, the treatment of toe
walking has similarities across diagnoses as it is focused on the maintece of
range of motion through the ankle. BACKGROUND: Idiopathic toe walking is a diagnosis of exclusion characterized by
a persistent toe-toe gait pattern after three years of age. Treatment for toe
walking includes physical therapy, orthotics, casting, Botulinum Toxin A
injection into gastrocnemius/soleus muscles, and/or surgery; yet, little
evidence exists regarding long-term treatment effects.
RESEARCH QUESTION: The objective of this study was to explore the differences in
longer-term gait outcomes and severity of idiopathic toe walking between
children treated actively with casting or inactively following recommendations
for stretching.
METHODS: Forty-three adolescents and young adults (14.3-28.8 years; 21 females,
22 males) who had participated in an idiopathic toe walking classification study
as children, returned for repeat physical examination and three-dimensional
computerized gait analysis (13.4 years follow-up, range 9.4-17.8 years); 23
participants had received active treatment with casting and ankle foot
orthotics ± Botulinum Toxin A injection as children and 20 participants had
received inactive treatment with recommended stretching exercises. Gait analysis
data were compared retrospectively from baseline to follow-up using analysis of
variance; toe walking severity was compared using a Wilcoxin Signed-Rank Sums
test.
RESULTS: Ankle angle at initial contact, peak dorsiflexion in stance, and toe
walking severity improved significantly in the active treatment group only at
follow-up. Significant improvement in peak ankle power and timing of ankle
kinematics and kinetics in the gait cycle were found in both groups; however,
greater changes occurred in the active treatment group. Both groups showed
significantly improved internal plantar flexor moments, whereas knee extension
increased in stance and passive ankle dorsiflexion decreased in both groups at
follow-up (p = 0.001). Intermittent toe walking was reported in 49% (21/43) of
participants at follow-up.
SIGNIFICANCE: The results of this study suggest that improvement in ankle
kinematic timing and ankle kinetic gait analysis variables is sustainable,
independent of conservative treatment for idiopathic toe walking in childhood. Idiopathic toe walking is a relatively common developmental condition often
leading to secondary problems such as pain and muscle contractures in the lower
extremities. The cause of idiopathic toe walking is unknown, which hinders the
development of treatment strategies. To test whether children with idiopathic
toe walking have functional alterations in their spinal motor circuits, we
studied the properties of the soleus H-reflex and its modulation with vibration
in 26 idiopathic toe walkers and 16 typically developing children. At the group
level, the H-reflex properties did not differ, but at the individual level, in 7
of 25 idiopathic toe walkers, some of the H-reflex parameters fell out of normal
limits of typically developing children. However, the H-reflex was suppressed by
vibration to the Achilles tendon similarly in both the idiopathic toe walkers
and typically developing children. In conclusion, idiopathic toe walking in some
children can be associated with functional alterations in their spinal motor
circuits. BACKGROUND: Children with idiopathic toe-walking, a common pediatric condition,
walk some or all of the time on their toes. This condition often causes parental
concern, with repeated medical contacts and a range of interventions including
stretching, casts, injection of botulinum toxin A, and surgical procedures. The
purpose of this cohort study was to document the natural history of this
condition.
METHODS: In a population-based cohort of 1,401 healthy 5.5-year-old Swedish
children, we found the prevalence of idiopathic toe-walking to be approximately
5% (63 of 1,401). Of the 63 children who had ever been a toe-walker, 26 still
were at the age of 5.5 years and were followed in the current study at 8 and 10
years of age. At the 8-year follow-up, parents were asked by telephone whether
their child had received any treatment or diagnosis since the 5.5-year
assessment, as well as to what extent (approximately 25%, 50%, 75%, or 100% of
the time) the child still walked on the toes. At the visit when the children
were 10 years of age, their parents were asked the same questions. All 26
children also underwent a neurological examination and an orthopaedic
examination focusing on the lower extremities.
RESULTS: At 8 years of age, 6 of 26 children had ceased toe-walking, and by the
age of 10 years, 50 (79%) of the original 63 patients had spontaneously ceased
toe-walking. Idiopathic toe-walking did not result in contractures of the
triceps surae. One subgroup of children displayed early contracture of the ankle
and should thus not be considered idiopathic toe-walkers. Four of the children
who still toe-walked at the age of 10 years demonstrated some neurodevelopmental
comorbidity.
CONCLUSIONS: By the age of 10 years, 79% of the children who have ever been a
toe-walker spontaneously develop a typical gait, without intervention or
contractures of the ankle dorsiflexion. The diagnosis of short tendo Achilles
should be retained as a separate diagnosis as there is a subset of children with
this entity who should be treated early in childhood. Neurodevelopmental
comorbidities are common among those who continue to toe-walk.
LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a
complete description of levels of evidence. BACKGROUND: Idiopathic toe walking (ITW) is a diagnosis of exclusion for
children walking on their toes with no medical cause. This systematic review
aimed to identify and evaluate the clinical utility, validity and reliability of
the outcome measures and tools used to quantify lower limb changes within
studies that included children with ITW.
METHODS: The following databases were searched from inception until March 2018:
Ovid MEDLINE, EBESCO, Embase, CINAHL Plus, PubMed. Inclusion criteria were
studies including children with ITW diagnosis, reporting use of measurement
tools or methods describing lower limb characteristics, published in
peer-reviewed journals, and in English. The relevant psychometric properties of
measurement tools were extracted, and assessed for reported reliability and
validity. Included articles were assessed for risk of bias using McMaster
quality assessment tool. Results were descriptively synthesized and logistic
regression used to determine associations between common assessments.
RESULTS: From 3164 retrieved studies, 37 full texts were screened and 27 full
texts included. There were 27 different measurement tools described across joint
range of motion measurement, gait analysis, electromyography, accelerometer,
strength, neurological or radiology assessment. Interventional studies were more
likely to report range of motion and gait analysis outcomes, than observational
studies. Alvarez classification tool in conjunction with Vicon motion system
appeared the contemporary choice for describing ITW gait. There was no
significant association between the use of range of motion and gait analysis
outcomes and any other outcome tool or assessment in all studies
(p > 0.05).There was limited reliability and validity reporting for many outcome
measures.
SIGNIFICANCE: This review highlighted that a consensus statement should be
considered to guide clinicians and researchers in the choice of the most
important outcome measures for this population. Having a standard set of
measures will enable future treatment trials to collect similar measures thus
allowing future systematic reviews to compare results. |
Is NicVAX vaccine effective for smoking cessation? | No. NicVAX vaccine failed to meet the primary endpoint in two large phase III studies, although the correlation of higher abstinence rates in subjects with higher immunity to nicotine was observed. The nicotine vaccine, NicVAX, does not appear to improve the chances of stopping smoking when given in addition to varenicline and behavioural support. | NicVAX, a nicotine vaccine (3'AmNic-rEPA), has been clinically evaluated to
determine whether higher antibody (Ab) concentrations are associated with higher
smoking abstinence rates and whether dosages and frequency of administration are
associated with increased Ab response. This randomized, double-blinded,
placebo-controlled multicenter clinical trial (N = 301 smokers) tested the
results of 200- and 400-µg doses administered four or five times over a period
of 6 months, as compared with placebo. 3'AmNic-rEPA recipients with the highest
serum antinicotine Ab response (top 30% by area under the curve (AUC)) were
significantly more likely than the placebo recipients (24.6% vs. 12.0%, P =
0.024, odds ratio (OR) = 2.69, 95% confidence interval (CI), 1.14-6.37) to
attain 8 weeks of continuous abstinence from weeks 19 through 26. The
five-injection, 400-µg dose regimen elicited the greatest Ab response and
resulted in significantly higher abstinence rates than placebo. This study
demonstrates, as proof of concept, that 3'AmNic-rEPA elicits Abs to nicotine and
is associated with higher continuous abstinence rates (CAR). Its further
development as a treatment for nicotine dependence is therefore justified. Smoking is a global healthcare problem. Current smoking cessation rates using
behavioral counseling and pharmacotherapeutic interventions have had modest
success, with ∼1:5 smokers remaining abstinent long-term. Nicotine vaccines are
a new class of immunotherapeutics under development. It is believed that
anti-nicotine antibodies arising from vaccination capture nicotine and prevent
or reduce its entry into the brain, as the antibody-bound nicotine is too large
to cross the blood-brain barrier. This in turn decreases the pleasurable effects
of smoking, reducing or eliminating positive reinforcement, thereby making it
easier for a smoker to quit smoking. Four vaccine candidates have advanced into
clinical testing with mixed success. Proof-of-concept has been established in
that individuals with higher levels of anti-nicotine antibodies were observed to
have higher smoking cessation and abstinence rates. Recently, the most advanced
candidate vaccine, NicVAX, failed to meet the primary endpoint in two large
phase III studies, although the correlation of higher abstinence rates in
subjects with higher immunity to nicotine was observed. Although the field has
had setbacks, the magnitude of the tobacco epidemic and the positive
pre-clinical research and observed clinical trends indicate continued research
is warranted. Several avenues are being actively pursued: a) improving vaccine
potency by introducing novel carriers and/or adjuvants to stimulate higher
immune response b) targeting subjects who have a robust response (e.g.
personalized medicine) c) combining vaccines with pharmacotherapy for
maintece of abstinence/relapse prevention. BACKGROUND: By reducing the amount of nicotine that reaches the brain when a
person smokes a cigarette, nicotine vaccines may help people to stop smoking or
to prevent recent quitters from relapsing.
OBJECTIVES: The aims of this review are to assess the efficacy of nicotine
vaccines for smoking cessation and for relapse prevention, and to assess the
frequency and type of adverse events associated with the use of nicotine
vaccines.
SEARCH METHODS: We searched the Cochrane Tobacco Addiction Review Group
specialised register for trials, using the term 'vaccine' in the title or
abstract, or in a keyword (date of most recent search April 2012). To identify
any other material including reviews and papers potentially relevant to the
background or discussion sections, we also searched MEDLINE, EMBASE, and
PsycINFO, combining terms for nicotine vaccines with terms for smoking and
tobacco use, without design limits or limits for human subjects. We searched the
Annual Meeting abstracts of the Society for Research on Nicotine and Tobacco up
to 2012, using the search string 'vaccin'. We searched Google Scholar for
'nicotine vaccine'. We also searched company websites and Google for information
related to specific vaccines. We searched clinicaltrials.gov in March 2012 for
'nicotine vaccine' and for the trade names of known vaccine candidates.
SELECTION CRITERIA: We included randomized controlled trials of nicotine
vaccines, at Phase II and Phase III trial stage and beyond, in adult smokers or
recent ex-smokers. We included studies of nicotine vaccines used as part of
smoking cessation or relapse prevention interventions.
DATA COLLECTION AND ANALYSIS: We extracted data on the type of participants, the
dose and duration of treatment, the outcome measures, the randomization
procedure, concealment of allocation, blinding of participants and personnel,
reporting of outcomes, and completeness of follow-up.Our primary outcome measure
was a minimum of six months abstinence from smoking. We used the most rigorous
definition of abstinence, and preferred cessation rates at 12 months and
biochemically validated rates where available. We have used the risk ratio (RR)
to summarize individual trial outcomes. We have not pooled the current group of
included studies as they cover different vaccines and variable regimens.
MAIN RESULTS: There are no nicotine vaccines currently licensed for public use,
but there are a number in development. We found four trials which met our
inclusion criteria, three comparing NicVAX to placebo and one comparing NIC002
(formerly NicQbeta) to placebo. All were smoking cessation trials conducted by
pharmaceutical companies as part of the drug development process, and all trials
were judged to be at high or unclear risk of bias in at least one domain.
Overall, 2642 smokers participated in the included studies in this review. None
of the four included studies detected a statistically significant difference in
long-term cessation between participants receiving vaccine and those receiving
placebo. The RR for 12 month cessation in active and placebo groups was 1.35
(95% Confidence Interval (CI) 0.82 to 2.22) in the trial of NIC002 and 1.74 (95%
CI 0.73 to 4.18) in one NicVAX trial. Two Phase III NicVAX trials, for which
full results were not available, reported similar quit rates of approximately
11% in both groups. In the two studies with full results available, post hoc
analyses detected higher cessation rates in participants with higher levels of
nicotine antibodies, but these findings are not readily generalisable. The two
studies with full results showed nicotine vaccines to be well tolerated, with
the majority of adverse events classified as mild or moderate. In the study of
NIC002, participants receiving the vaccine were more likely to report mild to
moderate adverse events, most commonly flu-like symptoms, whereas in the study
of NicVAX there was no significant difference between the two arms. Information
on adverse events was not available for the large Phase III trials of
NicVAX.Vaccine candidates are likely to undergo significant changes before
becoming available to the general public, and those included in this review may
not be the first to reach market; this limits the external validity of the
results reported in this review in terms of both effectiveness and tolerability.
