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Is Hirschsprung disease a mendelian or a multifactorial disorder?
Coding sequence mutations in RET, GDNF, EDNRB, EDN3, and SOX10 are involved in the development of Hirschsprung disease. The majority of these genes was shown to be related to Mendelian syndromic forms of Hirschsprung's disease, whereas the non-Mendelian inheritance of sporadic non-syndromic Hirschsprung disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model.
Hirschsprung disease (HSCR), or congenital intestinal aganglionosis, is a common hereditary disorder causing intestinal obstruction, thereby showing considerable phenotypic variation in conjunction with complex inheritance. Moreover, phenotypic assessment of the disease has been complicated since a subset of the observed mutations is also associated with several additional syndromic anomalies. Coding sequence mutations in e.g. RET, GDNF, EDNRB, EDN3, and SOX10 lead to long-segment (L-HSCR) as well as syndromic HSCR but fail to explain the transmission of the much more common short-segment form (S-HSCR). Furthermore, mutations in the RET gene are responsible for approximately half of the familial and some sporadic cases, strongly suggesting, on the one hand, the importance of non-coding variations and, on the other hand, that additional genes involved in the development of the enteric nervous system still await their discovery. For almost all of the identified HSCR genes incomplete penetrance of the HSCR phenotype has been reported, probably due to modifier loci. Therefore, HSCR has become a model for a complex oligo-/polygenic disorder in which the relationship between different genes creating a non-mendelian inheritance pattern still remains to be elucidated. Hirschsprung's disease is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the gastrointestinal tract. Genetic dissection was successful as nine genes and four loci for Hirschsprung's disease susceptibility were identified. Different approaches were used to find these loci such as classical linkage in large families, identity by descent mapping in an inbred kindred, candidate gene approaches based on naturally occurring mutant mice models, and finally the use of model-free linkage and association analyzes. In this study, we review the identification of genes and loci involved in the non-syndromic common form and syndromic Mendelian forms of Hirschsprung's disease. The majority of the identified genes are related to Mendelian syndromic forms of Hirschsprung's disease. The non-Mendelian inheritance of sporadic non-syndromic Hirschsprung's disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model. We discuss the practical implications of the elucidation of genes associated with Hirschsprung's disease susceptibility for genetic counseling. Finally, we speculate on possible strategies to identify new genes for Hirschsprung's disease. The major gene for Hirschsprung disease (HSCR) encodes the receptor tyrosine kinase RET. In a study of 690 European- and 192 Chinese-descent probands and their parents or controls, we demonstrate the ubiquity of a >4-fold susceptibility from a C-->T allele (rs2435357: p = 3.9 x 10(-43) in European ancestry; p = 1.1 x 10(-21) in Chinese samples) that probably arose once within the intronic RET enhancer MCS+9.7. With in vitro assays, we now show that the T variant disrupts a SOX10 binding site within MCS+9.7 that compromises RET transactivation. The T allele, with a control frequency of 20%-30%/47% and case frequency of 54%-62%/88% in European/Chinese-ancestry individuals, is involved in all forms of HSCR. It is marginally associated with proband gender (p = 0.13) and significantly so with length of aganglionosis (p = 7.6 x 10(-5)) and familiality (p = 6.2 x 10(-4)). The enhancer variant is more frequent in the common forms of male, short-segment, and simplex families whereas multiple, rare, coding mutations are the norm in the less common and more severe forms of female, long-segment, and multiplex families. The T variant also increases penetrance in patients with rare RET coding mutations. Thus, both rare and common mutations, individually and together, make contributions to the risk of HSCR. The distribution of RET variants in diverse HSCR patients suggests a "cellular-recessive" genetic model where both RET alleles' function is compromised. The RET allelic series, and its genotype-phenotype correlations, shows that success in variant identification in complex disorders may strongly depend on which patients are studied. Hirschsprung's disease (HSCR) is a fairly frequent cause of intestinal obstruction in children. It is characterized as a sex-linked heterogonous disorder with variable severity and incomplete penetrance giving rise to a variable pattern of inheritance. Although Hirschsprung's disease occurs as an isolated phenotype in at least 70% of cases, it is not infrequently associated with a number of congenital abnormalities and associated syndromes, demonstrating a spectrum of congenital anomalies. Certain of these syndromic phenotypes have been linked to distinct genetic sites, indicating underlying genetic associations of the disease and probable gene-gene interaction, in its pathogenesis. These associations with HSCR include Down's syndrome and other chromosomal anomalies, Waardenburg syndrome and other Domit sensorineural deafness, the Congenital Central Hypoventilation and Mowat-Wilson and other brain-related syndromes, as well as the MEN2 and other tumour associations. A number of other autosomal recessive syndromes include the Shah-Waardenburg, the Bardet-Biedl and Cartilage-hair hypoplasia, Goldberg-Shprintzen syndromes and other syndromes related to cholesterol and fat metabolism among others. The genetics of Hirschsprung's disease are highly complex with the majority of known genetic sites relating to the main susceptibility pathways (RET an EDNRB). Non-syndromic non-familial, short-segment HSCR appears to represent a non-Mendelian condition with variable expression and sex-dependent penetrance. Syndromic and familial forms, on the other hand, have complex patterns of inheritance and being reported as autosomal domit, recessive and polygenic patterns of inheritance. The phenotypic variability and incomplete penetrance observed in Hirschsprung's disease could also be explained by the involvement of modifier genes, especially in its syndromic forms. In this review, we look at the chromosomal and Mendelian associations and their underlying signalling pathways, to obtain a better understanding of the pathogenetic mechanisms involved in developing aganglionosis of the distal bowel.
List signaling molecules (ligands) that interact with the receptor EGFR?
The 7 known EGFR ligands are: epidermal growth factor (EGF), betacellulin (BTC), epiregulin (EPR), heparin-binding EGF (HB-EGF), transforming growth factor-α [TGF-α], amphiregulin (AREG) and epigen (EPG).
Autocrine, paracrine, and juxtacrine are recognized modes of action for mammalian EGFR ligands including EGF, TGF-α (TGFα), amphiregulin (AREG), heparin-binding EGF-like growth factor (HB-EGF), betacellulin, epiregulin, and epigen. We identify a new mode of EGFR ligand signaling via exosomes. Human breast and colorectal cancer cells release exosomes containing full-length, signaling-competent EGFR ligands. Exosomes isolated from MDCK cells expressing individual full-length EGFR ligands displayed differential activities; AREG exosomes increased invasiveness of recipient breast cancer cells 4-fold over TGFα or HB-EGF exosomes and 5-fold over equivalent amounts of recombit AREG. Exosomal AREG displayed significantly greater membrane stability than TGFα or HB-EGF. An average of 24 AREG molecules are packaged within an individual exosome, and AREG exosomes are rapidly internalized by recipient cells. Whether the composition and behavior of exosomes differ between nontransformed and transformed cells is unknown. Exosomes from DLD-1 colon cancer cells with a mutant KRAS allele exhibited both higher AREG levels and greater invasive potential than exosomes from isogenically matched, nontransformed cells in which mutant KRAS was eliminated by homologous recombination. We speculate that EGFR ligand signaling via exosomes might contribute to diverse cancer phenomena such as field effect and priming of the metastatic niche. BACKGROUND: In this study the total and phosphorylated amount of epidermal growth factor receptor 1 (EGFR) and 2 (HER2) were measured together with EGFR ligands in tissue samples of breast cancer patients in order to investigate interrelations and possible prognostic values. METHODS: Samples of maligt and non-cancer autologous reference tissue were collected from 415 breast cancer patients. The tissue samples were cut and either paraffin-embedded or homogenized in a lysis buffer to extract the proteins. HER2 was measured using both immunohistochemistry (IHC)/fluorescence in situ hybridization (FISH) and ADVIA Centaur. Phosphorylated HER2 and EGFR (pHER2, pEGFR), total EGFR and the ligands: epidermal growth factor (EGF), transforming growth factor-α (TGFα), amphiregulin (AREG), heparin-binding EGF-like growth factor (HB-EGF), betacellulin (BTC) and epiregulin (EREG) were measured using the Luminex. RESULTS: The HER2 positivity rate was determined to be 25.2% by the Centaur method vs. 15.8% by IHC and FISH. HER2, HB-EGF, TGFα and AREG were upregulated in cancer tissue as compared with autologous reference tissue while EGFR, pEGFR and EGF were downregulated (p<10-6). pEGFR in autologous reference tissue was negatively correlated to the number of positive lymph nodes and to the tumor size (p=0.0007 and p=0.001, respectively) and furthermore, decreased in the group of mastectomy operated patients as compared with the lumpectomy group (p<10-6). HB-EGF in cancer tissue was positively associated with high grade tumors (p<10-6) and pHER2, HB-EGF and BTC were associated with poor disease free survival (p=0.017, p=0.012 and p=0.0026, respectively). CONCLUSIONS: Our study demonstrated a profound activation of the EGFR system. HB-EGF was increased by factor 10 in cancer tissue and related to the biological aggressiveness of the tumors, and pHER2, HB-EGF and BTC were associated with poor clinical outcome. PURPOSE: Although KRAS mutation has been identified as a negative predictive biomarker of anti-EGFR antibodies in metastatic colorectal cancer (mCRC), the efficacy in mCRC patients with KRAS wild-type status remains limited. Anti-EGFR antibodies work by blocking ligand binding, but the significance of EGFR ligands in mCRC has not been completely described. This study was conducted to identify the correlation between all seven EGFR ligands and clinical outcomes in mCRC treated with anti-EGFR antibodies. Furthermore, we determined an appropriate predictive strategy for anti-EGFR antibodies using these EGFR ligands. METHODS: Among 36 mCRC patients who had been treated with cetuximab or panitumumab, we identified 26 mCRC patients with wild-type KRAS status treated properly as the second and further lines and analyzed the relationship between immunoreactivity to seven EGFR ligands and clinical outcomes. RESULTS: Good clinical outcomes were associated with immunoreactivity against amphiregulin (AR), heparin-binding epidermal growth factor (HB-EGF), transforming growth factor-α (TGF-α), and epiregulin (EREG). Further, patients with immunoreactivity to greater than two of these four ligands (AR, HB-EGF, TGF-α, and EREG) had significantly higher response rate (53.3 vs. 0.0 %, p = 0.004) and disease control rate (93.3 vs. 9.0 %, p = 0.00002) and longer progression-free survival (median PFS: 231 vs. 79 days, p = 0.000008), when compared with patients with immunoreactivity against zero or one ligand. CONCLUSIONS: Immunohistochemical analysis of four EGFR ligands (AR, HB-EGF, TGF-α, and EREG) might be a novel predictive biomarker and may help optimize patient selection for cetuximab and panitumumab therapy in patients with mCRC. Prolidase, also known as Xaa-Pro dipeptidase or peptidase D (PEPD), is a ubiquitously expressed cytosolic enzyme that hydrolyzes dipeptides with proline or hydroxyproline at the carboxyl terminus. In this article, however, we demonstrate that PEPD directly binds to and activates epidermal growth factor receptor (EGFR), leading to stimulation of signaling proteins downstream of EGFR, and that such activity is neither cell-specific nor dependent on the enzymatic activity of PEPD. In line with the pro-survival and pro-proliferation activities of EGFR, PEPD stimulates DNA synthesis. We further show that PEPD activates EGFR only when it is present in the extracellular space, but that PEPD is released from injured cells and tissues and that such release appears to result in EGFR activation. PEPD differs from all known EGFR ligands in that it does not possess an epidermal growth factor (EGF) motif and is not synthesized as a transmembrane precursor, but PEPD binding to EGFR can be blocked by EGF. In conclusion, PEPD is a ligand of EGFR and presents a novel mechanism of EGFR activation. The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family that plays a role in multiple cellular processes. Activation of EGFR requires binding of a ligand on the extracellular domain to promote conformational changes leading to dimerization and transphosphorylation of intracellular kinase domains. Seven ligands are known to bind EGFR with affinities ranging from sub-omolar to near micromolar dissociation constants. In the case of EGFR, distinct conformational states assumed upon binding a ligand is thought to be a determining factor in activation of a downstream signaling network. Previous biochemical studies suggest the existence of both low affinity and high affinity EGFR ligands. While these studies have identified functional effects of ligand binding, high-resolution structural data are lacking. To gain a better understanding of the molecular basis of EGFR binding affinities, we docked each EGFR ligand to the putative active state extracellular domain dimer and 25.0 ns molecular dynamics simulations were performed. MM-PBSA/GBSA are efficient computational approaches to approximate free energies of protein-protein interactions and decompose the free energy at the amino acid level. We applied these methods to the last 6.0 ns of each ligand-receptor simulation. MM-PBSA calculations were able to successfully rank all seven of the EGFR ligands based on the two affinity classes: EGF>HB-EGF>TGF-α>BTC>EPR>EPG>AR. Results from energy decomposition identified several interactions that are common among binding ligands. These findings reveal that while several residues are conserved among the EGFR ligand family, no single set of residues determines the affinity class. Instead we found heterogeneous sets of interactions that were driven primarily by electrostatic and Van der Waals forces. These results not only illustrate the complexity of EGFR dynamics but also pave the way for structure-based design of therapeutics targeting EGF ligands or the receptor itself. Aberrant epidermal growth factor receptor (EGFR) expression promotes the pathogenesis of maligt peripheral nerve sheath tumors (MPNSTs), the most common maligcy associated with neurofibromatosis type 1, but the mechanisms by which EGFR expression promotes MPNST pathogenesis are poorly understood. We hypothesized that inappropriately expressed EGFRs promote MPNST invasion and found that these kinases are concentrated in MPNST invadopodia in vitro. Epidermal growth factor receptor knockdown inhibited the migration of unstimulated MPNST cells in vitro, and exogenous EGF further enhanced MPNST migration in a substrate-specific manner, promoting migration on laminin and, to a lesser extent, collagen. In this setting, EGF acts as a chemotactic factor. We also found that the 7 known EGFR ligands (EGF, betacellulin, epiregulin, heparin-binding EGF, transforming growth factor-α [TGF-α], amphiregulin, and epigen) variably enhanced MPNST migration in a concentration-dependent manner, with TGF-α being particularly potent. With the exception of epigen, these factors similarly promoted the migration of nonneoplastic Schwann cells. Although transcripts encoding all 7 EGFR ligands were detected in human MPNST cells and tumor tissues, only TGF-α was consistently overexpressed and was found to colocalize with EGFR in situ. These data indicate that constitutive EGFR activation, potentially driven by autocrine or paracrine TGF-α signaling, promotes the aggressive invasive behavior characteristic of MPNSTs. The epidermal growth factor receptor (EGFR) is frequently expressed in triple-negative breast cancer (TNBC) and is a marker of poor prognosis in this patient population. Because activating mutations in this kinase are very rare events in breast cancer, we screened breast tumor gene expression profiles to examine the distribution of EGFR ligand expression. Of the six known EGFR ligands, transforming growth factor alpha (TGFα) was expressed more highly in triple-negative breast tumors than in tumors of other subtypes. TGFα is synthesized as a transmembrane precursor requiring tumor necrosis factor alpha converting enzyme (TACE)/ADAM17-dependent proteolytic release to activate its receptor. In our study, we show that an inhibitor of this proteolytic release blocks invasion, migration and colony formation by several TNBC cell lines. Each of the effects of the drug was reversed upon expression of a soluble TGFα mutant that does not require TACE activity, implicating this growth factor as a key metalloproteinase substrate for these phenotypes. Together, these data demonstrate that TACE-dependent TGFα shedding is a key process driving EGFR activation and subsequent proliferation and invasion in TNBC cell lines. Intrahepatic cholangiocarcinoma (CCA) is characterized by an abundant desmoplastic environment. Poor prognosis of CCA has been associated with the presence of alpha-smooth muscle actin (α-SMA)-positive myofibroblasts (MFs) in the stroma and with the sustained activation of the epidermal growth factor receptor (EGFR) in tumor cells. Among EGFR ligands, heparin-binding epidermal growth factor (HB-EGF) has emerged as a paracrine factor that contributes to intercellular communications between MFs and tumor cells in several cancers. This study was designed to test whether hepatic MFs contributed to CCA progression through EGFR signaling. The interplay between CCA cells and hepatic MFs was examined first in vivo, using subcutaneous xenografts into immunocompromised mice. In these experiments, cotransplantation of CCA cells with human liver myofibroblasts (HLMFs) increased tumor incidence, size, and metastatic dissemination of tumors. These effects were abolished by gefitinib, an EGFR tyrosine kinase inhibitor. Immunohistochemical analyses of human CCA tissues showed that stromal MFs expressed HB-EGF, whereas EGFR was detected in cancer cells. In vitro, HLMFs produced HB-EGF and their conditioned media induced EGFR activation and promoted disruption of adherens junctions, migratory and invasive properties in CCA cells. These effects were abolished in the presence of gefitinib or HB-EGF-neutralizing antibody. We also showed that CCA cells produced transforming growth factor beta 1, which, in turn, induced HB-EGF expression in HLMFs. CONCLUSION: A reciprocal cross-talk between CCA cells and myofibroblasts through the HB-EGF/EGFR axis contributes to CCA progression. PURPOSE: The aim of this study was to investigate the biological and clinical significance of epidermal growth factor receptor (EGFR) signaling pathway in follicular dendritic cell sarcoma (FDC-S). EXPERIMENTAL DESIGN: Expression of EGFR and cognate ligands as well as activation of EGFR signaling components was assessed in clinical samples and in a primary FDC-S short-term culture (referred as FDC-AM09). Biological effects of the EGFR antagonists cetuximab and panitumumab and the MEK inhibitor UO126 on FDC-S cells were determined in vitro on FDC-AM09. Direct sequencing of KRAS, BRAF, and PI3KCA was conducted on tumor DNA. RESULTS: We found a strong EGFR expression on dysplastic and neoplastic FDCs. On FDC-AM09, we could show that engagement of surface EGFR by cognate ligands drives the survival and proliferation of FDC-S cells, by signaling to the nucleus mainly via MAPK and STAT pathways. Among EGFR ligands, heparin-binding EGF-like growth factor, TGF-α and Betacellulin (BTC) are produced in the tumor microenvironment of FDC-S at RNA level. By extending this finding at protein level we found that BTC is abundantly produced by FDC-S cells and surrounding stromal cells. Finally, direct sequencing of tumor-derived genomic DNA showed that mutations in KRAS, NRAS, BRAF, and PI3KCA, which predicts resistance to anti-EGFR MoAb in other cancer models, are not observed in FDC-S. CONCLUSION: Activation of EGFR by cognate ligands produced in the tumor microenvironment sustain viability and proliferation of FDC-S indicating that the receptor blockade might be clinically relevant in this neoplasm. Based on gene expression patterns, breast cancers can be divided into subtypes that closely resemble various developmental stages of normal mammary epithelial cells (MECs). Thus, understanding molecular mechanisms of MEC development is expected to provide critical insights into initiation and progression of breast cancer. Epidermal growth factor receptor (EGFR) and its ligands play essential roles in normal and pathological mammary gland. Signals through EGFR is required for normal mammary gland development. Ligands for EGFR are over-expressed in a significant proportion of breast cancers, and elevated expression of EGFR is associated with poorer clinical outcome. In the present study, we examined the effect of signals through EGFR on MEC differentiation using the human telomerase reverse transcriptase (hTERT)-immortalized human stem/progenitor MECs which express cytokeratin 5 but lack cytokeratin 19 (K5(+)K19(-) hMECs). As reported previously, these cells can be induced to differentiate into luminal and myoepithelial cells under appropriate culture conditions. K5(+)K19(-) hMECs acquired distinct cell fates in response to EGFR ligands epidermal growth factor (EGF), amphiregulin (AREG) and transforming growth factor alpha (TGFα) in differentiation-promoting MEGM medium. Specifically, presence of EGF during in vitro differentiation supported development into both luminal and myoepithelial lineages, whereas cells differentiated only towards luminal lineage when EGF was replaced with AREG. In contrast, substitution with TGFα led to differentiation only into myoepithelial lineage. Chemical inhibition of the MEK-Erk pathway, but not the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, interfered with K5(+)K19(-) hMEC differentiation. The present data validate the utility of the K5(+)K19(-) hMEC cells for modeling key features of human MEC differentiation. This system should be useful in studying molecular/biochemical mechanisms of human MEC differentiation. BACKGROUND: Epidermal growth factor receptor (EGFR) activation plays a role in colorectal cancer (CRC) carcinogenesis, and anti-EGFR drugs are used in treatment of advanced CRC. One of the EGFR ligands is tumor-associated trypsinogen inhibitor TATI, also called serine protease inhibitor Kazal type1 (SPINK 1), which we recently showed to be an independent prognostic marker in CRC. METHODS: We studied the prognostic value of immunohistochemical expression of EGFR and concomitant expression of EGFR and TATI/SPINK1 in a series of 619 colorectal cancer patients. RESULTS: Of the samples, 92% were positive for EGFR. EGFR+/TATI+ was seen in 62.8%, EGFR+/TATI- in 29.5%, EGFR-/TATI+ in 4.9%, and EGFR-/TATI- in 2.7% of patients. EGFR expression correlated with WHO grade (p = 0.040). In univariate analysis, EGFR expression correlated with favourable survival (p = 0.006). EGFR+/TATI+ patients showed better survival than did those with other combinations (p<0.001). In multivariate analysis, EGFR+/TATI+ was an independent prognostic factor of favourable prognosis (p<0.001). CONCLUSION: Concomitant positivity of EGFR and TATI/SPINK1 predicts favourable prognosis in CRC. Pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide with trophic and cytoprotective effects, has been shown to affect cell survival, proliferation, and also differentiation of various cell types. The high PACAP level in the milk and its changes during lactation suggest a possible effect of PACAP on the differentiation of mammary epithelial cells. Mammary cell differentiation is regulated by hormones, growth factors, cytokines/chemokines, and angiogenic proteins. In this study, differentiation was hormonally induced by lactogenic hormones in confluent cultures of HC11 mouse mammary epithelial cells. We investigated the effect of PACAP on mammary cell differentiation as well as release of cytokines, chemokines, and growth factors. Differentiation was assessed by expression analysis of the milk protein β-casein. Differentiation significantly decreased the secretion of interferon gammainduced protein (IP)-10, "regulated upon activation normal T cell expressed and presumably secreted" (RANTES), insulin-like growth factor-binding protein (IGFBP)-3 and the epidermal growth factor receptor (EGFR) ligands, such as epidermal growth factor (EGF) and amphiregulin (AREG). The changes in the levels of IP-10 and RANTES may be relevant for the alterations in homing of T cells and B cells at different stages of mammary gland development, while the changes of the EGFR ligands may facilitate the switch from proliferative to lactating stage. PACAP did not modulate the expression of β-casein or the activity of hormone-induced pathways as determined by the analysis of phosphorylation of Akt, STAT5, and p38 MAPK. However, PACAP decreased the release of EGF and AREG from non-differentiated cells. This may influence the extracellular signal-related transactivation of EGFR in the non-differentiated mammary epithelium and is considered to have an impact on the modulation of oncogenic EGFR signaling in breast cancer.