AUTHORS' CONCLUSIONS: There is currently no evidence that nicotine vaccines
enhance long-term smoking cessation. Rates of serious adverse events recorded in
the two trials with full data available were low, and the majority of adverse
events reported were at mild to moderate levels. The evidence available suggests
nicotine vaccines do not induce compensatory smoking or affect withdrawal
symptoms. No nicotine vaccines are currently licensed for use in any country but
a number are under development.Further trials of nicotine vaccines are needed,
comparing vaccines with placebo for smoking cessation. Further trials are also
needed to explore the potential of nicotine vaccines to prevent relapse. Results
from past, current and future research should be reported in full. Adverse
events and serious adverse events should continue to be carefully monitored and
thoroughly reported. Most smokers are aware of the dangers of smoking and want to quit, yet few are
successful owing to the highly addictive properties of nicotine. Available
smoking cessation tools include pharmacotherapies that act in the CNS and show
modest long-term efficacy. Additionally, there are emerging concerns that they
may cause adverse neuropsychiatric events. Antinicotine vaccines have been used
experimentally as aids to smoking cessation. It is hypothesized that antibody
capture of nicotine in the bloodstream would prevent it from crossing the
blood-brain barrier and reaching the nicotinic receptors. The advantage of the
approach includes the relatively gradual rise of antibody levels, which may
reduce nicotine withdrawal symptoms, and the possible persistence of the
antibodies potentially provides long-term protection, possibly preventing
relapse. Proof-of-concept studies of at least two vaccine candidates have shown
correlations between antinicotine antibody exposure and smoking abstinence.
Unfortunately, the only vaccine tested in two large, randomized Phase III
trials, 3'-amino-methyl-nicotine r-exoprotein A conjugate vaccine (NicVAX(®),
Nabi Biopharmaceuticals, MD, USA), did not demonstrate efficacy. However,
despite the lack of efficacy, there is good reason for continued optimism. This
review will summarize the current status of the development of nicotine
vaccines, discuss possible causes for the mixed results and review future
scientific directions. |
Does natalizumab improve disease course of secondary progressive multiple sclerosis? | No. Atalizumab treatment for secondary progressive multiple sclerosis did not reduce progression on the primary multicomponent disability endpoint in part 1, but it did reduce progression on its upper-limb component. | Multiple sclerosis (MS) is a common and chronic central nervous system (CNS)
demyelinating disease and a leading cause of permanent disability. Patients most
often present with a relapsing-remitting disease course, typically progressing
over time to a phase of relentless advancement in secondary progressive MS
(SPMS), for which approved disease-modifying therapies are limited. In this
review, we summarize the pathophysiological mechanisms involved in the
development of SPMS and the rationale and clinical potential for natalizumab,
which is currently approved for the treatment of relapsing forms of MS, to exert
beneficial effects in reducing disease progression unrelated to relapses in
SPMS. In both forms of MS, active brain-tissue injury is associated with
inflammation; but in SPMS, the inflammatory response occurs at least partly
behind the blood-brain barrier and is followed by a cascade of events, including
persistent microglial activation that may lead to chronic demyelination and
neurodegeneration associated with irreversible disability. In patients with
relapsing forms of MS, natalizumab therapy is known to significantly reduce
intrathecal inflammatory responses which results in reductions in brain lesions
and brain atrophy as well as beneficial effects on clinical measures, such as
reduced frequency and severity of relapse and reduced accumulation of
disability. Natalizumab treatment also reduces levels of cerebrospinal fluid
chemokines and other biomarkers of intrathecal inflammation, axonal damage and
demyelination, and has demonstrated the ability to reduce innate immune
activation and intrathecal immunoglobulin synthesis in patients with MS. The
efficacy of natalizumab therapy in SPMS is currently being investigated in a
randomized, double-blind, placebo-controlled trial. Natalizumab, a monoclonal antibody that blocks lymphocyte infiltration in the
central nervous system, is a valuable tool in the treatment of relapsing forms
of multiple sclerosis (MS). In a phase III clinical trial comparing natalizumab
with placebo over 2 years, natalizumab reduced annualized relapse rate by 68%,
12-week confirmed disability progression by 42%, and reduced contrast-enhancing
lesions by 92%. In post hoc analyses, natalizumab treatment was associated with
37% of patients achieving no evidence of disease activity (versus 7% on placebo)
and 30% achieving sustained disability improvement (versus 19% on placebo).
Natalizumab did not achieve a statistically significant primary composite
disability outcome in a trial of 887 patients with secondary progressive MS, but
it did demonstrate a benefit on a prespecified component of the 9-Hole Peg Test.
The greatest risk of natalizumab treatment is progressive multifocal
leukoencephalopathy (PML), with a 23% mortality rate. Risk stratification on the
basis of immunosuppressant exposure, natalizumab treatment duration and
anti-John Cunningham virus (JCV) antibody status and index has greatly improved
clinical decision making. Other potential serious natalizumab-associated risks
reported in clinical trials and postmarketing settings include infusion
reactions, hepatotoxicity and rare, serious opportunistic infections. With more
than a decade of continuous postmarketing experience, natalizumab remains a very
effective option for patients with relapsing forms of MS. To optimize
appropriate selection of natalizumab for patients with relapsing MS, however, a
thorough understanding of individual patient risk factors for PML or other
adverse events is also required. BACKGROUND: Although several disease-modifying treatments are available for
relapsing multiple sclerosis, treatment effects have been more modest in
progressive multiple sclerosis and have been observed particularly in actively
relapsing subgroups or those with lesion activity on imaging. We sought to
assess whether natalizumab slows disease progression in secondary progressive
multiple sclerosis, independent of relapses.
METHODS: ASCEND was a phase 3, randomised, double-blind, placebo-controlled
trial (part 1) with an optional 2 year open-label extension (part 2). Enrolled
patients aged 18-58 years were natalizumab-naive and had secondary progressive
multiple sclerosis for 2 years or more, disability progression unrelated to
relapses in the previous year, and Expanded Disability Status Scale (EDSS)
scores of 3·0-6·5. In part 1, patients from 163 sites in 17 countries were
randomly assigned (1:1) to receive 300 mg intravenous natalizumab or placebo
every 4 weeks for 2 years. Patients were stratified by site and by EDSS score
(3·0-5·5 vs 6·0-6·5). Patients completing part 1 could enrol in part 2, in which
all patients received natalizumab every 4 weeks until the end of the study.
Throughout both parts, patients and staff were masked to the treatment received
in part 1. The primary outcome in part 1 was the proportion of patients with
sustained disability progression, assessed by one or more of three measures: the
EDSS, Timed 25-Foot Walk (T25FW), and 9-Hole Peg Test (9HPT). The primary
outcome in part 2 was the incidence of adverse events and serious adverse
events. Efficacy and safety analyses were done in the intention-to-treat
population. This trial is registered with ClinicalTrials.gov, number
NCT01416181.
FINDINGS: Between Sept 13, 2011, and July 16, 2015, 889 patients were randomly
assigned (n=440 to the natalizumab group, n=449 to the placebo group). In part
1, 195 (44%) of 439 natalizumab-treated patients and 214 (48%) of 448
placebo-treated patients had confirmed disability progression (odds ratio [OR]
0·86; 95% CI 0·66-1·13; p=0·287). No treatment effect was observed on the EDSS
(OR 1·06, 95% CI 0·74-1·53; nominal p=0·753) or the T25FW (0·98, 0·74-1·30;
nominal p=0·914) components of the primary outcome. However, natalizumab
treatment reduced 9HPT progression (OR 0·56, 95% CI 0·40-0·80; nominal p=0·001).
In part 1, 100 (22%) placebo-treated and 90 (20%) natalizumab-treated patients
had serious adverse events. In part 2, 291 natalizumab-continuing patients and
274 natalizumab-naive patients received natalizumab (median follow-up 160 weeks
[range 108-221]). Serious adverse events occurred in 39 (13%) patients
continuing natalizumab and in 24 (9%) patients initiating natalizumab. Two
deaths occurred in part 1, neither of which was considered related to study
treatment. No progressive multifocal leukoencephalopathy occurred.
INTERPRETATION: Natalizumab treatment for secondary progressive multiple
sclerosis did not reduce progression on the primary multicomponent disability
endpoint in part 1, but it did reduce progression on its upper-limb component.
Longer-term trials are needed to assess whether treatment of secondary
progressive multiple sclerosis might produce benefits on additional disability
components.
FUNDING: Biogen. |
Before 2019, what neurologic diseases are associated with the tau protein? | Tau proteins are involved in the pathogenesis of multiple sclerosis and amyotrophic lateral sclerosis. | The amyloid-forming proteins tau, αB crystallin, and amyloid P protein are all
found in lesions of multiple sclerosis (MS). Our previous work established that
amyloidogenic peptides from the small heat shock protein αB crystallin (HspB5)
and from amyloid β fibrils, characteristic of Alzheimer's disease, were
therapeutic in experimental autoimmune encephalomyelitis (EAE), reflecting
aspects of the pathology of MS. To understand the molecular basis for the
therapeutic effect, we showed a set of amyloidogenic peptides composed of six
amino acids, including those from tau, amyloid β A4, major prion protein (PrP),
HspB5, amylin, serum amyloid P, and insulin B chain, to be anti-inflammatory and
capable of reducing serological levels of interleukin-6 and attenuating
paralysis in EAE. The chaperone function of the fibrils correlates with the
therapeutic outcome. Fibrils composed of tau 623-628 precipitated 49 plasma
proteins, including apolipoprotein B-100, clusterin, transthyretin, and
complement C3, supporting the hypothesis that the fibrils are active biological
agents. Amyloid fibrils thus may provide benefit in MS and other
neuroinflammatory disorders. Multiple sclerosis (MS) is a disease which manifests demyelination of neuronal
cells in the brain. Despite extensive research on the mechanisms of disease
development and progression, the exact mechanism is not elucidated yet, which
has hampered drug development and subsequent treatment of the disease. We have
recently shown that the serum levels of arsenic and malondialdehyde, a lipid
peroxidation marker, are high in MS patients. In this article, we would like to
formulate the hypothesis that arsenic may cause MS by induction of inflammation,
degeneration, and apoptosis in neuronal cells. The induction of ROS generation
in cells upon exposure to arsenic as a heavy metal may be involved in the
pathogenesis of MS. Tau protein, a member of the family of
microtubule-associated proteins, is mainly expressed in neurons and contribute
to the assembly of neuronal microtubules network. Arsenic may affect the
hyperphosphorylation and aggregation of tau proteins and may be involved in the
cascade leading to deregulation of tau function associated with
neurodegeneration. For validation of this hypothesis, studies might be conducted
to evaluate the association of arsenic levels and tau protein levels in MS
patients. Further studies might also focus on the trafficking along microtubules
in neurons of MS patient with regard to hyperphosphorylation of tau protein.
This hypothesis may add a new dimension to the understanding of MS etiology and
help to design novel therapeutic agents against potential targets that might be
discovered. If this hypothesis proves to be true, tau phosphorylation inhibitors
can be potential candidates for MS drug development. Abnormally hyperphosphorylated tau is the major protein constituent of
neurofibrillary tangles (NFTs) in the brain of Alzheimer disease (AD) patients.
Cell cycle reactivation is considered an important neuropathological feature of
AD, and re-expression and activation of cell cycle regulators are known to occur
in neurons containing NFTs. The aim of the present study was to investigate cell
cycle reactivation during tau hyperphosphorylation in primary hippocampal
neurons. We used forskolin, a specific activator of PKA, to induce tau
hyperphosphorylation in cultured primary hippocampal neurons, and then measured
levels of cyclin D1 and cyclin B1. We found that forskolin induced
hyperphosphorylation of tau at Ser214, Ser396, and Ser202/Thr205 sites,
attaining peak levels at 6, 12, and 12 h, respectively, while returning to
normal levels at 24 h. Forskolin also induced a sustained cAMP elevation and PKA
activation, which peaked at 6 h, in association with activation and
overexpression of protein phosphatase-2A (PP-2A) at 24 h. The tau
hyperphosphorylation was accompanied by increases in cyclin D1 and cyclin B1
levels; immunostaining showed overlapping distribution of hyperphosphorylated
tau and cyclin D1 and cyclin B1 in primary hippocampal neurons. Forskolin
induced hyperphosphorylation of tau and increased cyclin D1 and cyclin B1
protein levels in HEK293/tau441 cells, but not in the HEK293/vector cells,
whereas the PKA inhibitor H89 inhibited the effects of forskolin on tau
hyperphosphorylation and cyclin D1 and cyclin B1 protein levels. These findings
suggest that forskolin induces tau hyperphosphorylation, which is itself
necessary for the subsequent increases of cyclin D1 and cyclin B1 levels. Alzheimer's disease (AD) is the most common cause of progressive dementia in the
elderly. It is characterized by a progressive and irreversible loss of cognitive
abilities and formation of senile plaques, composed mainly of amyloid β (Aβ),
and neurofibrillary tangles (NFTs), composed of tau protein, in the hippocampus
and cortex of afflicted humans. In brains of AD patients the metabolism of Aβ is
dysregulated, which leads to the accumulation and aggregation of Aβ. Metabolism
of Aβ and tau proteins is crucially influenced by autophagy. Autophagy is a
lysosome-dependent, homeostatic process, in which organelles and proteins are
degraded and recycled into energy. Thus, dysfunction of autophagy is suggested
to lead to the accretion of noxious proteins in the AD brain. In the present
review, we describe the process of autophagy and its importance in AD.
Additionally, we discuss mechanisms and genes linking autophagy and AD, i.e.,
the mTOR pathway, neuroinflammation, endocannabinoid system, ATG7, BCL2, BECN1,
CDK5, CLU, CTSD, FOXO1, GFAP, ITPR1, MAPT, PSEN1, SNCA, UBQLN1, and UCHL1. We
also present pharmacological agents acting via modulation of autophagy that may
show promise in AD therapy. This review updates our knowledge on autophagy
mechanisms proposing novel therapeutic targets for the treatment of AD. |
What is the difference between Daptacel and Pentacel? | Pentacel is a combination vaccine equivalent to the combination of Daptacel, IPOL and ActHIB vaccines. | |
AhR ligands are attractive drug targets for pharmaceutical development due to their induction of Cyp1a1, yes or no? | Yes, there is little evidence to support the indiscriminate exclusion of AhR activators/Cyp1a1 inducers from early drug developmental pipelines. | Expression of Cyp1a1 and its related enzyme activity have long been used as a
biomarker for aryl hydrocarbon receptor (AhR) activation and a warning of
dioxin-like toxicity. As a result, induction of Cyp1a1 by pharmaceutical drug
candidates or environmental contamits raises significant concern in risk
assessment. The current study evaluates the specificity of Cyp1a1 induction as a
marker for AhR affinity and activation and provides context to assess the
relevancy of AhR activation to risk assessment. In vivo experiments examined the
expression of Cyp1a1 and other AhR-regulated genes in liver, kidney, and heart
in response to 596 compounds. From this data set, a subset of 147 compounds was
then evaluated for their ability to activate or bind to the AhR using a
combination of gel shift, reporter gene, and competitive receptor binding
assays. Whereas in vivo Cyp1a1 mRNA expression is a sensitive marker for AhR
activation, it lacks specificity, because 81 (59%) of 137 compounds were found
to significantly induce Cyp1a1 in vivo but were not verified to bind or activate
the AhR in vitro. Combining in vivo and in vitro findings, we identified nine
AhR agonists, six of which are marketed therapeutics and have been approved by
the U.S. Food and Drug Administration, including leflunomide, flutamide, and
nimodipine. These drugs do not produce dioxin-like toxicity in rats or in
humans. These data demonstrate that induction of Cyp1a1 is a nonspecific
biomarker of direct AhR affinity and activation and lend further support to the
hypothesis that Cyp1a1 induction and/or AhR activation is not synonymous with
dioxin-like toxicity. |
Does the chromatin remodeling complex, RSC target H2A.Z nucleosomes? | H2A.Z probably helps RSC in keeping the gene nucleosome-free. | The genes transcribed by RNA polymerase III (Pol III) generally have intragenic
promoter elements. One of them, the yeast U6 snRNA (SNR6) gene is activated in
vitro by a positioned nucleosome between its intragenic box A and extragenic,
downstream box B separated by approximately 200 bp. We demonstrate here that the
in vivo chromatin structure of the gene region is characterized by the presence
of an array of positioned nucleosomes, with only one of them in the 5' end of
the gene having a regulatory role. A positioned nucleosome present between boxes
A and B in vivo does not move when the gene is repressed due to nutritional
deprivation. In contrast, the upstream nucleosome which covers the TATA box
under repressed conditions is shifted approximately 50 bp further upstream by
the ATP-dependent chromatin remodeler RSC upon activation. It is marked with the
histone variant H2A.Z and H4K16 acetylation in active state. In the absence of
H2A.Z, the chromatin structure of the gene does not change, suggesting that
H2A.Z is not required for establishing the active chromatin structure. These
results show that the chromatin structure directly participates in regulation of
a Pol III-transcribed gene under different states of its activity in vivo. The chromatin architecture of eukaryotic gene promoters is generally
characterized by a nucleosome-free region (NFR) flanked by at least one H2A.Z
variant nucleosome. Computational predictions of nucleosome positions based on
thermodynamic properties of DNA-histone interactions have met with limited
success. Here we show that the action of the essential RSC remodeling complex in
S. cerevisiae helps explain the discrepancy between theory and experiment. In
RSC-depleted cells, NFRs shrink such that the average positions of flanking
nucleosomes move toward predicted sites. Nucleosome positioning at distinct
subsets of promoters additionally requires the essential Myb family proteins
Abf1 and Reb1, whose binding sites are enriched in NFRs. In contrast, H2A.Z
deposition is dispensable for nucleosome positioning. By regulating H2A.Z
deposition using a steroid-inducible protein splicing strategy, we show that NFR
establishment is necessary for H2A.Z deposition. These studies suggest an
ordered pathway for the assembly of promoter chromatin architecture. FACT complex is involved in elongation and ensures fidelity in the initiation
step of transcription by RNA polymerase (pol) II. Histone variant H2A.Z is found
in nucleosomes at the 5'-end of many genes. We report here H2A.Z-chaperone
activity of the yeast FACT complex on the short, nucleosome-free, non-coding,
pol III-transcribed yeast tRNA genes. On a prototype gene, yeast SUP4, chromatin
remodeler RSC and FACT regulate its transcription through novel mechanisms,
wherein the two gene-flanking nucleosomes containing H2A.Z, play different
roles. Nhp6, which ensures transcription fidelity and helps load yFACT onto the
gene flanking nucleosomes, has inhibitory role. RSC maintains a nucleosome
abutting the gene terminator downstream, which results in reduced transcription
rate in active state while H2A.Z probably helps RSC in keeping the gene
nucleosome-free and serves as stress-sensor. All these factors maintain an
epigenetic state which allows the gene to return quickly from repressed to
active state and tones down the expression from the active SUP4 gene, required
probably to maintain the balance in cellular tRNA pool. |
List radioprotection agents. | Amifostine
CAPE
Melanin
Melatonin
Metformin
Tea polyphenols
alpha-2-macroglobulin | Amifostine is the first FDA approved cytoprotective and chemoprotective agent in
the treatment of cancer. However, it is not used widely because of its
ineffectiveness when administered orally. The objective of this study was to
prepare and evaluate the radioprotective efficacy of orally active amifostine
enteric microcapsules (amifostine mc). The microcapsules were prepared by spray
drying technique using Eudragit L100-55, and the yield was more than 80%. The
particle size and surface morphology were determined by particle analyzer and
scanning electron microscopy. Thermal characterization and infrared spectroscopy
were evaluated as well. In vitro release assay found that more than 60%
amifostine was released during the first 4h and the cumulative release ratio was
up to approximately 90% in 24h at 37°C. The radioprotective efficacy was
determined by 30-day survival study in mice acutely exposed to 6 Gy γ-ray
irradiation. The results showed that all dose groups of amifostine microcapsules
could significantly improve survival animal numbers and time. Furthermore,
tissue distribution studies indicated the concentrations of the active
metabolite WR-1065 in mice tissues of microcapsule group were higher than that
of oral amifostine group at 180 min (p<0.01). These results demonstrated that
oral administration of amifostine microcapsules provided effective
radioprotection compared to the bulk drug. As more cancer patients survive their disease, concerns about radiation
therapy-induced side effects have increased. The concept of radioprotection and
radiation injury mitigation and treatment offers the possibility to enhance the
therapeutic ratio of radiation therapy by limiting radiation therapy-induced
normal tissue injury without compromising its antitumor effect. Advances in the
understanding of the underlying mechanisms of radiation toxicity have stimulated
radiation oncologists to target these pathways across different organ systems.
These generalized radiation injury mechanisms include production of free
radicals such as superoxides, activation of inflammatory pathways, and vascular
endothelial dysfunction leading to tissue hypoxia. There is a significant body
of literature evaluating the effectiveness of various treatments in preventing,
mitigating, or treating radiation-induced normal tissue injury. Whereas some
reviews have focused on a specific disease site or agent, this critical review
focuses on a mechanistic classification of activity and assesses multiple agents
across different disease sites. The classification of agents used herein further
offers a useful framework to organize the multitude of treatments that have been
studied. Many commonly available treatments have demonstrated benefit in
prevention, mitigation, and/or treatment of radiation toxicity and warrant
further investigation. These drug-based approaches to radioprotection and
radiation injury mitigation and treatment represent an important method of
making radiation therapy safer. BACKGROUND: Use of natural agents is an upcoming area of research in cancer
biology. Caffeic acid phenethyl ester (CAPE) has received great attention
because of its therapeutic potential in various conditions including cancer. It
is an active/abundant component of propolis, a honey bee hive product produced
by bees using their enzyme-rich digestive secretions on resinous mix, bee wax
and pollen from plants. It is used to protect the beehive against bacteria and
other infections. Therefore a literature survey was done to understand the
therapeutic potential of this compound. Although a lot of work has been done on
chemotherapeutic aspects of CAPE and many reviews were available, yet its role
as a radiomodulator was not clear.
OBJECTIVE: The objective of the review was to collect data on role of Caffeic
acid phenethyl ester as radioprotector and /or sensitizer to evaluate its
potential as modulator of radiation effects during cancer therapy.
METHODS: For literature survey, Pubmed and Google search engines were used. Data
were collected up to August 2017. PubMed advanced search builder showed 845
papers on CAPE. This search was further narrowed down to synthesis,
bioavailability, CAPE derivatives, radioprotective and radiosensitizing effects
of CAPE.
RESULTS: This review focused on the differential radiomodulatory effects of CAPE
in normal and cancer cells. Besides chemistry and bioavailability, it's
potential as a therapeutic agent against radiation induced damage was also
evaluated.
CONCLUSION: CAPE was found to act both as radioprotector and radiosensitizer.
Depending on the tissue type it can modulate the radiation response by following
different mechanisms. PURPOSE: Exposure to ionizing radiation causes damage to the genomic integrity
and stability of the cell. Though a large number of molecules have been studied
for their radioprotective capability, no single agent is available today that
meets all the requirements of a good radiprotector. In this study, we have
investigated a combination of Resveratrol (RSV) and 3,3'-Diindolyl methane (DIM)
for its efficacy for radioprotection. It is our hypothesis that this combination
that possesses less toxicity than synthetic compounds, free radical scavenging
potential, and the capacity to interfere with the several of the signaling
cascades that trigger damage to cell by ionizing radiation may possess good
radioprotective capability.
MATERIALS AND METHODS: Mice were pre-treated with a combination of RSV and DIM
and the 30-day mortality assay, endogenous antioxidant levels in intestinal
mucosa, metaphase chromosomal aberrations, and micronuclei formation were
assessed after exposed to ionizing radiation.
RESULTS: The dose modifying factor (DRF) obtained for RSV, DIM, and the
combination is 1.15, 1.17, and 1.3, respectively. Pre-treatment of mice with the
combination results in significant (***p = .001) protection of the endogenous
antioxidant levels, chromosomal aberrations, micronuclei formation, after
exposure to ionizing radiation.