Is the protein Papilin secreted?
Yes, papilin is a secreted protein
A sulfated glycoprotein was isolated from the culture media of Drosophila Kc cells and named papilin. Affinity purified antibodies against this protein localized it primarily to the basement membranes of embryos. The antibodies cross-reacted with another material which was not sulfated and appeared to be the core protein of papilin, which is proteoglycan-like. After reduction, papilin electrophoresed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a broad band of about 900,000 apparent molecular weight and the core protein as a narrow band of approximately 400,000. The core protein was formed by some cell lines and by other cells on incubation with 1 mM 4-methylumbelliferyl xyloside, which inhibited formation of the proteoglycan-like form. The buoyant density of papilin in CsCl/4 M guanidine hydrochloride is 1.4 g/ml, that of the core protein is much less. Papilin forms oligomers linked by disulfide bridges, as shown by sodium dodecyl sulfate-agarose gel electrophoresis and electron microscopy. The protomer is a 225 +/- 15-nm thread which is disulfide-linked into a loop with fine, protruding thread ends. Oligomers form clover-leaf-like structures. The protein contains 22% combined serine and threonine residues and 25% combined aspartic and glutamic residues. 10 g of polypeptide has attached 6.4 g of glucosamine, 3.1 g of galactosamine, 6.1 g of uronic acid, and 2.7 g of neutral sugars. There are about 80 O-linked carbohydrate chains/core protein molecule. Sulfate is attached to these chains. The O-linkage is through an unidentified neutral sugar. Papilin is largely resistant to common glycosidases and several proteases. The degree of sulfation varies with the sulfate concentration of the incubation medium. This proteoglycan-like glycoprotein differs substantially from corresponding proteoglycans found in vertebrate basement membranes, in contrast to Drosophila basement membrane laminin and collagen IV which have been conserved evolutionarily. Two contrasting substrates, Drosophila laminin and human vitronectin, caused determined primary Drosophila embryo cells to follow alternate intermediate differentiation steps without affecting the final outcome of differentiation. Integrin alpha PS2 beta PS3 was essential for the initial spreading of myocytes on vitronectin: focal contacts rich in beta PS3 integrins formed and were connected by actin- and myosin-containing stress fibers. While alpha PS2 beta PS3 was unnecessary for myotube formation on laminin, it was required for the subsequent change to a sarcomeric cytoarchitecture. The differentiating primary cultures synthesized integrins and assembled them into detergent-insoluble, cytoskeleton-associated complexes. Collagen IV, laminin, glutactin, papilin, and other extracellular matrix proteins were made primarily by hemocytes and were secreted into the medium. Further differentiation within the cultures was influenced by secreted components and by later addition of vitronectin or bovine serum. Comparison of the differentiation of various cell types on the two substrates showed that vitronectin provided a selective advantage for the differentiation of myocytes, with enrichment over epithelia, epidermal cells, and neurites. Papilin is an extracellular matrix glycoprotein that we have found to be involved in, (1) thin matrix layers during gastrulation, (2) matrix associated with wandering, phagocytic hemocytes, (3) basement membranes and (4) space-filling matrix during Drosophila development. Determination of its cDNA sequence led to the identification of Caenorhabditis and mammalian papilins. A distinctly conserved 'papilin cassette' of domains at the amino-end of papilins is also the carboxyl-end of the ADAMTS subgroup of secreted, matrix-associated metalloproteinases; this cassette contains one thrombospondin type 1 (TSR) domain, a specific cysteine-rich domain and several partial TSR domains. In vitro, papilin non-competitively inhibits procollagen N-proteinase, an ADAMTS metalloproteinase. Inhibiting papilin synthesis in Drosophila or Caenorhabditis causes defective cell arrangements and embryonic death. Ectopic expression of papilin in Drosophila causes lethal abnormalities in muscle, Malpighian tubule and trachea formation. We suggest that papilin influences cell rearrangements and may modulate metalloproteinases during organogenesis. Papilins are extracellular matrix proteins that share a particular, common order of types of protein domains. They occur widely, from nematodes to man, and can differ in the number of repeats of a given type of domain. Protein variety is increased by differential splicing of pre-mRNA. We report that Drosophila, which has a compact genome, expresses three splice variants of papilin during embryogenesis in developmentally defined patterns. These isoforms have different numbers of Kunitz and IgC2 domains. The papilin isoforms are expressed in specific cell types and contribute to different extracellular matrices in gastrulation folds, early mesoderm, heart formation, basement membranes, and elaboration of the excorporeal peritrophic membrane that lines the gut. This finding indicates an unexpectedly broad spectrum of different pericellular matrices in Drosophila embryos. Such papilin-containing matrices have developmental as well as functional significance, as we previously showed that both suppression of papilin synthesis and ectopic overexpression lethally disrupt organogenesis. The TSR superfamily is a diverse family of extracellular matrix and transmembrane proteins, many of which have functions related to regulating matrix organization, cell-cell interactions and cell guidance. This review samples some of the contemporary literature regarding TSR superfamily members (e.g. F-spondin, UNC-5, ADAMTS, papilin, and TRAP) where specific functions are assigned to the TSR domains. Combining these observations with the published crystal structure of the TSRs of thrombospondin-1 may hold a key to the development of therapeutic agents for fighting parasitic infection and tumor growth. Papilins are homologous, secreted extracellular matrix proteins which share a common order of protein domains. They occur widely, from nematodes to man, and can differ in the number of repeats of a given type of domain. Within one species the number of repeats can vary by differential RNA splicing. A distinctly conserved cassette of domains at the amino-end of papilins is homologous with a cassette of protein domains at the carboxyl-end of the ADAMTS subgroup of secreted, matrix-associated metalloproteases. Papilins primarily occur in basement membranes. Papilins interact with several extracellular matrix components and ADAMTS enzymes. Papilins are essential for embryonic development of Drosophila melanogaster and Caenorhabditis elegans. The gonad arms of C. elegans hermaphrodites acquire invariant shapes by guided migrations of distal tip cells (DTCs), which occur in three phases that differ in the direction and basement membrane substrata used for movement. We found that mig-6 encodes long (MIG-6L) and short (MIG-6S) isoforms of the extracellular matrix protein papilin, each required for distinct aspects of DTC migration. Both MIG-6 isoforms have a predicted N-terminal papilin cassette, lagrin repeats and C-terminal Kunitz-type serine proteinase inhibitory domains. We show that mutations affecting MIG-6L specifically and cell-autonomously decrease the rate of post-embryonic DTC migration, mimicking a post-embryonic collagen IV deficit. We also show that MIG-6S has two separable functions - one in embryogenesis and one in the second phase of DTC migration. Genetic data suggest that MIG-6S functions in the same pathway as the MIG-17/ADAMTS metalloproteinase for guiding phase 2 DTC migrations, and MIG-17 is abnormally localized in mig-6 class-s mutants. Genetic data also suggest that MIG-6S and non-fibrillar network collagen IV play antagonistic roles to ensure normal phase 2 DTC guidance. OBJECTIVES: Suicidal ideation is an uncommon but worrisome symptom than can emerge during antidepressant treatment. We have described earlier the association between treatment-emergent suicidal ideation (TESI) and markers in genes encoding glutamate receptor subunits GRIK2 and GRIA3. The present genome-wide association study was conducted to identify additional genetic markers associated with TESI that may help identify individuals at high risk who may benefit from closer monitoring, alternative treatments, and/or specialty care. METHODS: A clinically representative cohort of outpatients with nonpsychotic major depressive disorder enrolled in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial were treated with citalopram under a standard protocol for up to 14 weeks. DNA samples from 90 White participants who developed TESI and a sex-matched and race-matched equal number of treated participants who denied any suicidal ideas were genotyped with 109 365 single nucleotide polymorphisms on the Illumina's Human-1 BeadChip. RESULTS: One marker was found to be associated with TESI in this sample at the experiment-wide adjusted P less than 0.05 level (marker rs11628713, allelic P = 6.2x10, odds ratio = 4.7, permutation P = 0.01). A second marker was associated at the experiment-wide adjusted P = 0.06 level (rs10903034, allelic P = 3.02x10, odds ratio = 2.7, permutation P = 0.06). These markers reside within the genes PAPLN and IL28RA, respectively. PAPLN encodes papilin, a protoglycan-like sulfated glycoprotein. IL28RA encodes an interleukin receptor. CONCLUSION: Together with our earlier report, these findings may shed light on the biological basis of TESI and may help identify patients at increased risk of this potentially serious adverse event. Cell invasion through basement membrane is a specialized cellular behavior critical for many developmental processes and leukocyte trafficking. Invasive cellular behavior is also inappropriately co-opted during cancer progression. Acquisition of an invasive phenotype is accompanied by changes in gene expression that are thought to coordinate the steps of invasion. The transcription factors responsible for these changes in gene expression, however, are largely unknown. C. elegans anchor cell (AC) invasion is a genetically tractable in vivo model of invasion through basement membrane. AC invasion requires the conserved transcription factor FOS-1A, but other transcription factors are thought to act in parallel to FOS-1A to control invasion. Here we identify the transcription factor HLH-2, the C. elegans ortholog of Drosophila Daughterless and vertebrate E proteins, as a regulator of AC invasion. Reduction of HLH-2 function by RNAi or with a hypomorphic allele causes defects in AC invasion. Genetic analysis indicates that HLH-2 has functions outside of the FOS-1A pathway. Using expression analysis, we identify three genes that are transcriptionally regulated by HLH-2: the protocadherin cdh-3, and two genes encoding secreted extracellular matrix proteins, mig-6/papilin and him-4/hemicentin. Further, we show that reduction of HLH-2 function causes defects in polarization of F-actin to the invasive cell membrane, a process required for the AC to generate protrusions that breach the basement membrane. This work identifies HLH-2 as a regulator of the invasive phenotype in the AC, adding to our understanding of the transcriptional networks that control cell invasion.
Are long non coding RNAs spliced?
Long non coding RNAs appear to be spliced through the same pathway as the mRNAs
Thousands of long noncoding RNAs (lncRNAs) have been found in vertebrate animals, a few of which have known biological roles. To better understand the genomics and features of lncRNAs in invertebrates, we used available RNA-seq, poly(A)-site, and ribosome-mapping data to identify lncRNAs of Caenorhabditis elegans. We found 170 long intervening ncRNAs (lincRNAs), which had single- or multiexonic structures that did not overlap protein-coding transcripts, and about sixty antisense lncRNAs (ancRNAs), which were complementary to protein-coding transcripts. Compared to protein-coding genes, the lncRNA genes tended to be expressed in a stage-dependent manner. Approximately 25% of the newly identified lincRNAs showed little signal for sequence conservation and mapped antisense to clusters of endogenous siRNAs, as would be expected if they serve as templates and targets for these siRNAs. The other 75% tended to be more conserved and included lincRNAs with intriguing expression and sequence features associating them with processes such as dauer formation, male identity, sperm formation, and interaction with sperm-specific mRNAs. Our study provides a glimpse into the lncRNA content of a nonvertebrate animal and a resource for future studies of lncRNA function. Splicing remains an incompletely understood process. Recent findings suggest that chromatin structure participates in its regulation. Here, we analyze the RNA from subcellular fractions obtained through RNA-seq in the cell line K562. We show that in the human genome, splicing occurs predomitly during transcription. We introduce the coSI measure, based on RNA-seq reads mapping to exon junctions and borders, to assess the degree of splicing completion around internal exons. We show that, as expected, splicing is almost fully completed in cytosolic polyA+ RNA. In chromatin-associated RNA (which includes the RNA that is being transcribed), for 5.6% of exons, the removal of the surrounding introns is fully completed, compared with 0.3% of exons for which no intron-removal has occurred. The remaining exons exist as a mixture of spliced and fewer unspliced molecules, with a median coSI of 0.75. Thus, most RNAs undergo splicing while being transcribed: "co-transcriptional splicing." Consistent with co-transcriptional spliceosome assembly and splicing, we have found significant enrichment of spliceosomal snRNAs in chromatin-associated RNA compared with other cellular RNA fractions and other nonspliceosomal snRNAs. CoSI scores decrease along the gene, pointing to a "first transcribed, first spliced" rule, yet more downstream exons carry other characteristics, favoring rapid, co-transcriptional intron removal. Exons with low coSI values, that is, in the process of being spliced, are enriched with chromatin marks, consistent with a role for chromatin in splicing during transcription. For alternative exons and long noncoding RNAs, splicing tends to occur later, and the latter might remain unspliced in some cases. The human genome contains many thousands of long noncoding RNAs (lncRNAs). While several studies have demonstrated compelling biological and disease roles for individual examples, analytical and experimental approaches to investigate these genes have been hampered by the lack of comprehensive lncRNA annotation. Here, we present and analyze the most complete human lncRNA annotation to date, produced by the GENCODE consortium within the framework of the ENCODE project and comprising 9277 manually annotated genes producing 14,880 transcripts. Our analyses indicate that lncRNAs are generated through pathways similar to that of protein-coding genes, with similar histone-modification profiles, splicing signals, and exon/intron lengths. In contrast to protein-coding genes, however, lncRNAs display a striking bias toward two-exon transcripts, they are predomitly localized in the chromatin and nucleus, and a fraction appear to be preferentially processed into small RNAs. They are under stronger selective pressure than neutrally evolving sequences-particularly in their promoter regions, which display levels of selection comparable to protein-coding genes. Importantly, about one-third seem to have arisen within the primate lineage. Comprehensive analysis of their expression in multiple human organs and brain regions shows that lncRNAs are generally lower expressed than protein-coding genes, and display more tissue-specific expression patterns, with a large fraction of tissue-specific lncRNAs expressed in the brain. Expression correlation analysis indicates that lncRNAs show particularly striking positive correlation with the expression of antisense coding genes. This GENCODE annotation represents a valuable resource for future studies of lncRNAs. NONCODE (http://www.bioinfo.org/noncode/) is an integrated knowledge database dedicated to non-coding RNAs (excluding tRNAs and rRNAs). Non-coding RNAs (ncRNAs) have been implied in diseases and identified to play important roles in various biological processes. Since NONCODE version 3.0 was released 2 years ago, discovery of novel ncRNAs has been promoted by high-throughput RNA sequencing (RNA-Seq). In this update of NONCODE, we expand the ncRNA data set by collection of newly identified ncRNAs from literature published in the last 2 years and integration of the latest version of RefSeq and Ensembl. Particularly, the number of long non-coding RNA (lncRNA) has increased sharply from 73 327 to 210 831. Owing to similar alternative splicing pattern to mRNAs, the concept of lncRNA genes was put forward to help systematic understanding of lncRNAs. The 56 018 and 46 475 lncRNA genes were generated from 95 135 and 67 628 lncRNAs for human and mouse, respectively. Additionally, we present expression profile of lncRNA genes by graphs based on public RNA-seq data for human and mouse, as well as predict functions of these lncRNA genes. The improvements brought to the database also include an incorporation of an ID conversion tool from RefSeq or Ensembl ID to NONCODE ID and a service of lncRNA identification. NONCODE is also accessible through http://www.noncode.org/.