CONCLUSIONS: Our findings suggest that pre-treatment with the combination of RSV
and DIM protects effectively from the ionizing radiation-induced damage at the
molecular, cellular, and tissue levels by counteracting both the direct and
indirect effects. There is a need for novel and effective prophylactic treatments and
radioprotective materials to protect civilians and military personnel from
ionizing radiation in contaminated environments. Melanin, a naturally occurring,
ubiquitous pigment, has been shown to confer radioresistance, acting as a
potential radioprotective agent. We have demonstrated that melanized
Cryptococcus neoformans (CN) cells had improved survival post ionizing
irradiation than non-melanized ones. The goal of this study was to identify
morphological changes in melanized and non-melanized CN cells following
irradiation with densely-ionizing deuterons and alpha particles relative to
sparsely-ionizing gamma radiation. We observed significant differences between
the melanized and non-melanized CN cellular ultrastructure following
irradiation. Melanized CN cells were relatively resistant to mid and max-dose
levels of alpha particles and deuterons irradiation. Following irradiation the
capsule was stripped, but the cell wall was intact and structural integrity was
maintained. At the maximum dose, cytoplasmic vacuolization, and mitochondrial
swelling started to occur. In contrast, the non-melanized CN strain was
sensitive to the mid-dose radiation. Non-melanized cells presented two
morphologies: small condensed, and swollen, lacking structural integrity. This
morphological investigation provides the first direct evidence of the
radioprotective properties of melanin in CN cells subjected to high RBE and high
LET ionizing radiation. BACKGROUND: Nowadays, ionizing radiation is used for several applications in
medicine, industry, agriculture, and nuclear power generation. Besides the
beneficial roles of ionizing radiation, there are some concerns about accidental
exposure to radioactive sources. The threat posed by its use in terrorism is of
global concern. Furthermore, there are several side effects to normal organs for
patients who had undergone radiation treatment for cancer. Hence, the modulation
of radiation response in normal tissues was one of the most important aims of
radiobiology. Although, so far, several agents have been investigated for
protection and mitigation of radiation injury. Agents such as amifostine may
lead to severe toxicity, while others may interfere with radiation therapy
outcomes as a result of tumor protection. Metformin is a natural agent that is
well known as an antidiabetic drug. It has shown some antioxidant effects and
enhances DNA repair capacity, thereby ameliorating cell death following exposure
to radiation. Moreover, through targeting endogenous ROS production within
cells, it can mitigate radiation injury. This could potentially make it an
effective radiation countermeasure. In contrast to other radioprotectors,
metformin has shown modulatory effects through induction of several genes such
as AMPK, which suppresses reduction/ oxidation (redox) reactions, protects cells
from accumulation of unrepaired DNA, and attenuates initiation of inflammation
as well as fibrotic pathways. Interestingly, these properties of metformin can
sensitize cancer cells to radiotherapy.
CONCLUSION: In this article, we aimed to review the interesting properties of
metformin such as radioprotection, radiomitigation and radiosensitization, which
could make it an interesting adjuvant for clinical radiotherapy, as well as an
interesting candidate for mitigation of radiation injury after a radiation
disaster. |
What is the effect of Satb1 knock-out in mice? | inhibited cell viability and migration | The genome organizer special AT-rich sequence binding protein 1 (SATB1)
regulates specific functions through chromatin remodeling in T helper cells. It
was recently reported by our team that T cells from SATB1 conditional knockout
(SATB1cKO) mice, in which the Satb1 gene is deleted from hematopoietic cells,
impair phosphorylation of signaling molecules in response to T cell receptor
(TCR) crosslinking. However, in vivo T cell responses upon antigen presentation
in the absence of SATB1 remain unclear. In the current study, it was shown that
SATB1 modulates T cell antigen responses during the induction and effector
phases. Expression of SATB1 was upregulated in response to TCR stimulation,
suggesting that SATB1 is important for this antigen response. The role of SATB1
in TCR responses and induced experimental autoimmune encephalomyelitis (EAE) was
therefore examined using the myelin oligodendrocyte glycoprotein peptide 35-55
(MOG35-55) and pertussis toxin. SATB1cKO mice were found to be resistant to EAE
and had defects in IL-17- and IFN-γ-producing pathogenic T cells. Thus, SATB1
expression appears necessary for T cell function in the induction phase. To
examine SATB1 function during the effector phase, a tamoxifen-inducible SATB1
deletion system, SATB1cKO-ER-Cre mice, was used. Encephalitogenic T cells from
MOG35-55-immunized SATB1cKO-ER-Cre mice were transferred into healthy mice. Mice
that received tamoxifen before the onset of paralysis were resistant to EAE.
Furthermore, no disease progression occurred in recipient mice treated with
tamoxifen after the onset of EAE. Thus, SATB1 is essential for maintaining TCR
responsiveness during the induction and effector phases and may provide a novel
therapeutic target for T cell-mediated autoimmune diseases. OBJECTIVE: Satb1 regulates chromatin structure and gene expression, and is
aberrantly expressed in many tumors. However, there is still no report about
Satb1 functions in peripheral nerve injury until now. In this study, we explored
the regulatory effect of Satb1 on Schwann cells.
MATERIALS AND METHODS: MTT assay, transwell assay, and flow cytometry assay were
respectively used to determine Schwann cell viability, migration, and apoptosis.
The mRNA and phosphorylation levels of Satb1 and SHIP1 were assessed by RT-PCR
and Western blotting analysis, respectively. The correlation between Satb1 and
SHIP1 was examined by ChIP assay. The expressions of PI3K/AKT pathway related
factors were detected by Western blotting.
RESULTS: In the present study, we found that knock-out of Satb1 significantly
inhibited cell viability and migration, and promoted Schwann cells apoptosis.
Conversely, over-expression of Satb1 promoted cell viability, migration, and
inhibited apoptosis. Satb1 inhibited SHIP1 expression by recruiting HDAC1.
Furthermore, results showed that Satb1 activated the PI3K/AKT signaling pathway
by inhibiting the expression of SHIP1. SHIP1 showed significant reversal effects
on the regulatory roles of Satb1 in Schwann cells. Over-expression of Satb1 and
SHIP1 inhibited cell viability, migration, and promoted apoptosis.
CONCLUSIONS: Our study demonstrated that the Satb1 knock-out could inhibit the
activation of PI3K/AKT pathway by up-regulating SHIP1, thus inhibiting cell
viability and migration, and promoting Schwann cell apoptosis. |
Has ZP-PTH been tested in a phase II clinical trial? | Yes, ZP-PTH was successfully tested in a phase II clinical trial for the treatment of post-menopausal women with osteoporosis. | |
PH motifs in which genes endow breast cancer growth? | Although emerging roles of protease-activated receptor1&2 (PAR1&2) in cancer are recognized, their underlying signalling events are poorly understood. Signal-binding motifs in PAR1&2 are critical for breast cancer growth. This occurs via the association of the pleckstrin homology (PH) domain with Akt/PKB as a key signalling event of PARs. Other PH-domain signal-proteins such as Etk/Bmx and Vav3 also associate with PAR1 and PAR2 through their PH domains. PAR1 and PAR2 bind with priority to Etk/Bmx. A point mutation in PAR2, H349A, but not in R352A, abrogates PH-protein association and is sufficient to markedly reduce PAR2-instigated breast tumour growth in vivo and placental extravillous trophoblast (EVT) invasion in vitro. Similarly, the PAR1 mutant hPar1-7A, which is unable to bind the PH domain, reduces mammary tumours and EVT invasion, endowing these motifs with physiological significance and underscoring the importance of these previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological and physiological invasion processes. | Despite the fact that G protein-coupled receptors (GPCRs) mediate numerous
physiological processes and represent targets for therapeutics for a vast array
of diseases, their role in tumor biology is under appreciated.
Protease-activated receptors (PARs) form a family which belongs to GPCR class A.
PAR1&2 emerge with a central role in epithelial maligcies. Although the part
of PAR1&2 in cancer is on the rise, their underlying signaling events are poorly
understood. We review hereby past, present, and future cancer-associated PAR
biology. Mainly, their role in physiological (placenta-cytotophobalst) and
patho-physiological invasion processes. The identification and characterization
of signal pleckstrin homology (PH)-domain-binding motifs established critical
sites for breast cancer growth in PAR1&2. Among the proteins found to harbor
important PH-domains and are involved in PAR biology are Akt/PKB as also Etk/Bmx
and Vav3. A point mutation in PAR2, H349A, but not R352A, abrogated PH-protein
association and is sufficient to markedly reduce PAR2-instigated breast tumor
growth in vivo as also placental extravillous trophoblast (EVT) invasion in
vitro is markedly reduced. Similarly, the PAR1 mutant hPar1-7A, which is unable
to bind PH-domain, inhibits mammary tumors and EVT invasion, endowing these
motifs with physiological significance and underscoring the importance of these
previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological
and physiological invasion processes. |
What is herd immunity? | Vaccines are very effective in providing individual and community (herd) immunity against a range of diseases.
We argue that individuals who have access to vaccines and for whom vaccination is not medically contraindicated have a moral obligation to contribute to the realisation of herd immunity by being vaccinated. | Vaccines are very effective in providing individual and community (herd)
immunity against a range of diseases. In addition to protection against a range
of diseases, vaccines also have social and economic benefits. However, for
vaccines to be effective, routine immunization programmes must be undertaken
regularly to ensure individual and community protection. Nonetheless, in many
countries in Africa, vaccination coverage is low because governments struggle to
deliver vaccines to the most remote areas, thus contributing to constant
outbreaks of various vaccine-preventable diseases. African governments fail to
deliver vaccines to a significant percentage of the target population due to
many issues in key areas such as policy setting, programme management and
ficing, supply chain, global vaccine market, research and development of
vaccines. This review gives an overview of the causes of these issues and what
is currently being done to address them. This review will discuss the role of
philanthropic organisations such as the Bill and Melinda Gates Foundation and
global partnerships such as the global alliance for vaccines and immunizations
in the development, purchase and delivery of vaccines. INTRODUCTION: Delays in vaccination can stymie the development of herd immunity,
and a large proportion of children in the U.S. are known not to receive vaccines
on time. This study quantifies delays in vaccination, compares vaccination
timeliness to the proportion of children vaccinated, and evaluates the impact of
combination vaccine use and timely administration of hepatitis B vaccine birth
dose on vaccine timeliness among Michigan children.
METHODS: This retrospective cohort study used data from the Michigan Care
Improvement Registry-the state immunization information system-for children born
2006-2010. Children aged 24 months as of December 31, 2012, were included. The
proportion of children with timely administration of vaccine doses was
calculated, and the mean days of vaccination delay with SD were reported.
RESULTS: Among 620,592 Michigan children, 42.2% had received all vaccines, but
only 13.2% were vaccinated on time by age 24 months. Children's vaccinations
were delayed an average of 59.2 (SD=91.2) days by age 24 months for all
recommended vaccine doses. Children who received a timely hepatitis B vaccine
birth dose or who received a combination vaccine had less delay in vaccination.
CONCLUSIONS: Michigan children have high vaccination coverage based on standard
measures but few receive these vaccines on time. Promoting use of combination
vaccines may improve parental compliance with timely vaccination of children. We argue that individuals who have access to vaccines and for whom vaccination
is not medically contraindicated have a moral obligation to contribute to the
realisation of herd immunity by being vaccinated. Contrary to what some have
claimed, we argue that this individual moral obligation exists in spite of the
fact that each individual vaccination does not significantly affect vaccination
coverage rates and therefore does not significantly contribute to herd immunity.
Establishing the existence of a moral obligation to be vaccinated (both for
adults and for children) despite the negligible contribution each vaccination
can make to the realisation of herd immunity is important because such moral
obligation would strengthen the justification for coercive vaccination policies.
We show that two types of arguments-namely a utilitarian argument based on
Parfit's Principle of Group Beneficence and a contractualist argument-can ground
an individual moral obligation to be vaccinated, in spite of the imperceptible
contribution that any single vaccination makes to vaccine coverage rates. We add
a further argument for a moral obligation to be vaccinated that does not require
embracing problematic comprehensive moral theories such as utilitarianism or
contractualism. The argument is based on a "duty of easy rescue" applied to
collectives, which grounds a collective moral obligation to realise herd
immunity, and on a principle of fairness in the distribution of the burdens that
must be borne to realise herd immunity. |
Are multipotent adult progenitor cells effective for treatment of stroke? | No. There was no difference between the multipotent adult progenitor cell group and placebo groups in global stroke recovery at day 90. Further clinical trials evaluating the efficacy of the intervention in an earlier time window after stroke (<36 h) are planned. | BACKGROUND: Multipotent adult progenitor cells are a bone marrow-derived,
allogeneic, cell therapy product that modulates the immune system, and
represents a promising therapy for acute stroke. We aimed to identify the
highest, well-tolerated, and safest single dose of multipotent adult progenitor
cells, and if they were efficacious as a treatment for stroke recovery.