Is RANKL secreted from the cells?
Receptor activator of nuclear factor κB ligand (RANKL) is a cytokine predominantly secreted by osteoblasts.
Bone destruction is a common feature of inflammatory arthritis and is mediated by osteoclasts, the only specialized cells to carry out bone resorption. Aberrant expression of receptor activator of nuclear factor kappa β ligand (RANKL), an inducer of osteoclast differentiation has been linked with bone pathology and the synovial fibroblast in rheumatoid arthritis (RA). In this manuscript, we challenge the current concept that an increase in RANKL expression governs osteoclastogenesis and bone destruction in autoimmune arthritis. We isolated human fibroblasts from RA, pyrophosphate arthropathy (PPA) and osteoarthritis (OA) patients and analyzed their RANKL/OPG expression profile and the capacity of their secreted factors to induce osteoclastogenesis. We determined a 10-fold increase of RANKL mRNA and protein in fibroblasts isolated from RA relative to PPA and OA patients. Peripheral blood mononuclear cells (PBMC) from healthy volunteers were cultured in the presence of RA, PPA and OA synovial fibroblast conditioned medium. Osteoclast differentiation was assessed by expression of tartrate-resistant acid phosphatase (TRAP), vitronectin receptor (VNR), F-actin ring formation and bone resorption assays. The formation of TRAP(+), VNR(+) multinucleated cells, capable of F-actin ring formation and lacunar resorption in synovial fibroblast conditioned medium cultures occured in the presence of osteoprotegerin (OPG) a RANKL antagonist. Osteoclasts did not form in these cultures in the absence of macrophage colony stimulating factor (M-CSF). Our data suggest that the conditioned medium of pure synovial fibroblast cultures contain inflammatory mediators that can induce osteoclast formation in human PBMC independently of RANKL. Moreover inhibition of the TNF or IL-6 pathway was not sufficient to abolish osteoclastogenic signals derived from arthritic synovial fibroblasts. Collectively, our data clearly show that alternate osteoclastogenic pathways exist in inflammatory arthritis and place the synovial fibroblast as a key regulatory cell in bone and joint destruction, which is a hallmark of autoimmune arthritis. Pulsed electromagnetic field (PEMF) has been shown to increase bone mineral density in osteoporosis patients and prevent bone loss in ovariectomized rats. But the mechanisms through which PEMF elicits these favorable biological responses are still not fully understood. Receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) are cytokines predomitly secreted by osteoblasts and play a central role in differentiation and functional activation of osteoclasts. The purpose of this study was to investigate the effects of PEMF on RANKL and OPG expression in ovariectomized rats. Thirty 3-month-old female Sprague-Dawley rats were randomly divided into three groups: sham-operated control (Sham), ovariectomy control (OVX), and ovariectomy with PEMF treatment (PEMF). After 12-week interventions, the results showed that PEMF increased serum 17β-estradiol level, reduced serum tartrate-resistant acid phosphatase level, increased bone mineral density, and inhibited deterioration of bone microarchitecture and strength in OVX rats. Furthermore, PEMF could suppress RANKL expression and improve OPG expression in bone marrow cells of OVX rats. In conclusion, this study suggests that PEMF can prevent ovariectomy-induced bone loss through regulating the expression of RANKL and OPG. Zebrafish scales consist of bone-forming osteoblasts, bone-resorbing osteoclasts, and calcified bone matrix. To elucidate the underlying molecular mechanism of the effects induced by dynamic and static acceleration, we investigated the scale osteoblast- and osteoclast-specific marker gene expression involving osteoblast-osteoclast communication molecules. Osteoblasts express RANKL, which binds to the osteoclast surface receptor, RANK, and stimulates bone resorption. OPG, on the other hand, is secreted by osteoblast as a decoy receptor for RANKL, prevents RANKL from binding to RANK and thus prevents bone resorption. Therefore, the RANK-RANKL-OPG pathway contributes to the regulation of osteoclastogenesis by osteoblasts. Semaphorin 4D, in contrast, is expressed on osteoclasts, and binding to its receptor Plexin-B1 on osteoblasts results in suppression of bone formation. In the present study, we found that both dynamic and static acceleration at 3.0×g decreased RANKL/OPG ratio and increased osteoblast-specific functional mRNA such as alkaline phosphatase, while static acceleration increased and dynamic acceleration decreased osteoclast-specific mRNA such as cathepsin K. Static acceleration increased semaphorin 4D mRNA expression, while dynamic acceleration had no effect. The results of the present study indicated that osteoclasts have predomit control over bone metabolism via semaphorin 4D expression induced by static acceleration at 3.0×g. Osteoprotegerin (OPG) is a secreted glycoprotein and a member of the tumor necrosis factor receptor superfamily. It usually functions in bone remodeling, by inhibiting osteoclastogenesis through interaction with a receptor activator of the nuclear factor κB (RANKL). Transglutaminases-2 (Tgase-2) is a group of multifunctional enzymes that plays a role in cancer cell metastasis and bone formation. However, relationship between OPG and Tgase-2 is not studied. Therefore, we investigated the involvement of 12-O-Tetradecanoylphorbol 13-acetate in the expression of OPG in MG-63 osteosarcoma cells. Interleukin-1β time-dependently induced OPG and Tgase-2 expression in cell lysates and media of the MG-63 cells by a Western blot. Additional 110 kda band was found in the media of MG-63 cells. 12-O-Tetradecanoylphorbol 13-acetate also induced OPG and Tgase-2 expression. However, an 110 kda band was not found in TPA-treated media of MG-63 cells. Cystamine, a Tgase-2 inhibitor, dose-dependently suppressed the expression of OPG in MG-63 cells. Gene silencing of Tgase-2 also signifi cantly suppressed the expression of OPG in MG-63 cells. Next, we examined whether a band of 110 kda of OPG contains an isopeptide bond, an indication of Tgase-2 action, by monoclonal antibody specifi c for the isopeptide bond. However, we could not fi nd the isopeptide bond at 110 kda but 77 kda, which is believed to be the band position of Tgase-2. This suggested that 110 kda is not the direct product of Tgase-2's action. All together, OPG and Tgase-2 is induced by IL-1β or TPA in MG-63 cells and Tgase-2 is involved in OPG expression in MG-63 cells. BACKGROUND: Resistance to apoptosis is a major problem in ovarian cancer (OC) and correlates with poor prognosis. Osteoprotegerin (OPG) is a soluble secreted factor that acts as a decoy receptor for receptor activator of NF-κB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). OPG has been reported to attenuate TRAIL-induced apoptosis in a variety of cancer cells, including OC cells. OPG-mediated protection against TRAIL has been attributed to its decoy receptor function. However, OPG activates integrin/focal adhesion kinase (FAK) signaling in endothelial cells. In OC cells, activation of integrin/FAK signaling inhibits TRAIL-induced apoptosis. Based on these observations, we hypothesized that OPG could attenuate TRAIL-induced apoptosis in OC cells through integrin/FAK signaling. METHODS: In vitro experiments including immunoblots, colony formation assays, and apoptosis measurements were used to assess the effect of OPG on TRAIL-induced apoptosis. RESULTS: Exogenous OPG protected from TRAIL-induced apoptosis in a TRAIL binding-independent manner and OPG protection was αvβ3 and αvβ5 integrin/FAK signaling-dependent. Moreover, OPG-mediated activation of integrin/FAK signaling resulted in the activation of Akt. Inhibition of both integrin/FAK and Akt signaling significantly inhibited OPG-mediated attenuation of TRAIL-induced apoptosis. Although OPG also stimulated ERK1/2 phosphorylation, inhibition of ERK1/2 signaling did not significantly altered OPG protection. CONCLUSIONS: Our studies provide evidence, for the first time, that OPG can attenuate TRAIL-induced apoptosis in a TRAIL binding-independent manner through the activation of integrin/FAK/Akt signaling in OC cells.
Does metformin interfere thyroxine absorption?
No. There are not reported data indicating that metformin reduce with thyroxine absorption.
Which miRNAs could be used as potential biomarkers for epithelial ovarian cancer?
miR-200a, miR-100, miR-141, miR-200b, miR-200c, miR-203, miR-510, miR-509-5p, miR-132, miR-26a, let-7b, miR-145, miR-182, miR-152, miR-148a, let-7a, let-7i, miR-21, miR-92 and miR-93 could be used as potential biomarkers for epithelial ovarian cancer.
OBJECTIVE: To determine the utility of serum miRNAs as biomarkers for epithelial ovarian cancer. METHODS: Twenty-eight patients with histologically confirmed epithelial ovarian cancer were identified from a tissue and serum bank. Serum was collected prior to definitive therapy. Fifteen unmatched, healthy controls were used for comparison. Serum was obtained from all patients. RNA was extracted using a derivation of the single step Trizol method. The RNA from 9 cancer specimens was compared to 4 normal specimens with real-time PCR using the TaqMan Array Human MicroRNA panel. Twenty-one miRNAs were differentially expressed between normal and patient serum. Real-time PCR for the 21 individual miRNAs was performed on the remaining 19 cancer specimens and 11 normal specimens. RESULTS: Eight miRNAs of the original twenty-one were identified that were significantly differentially expressed between cancer and normal specimens using the comparative C(t) method. MiRNAs-21, 92, 93, 126 and 29a were significantly over-expressed in the serum from cancer patients compared to controls (p<.01). MiRNAs-155, 127 and 99b were significantly under-expressed (p<.01). Additionally, miRs-21, 92 and 93 were over-expressed in 3 patients with normal pre-operative CA-125. CONCLUSION: We demonstrate that the extraction of RNA and subsequent identification of miRNAs from the serum of individuals diagnosed with ovarian cancer is feasible. Real-time PCR-based microarray is a novel and practical means to performing high-throughput investigation of serum RNA samples. miRNAs-21, 92 and 93 are known oncogenes with therapeutic and biomarker potential. MicroRNAs (miRNA) are approximately 22-nucleotide noncoding RNAs that negatively regulate protein-coding gene expression in a sequence-specific manner via translational inhibition or mRNA degradation. Our recent studies showed that miRNAs exhibit genomic alterations at a high frequency and their expression is remarkably deregulated in ovarian cancer, strongly suggesting that miRNAs are involved in the initiation and progression of this disease. In the present study, we performed miRNA microarray to identify the miRNAs associated with chemotherapy response in ovarian cancer and found that let-7i expression was significantly reduced in chemotherapy-resistant patients (n = 69, P = 0.003). This result was further validated by stem-loop real-time reverse transcription-PCR (n = 62, P = 0.015). Both loss-of-function (by synthetic let-7i inhibitor) and gain-of-function (by retroviral overexpression of let-7i) studies showed that reduced let-7i expression significantly increased the resistance of ovarian and breast cancer cells to the chemotherapy drug, cis-platinum. Finally, using miRNA microarray, we found that decreased let-7i expression was significantly associated with the shorter progression-free survival of patients with late-stage ovarian cancer (n = 72, P = 0.042). This finding was further validated in the same sample set by stem-loop real-time reverse transcription-PCR (n = 62, P = 0.001) and in an independent sample set by in situ hybridization (n = 53, P = 0.049). Taken together, our results strongly suggest that let-7i might be used as a therapeutic target to modulate platinum-based chemotherapy and as a biomarker to predict chemotherapy response and survival in patients with ovarian cancer. OBJECTIVES: Let-7 is a family of small non-coding RNAs regulating the expression of many genes that control important cellular activities. Let-7 is shown in vitro to sensitize cancer cells to platinum, but induce ovarian cancer resistance to paclitaxel. This study aims to investigate the effect of let-7a expression on survival outcomes of epithelial ovarian cancer (EOC) patients treated with different chemotherapy. METHODS: Let-7a expression was measured with qRT-PCR in ovarian tumors of 178 EOC patients who received platinum-based chemotherapy with and without paclitaxel after surgery. Survival analysis was performed to assess the effects of let-7a and chemotherapy on disease outcomes. RESULTS: Let-7a expression was detectable in the EOC samples, but the expression was not associated with disease stage, tumor grade, histology and debulking results. Patients who responded to platinum with paclitaxel had significantly lower let-7a than those who did not. Survival analyses showed that patients with high let-7a had better survival compared to those with low let-7a when they were treated with platinum without paclitaxel. The hazards ratios (HRs) for death and disease progression were 0.52 (95% CI: 0.29-0.96) and 0.48 (0.26-0.89) for high let-7a when compared to low let-7a, respectively. However, when patients were treated with platinum and paclitaxel, high let-7a was associated with worse progression-free and overall survival. The HRs for death and disease progression were 3.87 (95% CI: 1.28-11.66) and 3.48 (95% CI: 1.25-9.67) for high let-7a when compared to low let-7a, respectively. Further studies showed that among patients with low let-7a, those treated with paclitaxel in addition to platinum survived better than those treated without paclitaxel [adjusted-HRs were 0.31 (95% CI: 0.15-0.66) for death and 0.40 (95% CI: 0.22-0.75) for disease], while among those with high let-7a, the two types of treatment made no difference in patient survival. CONCLUSIONS: The study suggests that the beneficial impact of the addition of paclitaxel on EOC survival was significantly linked to let-7a levels, and that miRNAs such as let-7a may be a useful marker for selection of chemotherapeutic agents in EOC management. microRNAs (miRs) are endogenous small non-coding RNAs that are aberrantly expressed in various carcinomas. miR-152 and miR-148a have not been comprehensively investigated in ovarian cancer. Thus, the aim of this study was to identify the role of miR-152 and miR-148a in epithelial ovarian cancer. Total RNA was extracted from tissues of 78 patients with epithelial ovarian cancer, 17 normal ovarian epithelium tissues and two ovarian cancer cell lines. Using quantitative real-time PCR (qRT-PCR) followed by the 2-ΔΔCT method for calculating the results, we found that the expression levels of miR-152 were significantly decreased in ovarian cancer tissues compared to normal ovarian epithelium tissues (p<0.05). However, although the expression of miR-148a was also decreased in 65% of patients, no statistically significant difference in expression was found. A strong correlation was found between the expression of miR-152 and miR-148a (p<0.001, Pearson's correlation). The relationship between miR-152 or miR-148a expression levels in ovarian cancer and clinicopathological features, response to therapy and short-term survival was analyzed and the results showed that no correlation existed. In addition, we found that both miR-152 and miR-148a were down-regulated in ovarian cancer cell lines. After miR-152 or miR-148a mimics were transfected into ovarian cancer cell lines, the MTT cell proliferation assay showed that cell proliferation was significantly inhibited. Taken together, miR-152 and miR-148a may be involved in the carcinogenesis of ovarian cancer through deregulation of cell proliferation. They may be novel biomarkers for early detection or therapeutic targets of ovarian cancer. BACKGROUND: There is a critical need for improved diagnostic markers for high grade serous epithelial ovarian cancer (SEOC). MicroRNAs are stable in the circulation and may have utility as biomarkers of maligcy. We investigated whether levels of serum microRNA could discriminate women with high-grade SEOC from age matched healthy volunteers. METHODS: To identify microRNA of interest, microRNA expression profiling was performed on 4 SEOC cell lines and normal human ovarian surface epithelial cells. Total RNA was extracted from 500 μL aliquots of serum collected from patients with SEOC (n = 28) and age-matched healthy donors (n = 28). Serum microRNA levels were assessed by quantitative RT-PCR following preamplification. RESULTS: microRNA (miR)-182, miR-200a, miR-200b and miR-200c were highly overexpressed in the SEOC cell lines relative to normal human ovarian surface epithelial cells and were assessed in RNA extracted from serum as candidate biomarkers. miR-103, miR-92a and miR -638 had relatively invariant expression across all ovarian cell lines, and with small-nucleolar C/D box 48 (RNU48) were assessed in RNA extracted from serum as candidate endogenous normalizers. No correlation between serum levels and age were observed (age range 30-79 years) for any of these microRNA or RNU48. Individually, miR-200a, miR-200b and miR-200c normalized to serum volume and miR-103 were significantly higher in serum of the SEOC cohort (P < 0.05; 0.05; 0.0005 respectively) and in combination, miR-200b + miR-200c normalized to serum volume and miR-103 was the best predictive classifier of SEOC (ROC-AUC = 0.784). This predictive model (miR-200b + miR-200c) was further confirmed by leave one out cross validation (AUC = 0.784). CONCLUSIONS: We identified serum microRNAs able to discriminate patients with high grade SEOC from age-matched healthy controls. The addition of these microRNAs to current testing regimes may improve diagnosis for women with SEOC. OBJECTIVE: MicroRNA (miRNA) is an abundant class of small noncoding RNAs that act as gene regulators. Recent studies have suggested that miRNA deregulation is associated with the initiation and progression of human cancer. However, information about cancer-related miRNA is mostly limited to tissue miRNA. The aim of this study was to find specific profiles of serum-derived miRNAs of ovarian cancer based on a comparative study using a miRNA microarray of serum, tissue, and ascites. METHODS: From 2 ovarian cancer patients and a healthy control, total RNA was isolated from their serum, tissue, and ascites, respectively, and analyzed by a microarray. Under the comparative study of each miRNA microarray, we sorted out several miRNAs showing a consistent regulation tendency throughout all 3 specimens and the greatest range of alteration in serum as potential biomarkers. The availability of biomarkers was confirmed by qRT-PCR of 18 patients and 12 controls. RESULTS: Out of 2222 kinds of total miRNAs that were identified in the microarray analysis, 95 miRNAs were down-regulated and 88 miRNAs were up-regulated, in the serum, tissue, and ascites of cancer patients. Among the miRNAs that showed a consistent regulation tendency through all specimens and showed more than a 2-fold difference in serum, 5 miRNAs (miR-132, miR-26a, let-7b, miR-145, and miR-143) were determined as the 5 most markedly down-regulated miRNAs in the serum from ovarian cancer patients with respect to those of controls. Four miRNAs (miR-132, miR-26a, let-7b, and miR-145) out of 5 selected miRNAs were significantly underexpressed in the serum of ovarian cancer patients in qRT-PCR. CONCLUSIONS: Serum miR-132, miR-26a, let-7b, and miR-145 could be considered as potential candidates as novel biomarkers in serous ovarian cancer. Also, serum miRNAs is a promising and useful tool for discriminating between controls and patients with serous ovarian cancer. Recent investigations have confirmed up-regulation of serum miR-21 and its diagnostic and prognostic value in several human maligcies. In this study, we examined serum miR-21 levels in epithelial ovarian cancer (EOC) patients, and explored its association with clinicopathological factors and prognosis. The results showed significantly higher serum miR-21 levels in EOC patients than in healthy controls. In addition, increased serum miR-21 expression was correlated with advanced FIGO stage, high tumor grade, and shortened overall survival. These findings indicate that serum miR-21 may serve as a novel diagnostic and prognostic marker, and be used as a therapeutic target for the treatment of EOC. Epithelial ovarian cancer (EOC) is the leading cause of death among gynecologic maligcies. Despite great efforts to improve early detection and optimize chemotherapeutic regimens, the 5-year survival rate is only 30% for patients presenting with late-stage ovarian cancer. The high mortality of this disease is due to late diagnosis in over 70% of ovarian cancer cases. A class of small noncoding RNAs, or microRNAs, was found to regulate gene expression at the post-transcriptional level. Some, but not all, of the data indicated that the miR-200 family was dysregulated in a variety of maligcies. In this study, we demonstrated that miR-200a and E-cadherin were significantly upregulated in EOC compared to benign epithelial ovarian cysts and normal ovarian tissues. However, further stratification of the subject indicated that the expression levels of miR-200a were significantly downregulated in late-stage (FIGO III+V) and grade 3 groups compared with early stage (FIGO I+II) and grade 1 to 2 groups. Similarly, relatively low levels of miR-200a were observed in the lymph compared to the node-negative group. E-cadherin expression was found to be absent in normal ovarian tissue and was frequently expressed in benign epithelial ovarian cysts, with absence or low levels observed in late-stage ovarian cancers. There was a significantly positive correlation between miR-200a and E-cadherin in EOC. The biphasic expression pattern suggested that miR-200a levels may serve as novel biomarkers for the early detection of EOC, and miR-200a and E-cadherin are candidate targets for the development of new treatment modalities against ovarian cancer. MicroRNA-203 (miR-203), possessing tumor suppressive or promotive activities, has been found to be downregulated or upregulated in different cancer types. The purpose of this study was to investigate whether the increased expression of miR-203 can be used as a noninvasive diagnostic and prognostic biomarker in epithelial ovarian cancer (EOC). Real-time quantitative PCR was performed to detect the expression levels of miR-203 in EOC tissues. The expression levels of miR-203 were significantly higher in EOC tissues compared to adjacent non-cancerous tissues (p < 0.001). High expression of miR-203 was observed in 65.38 % (102/156) of EOC. In addition, high miR-203 expression was found to be closely correlated with advanced FIGO stage (p < 0.001), higher histological grade (p = 0.02), lymph node involvement (p < 0.001), and positive recurrence (p < 0.001). Moreover, high miR-203 expression was correlated with shorter overall survival (p < 0.001) and shorter progression-free survival (p < 0.001) of EOC patients. Furthermore, multivariate analysis showed that the status of miR-203 expression was an independent predictor for both overall survival and progression-free survival in EOC. These findings provide the convincing evidence for the first time that the upregulation of miR-203 may serve as a novel molecular marker to predict the aggressive tumor progression and unfavorable prognosis of EOC patients.