METHODS: We did a phase 2, randomised, double-blind, placebo-controlled,
dose-escalation trial of intravenous multipotent adult progenitor cells in 33
centres in the UK and the USA. We used a computer-generated randomisation
sequence and interactive voice and web response system to assign patients aged
18-83 years with moderately severe acute ischaemic stroke and a National
Institutes of Health Stroke Scale (NIHSS) score of 8-20 to treatment with
intravenous multipotent adult progenitor cells (400 million or 1200 million
cells) or placebo between 24 h and 48 h after symptom onset. Patients were
ineligible if there was a change in NIHSS of four or more points during at least
a 6 h period between screening and randomisation, had brainstem or lacunar
infarct, a substantial comorbid disease, an inability to undergo an MRI scan, or
had a history of splenectomy. In group 1, patients were enrolled and randomly
assigned in a 3:1 ratio to receive 400 million cells or placebo and assessed for
safety through 7 days. In group 2, patients were randomly assigned in a 3:1
ratio to receive 1200 million cells or placebo and assessed for safety through
the first 7 days. In group 3, patients were enrolled, randomly assigned, and
stratified by baseline NIHSS score to receive 1200 million cells or placebo in a
1:1 ratio within 24-48 h. Patients, investigators, and clinicians were masked to
treatment assignment. The primary safety outcome was dose-limiting toxicity
effects. The primary efficacy endpoint was global stroke recovery, which
combines dichotomised results from the modified Rankin scale, change in NIHSS
score from baseline, and Barthel index at day 90. Analysis was by intention to
treat (ITT) including all patients in groups 2 and 3 who received the
investigational agent or placebo. This study is registered with
ClinicalTrials.gov, number NCT01436487.
FINDINGS: The study was done between Oct 24, 2011, and Dec 7, 2015. After safety
assessments in eight patients in group 1, 129 patients were randomly assigned
(67 to receive multipotent adult progenitor cells and 62 to receive placebo) in
groups 2 and 3 (1200 million cells). The ITT populations consisted of 65
patients who received multipotent adult progenitor cells and 61 patients who
received placebo. There were no dose-limiting toxicity events in either group.
There were no infusional or allergic reactions and no difference in
treatment-emergent adverse events between the groups (64 [99%] of 65 patients in
the multipotent adult progenitor cell group vs 59 [97%] of 61 in the placebo
group). There was no difference between the multipotent adult progenitor cell
group and placebo groups in global stroke recovery at day 90 (odds ratio 1·08
[95% CI 0·55-2·09], p=0·83).
INTERPRETATION: Administration of multipotent adult progenitor cells was safe
and well tolerated in patients with acute ischaemic stroke. Although no
significant improvement was observed at 90 days in neurological outcomes with
multipotent adult progenitor cells treatment, further clinical trials evaluating
the efficacy of the intervention in an earlier time window after stroke (<36 h)
are planned.
FUNDING: Athersys Inc. |
List the stages/types of Multiple Sclerosis. | Multiple sclerosis presents with different phenotypes, most commonly a relapsing-remitting course and, less frequently, a progressive accumulation of disability from disease onset (primary progressive multiple sclerosis). The majority of people with relapsing-remitting multiple sclerosis, after a variable time, switch to a stage characterised by gradual neurological worsening known as secondary progressive multiple sclerosis. | OBJECTIVE: To perform systematic transcriptomic analysis of multiple sclerosis
(MS) risk genes in peripheral blood mononuclear cells (PBMCs) of subjects with
distinct MS stages and describe the pathways characterized by dysregulated gene
expressions.
METHODS: We monitored gene expression levels in PBMCs from 3 independent cohorts
for a total of 297 cases (including clinically isolated syndromes (CIS),
relapsing-remitting MS, primary and secondary progressive MS) and 96 healthy
controls by distinct microarray platforms and quantitative PCR. Differential
expression and pathway analyses for distinct MS stages were defined and
validated by literature mining.
RESULTS: Genes located in the vicinity of MS risk variants displayed altered
expression in peripheral blood at distinct stages of MS compared with the
healthy population. The frequency of dysregulation was significantly higher than
expected in CIS and progressive forms of MS. Pathway analysis for each MS
stage-specific gene list showed that dysregulated genes contributed to
pathogenic processes with scientific evidence in MS.
CONCLUSIONS: Systematic gene expression analysis in PBMCs highlighted selective
dysregulation of MS susceptibility genes playing a role in novel and well-known
pathogenic pathways. Multiple sclerosis is an immune-mediated inflammatory disease of the central
nervous system characterised by demyelination, neuroaxonal loss and a
heterogeneous clinical course. Multiple sclerosis presents with different
phenotypes, most commonly a relapsing-remitting course and, less frequently, a
progressive accumulation of disability from disease onset (primary progressive
multiple sclerosis). The majority of people with relapsing-remitting multiple
sclerosis, after a variable time, switch to a stage characterised by gradual
neurological worsening known as secondary progressive multiple sclerosis. We
have a limited understanding of the mechanisms underlying multiple sclerosis,
and it is believed that multiple genetic, environmental and endogenous factors
are elements driving inflammation and ultimately neurodegeneration. Axonal loss
and grey matter damage have been regarded as amongst the leading causes of
irreversible neurological disability in the progressive stages. There are over a
dozen disease-modifying therapies currently licenced for relapsing-remitting
multiple sclerosis, but none of these has provided evidence of effectiveness in
secondary progressive multiple sclerosis. Recently, there has been some early
modest success with siponimod in secondary progressive multiple sclerosis and
ocrelizumab in primary progressive multiple sclerosis. Finding treatments to
delay or prevent the courses of secondary progressive multiple sclerosis is an
unmet and essential goal of the research in multiple sclerosis. In this review,
we discuss new findings regarding drugs with immunomodulatory, neuroprotective
or regenerative properties and possible treatment strategies for secondary
progressive multiple sclerosis. We examine the field broadly to include trials
where participants have progressive or relapsing phenotypes. We summarise the
most relevant results from newer investigations from phase II and III randomised
controlled trials over the past decade, with particular attention to the last 5
years. |
What is known about Opicinumab for multiple sclerosis? | Opicinumab is a new Anti lingo 1 monoclonal antibody that is tested in relapsing remitting multiple sclerosis. The anti-LINGO-1 trial showed that the drug is safe and tolerable. A future phase II trial will provide more insights regarding the compound. | Multiple sclerosis (MS) is a chronic demyelinating disease of the central
nervous system (CNS). The modern treatment era for MS witnessed a growing pool
of drugs now available for use in clinical practice. These therapies work at
different levels, however there is a lack of treatments acting on the
neurodegenerative component or improving mechanism of repair. Areas covered: The
latest knowledge about the pathophysiological changes occurring in MS have
translated into novel treatments at different stages of development. Drugs for
MS work mainly through modulating the inflammatory factors of the disease, but
enhancing remyelination may be more successful in reducing long-term disability.
Anti-LINGO-1 (opicinumab) is the first investigational product that achieved
phase I trial with the aim of remyelination and axonal protection and/or repair
in MS. Expert commentary: Over the past decade considerable strength has been
applied to find more reliable strategies to improve myelin repair. The
anti-LINGO-1 trial showed that the drug is safe and tolerable. A future phase II
trial will provide more insights regarding the compound. The greatest challenge
for myelin repair therapies will be how to monitor their efficacy. Eventually
research will need to focus on consistent tools to assess the grade of
remyelination in vivo. Management of progressive multiple sclerosis (MS) is one of the main challenges
of the new century. Based on our knowledge of pathophysiology, three therapeutic
strategies are proposed: anti-inflammatory (ocrelizumab, siponimod…);
remyelinating (opicinumab); and neuroprotective (high-dose biotin, ibudilast,
simvastatin…). Nevertheless, despite recent promising positive clinical trials,
new methodological approaches for therapeutic protocols with adaptable outcomes
to assess progression are still needed. BACKGROUND: Opicinumab is a human monoclonal antibody against LINGO-1, an
inhibitor of oligodendrocyte differentiation and axonal regeneration. Previous
findings suggested that opicinumab treatment might enhance remyelination in
patients with CNS demyelinating diseases. We aimed to assess the safety and
efficacy of opicinumab in patients with relapsing multiple sclerosis.
METHODS: We did a randomised, double-blind, placebo-controlled, dose-ranging,
phase 2 study (SYNERGY) at 72 sites in 12 countries. Participants (aged 18-58
years) with relapsing multiple sclerosis (relapsing-remitting multiple sclerosis
and secondary progressive multiple sclerosis with relapses) were randomised in a
1:2:2:2:2 ratio by an interactive voice and web response system to opicinumab 3
mg/kg, 10 mg/kg, 30 mg/kg, or 100 mg/kg, or placebo. An identical volume of
study drug was administered intravenously once every 4 weeks. All participants
self-administered intramuscular interferon beta-1a as background
anti-inflammatory treatment once a week. The primary endpoint was the percentage
of participants achieving confirmed disability improvement over 72 weeks, which
was a multicomponent endpoint measured by the Expanded Disability Status Scale,
the Timed 25-Foot Walk, the Nine-Hole Peg Test, and the 3 s Paced Auditory
Serial Addition Test. The primary endpoint was analysed under intention-to-treat
principles. This study is registered at ClinicalTrials.gov, number NCT01864148.
FINDINGS: Between Aug 13, 2013, and July 31, 2014, 419 patients were enrolled
and randomly assigned either placebo (n=93) or opicinumab 3 mg/kg (n=45), 10
mg/kg (n=95), 30 mg/kg (n=94; one patient did not receive the assigned
treatment), or 100 mg/kg (n=92). The last patient visit was on March 29, 2016.
Confirmed disability improvement over 72 weeks was seen in 45 (49%) of 91
patients assigned to placebo, 21 (47%) of 45 assigned to opicinumab 3 mg/kg, 59
(63%) of 94 assigned to opicinumab 10 mg/kg, 59 (65%) of 91 assigned to
opicinumab 30 mg/kg, and 36 (40%) of 91 assigned to opicinumab 100 mg/kg. A
linear dose-response in the probability of confirmed disability improvement was
not seen (linear trend test p=0·89). Adverse events occurred in 79 (85%)
patients assigned placebo and in 275 (85%) assigned any dose of opicinumab. The
most common adverse events of any grade in patients assigned any dose of
opicinumab included influenza-like illness (140 [43%] with any dose of
opicinumab vs 37 [40%] with placebo), multiple sclerosis relapses (117 [36%] vs
30 [32%]), and headache (51 [16%] vs 23 [25%]). Serious adverse events reported
as related to treatment were urinary tract infection in one (1%) participant in
the the placebo group, suicidal ideation and intentional overdose in one (1%)
participant in the 30 mg/kg opicinumab group, bipolar disorder in one (1%)
participant in the 100 mg/kg opicinumab group, and hypersensitivity in four (4%)
participants in the 100 mg/kg opicinumab group. One patient in the opicinumab 30
mg/kg group died during the study due to a traffic accident, which was not
considered related to study treatment.
INTERPRETATION: Our findings did not show a significant dose-linear improvement
in disability compared with placebo in patients with relapsing multiple
sclerosis. Further studies are needed to investigate whether some subpopulations
identified in the study might benefit from opicinumab treatment at an optimum
dose.
FUNDING: Biogen. |
What is the target of Inebilizumab? | Inebilizumab is an anti-CD19 antibody with enhanced antibody-dependent cell-mediated cytotoxicity against B cells, is currently being evaluated in multiple sclerosis and neuromyelitis optica. | Monoclonal antibody therapy is a new treatment strategy for many types of
diseases including cancers and autoimmune diseases, realizing a high efficacy
and tolerability. In multiple sclerosis (MS) and neuromyelitis optica (NMO)
spectrum disorders, several monoclonal antibodies have been suggested to
decrease the incidence of clinical relapse and the disease activity. In MS,
anti-α4 integrin (natalizumab), anti-CD52 (alemtuzumab), anti-CD25 (daclizumab)
and anti-CD20 (ocrelizumab) have been shown to effectively reduce the relapses
in randomized controlled trials and have been approved by the Food and Drug
Administration. Specifically, ocrelizumab is the first drug that has shown
significant suppression of brain volume loss and suppression of chronic
disability progression. In NMO, though there have yet to be any approved
monoclonal antibodies, rituximab, anti-complement C5 (eculizumab), anti-IL-6
receptor (tocilizumab), anti-CD19 (inebilizumab) and non-pathogenic
anti-aquaporin 4 (aquaporumab) have been suggested to be effective, and some of
these are now under clinical trials. Aquaporumab is a non-pathogenic recombit
human monoclonal antibody that competitively inhibits the binding of the
pathogenic auto-antibody against aquaporin 4 in NMO patients; thus, it is
expected to be highly disease specific with less non-specific adverse events.