Which acetylcholinesterase inhibitors are used for treatment of myasthenia gravis?
Pyridostigmine and neostygmine are acetylcholinesterase inhibitors that are used as first-line therapy for symptomatic treatment of myasthenia gravis. Pyridostigmine is the most widely used acetylcholinesterase inhibitor. Extended release pyridotsygmine and novel acetylcholinesterase inhibitors inhibitors with oral antisense oligonucleotides are being studied.
Treatment for myasthenia gravis should be individualized to each patient based on the clinical characteristics of myasthenia including the distribution, duration, and severity of weakness and resulting functional impairment; the risks for treatment complications related to age, gender, and medical comorbidities; and the presence of thymoma. Acetylcholinesterase inhibitors provide temporary, symptomatic treatment for all forms of myasthenia gravis. Immune modulators address the underlying autoimmune process in myasthenia gravis, but are associated with potential complications and side effects. Most patients with generalized myasthenia who have significant weakness beyond the ocular muscles and who remain symptomatic, despite treatment with cholinesterase inhibitors, are candidates for immune modulation. Although corticosteroids are effective for long-term immune modulation in myasthenia gravis, several more contemporary immunomodulators including azathioprine, cyclosporine, and mycophenolate mofetil have shown efficacy in myasthenia gravis and are used increasingly as first-line treatments and as steroid-sparing agents. Plasma exchange is used to achieve rapid improvement in patients with myasthenic crisis or exacerbation, to improve strength before a surgical procedure or thymectomy, and to minimize steroid-induced exacerbation in patients with oropharyngeal or respiratory muscle weakness. Intravenous immunoglobulin represents an alternative to plasma exchange in patients requiring relatively rapid short-term improvement in the setting of poor venous access. Because of a lack of controlled trials, the role of thymectomy in nonthymomatous myasthenia gravis is unclear, although evidence suggests that thymectomy increases the probability for myasthenic remission or improvement. INTRODUCTION: For more than 50 years the acetylcholinesterase inhibitor pyridostigmine bromide has been the drug of choice in the symptomatic therapy for myasthenia gravis. The sustained-release dosage form of pyridostigmine (SR-Pyr) is only available in a limited number of countries (e.g. in the United States and Germany). Astonishingly, the therapeutic usefulness of SR-Pyr has not yet been evaluated. METHODS: In this non-interventional prospective open-label trial, 72 patients with stable myasthenia gravis were switched from instant-release dosage forms of pyridostigmine bromide to SR-Pyr. The results from the 37 patients younger than 60 years were separately analyzed. RESULTS: The initial daily dose of SR-Pyr was 288.1 ± 171.0mg. The drug switch was unproblematic in all patients. The number of daily doses was significantly reduced from 4.3 to 3.6 (p=0.011). The switch to SR-Pyr ameliorated the total quantified myasthenia gravis (QMG) score from 0.9 ± 0.5 to 0.6 ± 0.4 (p<0.001) in all patients and in the younger subgroup. This was accompanied by a significant improvement in the quality of life parameters. The health status valued by EuroQoL questionnaire improved from 0.626 ± 0.286 to 0.782 ± 0.186 (p<0.001). After switching to SR-Pyr, 28 adverse reactions disappeared and 24 adverse reactions occurred less frequent or weaker, however, 17 new adverse reactions were documented. CONCLUSIONS: Our results support the usefulness of SR-Pyr in an individualized therapeutic regimen to improve quality of life regardless of the patient's age in myasthenia gravis. Myasthenia gravis (MG) is caused by failure of chemical transmission at the neuromuscular junction. It is an autoimmune disorder in which antibodies interfere with neuromuscular transmission. It has a prevalence of around 20 per 100,000. The incidence is bimodal with a 2:1 female to male ratio in the younger population and a reversed sex ratio over the age of 60. Around 15% of cases are associated with a thymoma. MG presents with fatiguable painless muscle weakness. Diplopia and ptosis are the most common presenting features. Around 80% of patients presenting with ocular MG will subsequently develop more generalised weakness. Respiratory muscle weakness is the most serious manifestation of MG and can be fatal. A detailed history is the most valuable tool in the diagnosis of MG. This should elicit the pattern of weakness, severity and diurnal variation. Exacerbating factors including extremes of weather, emotional stress, menstruation and intercurrent illness should be enquired about. No one diagnostic test is 100% sensitive and patients who have negative antibodies and normal neurophysiology may still have MG. Treatment should be directed at ameliorating weakness with acetylcholinesterase blockers and modulating the immune system. Pyridostigmine is the most widely used acetylcholinesterase inhibitor. Most patients with generalised MG require immunomodulatory therapy and prednisolone is generally used as the first-line agent. Despite the availability of symptomatic and immunomodulatory treatment, up to 20% of patients will experience a myasthenic crisis requiring admission for ventilatory support at some stage. Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Available therapies include oral acetylcholinesterase (AChE) inhibitors for symptomatic treatment, and short- and long-term disease-modifying treatments. This review focuses on treatment of MG, mainly on the use of the AChE inhibitor pyridostigmine. Despite a lack of data from well controlled clinical trials to support their use, AChE inhibitors, of which pyridostigmine is the most commonly used, are recommended as first-line therapy for MG. Pyridostigmine has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Novel AChE inhibitors with oral antisense oligonucleotides have been developed and preliminary results appear to be promising. In general, however, AChE inhibitors provide only partial benefit and most patients eventually switch to long-term immunosuppressive therapies, most frequently corticosteroids and/or azathioprine. Although AChE inhibitors are known to be well tolerated and effective in relieving the symptoms of MG, further efforts are required to improve treatment options for the management of this disorder. Myasthenia gravis is an autoimmune neuromuscular disorder. There are several treatment options, including symptomatic treatment (acetylcholinesterase inhibitors), short-term immunosuppression (corticosteroids), long-term immunosuppression (azathioprine, cyclosporine, cyclophosphamide, methotrexate, mycophenolate mofetil, rituximab, tacrolimus), rapid acting short-term immunomodulation (intravenous immunoglobulin, plasma exchange), and long-term immunomodulation (thymectomy). This review explores in detail these different treatment options. Potential future treatments are also discussed.
Has Denosumab (Prolia) been approved by FDA?
Yes, Denosumab was approved by the FDA in 2010.
Osteoporosis in men is finally receiving some attention; it has been realized that men are more likely to die after hip fracture. Methods for screening men for osteoporosis include dual energy x-ray absorptiometry and use of fracture risk calculators such as FRAX (World Health Organization) and the Garvan nomogram. Evaluation of men will often identify secondary causes of osteoporosis as well as multiple risk factors. Alendronate, risedronate, zoledronic acid, and teriparatide are US Food and Drug Administration (FDA)--approved therapy for men. Men on androgen deprivation therapy (ADT) are at high risk for bone loss and fracture, and all the bisphosphonates have been shown to increase bone density. The new antiresorptive drug, denosumab, although FDA-approved only for postmenopausal women, has been shown in a study of men on ADT to increase bone density in spine, hip, and forearm and decrease vertebral fractures on x-ray. Thus, there is great progress in osteoporosis in men, and recognition of its importance is increasing. Osteoporosis is a common consequence of androgen deprivation therapy (ADT) for prostate cancer. Up to 20% of men on ADT for localized prostate cancer will fracture within 5 years. Fortunately, generally safe and effect therapy is available. Although once considered non-controversial, there is some concern about calcium supplementation, but all studies of osteoporosis therapy in men have included calcium. In most older men, serum 25-hydroxyvitamin D levels are likely to be low, although again there is controversy about the ideal level. Many experts believe that all older men, including those on ADT, need to have a level of >30 ng/ml, which is easily accomplished. Bone mineral density (BMD) testing by dual energy X-ray absorptiometry (DXA) is indicated for men on ADT. Interestingly, forearm DXA may be particularly important in ADT men, in addition to spine and hip. Some experts have suggested that men on ADT with a T-score of ≤-1.5 should be treated. Alternatively FRAX or another risk calculator can be used. Oral and intravenous bisphosphonates are FDA approved treatments for men with osteoporosis and increase BMD in men on ADT. Potential off-label agents include raloxifene and toremifene. The latter and denosumab have been shown to increase bone density and decrease vertebral fractures in men on ADT. Raloxifene and denosumab are only FDA approved for postmenopausal osteoporosis. Thus, prevention of fractures can be accomplished in this high risk population. The Austrian Society for Bone and Mineral Research routinely publishes evidence-based guidelines for the treatment of postmenopausal osteoporosis. The fully human monoclonal antibody denosumab (Prolia(®)) has been recently approved by the European Medical Agency (EMEA) and the Food and Drug Administration (FDA) for the treatment of postmenopausal osteoporosis. Denosumab has been shown to reduce vertebral, non-vertebral,and hip-fracture risk effectively. Together with alendronate, risedronate, zoledronate, ibandronate, strontium ranelate, and raloxifene, denosumab constitutes an effective option in the treatment of postmenopausal osteoporosis. Therapeutic antibodies have captured substantial attention due to the relatively high rate at which these products reach marketing approval, and the subsequent commercial success they frequently achieve. In the 2000s, a total of 20 antibodies (18 full-length IgG and 2 Fab) were approved by the Food and Drug Administration (FDA) or European Medicines Agency (EMA). In the 2010s to date, an additional 3 antibodies (denosumab, belimumab, ipilimumab) have been approved and one antibody-drug conjugate (brentuximab vedotin) is undergoing regulatory review and may be approved in the US by August 30, 2011. However, a less heralded group of antibody-based therapeutics comprising proteins or peptides fused with an Fc is following the success of classical antibodies. BACKGROUND: Bone metastases are common in patients with hormone-refractory prostate cancer. In a study of autopsies of patients with prostate cancer, 65%-75% had bone metastases. Bone metastases place a substantial economic burden on payers with estimated total annual costs of $1.9 billion in the United States. Skeletal-related events (SREs), including pathologic fractures, spinal cord compression, surgery to bone, and radiation to bone, affect approximately 50% of patients with bone metastases. They are associated with a decreased quality of life and increased health care costs. Zoledronic acid is an effective treatment in preventing SREs in solid tumors and multiple myeloma. Recently, denosumab was FDA-approved for prevention of SREs in patients with bone metastases from solid tumors. A Phase 3 clinical trial (NCT00321620) demonstrated that denosumab had superior efficacy in delaying first and subsequent SREs compared with zoledronic acid. However, the economic value of denosumab has not been assessed in patients with hormone-refractory prostate cancer. OBJECTIVE: To compare the cost-effectiveness of denosumab with zoledronic acid in the treatment of bone metastases in men with hormone-refractory prostate cancer. METHODS: An Excel-based Markov model was developed to assess costs and effectiveness associated with the 2 treatments over a 1- and 3-year time horizon. Because the evaluation was conducted from the perspective of a U.S. third-party payer, only direct costs were included. Consistent with the primary outcome in the Phase 3 trial, effectiveness was assessed based on the number of SREs. The model consisted of 9 health states defined by SRE occurrence, SRE history, disease progression, and death. A hypothetical cohort of patients with hormone-refractory prostate cancer received either denosumab 120 mg or zoledronic acid 4 mg at the model entry and transitioned among the 9 health states at the beginning of each 13-week cycle. Transition probabilities associated with experiencing the first SRE, subsequent SREs, disease progression, and death were primarily derived from the results of the Phase 3 clinical trial and were supplemented with published literature. The model assumed that a maximum of 1 SRE could occur in each cycle. Drug costs included wholesale acquisition cost, health care professional costs associated with drug administration, and drug monitoring costs, if applicable. Nondrug costs included incremental costs associated with disease progression, costs associated with SREs, and terminal care costs, which were derived from the literature. Adverse event (AE) costs were estimated based on the incidence rates reported in the Phase 3 trial. Resource utilization associated with AEs was estimated based on consultation with a senior medical director employed by the study sponsor. All costs were presented in 2010 dollars. The base case estimated the incremental total cost per SRE avoided over a 1-year time horizon. Results for a 3-year time horizon were also estimated. One-way sensitivity analyses and probabilistic sensitivity analyses (PSA) were performed to test the robustness of the model. RESULTS: In the base case, the total per patient costs incurred over 1 year were estimated at $35,341 ($19,230 drug costs and $16,111 nondrug costs) for denosumab and $27,528 ($10,960 drug costs and $16,569 nondrug costs) for zoledronic acid, with an incremental total direct cost of $7,813 for denosumab. The estimated numbers of SREs per patient during the 1-year period were 0.49 for denosumab and 0.60 for zoledronic acid, resulting in an incremental number of SREs of -0.11 in the denosumab arm. The estimated incremental total direct costs per SRE avoided with the use of denosumab instead of zoledronic acid were $71,027 for 1 year and $51,319 for 3 years. The 1-way sensitivity analysis indicated that the results were sensitive to the drug costs, median time to first SRE, and increased risk of SRE associated with disease progression. Results of the PSA showed that based on willingness-to-pay thresholds of $70,000, $50,000, and $30,000 per SRE avoided, respectively, denosumab was cost-effective compared with zoledronic acid in 49.5%, 17.5%, and 0.3% of the cases at 1 year, respectively, and 79.0%, 49.8%, and 4.1% of the cases at 3 years, respectively. CONCLUSIONS: Although denosumab has demonstrated benefits over zoledronic acid in preventing or delaying SREs in a Phase 3 trial, it may be a costly alternative to zoledronic acid from a U.S. payer perspective. Most men with recurrent prostate cancer (CaP) initially respond to androgen deprivation therapy but eventually develop metastatic castration-resistant prostate cancer (CRPC). Over the last decade, new therapeutic targets have been identified in CRPC and several new drugs have reached advanced stages of clinical development. In 2010, the Food and Drug Administration (FDA) approved sipuleucel-T and cabazitaxel, and in 2011, abiraterone for patients with metastatic CRPC based on phase 3 trials showing improved survival. Although not yet available for clinical use, a press release in June 2011 announced that radium 223 also demonstrated a survival advantage in men with metastatic CRPC. Emerging therapies in advanced stages of clinical development in CRPC include the hormonal therapies MDV3100 and TAK 700, and the immunotherapy ipilimumab. Results are also pending on phase 3 studies comparing docetaxel plus prednisone with docetaxel given with the novel agents aflibercept, dasatinib, lenalidomide, and custirsen. In addition to these new and emerging therapeutic agents, denosumab was approved for the prevention of skeletal complications in patients with bone metastases due to solid tumor maligcies, providing an alternative to zoledronic acid. While the addition of these new treatment options is a great advance for men with metastatic CRPC, there are many new questions arising regarding sequencing of these treatments with each other, with previously existing therapies, and with the emerging agents now in clinical trials. Furthermore, there