Some of these monoclonal antibodies in MS and NMO are known to cause several
notable adverse events. Natalizumab and rituximab increase the risk of
progressive multifocal leukoencephalopathy. Eculizumab increases the risk of
meningococcal infection. Tocilizumab is known to cause intestinal diverticulitis
that can cause intestinal perforation. In this review, we summarize the
characteristics of, evidence for and notable adverse events of each monoclonal
antibody in MS and NMO. BACKGROUND: B cells may be involved in the pathophysiology of multiple sclerosis
(MS). Inebilizumab (formerly MEDI-551) binds to and depletes CD19+ B cells.
OBJECTIVES: To assess safety, tolerability, pharmacokinetics, pharmacodynamics
and immunogenicity of inebilizumab in adults with relapsing MS.
METHODS: This phase 1 trial randomised 28 patients 3:1 (21, inebilizumab; 7,
placebo) to inebilizumab (2 intravenous (IV) doses, days 1 and 15: 30, 100 or
600 mg; or single subcutaneous (SC) dose on day 1: 60 or 300 mg) or matching
placebo, with follow-up until at least week 24 or return of CD19+ B-cell count
to ⩾80 cells/µL.
RESULTS: Complete B-cell depletion was observed across all doses.
Infusion/injection (grade 1/2) reactions occurred in 6/15 patients receiving
inebilizumab IV, 2/5 placebo IV and 1/6 inebilizumab SC. Serious adverse events
occurred in three patients receiving inebilizumab: pyrexia, mixed-drug
intoxication (unrelated to inebilizumab; resulted in death) and urinary tract
infection. Mean number of cumulative new gadolinium-enhancing lesions over
24 weeks was 0.1 with inebilizumab versus 1.3 with placebo; mean numbers of
new/newly enlarging T2 lesions were 0.4 and 2.4, respectively.
CONCLUSION: Inebilizumab had an acceptable safety profile in relapsing MS
patients and showed a trend in reductions in new/newly enlarging and
gadolinium-enhancing lesions. BACKGROUND: The present review is part of the ESCMID Study Group for Infections
in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and
biological therapies.
AIMS: To review, from an Infectious Diseases perspective, the safety profile of
agents targeting CD19, CD20 and CD52 and to suggest preventive recommendations.
SOURCES: Computer-based MEDLINE searches with MeSH terms pertaining to each
agent or therapeutic family.
CONTENT: Although CD19-targeted agents (blinatumomab or inebilizumab) are not
associated with an increased risk of infection, they may cause IgG
hypogammaglobulinaemia and neutropenia. The requirement for prolonged
intravenous infusion of blinatumomab may increase the risk of
catheter-associated bloodstream infections. Infection remains the most common
non-haematological adverse effect of anti-CD20 monoclonal antibodies, including
severe respiratory tract infection, hepatitis B virus (HBV) reactivation and
varicella-zoster virus infection. Screening for chronic or resolved HBV
infection is recommended for patients receiving anti-CD20 monoclonal antibodies.
Antiviral prophylaxis should be offered for 12-18 months to hepatitis B surface
antigen (HBsAg)-positive and HBsAg-negative/anti-hepatitis B core antibody
(HBc)-positive patients. Anti-Pneumocystis prophylaxis should be considered in
patients receiving concomitant chemotherapy, particularly steroids. Alemtuzumab
(anti-CD52) increases the risk of infections, in particular among leukaemia and
solid organ transplant patients. These populations benefit from
anti-Pneumocystis prophylaxis, prevention strategies for cytomegalovirus
infection, and screening for HBV, hepatitis C virus and tuberculosis. Antiviral
prophylaxis for at least 6-12 months should be provided for HBsAg-positive
patients.
IMPLICATIONS: As there are limited clinical data for many of the reviewed
agents, special attention must be given to promptly detect and report emerging
infectious complications. For decades, B cells were ignored in multiple sclerosis (MS) pathogenesis, and
the disease was always regarded as a T cell-mediated disorder. Recent evidence
shows that there is an antigen-driven B-cell response in the central nervous
system of patients with MS, and memory B cells/plasma cells are detectable in MS
lesions. The striking efficacy of B cell-depleting therapies in reducing the
inflammatory activity of the disease highlights that B cells may play more
pathogenetic roles than expected. B cells express several unique characteristic
markers on their surface, for example, CD19, CD20 molecules, that provide
selective targets for monoclonal antibodies. In this respect, several B
cell-targeted therapies emerged, including anti-CD20 antibodies (rituximab,
ocrelizumab, and ofatumumab), anti-CD19 antibody (inebilizumab), and agents
targeting the BAFF/APRIL signaling pathway (atacicept, belimumab, and
LY2127399). In this review, we discuss, in detail, the immunobiology of B cells
and their protective and destructive roles in MS pathogenesis. In the second
part, we list the completed and ongoing clinical trials investigating the safety
and efficacy of B cell-related monoclonal antibodies in MS. OBJECTIVE: B cells impact the progression of systemic sclerosis (SSc;
scleroderma) through multiple pathogenic mechanisms. CD19 inhibition in mice
reduced skin thickness, collagen production, and autoantibody levels, consistent
with CD19 expression on plasma cells (PCs), the source of antibody production.
PC depletion could effectively reduce collagen deposition and inflammation in
SSc; therefore, we investigated the effects of PC depletion on SSc disease
activity.
METHODS: A PC gene signature was evaluated in SSc skin biopsy samples in 2 phase
I clinical trials. We assessed microarray data from tissue from public studies
of chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis
(IPF), dermatomyositis (DM), systemic lupus erythematosus (SLE), and atopic
dermatitis, as well as blood from a phase IIb clinical trial in SLE.
RESULTS: The PC signature was elevated in SSc skin specimens compared to healthy
donor skin (P = 2.28 × 10-6 ) and correlated with the baseline modified Rod
skin thickness score (MRSS) (r = 0.64, P = 0.0004). Patients with a high PC
signature at baseline showed greater improvement in the MRSS (mean ± SD change
35 ± 16%; P = 6.30 × 10-4 ) following anti-CD19 treatment with inebilizumab
(MEDI-551) than did patients with a low PC signature at baseline (mean ± SD
change 8 ± 12%; P = 0.104). The PC signature was overexpressed in tissue from
patients with SLE, DM, COPD, interstitial lung disease, and IPF relative to
controls (all fold change >2; P < 0.001). The PC signature also differed
significantly between SLE patients with mild-to-moderate disease and those with
severe disease (SLE Disease Activity Index cutoff at 10) (fold change 1.44; P =
3.90 × 10-3 ) and correlated significantly with the degree of emphysema in COPD
(r = 0.53, P = 7.55 × 10-8 ).
CONCLUSION: Our results support the notion that PCs have a role in the
pathogenesis of SSc and other autoimmune or pulmonary indications. An elevated
pretreatment PC signature was associated with increased benefit from MEDI-551 in
SSc. BACKGROUND: No approved therapies exist for neuromyelitis optica spectrum
disorder (NMOSD), a rare, relapsing, autoimmune, inflammatory disease of the CNS
that causes blindness and paralysis. We aimed to assess the efficacy and safety
of inebilizumab, an anti-CD19, B cell-depleting antibody, in reducing the risk
of attacks and disability in NMOSD.
METHODS: We did a multicentre, double-blind, randomised placebo-controlled phase
2/3 study at 99 outpatient specialty clinics or hospitals in 25 countries.
Eligible participants were adults (≥18 years old) with a diagnosis of NMOSD, an
Expanded Disability Status Scale score of 8·0 or less, and a history of at least
one attack requiring rescue therapy in the year before screening or at least two
attacks requiring rescue therapy in the 2 years before screening. Participants
were randomly allocated (3:1) to 300 mg intravenous inebilizumab or placebo with
a central interactive voice response system or interactive web response system
and permuted block randomisation. Inebilizumab or placebo was administered on
days 1 and 15. Participants, investigators, and all clinical staff were masked
to the treatments, and inebilizumab and placebo were indistinguishable in
appearance. The primary endpoint was time to onset of an NMOSD attack, as
determined by the adjudication committee. Efficacy endpoints were assessed in
all randomly allocated patients who received at least one dose of study
intervention, and safety endpoints were assessed in the as-treated population.
The study is registered with ClinicalTrials.gov, number NCT02200770.
FINDINGS: Between Jan 6, 2015, and Sept 24, 2018, 230 participants were randomly
assigned to treatment and dosed, with 174 participants receiving inebilizumab
and 56 receiving placebo. The randomised controlled period was stopped before
complete enrolment, as recommended by the independent data-monitoring committee,
because of a clear demonstration of efficacy. 21 (12%) of 174 participants
receiving inebilizumab had an attack versus 22 (39%) of 56 participants
receiving placebo (hazard ratio 0·272 [95% CI 0·150-0·496]; p<0·0001). Adverse
events occurred in 125 (72%) of 174 participants receiving inebilizumab and 41
(73%) of 56 participants receiving placebo. Serious adverse events occurred in
eight (5%) of 174 participants receiving inebilizumab and five (9%) of 56
participants receiving placebo.
INTERPRETATION: Compared with placebo, inebilizumab reduced the risk of an NMOSD
attack. Inebilizumab has potential application as an evidence-based treatment
for patients with NMOSD.
FUNDING: MedImmune and Viela Bio. |
Is eculizumab effective for Guillain-Barré syndrome? | In a clinical trial eculizumab did not achieve primary outcome for Guillain-Barre syndrome. However, because this was a small study without statistical comparison with the placebo group, the efficacy and safety of eculizumab could be investigated in larger, randomised controlled trials. | The outcome of Guillain-Barré syndrome (GBS) remains unchanged since plasma
exchange and intravenous immunoglobulin (IVIg) were introduced over 20 years
ago. Pathogenesis studies on GBS have identified the terminal component of
complement cascade as a key disease mediator and therapeutic target. We report
the first use of terminal complement pathway inhibition with eculizumab in
humans with GBS. In a randomised, double-blind, placebo-controlled trial, 28
subjects eligible on the basis of GBS disability grade of at least 3 were
screened, of whom 8 (29%) were randomised. Five received eculizumab for 4 weeks,
alongside standard IVIg treatment. The safety outcomes, monitored via adverse
events capture, showed eculizumab to be well-tolerated and safe when
administered in conjunction with IVIg. Primary and secondary efficacy outcomes
in the form of GBS disability scores (GBS DS), MRC sum scores, Rasch overall
disability scores, and overall neuropathy limitation scores are reported
descriptively. For the primary efficacy outcome at 4 weeks after recruitment,
two of two placebo- and two of five eculizumab-treated subjects had improved by
one or more grades on the GBS DS. Although the small sample size precludes a
statistically meaningful analysis, these pilot data indicate further studies on
complement inhibition in GBS are warranted. BACKGROUND: Despite the introduction of plasmapheresis and immunoglobulin
therapy, many patients with Guillain-Barré syndrome still have an incomplete
recovery. Evidence from pathogenesis studies suggests the involvement of
complement-mediated peripheral nerve damage. We aimed to investigate the safety
and efficacy of eculizumab, a humanised monoclonal antibody against the
complement protein C5, in patients with severe Guillain-Barré syndrome.
METHODS: This study was a 24 week, multicentre, double-blind,
placebo-controlled, randomised phase 2 trial done at 13 hospitals in Japan.
Eligible patients with Guillain-Barré syndrome were aged 18 years or older and
could not walk independently (Guillain-Barré syndrome functional grade 3-5).
Patients were randomly assigned (2:1) to receive 4 weeks of intravenous
immunoglobulin plus either eculizumab (900 mg) or placebo; randomisation was
done via a computer-generated process and web response system with minimisation
for functional grade and age. The study had a parallel non-comparative
single-arm outcome measure. The primary outcomes were efficacy (the proportion
of patients with restored ability to walk independently [functional grade ≤2] at
week 4) in the eculizumab group and safety in the full analysis set. For the
efficacy endpoint, we predefined a response rate threshold of the lower 90% CI
boundary exceeding 50%. This trial is registered with ClinicalTrials.gov,
number, NCT02493725.
FINDINGS: Between Aug 10, 2015, and April 21, 2016, 34 patients were assigned to
receive either eculizumab (n=23) or placebo (n=11). At week 4, the proportion of
the patients able to walk independently (functional grade ≤2) was 61% (90% CI
42-78; n=14) in the eculizumab group, and 45% (20-73; n=5) in the placebo group.
Adverse events occurred in all 34 patients. Three patients had serious adverse
events: two in the eculizumab group (anaphylaxis in one patient and intracranial
haemorrhage and abscess in another patient) and one in the placebo group
(depression). The possibility that anaphylaxis and intracranial abscess were
related to eculizumab could not be excluded. No deaths or meningococcal
infections occurred.
INTERPRETATION: The primary outcome measure did not reach the predefined
response rate. However, because this is a small study without statistical
comparison with the placebo group, the efficacy and safety of eculizumab could
be investigated in larger, randomised controlled trials.
FUNDING: The Japan Agency for Medical Research and Development, Ministry of
Health, Labor and Welfare, and Alexion Pharmaceuticals. |
List Mcl-1 inhibitors. | A-1210477
S63845 | OBJECTIVE: There are number of studies which report that BCL-2 anti-apoptotic
proteins (e.g. BCL-2, BCL-XL, and MCL-1) are highly expressed in cervical cancer
tissues compared to the normal cervical epithelia. Despite these reports,
targeting these proteins for cervical cancer treatment has not been explored
extensively. BH3-mimetics that inhibit specific BCL-2 anti-apoptotic proteins
may hold encouraging treatment outcomes for cervical cancer management. Hence,
the aim of this pilot study is to investigate the sensitivity of cervical cancer
cell lines to combination of two BH3-mimetics namely ABT-263 which selectively
inhibits BCL-2, BCL-XL and BCL-w and A-1210477, a selective MCL-1 inhibitor.
RESULTS: We report that combination of A-1210477 and ABT-263 exhibited
synergistic effects on all cervical cancer cell lines tested. Drug sensitization
studies revealed that A-1210477 sensitised the cervical cancer cell lines SiHa
and CaSki to ABT-263 by 11- and fivefold, respectively. Sensitization also
occurred in the opposite direction whereby ABT-263 sensitised SiHa and CaSki to
A-1210477 by eightfold. This report shows that combination of ABT-263 and
A-1210477 could be a potential treatment strategy for cervical cancer. Extensive
drug mechanistic studies and drug sensitivity studies in physiological models
are necessary to unleash the prospect of this combination for cervical cancer
therapy. BACKGROUND: Aberrant overexpression of Bcl-2 protein has been detected in 80% of
nasopharyngeal carcinoma (NPC), and Bcl-2 family proteins are implicated in both
NPC oncogenesis and chemotherapy resistance. Previous studies have shown that
while treatment of NPC cells with Bcl-2 family inhibitors alone is rarely
effective, concomitant treatment with a cytotoxic reagent such as cisplatin can
increase efficacy through a synergistic effect. The aim of the current work was
to determine how we might increase the efficacy of Bcl-2 family inhibitors in
the absence of cytotoxic reagents, which are associated with negative side
effect profiles.
METHODS: We assessed cell proliferation in Bcl-2 high-expressing NPC cells by
CCK-8 assay after treatment with the Bcl-2 inhibitor ABT-199 and/or the Mcl-1
inhibitor S63845. Apoptotic induction by ABT-199 was evaluated by Annexin V-FITC
and PI double staining. We also evaluated Bcl-2 family protein expression (Bim,
Mcl-1, Bcl-xL, Noxa) after treatment with ABT-199 by western blotting. Finally,
xenografted Balb/c nude mice were used to test ABT-199 efficacy in vivo, H&E and
immunohistochemistry assay were used to analyze tumor samples.
RESULTS: ABT-199 effectively induced NPC cell apoptosis in vitro and in the
xenograft model. Following ABT-199 treatment in NPC cells, upregulation of Mcl-1
and Bcl-xL can lead to drug resistance, while concomitant Noxa overexpression
partially neutralized the Mcl-1-caused resistance. Given that ABT-199 induces
apoptosis in NPC cells through the Bcl-2/Noxa/Mcl-1 axis, treatment avenues
further targeting this pathway should be promising. Indeed, the newly developed
Mcl-1 inhibitor S63845 in combination with ABT-199 had a synergistic effect on
NPC cell apoptosis.
CONCLUSION: Bcl-2 inhibition in NPC cells with ABT-199 triggers apoptosis
through the Bcl-2/Noxa/Mcl-1 axis, and dual inhibition of the anti-apoptotic
Bcl-2 family proteins Bcl-2 and Mcl-1 provided a strong synergistic effect
without the need for adjunctive cytotoxic agent treatment with cisplatin. Despite the recent advancement in treating melanoma, options are still limited
for patients without BRAF mutations or in relapse from current treatments. BH3
mimetics against members of the BCL-2 family have gained excitement with the
recent success in hematological maligcies. However, single drug BH3 mimetic
therapy in melanoma has limited effectiveness due to escape by the
anti-apoptotic protein MCL-1 and/or survival of melanoma-initiating cells
(MICs). We tested the efficacy of the BH3 mimetic combination of A-1210477 (an
MCL-1 inhibitor) and ABT-263 (a BCL-2/BCL-XL/BCL-W inhibitor) in killing
melanoma, especially MICs. We also sought to better define Dynamin-Related
Protein 1 (DRP-1)'s role in melanoma; DRP-1 is known to interact with members of
the BCL-2 family and is a possible therapeutic target for melanoma treatment. We
used multiple assays (cell viability, apoptosis, bright field, immunoblot, and
sphere formation), as well as the CRISPR/Cas9 genome-editing techniques. For
clinical relevance, we employed patient samples of different mutation status,
including some relapsed from current treatments such as anti-PD-1 immunotherapy.
We found the BH3 mimetic combination kill both the MICs and non-MICs (bulk of
melanoma) in all cell lines and patient samples irrespective of the mutation
status or relapsed state (p < 0.05). Unexpectedly, the major pro-apoptotic
proteins, NOXA and BIM, are not necessary for the combination-induced cell
death. Furthermore, the combination impedes the activation of DRP-1, and
inhibition of DRP-1 further enhances apoptosis (p < 0.05). DRP-1 effects in
melanoma differ from those seen in other cancer cells. These results provide new
insights into BCL-2 family's regulation of the apoptotic pathway in melanoma,
and suggest that inhibiting the major anti-apoptotic proteins is sufficient to
induce cell death even without involvement from major pro-apoptotic proteins.
Importantly, our study also indicates that DRP-1 inhibition is a promising
adjuvant for BH3 mimetics in melanoma treatment. The impressive selectivity and efficacy of BH3 mimetics for treating cancer has
largely been limited to BCL-2 dependent hematological maligcies. Most solid
tumors depend on other anti-apoptotic proteins, including MCL-1, for survival.
The recent description of S63845 as the first specific and potent MCL-1
inhibitor represents an important therapeutic advance, since MCL-1 is not
targeted by the currently available BH3 mimetics, Navitoclax or Venetoclax, and
is commonly associated with chemoresistance. In this study, we confirm a high
binding affinity and selectivity of S63845 to induce apoptosis in
MCL-1-dependent cancer cell lines. Furthermore, S63845 synergizes with other BH3
mimetics to induce apoptosis in cell lines derived from both hematological and
solid tumors. Although the anti-apoptotic BCL-2 family members in these cell
lines interact with a spectrum of pro-apoptotic BH3-only proteins to regulate
apoptosis, these interactions alone do not explain the relative sensitivities of
these cell lines to BH3 mimetic-induced apoptosis. These findings necessitated
further investigation into the requirement of BH3-only proteins in BH3
mimetic-mediated apoptosis. Concurrent inhibition of BCL-XL and MCL-1 by BH3
mimetics in colorectal HCT116 cells induced apoptosis in a BAX- but not
BAK-dependent manner. Remarkably this apoptosis was independent of all known
BH3-only proteins. Although BH3-only proteins were required for apoptosis
induced as a result of BCL-XL inhibition, this requirement was overcome when
both BCL-XL and MCL-1 were inhibited, implicating distinct mechanisms by which
different anti-apoptotic BCL-2 family members may regulate apoptosis in cancer. |
Autophagy is the process where a virus obtains nutrients from it's host, yes or no? | No, autophagy is important in cellular homeostasis for the cell survival mechanism and is involved apoptosis. | Autophagy is a homeostatic process involved in the turnover or elimination of
cytoplasmic components, damaged organelles, and protein aggregates via a
lysosomal degradation mechanism. Autophagy also provides a mechanism of innate
immunity, known as xenophagy, designed to protect cells from intracellular
pathogens, but it may unfortunately be subverted to act as a pro-viral pathway
facilitating the replication of certain viruses. Herpes simplex virus type I
(HSV-1) is a neurotropic virus that remains latent in host neurons; it is the
most common cause of sporadic viral encephalitis. Moreover, HSV-1 has been
related to the pathogenesis of Alzheimer's disease. HSV-1 can modulate the
autophagic process through a mechanism mediated by the viral protein ICP34.5.
Here we report that HSV-1 induces a strong increase in GFP-LC3 and endogenous
LC3 lipidation, and triggers the accumulation of intracellular autophagic
compartments (mainly autophagosomes) without enhancing autophagic long-lived
protein degradation in the late stages of infection. Autophagy inhibition
mediated by ATG5 gene silencing had no effect on viral growth. The present
results suggest that HSV-1 infection activates the host autophagic machinery and
strongly controls the autophagic process, blocking the fusion of autophagosomes
with lysosomes. These events might be important in the neurodegenerative process
associated with HSV-1 infection. Influenza A virus is a dreadful pathogen of animals and humans, causing
widespread infection and severe morbidity and mortality. It is essential to
characterize the influenza A virus-host interaction and develop efficient
counter measures against the viral infection. Autophagy is known as a catabolic
process for the recycling of the cytoplasmic macromolecules. Recently, it has
been shown that autophagy is a critical mechanism underlying the interaction
between influenza A virus and its host. Autophagy can be induced by the
infection with influenza A virus, which is considered as a necessary process for
the viral proliferation, including the accumulation of viral elements during the
replication of influenza A virus. On the other hand, influenza A virus can
inhibit the autophagic formation via interaction with the autophagy-related
genes (Atg) and signaling pathways. In addition, autophagy is involved in the
influenza virus-regulated cell deaths, leading to significant changes in host
apoptosis. Interestingly, the high pathogenic strains of influenza A virus, such
as H5N1, stimulate autophagic cell death and appear to interplay with the
autophagy in distinct ways as compared with low pathogenic strains. This review
discusses the regulation of autophagy, an influenza A virus driven process. Autophagy is a lysosome-associated, degradative process that catabolizes
cytosolic components to recycle nutrients for further use and maintain cell
homeostasis. Hepatitis C virus (HCV) is a major cause of chronic hepatitis,
which often leads to end-stage liver-associated diseases and is a significant
burden on worldwide public health. Emerging lines of evidence indicate that
autophagy plays an important role in promoting the HCV life cycle in host cells.
Moreover, the diverse impacts of autophagy on a variety of signaling pathways in
HCV-infected cells suggest that the autophagic process is required for balancing
HCV-host cell interactions and involved in the pathogenesis of HCV-related liver
diseases. However, the detailed molecular mechanism underlying how HCV activates
autophagy to benefit viral growth is still enigmatic. Additionally, how the
autophagic response contributes to disease progression in HCV-infected cells
remains largely unknown. Hence, in this review, we overview the interplay
between autophagy and the HCV life cycle and propose possible mechanisms by
which autophagy may promote the pathogenesis of HCV-associated chronic liver
diseases. Moreover, we outline the related studies on how autophagy interplays
with HCV replication and discuss the possible implications of autophagy and
viral replication in the progression of HCV-induced liver diseases, e.g.,
steatosis and hepatocellular carcinoma. Finally, we explore the potential
therapeutics that target autophagy to cure HCV infection and its related liver
diseases. We recently reported an unconventional mechanism by which miRNAs inhibit HIV-1
viral production. This occurs when miRNAs bind nonspecifically to the viral
structural protein Gag, interfering with viral RNA-mediated Gag assembly at the
plasma membrane. Consequently, misassembled viral complexes are redirected into
the endocytic pathway where they are delivered to lysosomes for degradation. In
this study, we demonstrate that autophagy is a critical mediator of the viral
degradation pathway and that this pathway is not HIV-1 specific. Misassembled
viral complexes were found to colocalize extensively with LC3 and p62 in late
endosomes/lysosomes, demonstrating a convergence of autophagy with functional
degradative compartments. Knocking down autophagosome formation machineries
reduced this convergence, while treatment with autophagy-inducer rapamycin
enhanced the convergence. Furthermore, similar autophagy-dependent nonspecific
miRNA inhibition of murine leukemia virus (MLV) assembly was shown. Overall,
these results reveal autophagy as a crucial regulator of the retroviral
degradation pathway in host cells initiated by nonspecific miRNA-Gag
interactions. These findings could have significant implications for
understanding how cells may regulate retroviral complex assembly by miRNA
expression and autophagy, and raise the possibility that similar regulations can
occur in other biological contexts. Autophagy is important in cellular homeostasis for the cell survival mechanism.