are concerns that on-going phase 3 trials may be contaminated if patients go off study treatment to start 1 of the newly approved agents or take the agent subsequently. These realities make clinical trial design more challenging than ever. BACKGROUND: In 2007, the Agency for Healthcare Research and Quality(AHRQ) published a systematic review on the comparative effectiveness of treatments for osteoporosis. The review included studies on the benefits and risks of medications and therapies used to prevent fractures in postmenopausal women and men with low bone density (osteopenia) or osteoporosis. Factors that may affect adherence to treatment, and monitoring for the identification of those most likely to benefit from treatment were also included in this review. AHRQ published an updated review in March 2012 that summarized the benefits and risks of osteoporosis medications in treatment and prevention of osteoporosis, including bisphosphonates (aledronate, risedronate, ibandronate, zoledronic acid), parathyroid hormone, teriparatide, calcitonin, estrogens (for prevention in postmenopausal women), selective estrogen receptor modulators (raloxifene), and denosumab(approved by the FDA in 2010). In addition, dietary and supplemental calcium and vitamin D, as well as weight-bearing exercise, for the preservation of bone mass and the decrease of fracture risk in patients with osteoporosis, were evaluated. OBJECTIVES: To (a) familiarize health care professionals with the methods and findings from AHRQ's 2012 comparative effectiveness review on treatments to prevent fractures in men and women with low bone density or osteoporosis, (b) encourage consideration and application of the findings of this review in clinical and managed care settings, and (c) identify limitations and gaps in the existing research with respect to the benefits and risks of treatments for osteoporosis. SUMMARY: Osteoporosis is a prevalent systemic skeletal disease caused by bone deterioration and loss of mass resulting in fractures, chronic pain and physical disability. It is common in postmenopausal women but men are at risk as well for fractures associated with low bone density. The increasing prevalence and cost of treating osteoporosis make the study of safety and effectiveness for currently available osteoporosis therapies pertinent and timely. In 2012, the Agency for Healthcare Research and Quality (AHRQ) published an updated review on the effectiveness and safety of treatments for osteoporosis, including new therapies for the prevention of vertebral and nonvertebral fractures in postmenopausal women and men.The interventions assessed in the review included 1 biological agent, pharmacological agents, dietary and supplemental calcium and vitamin D, and weight-bearing exercise. The updated report included the new agents and indications approved after the 2007 report and new data on effectiveness and adverse events associated with the bisphosponates; calcitonin was determined by the reviewers to not be appropriate therapy for osteoporosis and was excluded. The updated review examined 5 key questions focused on comparative review of all FDA-approved medicines for osteoporosis in fracture risk reduction, effectiveness in racial/ethnic subpopulations as well as different risk stratification using FRAX (World Health Organization Fracture Risk Assessment Tool) or other cutoffs, compliance and adherence, adverse effects of medications, the prediction of treatment efficacy using bone mineral density (BMD) monitoring by dual energy x-ray absorptiometry (DXA), and comparative effectiveness of long-term therapy.The AHRQ reviewers found high strength of evidence to support a reduction in risk of vertebral, nonvertebral and hip fractures in postmenopausal women with osteoporosis treated with 1 of 4 agents (alendronate, risedronate, zoledronic acid, or denosumab). A risk reduction for vertebral fractures in postmenopausal women with osteoporosis treated with ibandronate, teriparatide, or raloxifene therapy was supported with high-strength evidence. Evidence was graded high strength for reduction of vertebral and hip fracture with estrogen therapy in postmenopausal women but not in women with established osteoporosis. Evidence was graded moderate for a reduction in nonvertebral fractures with teriparatide or calcium monotherapy. Moderate or low-moderate strength of evidence showed that calcium alone does not reduce the risk of vertebral or nonvertebral fracture, and that vitamin D has mixed results on decreasing overall fracture risk. High-strength evidence supports a reduction in the risk of hip fracture with calcium treatment. Vitamin D treatment significantly reduced vertebral fractures among patients with primary osteoporosis. The combination of calcium plus vitamin C did not reduce vertebral fracture risk, but did reduce nonvertebral fracture risk in certain populations. Calcium plus vitamin D did decrease the risk of fracture in elderly women but not in elderly men. Adherence and persistence to osteoporosis medications varied depending on patient age, prior history of fracture, dosing frequency, concomitant use of other medications, and adverse effects. Adherence to treatment improved with weekly dosing compared with daily regimens, but evidence was lacking to show monthly regimens improved adherence over weekly regimens. This article recaps the key findings from the AHRQ 2012 review for the purpose of informing health care providers about the efficacy and safety of therapies used to prevent osteoporotic vertebral, nonvertebral, hip, and wrist fractures. Scientific literature on the effects of risk factors, adherence, BMD monitoring, and long-term therapy on patient outcomes is reviewed in order to inform prescribing decisions. In addition, applications of the AHRQ findings to practice are discussed to provide clinicians with information needed to provide evidence-based care for their patients. Prostate cancer (PC) is the leading cause of cancer and the second leading cause of cancer-death among men in the Western world. About 10-20% of men with PC present with metastatic disease at diagnosis, while 20-30% of patients diagnosed with localized disease will eventually develop metastases. Although most respond to initial androgen-deprivation therapy (ADT), progression to castration-resistant PC (CRPC) is universal. In 2004 the docetaxel/prednisone regimen was approved for the management of patients with metastatic CRPC, becoming the standard first-line therapy. Recent advances have now led to an unprecedented number of new drug approvals within the past years, providing many new treatment options for patients with metastatic CRPC. Four new drugs have received U.S. Food and Drug Administration (FDA)-approval in 2010 and 2011: sipuleucel-T, an immunotherapeutic agent; cabazitaxel, a novel microtubule inhibitor; abiraterone acetate, a new androgen biosynthesis inhibitor; and denosumab, a bone-targeting agent. The data supporting the approval of each of these agents are described in this review, as are current approaches in the treatment of metastatic CRPC and ongoing clinical trials of novel treatments and strategies. Prostate cancer is the second leading cause of cancer death in men in the western world. Most deaths will occur due to the progression of cancer into a hormone refractory state. Until recently, docetaxel-based chemotherapy was the only established treatment (shown to increase survival) for patients with metastatic hormone refractory prostate cancer. The improved understanding of prostate cancer biology in recent years led to the development of drugs directed against precise tumorigenesis-associated molecular pathways, and significant expansion of treatment horizons for these patients. In 2010-2011, three more agents, with different mechanisms of action, were shown to be associated with a survival benefit in mHRPC, including the dendritic cell vaccine sipuleucel-T (immunotherapy), the 17,20 lyase inhibitor abiraterone (hormonal therapy), and the taxane cabazitaxel (chemotherapy). A fourth agent, denosumab (bone targeted therapy) was also recently approved by the FDA for patients with bone metastasis after showing a reduction in the occurrence of skeletal-related events. This review will focus on recent advances in the standard treatments paradigm in mHRPC. Worldwide over 12 million people were diagnosed with cancer (excluding non-melanoma skin cancer) and 8 million individuals died from cancer in 2008. Recent data indicate that 75-90% of patients with advanced stage diseases or metastatic cancer will experience significant cancer pain. Bone cancer pain is common in patients with advanced breast, prostate, and lung cancer as these tumors have a marked affinity to metastasize to bone. Once tumors metastasize to bone, they are a major cause of morbidity and mortality as the tumor induces significant skeletal remodeling, fractures, pain and anemia; all of which reduce the functional status, quality of life and survival of the patient. Currently, the factors that drive cancer pain are poorly understood, however, several recently introduced models of bone cancer pain that mirror the human condition, are providing insight into the mechanisms that drive bone cancer pain and guiding the development of novel therapies to treat the cancer pain. Several of these therapies have recently been approved by the FDA to treat bone cancer pain (bisphosphonates, denosumab) and others are currently being evaluated in human clinical trials (tanezumab). These new mechanism-based therapies are enlarging the repertoire of modalities available to treat bone cancer pain and improving the quality of life and functional status of patients with bone cancer. OBJECTIVE: To review information pertinent to bone health and osteoporosis in men. METHODS: A review of pertinent literature was conducted. RESULTS: Osteoporosis affects approximately 2 million men in the US and accounts for an estimated 600,000 fractures each year. There are significant differences in skeletal size and structure between men and women that account for differences in fracture incidence, location, and outcomes. Bone density testing is appropriate for men age 70 and older and younger men (50-69) who have risk factors for osteoporosis. Lifestyle management, including adequate calcium and vitamin D intake, appropriate physical activity, and avoidance of tobacco and heavy alcohol use, is appropriate for all men. Pharmacologic therapy to reduce fracture risk is advisable for men with a clinical diagnosis of osteoporosis (a spine or hip fracture) or a T-score of -2.5 or below in the spine, femoral neck, total hip or 1/3 radius; however, the majority of men at high risk will only be identified using a fracture risk assessment tool, such as FRAX. Alendronate, risedronate, zoledronic acid, denosumab, and teriparatide are Food and Drug Administration (FDA)-approved therapeutic options. CONCLUSIONS: Osteoporosis in men presents an important public health problem with significant morbidity and mortality. There are recommended strategies for identifying men at high risk of fracture, and effective agents are available for treatment. In women with advanced breast cancer, approximately three-quarters develop metastases to the bone, with a median survival after diagnosis of 2-3 years. Receptor activator of nuclear factor-κB (RANK) and RANK ligand (RANKL) belong to a signal pathway highly implicated in the development of bone metastases. Denosumab, a human monoclonal antibody with high affinity and specificity for RANKL, prevents the RANKL/RANK interaction and inhibits osteoclast formation and function, thereby decreasing bone resorption and increasing bone mass. Denosumab compared with zoledronic acid showed superior efficacy in delaying time to first-on study SRE and time to first- and subsequent-on study SREs as well as reduction in bone turnover markers. These results led to the approval of denosumab by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA), for the prevention of SREs in adults with bone metastases from solid tumors, including breast cancer. Postmenopausal osteoporosis is a major concern to public health. Fractures are the major clinical consequence of osteoporosis and are associated with substantial morbidity, mortality and health care costs. Bone strength determits such as bone mineral density and bone quality parameters are determined by life-long remodeling of skeletal tissue. Receptor activator of nuclear factor-kB ligand (RANKL) is a cytokine essential for osteoclast differentiation, activation and survival. Denosumab (Prolia®) is a fully human monoclonal antibody for RANKL, which selectively inhibits osteoclastogenesis, being recently approved for the treatment of postmenopausal osteoporosis in women at a high or increased risk of fracture by the FDA in the United States and by the European Medicines Agency in Europe since June 2010. FREEDOM, DECIDE and STAND are the phase 3 trials comparing denosumab with placebo and alendronate in postmenopausal osteoporosis. The authors aim to update denosumab role in postmenopausal osteoporosis with a physiopathological review. Giant cell tumor of bone (GCTB) is an osteolytic, usually benign neoplasm characterized by infiltration with osteoclast-like giant cells, and the osteoclast differentiation factor receptor activator of nuclear factor kappa-B ligand (RANKL) is heavily involved in its pathogenesis. Denosumab belongs to a new class of drugs that inhibit RANKL. Prior to denosumab, multimodality treatment in refractory, recurrent and metastatic GCTB has shown variable results. Recent phase II data have demonstrated denosumab's activity with regard to disease and symptom control, without significant adverse effects. On the basis of this data, the FDA approved denosumab for the treatment of patients whose GCTB is unresectable, or when surgery is likely to result in severe morbidity. Ongoing questions remain, including the optimal scheduling, patient selection, use in the adjuvant setting and long-term toxicity concerns. BACKGROUND CONTEXT: Denosumab (XGeva) is a receptor activator of nuclear factor-κB ligand (RANKL)-antibody that was approved by the Food and Drug Administration (FDA) in 2010 for the prevention of skeletal fractures in patients with bone metastases from solid tumors. Although there is a widespread use of such drug in patients under risk of pathological fractures, the compatibility of denosumab therapy with percutaneous vertebroplasty (an interventional procedure commonly used for pain control in such population) has not yet been established. PURPOSE: To present the serial imaging findings and technical report of an attempted percutaneous vertebroplasty in a patient with refractory pain and a lytic pathological vertebral fracture related to small cell lung cancer spinal metastasis and who was actively under medical treatment with denosumab. STUDY DESIGN: Retrospective review and case report. METHODS: The authors present the imaging findings and technical report of an attempted percutaneous vertebroplasty in the only patient found to be actively under treatment with denosumab after a retrospective review of the databank of patients with pathological fractures referred to the Department of Radiology of the Ohio State University for percutaneous vertebroplasty (a total sample of 20 patients) since the FDA approval of denosumab (November 2010) until June 2013 (a 30-month period). RESULTS: Although the computed tomography scan of the thoracic spine, performed 6 weeks after the initiation of the treatment with denosumab, presented a remarkable remodeling of the previously lytic vertebral lesion (which became markedly sclerotic in appearance), the clinical response in terms of pain improvement was not satisfactory. At the time of the percutaneous vertebroplasty (which was indicated for pain control), after advancing the 11-gauge needle through the pedicle with extreme difficulty, the needle repeatedly deviated laterally and, despite several attempts, it was not possible to penetrate the vertebral body and perform the cement injection. CONCLUSIONS: This is the first report of the technical peculiarities of percutaneous vertebroplasty in patients under medical treatment with denosumab. According to our experience, because of its RANKL-mediated effects on osteoclasts activity, denosumab has been shown to induce a fast and marked sclerotic response on vertebral bodies that may not be accompanied by a satisfactory improvement in pain control (especially in patients with mechanical type of pain) and which may actually prevent the successful performance of percutaneous vertebroplasty. Therefore, it is of paramount importance that future studies evaluating patients with vertebral fractures under treatment with denosumab include long-term pain outcome measures. Additionally, further investigation is warranted to determine the optimal order of treatment and the best timeframe for combining percutaneous vertebroplasty and denosumab therapy in patients presenting with acute vertebral compression fractures and refractory axial pain.
List the human genes encoding for the dishevelled proteins?