Deficiency or excess of autophagy is generally related to some of diseases such
as cancer and neurodegeneration. Although autophagy is a cell survival
mechanism, it can mediate programmed cell death in several conditions.
Autophagy-related genes (ATGs) regulate the autophagy and also control the
crosstalk with autophagy-associated cell death and apoptosis in some condition.
Various methods have been used to detect the marker genes and the proteins
involved in these processes. Quantitative real-time PCR (qRT-PCR) method for
monitoring the expression of genes involved in autophagy or autophagic cell
death is often preferred because of its sensitivity, high efficiency potential,
accurate quantification, and high-grade potential automation. The detection of
the markers for autophagy-related process by immunohistochemistry in paraffin
sections of various patient tissues has become a reliable method for monitoring
autophagy. Here, we introduce protocols for detecting autophagy and
autophagy-associated cell death in HeLa cells by using gene expression assays
qRT-PCR, and also in paraffin-embedded tissue section from human biopsy material
by using immunohistochemistry. Autophagy is a cellular survival pathway that is necessary for the degradation
of cellular constituents such as long-lived proteins and damaged organelles.
Conditions resulting in cellular stress such as starvation or hypoxia might
activate autophagy. Being at the crossroads of various cellular response
pathways, dysregulation of autophagy might result in pathological states
including cancer and neurodegenerative diseases. Autophagy has also been shown
to participate in stemness. MicroRNAs were introduced as novel regulators of
autophagy, and accumulating results underlined the fact that they constituted an
important layer of biological control mechanism on the autophagic
activity.MicroRNAs are protein noncoding small RNAs that control cellular levels
of transcripts and proteins through posttrancriptional mechanisms. Novel miRNAs
in human and mouse genomes are yet to be identified. Considering the emerging
role of autophagy in health and disease, identification of novel
autophagy-regulating miRNAs and determination of relations between miRNA
expression and physiological and pathological conditions might contribute to a
better understanding of mechanisms governing health and disease. High-throughput
techniques were developed for miRNA profiling, yet for a thorough
characterization and miRNA target determination, miRNA cloning remains as an
important step. Here, we describe a modified miRNA cloning method for the
characterization of novel autophagy-regulating miRNAs. Autophagy is an evolutionarily conserved cellular process in which intracellular
components are eliminated via lysosomal degradation to supply nutrients for
organelle biogenesis and metabolic homeostasis. Flavivirus infections underlie
multiple human diseases and thus exert an immense burden on public health
worldwide. Mounting evidence indicates that host autophagy is subverted to
modulate the life cycles of flaviviruses, such as hepatitis C virus, dengue
virus, Japanese encephalitis virus, West Nile virus and Zika virus. The diverse
interplay between autophagy and flavivirus infection not only regulates viral
growth in host cells but also counteracts host stress responses induced by viral
infection. In this review, we summarize the current knowledge on the role of
autophagy in the flavivirus life cycle. We also discuss the impacts of
virus-induced autophagy on the pathogeneses of flavivirus-associated diseases
and the potential use of autophagy as a therapeutic target for curing flavivirus
infections and related human diseases. Autophagy is a self-eating process, in which the damaged or excessed cell
organelles and misfolded protein aggregates are removed from the cellular
microenvironment. Autophagy is generally thought of as a pro-survival mechanism
which is not only important for balancing energy supply at times of nutrient
deprivation but also in the removal of various stress stimuli to ensure
homeostasis. In addition to the target materials of "self" origin, autophagy can
also eliminate intracellular pathogens and acts as a defense mechanism to curb
infections. In addition, autophagy is linked to the host cell's innate immune
response. However, viruses have evolved various strategies to manipulate and
overtake host cell machinery to establish productive replication and maintain
infectious process. In fact, replication of many viruses has been found to be
autophagy-dependent and suppression of autophagy can potentially affect the
viral replication. Thus, autophagy can either serve as an anti-viral defense
mechanism or a pro-viral process that supports viral replication. Hepatitis B
virus (HBV) and hepatitis C virus (HCV) are known to co-opt cellular autophagy
process as a pro-viral tool. Both viruses also induce mitophagy, which
contributes to the establishment of chronic hepatitis. This review focuses on
the roles of autophagy and mitophagy in the chronic liver disease pathogenesis
associated with HBV and HCV infections. |
What is the basis of the methidiumpropyl-EDTA sequencing (MPE-seq) method? | MPE-seq (methidiumpropyl-EDTA sequencing) is a new method for the genome-wide characterization of chromatin that involves the digestion of nuclei with MPE-Fe(II) followed by massively parallel sequencing of the whole genome. Like micrococcal nuclease (MNase), MNase preferentially cleaves the linker DNA between nucleosomes. However, there are differences in the cleavage of nuclear chromatin by MP e-seq relative to MNase. Moreover, unlike MNase, MPe-seq cleaves nuclear DNA | |
Name two rotavirus vaccines. | Two rotavirus vaccines licensed for global use are RotaTeq and Rotarix. | Two rotavirus vaccines, RotaTeq and Rotarix, are licensed for global use;
however, the protection they confer to unvaccinated individuals through indirect
effects remains unknown. We systematically reviewed the literature and
quantified indirect rotavirus vaccine effectiveness (VE) for preventing
rotavirus hospitalization in children aged less than 5 years. From 148
identified abstracts, 14 studies met our eligibility criteria. In our main
analysis using a random-effects model, indirect rotavirus VE was 48% (95%
confidence interval [CI]: 39-55%). In a subgroup analysis by country income
level, indirect VE was greater in high-income countries (52%; 95% CI: 43-60%)
than in low- and middle-income countries (LMICs) (25%; 95% CI: 5-41%). In a
sensitivity analysis using a quality-effects model, the indirect VE in LMICs was
not statistically significant (25%; 95% CI: 0-44%). Our findings highlight the
importance of increasing rotavirus vaccine coverage, particularly in LMICs where
evidence for indirect VE is limited and rotavirus burden is high. |
Does CXorf21 escape X chromosome inactivation? | CXORF21 belongs to a set of X-linked differentially expressed genes that show verbal cognition-gene expression correlations may establish a causal link between these genes, neurodevelopment, and language function. | Klinefelter's Syndrome (KS) is a chromosomal karyotype with one or more extra X
chromosomes. KS individuals often show language impairment and the phenotype
might be due to overexpression of genes on the extra X chromosome(s). We
profiled mRNA derived from lymphoblastoid cell lines from males with documented
KS and control males using the Affymetrix U133P microarray platform. There were
129 differentially expressed genes (DEGs) in KS group compared with controls
after Benjamini-Hochberg false discovery adjustment. The DEGs included 14 X
chromosome genes which were significantly over-represented. The Y chromosome had
zero DEGs. In exploratory analysis of gene expression-cognition relationships,
12 DEGs showed significant correlation of expression with measures of verbal
cognition in KS. Overexpression of one pseudoautosomal gene, GTPBP6 (GTP binding
protein 6, putative) was inversely correlated with verbal IQ (r = -0.86, P <
0.001) and four other measures of verbal ability. Overexpression of XIST was
found in KS compared to XY controls suggesting that silencing of many genes on
the X chromosome might occur in KS similar to XX females. The microarray
findings for eight DEGs were validated by quantitative PCR. The 14 X chromosome
DEGs were not differentially expressed in prior studies comparing female and
male brains suggesting a dysregulation profile unique to KS. Examination of
X-linked DEGs, such as GTPBP6, TAF9L, and CXORF21, that show verbal
cognition-gene expression correlations may establish a causal link between these
genes, neurodevelopment, and language function. A screen of candidate genes may
serve as biomarkers of KS for early diagnosis. CONTEXT: Testis development is a tightly regulated process that requires an
efficient and coordinated spatiotemporal action of many factors, and it has been
shown that several genes involved in gonadal development exert a dosage effect.
Chromosomal imbalances have been reported in several patients presenting with
gonadal dysgenesis as part of severe dysmorphic phenotypes.
RESULTS: We screened for submicroscopic DNA copy number variations in two
sisters with an apparent normal 46,XY karyotype and female external genitalia
due to gonadal dysgenesis, and in which mutations in known candidate genes had
been excluded. By high-resolution tiling bacterial artificial chromosome array
comparative genome hybridization, a submicroscopic duplication at Xp21.2
containing DAX1 (NR0B1) was identified. Using fluorescence in situ
hybridization, multiple ligation probe amplification, and PCR, the rearrangement
was further characterized. This revealed a 637-kb tandem duplication that in
addition to DAX1 includes the four MAGEB genes, the hypothetical gene CXorf21,
GK, and part of the MAP3K7IP3 gene. Sequencing and analysis of the breakpoint
boundaries and duplication junction suggest that the duplication originated
through a coupled homologous and nonhomologous recombination process.
CONCLUSIONS: This represents the first duplication on Xp21.2 identified in
patients with isolated gonadal dysgenesis because all previously described XY
subjects with Xp21 duplications presented with gonadal dysgenesis as part of a
more complex phenotype, including mental retardation and/or malformations. Thus,
our data support DAX1 as a dosage sensitive gene responsible for gonadal
dysgenesis and highlight the importance of considering DAX1 locus duplications
in the evaluation of all cases of 46,XY gonadal dysgenesis. Thiazide diuretics and statins are used to improve cardiovascular outcomes, but
may also cause type 2 diabetes (T2DM), although mechanisms are unknown. Gene
expression studies may facilitate understanding of these associations.
Participants from ongoing population-based studies were sampled for these
longitudinal studies of peripheral blood microarray gene expression, and
followed to incident diabetes. All sampled subjects were statin or thiazide
users. Those who developed diabetes during follow-up comprised cases (44
thiazide users; 19 statin users), and were matched to drug-using controls who
did not develop diabetes on several factors. Supervised normalization, surrogate
variable analyses removed technical bias and confounding.
Differentially-expressed genes were those with a false discovery rate
Q-value<0.05. Among thiazide users, diabetes cases had significantly different
expression of CCL14 (down-regulated 6%, Q-value=0.0257), compared with controls.
Among statin users, diabetes cases had marginal but insignificantly different
expression of ZNF532 (up-regulated 15%, Q-value=0.0584), CXORF21 (up-regulated
11%, Q-value=0.0584), and ZNHIT3 (up-regulated 19%, Q-value=0.0959), compared
with controls. These genes comprise potential targets for future expression or
mechanistic research on medication-related diabetes development. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects
multiple organ systems. Although the etiology of SLE remains unclear, it is
widely accepted that genetic factors could be involved in its pathogenesis. A
number of genome-wide association studies (GWASs) have identified novel
single-nucleotide polymorphisms (SNPs) associated with the risk of SLE in
diverse populations. However, not all the SNP candidates identified from
non-Asian populations have been validated in Koreans. In this study, we aimed to
replicate the SNPs that were recently discovered in the GWAS; these SNPs have
not been validated in Koreans or have only been replicated in Koreans with an
insufficient sample size to conclude any association. For this, we selected five
SNPs (rs1801274 in FCGR2A and rs2286672 in PLD2, rs887369 in CXorf21, rs9782955
in LYST, and rs3794060 in NADSYN1). Through the replication study with 656 cases
and 622 controls, rs1801274 in FCGR2A was found to be significantly associated
with SLE in Koreans (odds ratio, 1.26, 95% confidence interval, 1.06 to 1.50; p
= 0.01 in allelic model). This association was also significant in two other
models (domit and recessive). The other four SNPs did not show a significant
association. Our data support that FCGR polymorphisms play important roles in
the susceptibility to SLE in diverse populations, including Koreans. |