DVL-1 DVL-2 DVL-3
The dishevelled gene of Drosophila is required to establish coherent arrays of polarized cells and is also required to establish segments in the embryo. Here, we show that loss of dishevelled function in clones, in double heterozygotes with wingless mutants and in flies bearing a weak dishevelled transgene leads to patterning defects which phenocopy defects observed in wingless mutants alone. Further, polarized cells in all body segments require dishevelled function to establish planar cell polarity, and some wingless alleles and dishevelled; wingless double heterozygotes exhibit bristle polarity defects identical to those seen in dishevelled alone. The requirement for dishevelled in establishing polarity in cell autonomous. The dishevelled gene encodes a novel intracellular protein that shares an amino acid motif with several other proteins that are found associated with cell junctions. Clonal analysis of dishevelled in leg discs provides a unique opportunity to test the hypothesis that the wingless dishevelled interaction species at least one of the circumferential positional values predicted by the polar coordinate model. We propose that dishevelled encodes an intracellular protein required to respond to a wingless signal and that this interaction is essential for establishing both cell polarity and cell identity. The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proliferation, acting as a transducer molecule for developmental processes, including segmentation and neuroblast specification. We have isolated and characterized cDNA clones from two different human dsh-homologous genes, designated as DVL-1 and DVL-3. DVL-1 and DVL-3 putative protein products show 64% amino acid identity. The DVL-1 product is 50% identical to dsh and 92% to a murine dsh homologue (Dvl-1). Both human DVL genes are widely expressed in fetal and adult tissues, including brain, lung, kidney, skeletal muscle and heart. DVL-1 locus maps to chromosome 1p36 and DVL-3 to chromosome 3q27. DVL-1 locus on chromosome 1 corresponds to the murine syntenic region where Dvl-1 is located. DVL-1 and DVL-3 are members of a human dsh-like gene family, which is probably involved in human development. Although the precise role of these genes in embryogenesis is only conjectural at present, the structural and evolutionary characteristics suggest that mutations at their loci may be involved in neural and heart developmental defects. The Wnt family of proto-oncogenes encodes secreted signaling proteins that are required for mouse development. The Drosophila Wnt homolog, the wingless (Wg) segment polarity gene, mediates a signal transduction pathway in which the downstream elements appear to be conserved through evolution. One such element, the dishevelled gene product, becomes hyperphosphorylated and translocates to the plasma membrane in response to Wg (Yanagawa et al., 1995). We report here that the mouse Dishevelled-1 (Dvl-1) and Dishevelled-2 genes encode proteins that are differentially localized in Wnt-overexpressing PC12 cell lines (PC12/Wnt). Whereas Dvl-1 and Dvl-2 proteins are limited to the soluble fraction of parental PC12 cells, PC12/Wnt cells display a subset of Dvl-1 protein associated with the membrane and Dvl-2 protein with the cytoskeletal fraction. These results suggest a conserved role for Dvl in Wnt/wg signal transduction. The Dvl-1 gene on chromosome 1p36 belongs to a family of highly conserved secreted proteins which regulates embryonic induction, generation of cell polarity and specification of cell fate through activation of Wnt signaling pathways. Wnt signaling activates the gene encoding DVL-1; the latter suppresses beta-catenin by promoting its degradation through enhanced inactivation of glycogen-synthase-kinase 3 (GSK3). Here we demonstrate increased expression of DVL-1 mRNA in over two thirds of primary cervical squamous cell cancers (11 of 15 cases) when compared to corresponding non-cancerous uterine squamous cell tissues. In addition, we noted up-regulation of cyclin D1, a downstream effector of Wnt signal pathway in cervical cancer. Immunohistochemical staining demonstrated that DVL-1 protein was prominent in the cytoplasm of cancer cells whereas it was unreactive in the surrounding normal cervical squamous cells. These data indicate that amplification and increased expression of the DVL-1 gene may play some role in the development of a portion of human cervical squamous cell cancer through derangement of the Wnt signaling pathway. AIMS AND BACKGROUND: The Wnt/beta-catenin signaling pathway is one of the main carcinogenic mechanisms in human maligcies including prostate cancer. Recently, the DVL1 gene was identified as a middle molecule of the Wnt/beta-catenin signaling pathway. In addition, alterations of the DVL1 gene have been reported in breast and cervical cancer. The abnormality of beta-catenin in prostate cancer has been well studied, so the examination of the DVL1 gene in prostate cancer is appealing. METHODS: We investigated DVL1 messenger RNA alterations by semiquantitative PCR (SQ-PCR) in 20 primary prostate cancers and assessed the protein expression by immunohistochemical analysis in the same samples. In addition, DVL1 and beta-catenin protein expression was evaluated with a new validated set of 20 prostate cancers. RESULTS: SQ-PCR revealed significant overexpression of DVL1 in prostate cancer (65%). Upregulation of the DVL1 gene product in prostate cancer was confirmed by immunostaining. With SQ-PCR and immunostaining, none of the cases showed underexpression or downregulation of DVL1. In addition, the data showed correlations between DVL1 mRNA and protein expression. Interestingly, the expression level of DVL1 increased with worsening histological grade. In addition, a correlation between DVL1 expression and beta-catenin expression was confirmed. CONCLUSIONS: DVL1 was overexpressed in prostate cancer and its overexpression might be related to prostate cancer progression through the Wnt/beta-catenin pathway. Dishevelled (Dvl) proteins are key transducers of Wnt signaling encoded by members of a multi-gene family in vertebrates. We report here the divergent, tissue-specific expression patterns for all three Dvl genes in Xenopus embryos, which contrast dramatically with their expression patterns in mice. Moreover, we find that the expression patterns of Dvl genes in the chick diverge significantly from those of Xenopus. In addition, in hemichordates, an outgroup to chordates, we find that the one Dvl gene is dynamically expressed in a tissue-specific manner. Using knockdowns, we find that Dvl1 and Dvl2 are required for early neural crest specification and for somite segmentation in Xenopus. Most strikingly, we report a novel role for Dvl3 in the maintece of gene expression in muscle and in the development of the Xenopus sclerotome. These data demonstrate that the expression patterns and developmental functions of specific Dvl genes have diverged significantly during chordate evolution. Hirschsprung's disease (HSCR) is a congenital disorder of the enteric nervous system and is characterized by an absence of enteric ganglion cells in terminal regions of the gut during development. Dishevelled (DVL) protein is a cytoplasmic protein which plays pivotal roles in the embryonic development. In this study, we explore the cause of HSCR by studying the expression of DVL-1 and DVL-3 genes and their proteins in the aganglionic segment and the ganglionic segment of colon in HSCR patients. MATERIALS AND METHODS: Specimen of aganglionic segment and ganglionic segment of colon in 50 cases of HSCR patients. Expression levels of mRNA and proteins of DVL-1 and DVL-3 were confirmed by quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry staining between the aganglionic segment and the ganglionic segment of colon in HSCR patients. RESULTS: The mRNA expression of DVL-1 and DVL-3 were 2.06 fold and 3.12 fold in the aganglionic segment colon tissues compared to the ganglionic segment, respectively. Similarly, the proteins expression of DVL-1 and DVL-3 were higher (39.71 ± 4.53 vs and 53.90 ± 6.79 vs) in the aganglionic segment colon tissues than in the ganglionic segment (15.01 ± 2.66 and 20.13 ± 3.63) by western blot. Besides, immunohistochemical staining showed that DVL-1 and DVL-3 have a significant increase in mucous and submucous layers from aganglionic colon segments compared with ganglionic segments. CONCLUSION: The study showed an association of DVL-1 and DVL-3 with HSCR, it may play an important role in the pathogenesis of HSCR.
Name synonym of Acrokeratosis paraneoplastica.
Acrokeratosis paraneoplastic (Bazex syndrome) is a rare, but distinctive paraneoplastic dermatosis characterized by erythematosquamous lesions located at the acral sites and is most commonly associated with carcinomas of the upper aerodigestive tract.
Acrokeratosis paraneoplastica of Bazex is a rare cutaneous syndrome associated with maligt neoplasms of the pulmonary and upper gastrointestinal tract, or cervical metastatic adenopathy, usually seen in middle-aged white men. We present a unique case of Bazex syndrome in that the patient was young, black, and a woman. A 55-year-old white man born in Canada presented with all the clinical features of acrokeratosis paraneoplastica of Bazex. He showed the characteristic violaceous erythema and scaling of the nose and face, the aural helices, and the palmoplantar regions with severe nail dystrophy. Extensive examinations failed to reveal any associated maligcy up to 5 months after the onset of the skin eruption. While the skin was improving, and although the patient was still asymptomatic except for a weight loss of 5 kg, evidence of metastatic squamous cell carcinoma of the cervical region was obtained. Only palliative treatment could be undertaken. The bizarre clinical aspects of the syndrome are reviewed. Acrokeratosis paraneoplastica (Bazex' syndrome) is a rare but clinically distinctive dermatosis that has been associated in all reported cases, to our knowledge, with either a primary maligt neoplasm of the upper aerodigestive tract or metastatic cancer to the lymph nodes of the neck. Acrokeratosis paraneoplastica was found in a 53-year-old black man with squamous cell carcinoma of the tonsil. A distinctive series of changes was found on histopathologic examination of biopsy specimens taken from his skin lesions, and direct immunofluorescence microscopy of both lesional and nonlesional skin specimens showed immunoglobulin and complement deposition on the epidermal basement membrane. The skin lesions largely resolved following radiation therapy of the neoplasm and of the presumably involved lymph nodes. The focus of this article is acrokeratosis paraneoplastica, one of two disorders that have acquired the eponym Bazex syndrome. To date, all of the patients reported in the literature have had an underlying neoplasm, most commonly squamous cell carcinoma of the upper aerodigestive tract. In this review of 113 cases of acrokeratosis paraneoplastica (mean age, 61 years; 105 males, 8 females), the psoriasiform lesions preceded the diagnosis of the associated maligcy in 73 (67%) of 109 patients, whereas the cutaneous manifestations followed the diagnosis of the neoplasm in only 16 (15%) of 109; in the remainder, the onset of the skin lesions and the diagnosis of the tumor occurred simultaneously. Therefore, awareness of the cutaneous signs of Bazex syndrome is of obvious importance to dermatologists. Evidence in favor of the paraneoplastic nature of this disease is as follows: in 81 (93%) of 87 patients with adequate clinical descriptions, the skin lesions either improved significantly (or resolved) when the underlying neoplasm was treated or they remained unchanged in the setting of persistent disease. Occasionally, the reappearance of skin lesions has signaled a recurrence of the tumor. A 65-year-old white man presented with all the clinical features of acrokeratosis paraneoplastica of Bazex, characterized by violaceous erythema and scaling of the nose, aural helices, fingers, and toes, with keratoderma and severe nail dystrophy. Examination of the patient for possible associated maligcy disclosed an asymptomatic squamous cell carcinoma at the oropharyngeal region. The skin lesions resolved almost completely following radiation therapy of the neoplasm, but the onychodystrophy persisted. This case report illustrates the importance of early recognition of Bazex syndrome. Bazex syndrome, or acrokeratosis paraneoplastica, is a cutaneous paraneoplastic syndrome characterized by psoriasiform lesions associated with, usually, a squamous cell carcinoma of the upper aerodigestive tract. We present a case of Bazex syndrome associated with metastatic cervical squamous cell carcinoma with an unknown primary. The features of the condition are discussed in the light of current knowledge. PURPOSE: Obligatory cutaneous paraneoplastic disorders comprising acanthosis nigricans maligna, erythema gyratum repens, paraneoplastic pemphigus, hypertrichosis lanuginosa acquisita, erythema necrolyticum migrans and acrokeratosis paraneoplastica are rare. However, as markers of an underlying internal maligcy they are of utmost importance for the patient. Acrokeratosis paraneoplastica (first described by Gougerot and Rupp in 1922) was named after Bazex who had then reported several cases in a French dermatological journal since 1965 (Bazex et al. in Bull Soc Fr Dermatol Syphiligr 72:182, 1965; Bazex and Griffiths in Br J Dermatol 102:301-306, 1980). METHOD: The study is a clinical case of a patient with acrokeratosis paraneoplastica. RESULTS: the patient was later diagnosed with a cervical lymph node metastasis and thereafter with a primary squamous cell carcinoma of the left upper lobe and upon treatment responded with the clearing of the skin changes. CONCLUSION: Identification of a paraneoplastic syndrome may enhance the earlier diagnosis of the associated tumor and may thus enable curative treatment. Acrokeratosis paraneoplastica (Bazex's syndrome) is a rare obligate paraneoplastic dermatosis characterized by erythematosquamous lesions localized symmetrically at the acral sites. The condition almost exclusively affects Caucasian men older than 40 years. It is usually associated with primary maligt neoplasms of the upper aerodigestive tract. In most cases, the skin changes precede the clinical manifestation of the underlying neoplasm. The dermatosis can be cured only by removal of the underlying carcinoma. We describe a case of acrokeratosis paraneoplastica associated with a retroperitoneal liposarcoma in a 71-year-old Caucasian man. The liposarcoma was surgically removed but recurred several times, with acrokeratosis paraneoplastica showing a parallel development. We, therefore, add liposarcoma to the growing list of maligt neoplasms associated with acrokeratosis paraneoplastica. BACKGROUND: Bazex syndrome (acrokeratosis paraneoplastica) is a rare paraneoplastic syndrome that usually occurs in males over 40 years old and is particularly associated with squamous cell carcinoma of the upper aerodigestive tract and adenopathy above the diaphragm. OBJECTIVE: The objectives of our article are (1) to describe a unique case of acrokeratosis paraneoplastica and (2) to review the current literature regarding skin findings, commonly associated neoplasms, and treatment options relative to this condition. PATIENT: We describe a 68-year-old female with lobular breast carcinoma, complicated by local and distant recurrences, who presented with a 1-year history of prominent acral skin and nail changes. RESULTS: Our patient's clinical skin findings improved significantly following treatment and partial remission of her underlying maligcy. CONCLUSIONS: Our patient represents one of few females described with this syndrome, which is especially rare in association with lobular breast carcinoma. Further, the patient's presentation is unique as she was discovered to demonstrate laboratory findings consistent with coexistent porphyria cutanea tarda and relative zinc deficiency. BACKGROUND: Acrokeratosis paraneoplastica Bazex (APB) is a very rare disease in the group of obligate paraneoplastic dermatoses, associated mostly with squamous cell carcinoma of the upper aerodigestive tract and metastatic cervical lymphadenopathy. The disease is characterized by violaceous erythemosquamous changes on the acral regions. This entity was first reported by Bazex in 1965. About 160 cases have been presented so far. CASE REPORT: We presented a patient with a three-month history of violaceous erythema, edema, erosions and scaling on the acral regions, elbows and knees and severe nail dystrophy. When the diagnosis was established, he did not have any symptom of internal maligcy. Esophagogastroscopy revealed ulcerovegetant lesion of the esophagus, while histology showed squamocellular invasive carcinoma. Surgical tumor removal resulted in significant improvement of skin changes in 15 days. Unfortunately, four months later, extensive skin lesions pointed to metastasis of squamous cell carcinoma. CONCLUSION: Skin changes can precede a few years the first manifestations of neoplasia. The course of the disease in our patient proved that APB is a specific marker of underlying maligcy. Acrokeratosis paraneoplastica is a rare paraneoplastic syndrome commonly affecting males over 40 years of age. There exists a strong association with squamous cell carcinoma (SCC) of the upper aerodigestive tract or cervical metastatic disease originating from an unknown primary. We report a case associated with SCC of the right tonsil with persistent paraneoplastic cutaneous lesions 2 years after successful treatment of the underlying neoplasm. Acrokeratosis paraneoplastic (Bazex syndrome) is a rare, but distinctive paraneoplastic dermatosis characterized by erythematosquamous lesions located at the acral sites and is most commonly associated with carcinomas of the upper aerodigestive tract. We report a 58-year-old female with a history of a pigmented rash on her extremities, thick keratotic plaques on her hands, and brittle nails. Chest imaging revealed a right upper lobe mass that was proven to be small cell lung carcinoma. While Bazex syndrome has been described in the dermatology literature, it is also important for the radiologist to be aware of this entity and its common presentations.
Which are the classes of anti-arrhythmic drugs according to Vaughan-Williams classification?
Antiarrhythmic drugs can be divided into four Vaughan Williams classes (I-IV). Class I antiarrhythmic agents have as a common action, blockade of the sodium channels. Class II agents are antisympathetic drugs, particularly the beta-adrenoceptor blockers. Class-III antiarrhythmics have as a common action the potassium-channel blockade. Class IV antiarrhythmic drugs are calcium channel blockers.
The present paper reviews classification and mode of action of agents that suppress extrasystoles and tachyarrhythmias. These are classified according to their electrophysiological effects observed in isolated cardiac tissues in vitro (Vaughan Williams, 1989). Fast sodium channel blockers (class I) which reduce the upstroke velocity of the action potential are usually subclassified into three groups, class I A-C, according to their effect on the action potential duration. Beta-adrenergic antagonists (class II) exert their effects by antagonizing the electrophysiological effects of beta-adrenergic catecholamines. Class III antiarrhythmic agents (eg amiodarone) prolong the action potential and slow calcium channel blockers (class IV) suppress the calcium inward current and calcium-dependent action potentials. The classification of antiarrhythmic drugs is still under debate. This particularly applies to agents of class I and III. The effect of class I agents is frequency-dependent because the binding affinity of these drugs to the sodium channel is modulated by the state of the channel (modulated receptor hypothesis). Class I agents bind to the channel in the activated and inactivated state and dissociate from the channel in the rested state. This occurs at a drug-specific rate so that class I agents can be subclassified into only two groups, namely in those of the slow- and fast-recovery type respectively (time constant of reactivation greater or smaller than 1 s). Slow-recovery class I agents affect regular action potentials at normal heart rates which can more easily lead to a lengthening of the QRS duration in the ECG, to conduction disturbances and hence to pro-arrhythmic effects.(ABSTRACT TRUNCATED AT 250 WORDS) Antiarrhythmic drugs can be divided into four Vaughan Williams classes (I-IV) according to defined electrophysiological effects on the myocardium. Thus, the Vaughan Williams classification also coincides with the main myocardial targets of the antiarrhythmics, i.e., myocardial sodium-, potassium-, and calcium-channels or beta-adrenergic receptors. A more detailed characterization which is also based on the myocardial targets of a drug is given by the "Sicilian Gambit" approach of classification. Nevertheless, the appropriate drug for the management of a given clinical arrhythmia has to be chosen according to the electrophysiological effects of the respective drug. A main determit of the antiarrhythmic or proarrhythmic properties of a drug is the frequency dependence of its electrophysiological effects. The sodium-channel blockade induced by class-I substances is enhanced with increasing heart rates. Thus, class-I antiarrhythmics can be subclassified as substances showing a more exponential, an approximately linear, or rather saturated block-frequency relation. Class-III antiarrhythmics (potassium-channel blockade) can be further differentiated according to the component of the delayed rectifier potassium current (IK) which is inhibited by a drug. Class-III drugs inhibiting selectively the rapidly activating and deactivating IKr component exhibit a marked reverse rate dependence, i.e., the drug induced prolongation of the cardiac action potential is minimized at high rates. On the other hand, during bradycardia the pronounced action potential prolongation may cause early afterdepolarizations and triggered activity leading to torsades de pointes arrhythmias (acquired QT syndrome). Class-III substances inhibiting the slowly activating IKs component are currently under investigation and are expected to show a direct rate dependence. Experimental data available so far point to an action potential prolonging effect at least independent of rate. However, it is uncertain whether proarrhythmic effects can be thus avoided, especially in light of the fact that one form of congenital QT syndrome (LQT1) seems to be linked to dysfunction of the IKs-channel. Antiarrhythmic agents are traditionally classified according to Vaughan Williams into four classes of action. Class I antiarrhythmic agents include most of the drugs traditionally thought of as antiarrhythmics, and have as a common action, blockade of the fast-inward sodium channel on myocardium. These agents have a very significant toxicity, and while they are being used less, therapeutic drug monitoring (TDM) does significantly increase the safety with which they can be administered. Class II agents are antisympathetic drugs, particularly the b-adrenoceptor blockers. These are generally safe agents which do not normally require TDM. Class III antiarrhythmic agents include sotalol and amiodarone. TDM can be useful in the case of amiodarone to monitor compliance and toxicity but is generally of little value for sotalol. Class IV antiarrhythmic drugs are the calcium channel blockers verapamil and diltiazem. These are normally monitored by haemodynamic effects, rather than using TDM. Other agents which do not fall neatly into the Vaughan Williams classification include digoxin and perhexiline. TDM is very useful for monitoring the administration (and particularly the safety) of both of these agents.
Which are the different isoforms of the mammalian Notch receptor?
Notch signaling is an evolutionarily conserved mechanism, used to regulate cell fate decisions. Four Notch receptors have been identified in man: Notch-1, Notch-2, Notch-3 and Notch-4.
Notch signaling is an evolutionarily conserved mechanism, used to regulate cell fate decisions. Four Notch receptors have been identified in man (Notch-1 to -4). In this study, semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to examine the expression pattern of Notch receptor genes in whole adult human liver and isolated liver cell preparations. All 4 receptors were expressed in the adult liver, with no significant differences in the levels of Notch-1, -2, and -4 messenger RNA (mRNA) between normal and diseased liver. However, Notch-3 expression appeared to be increased in diseased tissue. The distribution of Notch-1 and -4 in normal tissue was similar, with Notch-1 also detectable at low levels in the sinusoidal endothelium. Notch-2 expression was more widely distributed, and detectable in hepatocytes, medium-sized bile ducts, and the sinusoidal endothelium. Notch-3 expression was seen on hepatocytes, with weaker expression detectable in portal veins, hepatic arteries, and the sinusoids. In normal liver tissue Notch-1, -2, and -3 were found to be coexpressed on bile duct epithelium; however, with the exception of Notch-3 in primary sclerosing cholangitis (PSC) livers, expression was absent on proliferating ductules in all disease states examined. Interestingly, the expression of Notch-2 and -3 was associated with numerous small vessels within the portal tract septa of diseased tissue. The absence of Notch receptor expression on proliferating bile ductules and its presence on neovessels suggests that Notch signaling may be important for normal bile duct formation and the aberrant neovascularization seen in diseased liver tissue. BACKGROUND: The interaction of Notch receptors with their transmembrane ligands Delta and Jagged plays an important role not only in the organization of a variety of tissues but also in several genetic disorders and cancer development. The functional involvement of the Notch signaling in rheumatoid arthritis (RA) has been reported previously, but the expression profile of Notch-related molecules, as well as their relation with clinicopathological parameters, remains unclear. METHODS: In this study, we analyzed the immunohistochemical staining pattern of four Notch receptors (Notch1-4) and their ligands (Delta1 and Jagged1) in 14 synovial tissues obtained from 14 RA patients. RESULTS: Notch2 and Notch4 were expressed in limited areas in a few samples or in small blood vessels, respectively. Notch1, Notch3, Delta1, and Jagged1 were overexpressed in the synovial lining and sublining cells on synovial hyperplastic lesions in all samples. Notch1 expression was also observed in T and B lymphocytes of lymphoid follicles independently. Notch1 and Notch3 expression overlapped with that of Jagged1, as determined by confocal microscopy. Activation of Notch1 signaling in the RA synovium was identified using a specific antibody to the cleaved form of Notch1. The expression of these molecules did not show any correlation with clinicopathological parameters. CONCLUSIONS: Our results suggest that Notch signaling is activated in RA synovium but does not necessarily reflect the pathological condition of RA. Hepatoblastoma is a pediatric maligcy characterized by the uncontrolled proliferation of immature hepatocytes (hepatoblasts). This disease is diagnosed primarily in children younger than 5 years and is disproportionately observed in former premature infants. Cytogenetically, hepatoblastoma is characterized by numerical aberrations, as well as unbalanced translocations involving the proximal region of chromosome 1q. The NOTCH2 gene has been mapped to this locus, and it is well established that the NOTCH gene family is an important regulator of several developmental pathways. Specifically, the NOTCH2 protein is known to delay hepatoblast maturation during early hepatic organogenesis, and the reduction of NOTCH2 expression correlates with the differentiation of hepatoblasts into hepatocytes and biliary cells in the developing liver. We hypothesized that NOTCH2 is involved in the pathogenesis of hepatoblastoma by maintaining a population of undifferentiated hepatoblasts. We studied the immunohistochemical expression of NOTCH2 and its isoforms NOTCH1, NOTCH3, and NOTCH4 and the NOTCH2 primary ligand JAGGED1 in hepatoblastomas. Compared with the normal liver, an increased level of NOTCH2 expression was seen in 22 of 24 (92%) hepatoblastomas. There was no significant staining for other NOTCH isoforms and JAGGED1 in hepatoblastomas. Therefore, we suggest that NOTCH2 expression and activation, independent of JAGGED1 expression, may contribute to the pathogenesis of hepatoblastoma. In the hepatoblastoma sinusoidal vasculature, we saw NOTCH3 and NOTCH1 expression. These observations have potential implications with regard to therapeutic targeting of the NOTCH signaling pathway in hepatoblastomas. Notch signalling occurs via direct cell-cell interactions and plays an important role in linking the fates of neighbouring cells. There are four different mammalian Notch receptors that can be activated by five cell surface ligands. The ability to inhibit specific Notch receptors would help identify the roles of individual family members and potentially provide a means to study and control cell differentiation. Anti-Notch antibodies in the form of single chain Fvs were generated from an antibody phage display library by selection on either the ligand binding domain or the negative regulatory region (NRR) of Notch1 and Notch2. Six antibodies targeting the NRR of Notch1 and four antibodies recognising the NRR of Notch2 were found to prevent receptor activation in cell-based luciferase reporter assays. These antibodies were potent, highly specific inhibitors of individual Notch receptors and interfered with endogenous signalling in stem cell systems of both human and mouse origin. Antibody-mediated inhibition of Notch efficiently down-regulated transcription of the immediate Notch target gene hairy and enhancer of split 5 (Hes5) in both mouse and human neural stem cells and revealed a redundant regulation of Hes5 in these cells as complete down-regulation was seen only after simultaneous blocking of Notch1 and Notch2. In addition, these antibodies promoted differentiation of neural stem cells towards a neuronal fate. In contrast to the widely used small molecule γ-secretase inhibitors, which block all 4 Notch receptors (and a multitude of other signalling pathways), antibodies allow blockade of individual Notch family members in a highly specific way. Specific inhibition will allow examination of the effect of individual Notch receptors in complex differentiation schemes regulated by the co-ordinated action of multiple signalling pathways. Cerebral Autosomal Domit Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the best understood cause of domitly inherited stroke and results from NOTCH3 mutations that lead to NOTCH3 protein accumulation and selective arterial smooth muscle degeneration. Previous studies show that NOTCH3 protein forms multimers. Here, we investigate protein interactions between NOTCH3 and other vascular Notch isoforms and characterize the effects of elevated NOTCH3 on smooth muscle gene regulation. We demonstrate that NOTCH3 forms heterodimers with NOTCH1, NOTCH3, and NOTCH4. R90C and C49Y mutant NOTCH3 form complexes which are more resistant to detergents than wild type NOTCH3 complexes. Using quantitative NOTCH3-luciferase clearance assays, we found significant inhibition of mutant NOTCH3 clearance. In coculture assays of NOTCH function, overexpressed wild type and mutant NOTCH3 significantly repressed NOTCH-regulated smooth muscle transcripts and potently impaired the activity of three independent smooth muscle promoters. Wildtype and R90C recombit NOTCH3 proteins applied to cell cultures also blocked canonical Notch fuction. We conclude that CADASIL mutants of NOTCH3 complex with NOTCH1, 3, and 4, slow NOTCH3 clearance, and that overexpressed wild type and mutant NOTCH3 protein interfere with key NOTCH-mediated functions in smooth muscle cells.
Which are the major characteristics of cellular senescence?
The defining characteristics of cellular senescence are altered morphology, arrested cell-cycle progression, development of aberrant gene expression with proinflammatory behavior, and telomere shortening.
Although reactive oxygen species have been proposed to play a major role in the aging process, the exact molecular mechanisms remain elusive. In this study we investigate the effects of a perturbation in the ratio of Cu/Zn-superoxide dismutase activity (Sod1 dismutases .O2-to H2O2) to glutathione peroxidase activity (Gpx1 catalyses H2O2 conversion to H2O) on cell growth and development. Our data demonstrate that Sod1 transfected cell lines that have an elevation in the ratio of Sod1 activity to Gpx1 activity produce higher levels of H2O2 and exhibit well characterised markers of cellular senescence viz. slower proliferation and altered morphology. On the contrary, Sod1 transfected cell lines that have an unaltered ratio in the activity of these two enzymes, have unaltered levels of H2O2 and fail to show characteristics of senescence. Furthermore, fibroblasts established from individuals with Down syndrome have an increase in the ratio of Sod1 to Gpx1 activity compared with corresponding controls and senesce earlier. Interestingly, cells treated with H2O2 also show features of senescence and/or senesce earlier. We also show that Cip1 mRNA levels are elevated in Down syndrome cells, Sod1 transfectants with an altered Sod1 to Gpx1 activity ratio and those treated with H2O2, thus suggesting that the slow proliferation may be mediated by Cip1. Furthermore, our data demonstrate that Cip1 mRNA levels are induced by exposure of cells to H2O2. These data give valuable insight into possible molecular mechanisms that contribute tribute to cellular senescence and may be useful in the evolution of therapeutic strategies for aging. Recent research has shown that inserting a gene for the protein component of telomerase into senescent human cells reextends their telomeres to lengths typical of young cells, and the cells then display all the other identifiable characteristics of young, healthy cells. This advance not only suggests that telomeres are the central timing mechanism for cellular aging, but also demonstrates that such a mechanism can be reset, extending the replicative life span of such cells and resulting in markers of gene expression typical of "younger" (ie, early passage) cells without the hallmarks of maligt transformation. It is now possible to explore the fundamental cellular mechanisms underlying human aging, clarifying the role played by replicative senescence. By implication, we may soon be able to determine the extent to which the major causes of death and disability in aging populations in developed countries-cancer, atherosclerosis, osteoarthritis, macular degeneration, and Alzheimer dementia--are attributable to such fundamental mechanisms. If they are amenable to prevention or treatment by alteration of cellular senescence, the clinical implications have few historic precedents.
Orteronel was developed for treatment of which cancer?
Orteronel was developed for treatment of castration-resistant prostate cancer.
A novel naphthylmethylimidazole derivative 1 and its related compounds were identified as 17,20-lyase inhibitors. Based on the structure-activity relationship around the naphthalene scaffold and the results of a docking study of 1a in the homology model of 17,20-lyase, the 6,7-dihydro-5H-pyrrolo[1,2-c]imidazole derivative (+)-3c was synthesized and identified as a potent and highly selective 17,20-lyase inhibitor. Biological evaluation of (+)-3c at a dose of 1mg/kg in a male monkey model revealed marked reductions in both serum testosterone and dehydroepiandrosterone concentrations. Therefore, (+)-3c (termed orteronel [TAK-700]) was selected as a candidate for clinical evaluation and is currently in phase III clinical trials for the treatment of castration-resistant prostate cancer. PURPOSE: The androgen receptor pathway remains active in men with prostate cancer whose disease has progressed following surgical or medical castration. Orteronel (TAK-700) is an investigational, oral, nonsteroidal, selective, reversible inhibitor of 17,20-lyase, a key enzyme in the production of androgenic hormones. EXPERIMENTAL DESIGN: We conducted a phase I/II study in men with progressive, chemotherapy-naïve, metastatic castration-resistant prostate cancer, and serum testosterone <50 ng/dL. In the phase I part, patients received orteronel 100 to 600 mg twice daily or 400 mg twice a day plus prednisone 5 mg twice a day. In phase II, patients received orteronel 300 mg twice a day, 400 mg twice a day plus prednisone, 600 mg twice a day plus prednisone, or 600 mg once a day without prednisone. RESULTS: In phase I (n = 26), no dose-limiting toxicities were observed and 13 of 20 evaluable patients (65%) achieved ≥50% prostate-specific antigen (PSA) decline from baseline at 12 weeks. In phase II (n = 97), 45 of 84 evaluable patients (54%) achieved a ≥50% decline in PSA and at 12 weeks, substantial mean reductions from baseline in testosterone (-7.5 ng/dL) and dehydroepiandrosterone-sulfate (-45.3 μg/dL) were observed. Unconfirmed partial responses were reported in 10 of 51 evaluable phase II patients (20%). Decreases in circulating tumor cells were documented. Fifty-three percent of phase II patients experienced grade ≥3 adverse events irrespective of causality; most common were fatigue, hypokalemia, hyperglycemia, and diarrhea. CONCLUSIONS: 17,20-Lyase inhibition by orteronel was tolerable and results in declines in PSA and testosterone, with evidence of radiographic responses. Orteronel (also known as TAK-700) is a novel hormonal therapy that is currently in testing for the treatment of prostate cancer. Orteronel inhibits the 17,20 lyase activity of the enzyme CYP17A1, which is important for androgen synthesis in the testes, adrenal glands and prostate cancer cells. Preclinical studies demonstrate that orteronel treatment suppresses androgen levels and causes shrinkage of androgen-dependent organs, such as the prostate gland. Early reports of clinical studies demonstrate that orteronel treatment leads to reduced prostate-specific antigen levels, a marker of prostate cancer tumor burden, and more complete suppression of androgen synthesis than conventional androgen deprivation therapies that act in the testes alone. Treatment with single-agent orteronel has been well tolerated with fatigue as the most common adverse event, while febrile neutropenia was the dose-limiting toxicity in a combination study of orteronel with docetaxel. Recently, the ELM-PC5 Phase III clinical trial in patients with advanced-stage prostate cancer who had received prior docetaxel was unblinded as the overall survival primary end point was not achieved. However, additional Phase III orteronel trials are ongoing in men with earlier stages of prostate cancer. Author information: (1)Karim Fizazi, Institut Gustave Roussy, University of Paris Sud, Villejuif; Stephane Oudard, Université Paris Descartes, Paris, France; Robert Jones, Institute of Cancer Sciences, University of Glasgow, Glasgow; Johann De Bono, The Institute of Cancer Research, London, United Kingdom; Eleni Efstathiou, University of Athens Medical School, Athens; George Fountzilas, Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece; Fred Saad, University of Montreal Hospital Center, Montreal, Canada; Ronald de Wit, Erasmus University Medical Center, Rotterdam, the Netherlands; Felipe Melo Cruz, ABC Foundation School of Medicine, Santo André; Flavio Carcano, Hospital de Cancer de Barretos, Barretos, Brazil; Albertas Ulys, Institut of Oncology, Vilnius University, Vilnius, Lithuania; Neeraj Agarwal, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT; David Agus, University of Southern California, Los Angeles, CA; Daniel P. Petrylak, Yale University Cancer Center, New Haven, CT; Shih-Yuan Lee, Bindu Tejura, Niels Borgstein, Takeda Pharmaceuticals International; Iain J. Webb, Millennium: The Takeda Oncology Company, Cambridge, MA; Robert Dreicer, Cleveland Clinic, Cleveland, OH; Joaquim Bellmunt, University Hospital del Mar-IMIM, Barcelona, Spain. [email protected]. (2)Karim Fizazi, Institut Gustave Roussy, University of Paris Sud, Villejuif; Stephane Oudard, Université Paris Descartes, Paris, France; Robert Jones, Institute of Cancer Sciences, University of Glasgow, Glasgow; Johann De Bono, The Institute of Cancer Research, London, United Kingdom; Eleni Efstathiou, University of Athens Medical School, Athens; George Fountzilas, Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece; Fred Saad, University of Montreal Hospital Center, Montreal, Canada; Ronald de Wit, Erasmus University Medical Center, Rotterdam, the Netherlands; Felipe Melo Cruz, ABC Foundation School of Medicine, Santo André; Flavio Carcano, Hospital de Cancer de Barretos, Barretos, Brazil; Albertas Ulys, Institut of Oncology, Vilnius University, Vilnius, Lithuania; Neeraj Agarwal, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT; David Agus, University of Southern California, Los Angeles, CA; Daniel P. Petrylak, Yale University Cancer Center, New Haven, CT; Shih-Yuan Lee, Bindu Tejura, Niels Borgstein, Takeda Pharmaceuticals International; Iain J. Webb, Millennium: The Takeda Oncology Company, Cambridge, MA; Robert Dreicer, Cleveland Clinic, Cleveland, OH; Joaquim Bellmunt, University Hospital del Mar-IMIM, Barcelona, Spain. Collaborators: Troon S, Underhill C, Dittrich C, Krainer M, Kramer G, Loidl W, Pummer K, Belyakovskiy V, Polyakov S, Goeminne JC, Hoekx L, Luyten D, Van Poppel H, Werbrouck P, Azambuja A, Barrios C, Brust L, Cabral Filho S, Carcano F, Cruz F, Damião R, Delgado G, Diógenes Â, Dzik C, Faccio A, de Faria G, Faulhaber A, Ferdes H, Ferreira U, Filho R, Franke F, Girotto G, Koff W, Kussumoto C, Malzyner A, de Moraes A, Padílha S, de Pádua C, Pinto L, Portella M, Reiriz A, da Silva Teixeira V, Vieiralves L, Dimitrov B, Dudov A, Micheva R, Petrov P, Taskova V, Carmel M, Casey R, Chin J, Jacobson A, Jansz G, Kapoor A, Kinahan T, Love W, Martin AG, Saad F, Trachtenberg J, Webster T, Acevedo Gaete A, Arén Frontera O, Leyton Naranjo R, Miranda Benabarre A, Pastor Arroyo P, Neira Reyes L, Ramirez Pinto G, Restrepo Molina J, Grgic M, Babjuk M, Domes L, Jansa J, Lukes M, Pavlik I, Zachoval R, Kahu J, Tamm T, Marttila T, Tammela T, Vaarala M, Vitanen J, Bompas E, Colombel M, Delva R, Deplanque G, Fizazi K, Flechon A, Giroux J, Joly F, Lechevallier E, Mottet Auselo N, Priou F, Roubaud G, Roupret M, Spaeth D, De La Taille A, Tourani JM, Feyerabend S, De Geeter P, Geiges G, Gleißner J, Hammerer P, Klotz T, Kuczyk M, Marin J, Schrader A, Stenzl A, Steuber T, Wirth M, Efstathiou E, Georgoulias V, Hatzimouratidis K, Kalofonos H, Papandreou C, Thanos A, Leung KC, Ng C, Farkas L, Pintér J, McDermott R, Sullivan F, Berger R, Gabizon A, Gez E, Rosenbaum E, Sella A, Semenisty V, Tavdy E, Alabiso O, Ciuffreda L, Fratino L, Sternberg C, Tubaro A, Akakura K, Arai Y, Egawa S, Fujimoto H, Ichikawa T, Kakehi Y, Kitamura H, Maniwa A, Miyanaga N, Mizokami A, Nakatani T, Nishimura K, Niwakawa M, Sato F, Sugiyama T, Suzuki H, Suzuki K, Takahashi S, Tomita Y, Ueda T, Uemura H, Yamaguchi R, Yokomizo A, Yoshimura K, Brize A, Litavnience D, Vjaters E, Jankevicius F, Jievaltas M, Jocys G, Ulys A, Calvo Domínguez D, González Perez J, de Leon Jaen S, Pérez O, Rodriguez Rivera J, Valdés A, Blaisse R, Hamberg A, Loosveld O, Los M, Van Oort I, de la Rosette J, De Vries P, Vrijhof H, de Wit R, Costello S, Davidson P, Fong C, Gilling P, Neill M, Abrill Mendoza G, Cano Rivera J, Garcia Ahumada S, Huaringa Leiva R, Pazos Franco A, Jablonska Z, Kmieciak R, Coelho J, Sousa N, Bucuras C, Cebotaru C, Ciuleanu T, Jinga V, Anatolyevich I, Yurievich P, Hiang T, Sing N, Balaz V, Brezovsky M, Kliment J, Mikulas J, Mincik I, Sokol R, Botha M, Hart G, Kraus P, Landers G, Malan J, Bellmunt J, Castellano D, Climent Duran M, Veiga F, González B, Pérez Gracia J, Valderrama B, Provencio M, Damber JE, Häggman M, Nyman C, Berthold D, Fischer N, Popescu R, Stenner F, Chang YH, Ou YC, Tsai YC, Wu HC, Wu TL, Bondarenko I, Ivashchenko P, Kobets V, Pasiechnikov S, Semenukha V, Sernyak Y, Stus V, Bahl A, Birtle A, Chowdhury S, Crabb S, Dixit S, Elliott P, Hoskin P, Jones R, Khoo V, MacDonald A, Malik Z, O'Sullivan J, Simms M, Stockdale A, Agarwal N, Alter R, Anderson TC, Bailen J, Berry W, Bidair M, Clark W, Cohn AL, Crawford E, DiSimone C, Feliciano L, Fleming MT, Forero L, Friday B, Fruehauf JP, Gelmann E, George D, Gignac G, Given R, Gullo J, Hainsworth J, Hajdenberg J, Haluschak JJ, Hamid O, Hammers H, Hart LL, Hussain A, Hutson TE, Ibrahim E, Jain SK, Khojasteh A, Kohli M, Lara PN Jr, Lilly M, Lipton A, Mackey DW, Mao SS, Mehta AR, Modiano MR, Morris M, Muscato JJ, Nordquist LT, Richards DA, Ryan C, Sartor AO, Schnadig ID, Sieber PR, Singal R, Smith F, Somer B, Srkalovic G, Tagawa S, Tan W, Twardowski P, Van Veldhuizen PJ, Vogelzang N, Watkins DL, Wertheim M, Wong YN, Zhang J. OBJECTIVE: We performed a systematic review of the literature to assess the efficacy and the safety of second-line agents targeting metastatic castration-resistant prostate cancer (mCRPC) that has progressed after docetaxel. Pooled-analysis was also performed, to assess the effectiveness of agents targeting the androgen axis via identical mechanisms of action (abiraterone acetate, orteronel). MATERIALS AND METHODS: We included phase III randomized controlled trials that enrolled patients with mCRPC progressing during or after first-line docetaxel treatment. Trials were identified by electronic database searching. The primary outcome of the review was overall survival. Secondary outcomes were radiographic progression-free survival (rPFS) and severe adverse effects (grade 3 or higher). RESULTS: Ten articles met the inclusion criteria for the review. These articles reported the results of five clinical trials, enrolling in total 5047 patients. The experimental interventions tested in these studies were enzalutamide, ipilimumab, abiraterone acetate, orteronel and cabazitaxel. Compared to control cohorts (active drug-treated or placebo-treated), the significant overall survival advantages achieved were 4.8 months for enzalutamide (hazard ratio for death vs. placebo: 0.63; 95% CI 0.53 to 0.75, P < 0.0001), 4.6 months for abiraterone (hazard ratio for death vs. placebo: 0.66, 95% CI 0.58 to 0.75, P < 0.0001) and 2.4 months for cabazitaxel (hazard ratio for death vs. mitoxantrone-prednisone: 0.70, 95% CI 0.59 to 0.83, p < 0.0001). Pooled analysis of androgen synthesis inhibitors orteronel and abiraterone resulted in significantly increased overall and progression-free survival for anti-androgen agents, compared to placebo (hazard ratio for death: 0.76, 95% CI 0.67 to 0.87, P < 0.0001; hazard ratio for radiographic progression: 0.7, 95% CI 0.63 to 0.77, P < 0.00001). Androgen synthesis inhibitors induced significant increases in risk ratios for adverse effects linked to elevated mineralocorticoid secretion, compared to placebo (risk ratio for hypokalemia: 5.75, 95% CI 2.08 to 15.90; P = 0.0008; risk-ratio for hypertension: 2.29, 95% CI 1.02 to 5.17; P = 0.05). CONCLUSIONS: In docetaxel-pretreated patients enzalutamide, abiraterone-prednisone and cabazitaxel-prednisone can improve overall survival of patients, compared to placebo or to best of care at the time of study (mitoxantrone-prednisone). Agents targeting the androgen axis (enzalutamide, abiraterone, orteronel) significantly prolonged rPFS, compared to placebo. Further investigation is warranted to evaluate the benefit of combination or sequential administration of these agents. Large-scale studies are also necessary to evaluate the impact of relevant toxic effects observed in a limited number of patients (e.g., enzalutamide-induced seizures, orteronel-induced pancreatitis, and others).
Is the monoclonal antibody Trastuzumab (Herceptin) of potential use in the treatment of prostate cancer?
Although is still controversial, Trastuzumab (Herceptin) can be of potential use in the treatment of prostate cancer overexpressing HER2, either alone or in combination with other drugs.
Antibody to the Her-2/neu gene product has been shown to inhibit the growth of breast cancer cells overexpressing Her-2/neu and to have clinical utility in treating breast cancer. We studied a recombit, humanized anti-Her-2/neu antibody (Herceptin) in preclinical models of human prostate cancer. The androgen-dependent CWR22 and LNCaP human prostate cancer xenograft models and androgen-independent sublines of CWR22 were used. Her-2/neu staining of the parental, androgen-dependent, and androgen-independent CWR22 tumors and LNCaP tumors demonstrated variable Her-2/neu expression. Herceptin was administered i.p. at a dose of 20 mg/kg twice weekly after the xenograft had been established. No effect of Herceptin on tumor growth was observed in any of the androgen-independent tumors; however, significant growth inhibition was observed in both of the androgen-dependent xenograft models, CWR22 (68% growth inhibition at the completion of the experiment; P = 0.03 for trajectories of the average tumor volume of the groups) and LNCaP (89% growth inhibition; P = 0.002). There was a significant increase in prostate-specific antigen (PSA) index (ng PSA/ml serum/mm3 tumor) in Herceptin-treated androgen-dependent groups compared with control (CWR22, 18-fold relative to pretreatment value versus 1.0-fold, P = 0.0001; LNCaP, 2.35-fold relative to pretreatment value versus 0.6-fold, P = 0.001). When paclitaxel (6.25 mg/kg s.c., five times/week) was given to animals with androgen-dependent and -independent tumors, there was growth inhibition in each group. Paclitaxel and Herceptin cotreatment led to greater growth inhibition than was seen for the agents individually. Thus, in these prostate cancer model systems, Herceptin alone has clinical activity only in the androgen-dependent tumor and has at least an additive effect on growth, in combination with paclitaxel, in both androgen-dependent and androgen-independent tumors. Response to Herceptin did not correlate with the PSA levels, because the PSA index markedly increased in the Herceptin-treated group, whereas it remained constant in the control group. These results suggest the utility of Herceptin in the treatment of human prostate cancer. The HER2/neu oncogene is overexpressed in human pancreatic cancer, but the clinical significance of that overexpression is uncertain. In the present study we investigated the antitumor efficacy of Herceptin, a new recombit humanized anti-HER2/neu antibody, which exhibits cytostatic activity on breast and prostate cancer cells that overexpress the HER2 oncogene. That antibody may retard tumor growth in certain patients with those diseases. We quantified HER2 expression in various human pancreatic cancer cell lines and studied the bioactivity of this antibody both in vitro and in vivo. Growth inhibition by Herceptin was observed in vitro in cell lines with high levels of HER2/neu expression. Cell lines with low levels of this protein did not respond significantly to the antibody. In vivo we studied two different pancreatic cancer cell lines in an orthotopic mouse model of the disease. Herceptin treatment suppressed tumor growth in the MIA PaCa-2 tumor cell line, which expressed high levels of HER2/neu. These data suggest that Herceptin treatment of patients with pancreatic cancer who express high levels of the HER2/neu oncogene may be reasonable. Docetaxel, a semisynthetic taxane, has exhibited significant single-agent activity against prostatic tumors. In phase I/II studies, single-agent docetaxel and the combination of docetaxel plus estramustine were effective in inducing prostate-specific antigen reductions of > or =50% in men with androgen-independent prostate cancer (AIPC). The underlying reason for docetaxel's clinical activity against prostate cancer has been a focus of ongoing research. Docetaxel is believed to have a twofold mechanism of antineoplastic activity: (1) inhibition of microtubular depolymerization, and (2) attenuation of the effects of bcl-2 and bcl-xL gene expression. Taxane-induced microtubule stabilization arrests cells in the G(2)M phase of the cell cycle and induces bcl-2 phosphorylation, thereby promoting a cascade of events that ultimately leads to apoptotic cell death. In preclinical studies, docetaxel had a higher affinity for tubulin and was shown to be a more potent inducer of bcl-2 phosphorylation than paclitaxel. Laboratory evidence also supports the clinical evaluation of docetaxel-based combinations that include agents such as trastuzumab and/or estramustine. The pathways for docetaxel-induced apoptosis appear to differ in androgen-dependent and androgen-independent prostate cancer cells. Further elucidation of these differences will be instrumental in designing targeted regimens for the treatment of localized and advanced prostate cancer. The incidence of human epidermal growth factor receptor 2 (HER2) protein overexpression and its prognostic value are not well characterized in patients with prostate cancer. A phase I study was designed to evaluate docetaxel/estramustine plus trastuzumab, a humanized monoclonal antibody that binds to the HER2 receptor, in patients with metastatic androgen-independent prostate cancer (AIPC). HER2 positivity was not required because safety was the primary endpoint. Patients received oral estramustine 280 mg three times daily (days 1 to 5); docetaxel, 70 mg/m(2) intravenously (day 2); and trastuzumab, 2 mg/kg intravenously (days 2, 9, and 19), every 21 days until the disease progressed or toxicity became unacceptable. This regimen was well tolerated among the first 13 treated patients. Grade 4 neutropenia was seen in 10% of administered cycles. There were two episodes of febrile neutropenia and two thrombembolic events. Of the 13 patients evaluable for prostate-specific antigen (PSA) response, nine (69%) experienced a decrease in PSA level of >50%. Two (33%) of six patients with measurable disease had objective responses, and one complete response was seen on bone scan. Docetaxel/estramustine/trastuzumab appears to be a safe combination when used in the treatment of metastatic AIPC. The response data are too preliminary for speculation about the relative benefits of this 3-drug regimen compared with the combination of only docetaxel and estramustine in this clinical setting. BACKGROUND: Overexpression of the HER-2/neu oncoprotein has been reported to occur in </= 60% of patients with prostate carcinoma and to correlate with shortened survival. Trastuzumab is a humanized monoclonal antibody to the HER-2 receptor and has activity against HER-2-positive breast carcinoma, more so when combined with a taxane. The authors screened for HER-2 overexpression in patients developing hormone-refractory prostate carcinoma (HRPC) and conducted a Phase II trial of trastuzumab plus docetaxel in HER-2-positive patients. METHODS: Paraffin-embedded tumor specimens from potentially eligible patients were screened for HER-2 expression by immunohistochemistry (IHC) and/or amplification by fluorescent in situ hybridization (FISH). Shed HER-2 was also assessed by enzyme-linked immunoradsorbent assay (ELISA). Patients with HER-2-positive tumor specimens (IHC 2+ or 3+ or FISH ratio > 2) were initially randomized to receive either single-agent trastuzumab or docetaxel. After two treatment cycles, nonresponding patients received the trastuzumab/docetaxel combination. Treatment was comprised of 30 mg/m(2) of docetaxel weekly for 6 weeks followed by a 2-week break and 4 mg/kg of trastuzumab intravenously during Week 1 then 2 mg/kg per week thereafter. The cycle length was 8 weeks. RESULTS: One hundred patients with HPRC were screened. IHC results were as follows: 3+ (n = 1), 2+ (n = 6), 1+ (n = 26), 0 (n = 39), and insufficient tissue specimen/not tested (n = 28). Only 3 of 37 patients had elevated shed HER-2 by ELISA (> 15 mg/mL). None overexpressed HER-2 by IHC. FISH amplification was found in 0 of 34 tissue samples. Of seven patients with IHC 3+ or 2+, four were tested by ELISA and two by FISH. None were abnormal. Age and Gleason score did not correlate with IHC status. Of the seven patients eligible for the Phase II study, only four agreed to participate. The trial was thus closed for nonfeasibility (the overall HER-2 positivity rate was < 20%). No patient responded to trastuzumab alone. The median survival was not reached and the median progression-free survival was 7 months. CONCLUSIONS: HER-2 overexpression by IHC in archival prostate carcinoma specimens was infrequent. There was no apparent correlation among IHC, ELISA, and FISH, although the sample size was limited. Conclusions regarding the predictive value of HER-2 status on outcome after trastuzumab-based therapy were not reached and were only drawn after larger-scale screening efforts. The authors estimated that 1000 patients need to be screened to complete accrual to a 40-patient efficacy trial. PURPOSE: To investigate the efficacy and toxicity of the antibody to the HER-2/neu receptor (trastuzumab, Herceptin) in the treatment of advanced hormone-refractory prostate cancer (HRPC). MATERIALS AND METHODS: Eighteen patients with HRPC were recruited for this phase II trial in which they received trastuzumab for 12 weeks or until disease progression or unacceptable toxicity was documented. HER-2 receptor overexpression was evaluated using immunohistochemistry (IHC) and dual-color fluorescence in-situ hybridization (FISH) assays. RESULTS: Trastuzumab as a single agent demonstrated little efficacy in treating HRPC. Two patients demonstrated stable disease based on a decrease in PSA level to less than 50% of baseline. No patient demonstrated a regression of radiographic bony or soft tissue metastatic disease. The medication was well tolerated in 16 patients (89%), and 2 patients (11%) had to be hospitalized for cardiac complications. CONCLUSIONS: Trastuzumab (Herceptin) as a single agent demonstrated poor efficacy in treating HRPC. Based on promising results in treating breast cancer with regimens using Herceptin and cytotoxic agents, a similar combination approach might demonstrate better efficacy in treating HRPC. New drugs and new combinations of drugs have recently shown promising clinical activity in hormone refractory prostate cancer. We studied the association of gefitinib with trastuzumab on the androgen-refractory prostate cancer cell line DU145 expressing both epidermal growth factor receptor (EGFR) and HER-2. Drug combinations with radiotherapy (RT) were considered along with the analysis of factors linked to cell proliferation and apoptosis. The antitumour effects of gefitinib were more pronounced than those observed with trastuzumab. In mice receiving the gefitinib-trastuzumab combination, reduction in tumour volume was inferior to that predicted by the observed impact of the agents alone. The presence of trastuzumab markedly attenuated the relative increase on p27 expression and the Bax:Bcl2 ratio induced by gefitinib. The combination gefitinib-RT had similar antitumour effects as those predicted by the impact of the individual treatments, whereas the effect of the trastuzumab-RT combination was inferior to that predicted by the individual effects. The present data should be borne in mind when designing new clinical schedules for treatment of hormone-refractory prostate cancer including the use of HER inhibitors. The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases is part of a network of pathways that are involved in the development and progression of prostate cancer. HER-kinase receptors include epidermal growth factor receptor (EGFR), HER2, HER3, and HER4, which must combine as dimers to affect signaling. Different combinations of receptors produce different qualities and levels of pathway activation. Among HER-family receptors, HER2 activation is particularly important in breast cancer, as HER2 gene amplification is associated with a distinct clinical course and response to treatment with a HER2-directed therapy (trastuzumab). Although HER2 can be over-expressed in prostate cancer, there is no clinical data to support the use of trastuzumab for prostate cancer patients. Preclinical and clinical data show that the activation of the HER-kinase axis is important for the progression of prostate cancer to androgen-independent disease. Data points towards the importance of inhibiting multiple members of the HER-kinase family to achieve more complete blockade of this axis for cancers other than HER2-overexpressing breast cancer. Multiple pharmaceutical agents that block the HER-kinase axis are currently being tested for patients with prostate cancer. These include antibodies, tyrosine kinase inhibitors, and novel strategies which seek to decrease HER2 expression. Present management of metastatic prostate cancer, which includes hormonal therapy, chemotherapy, and radiotherapy, are frequently palliative. Taxanes, and specifically docetaxel, are being extensively investigated to improve the survival of metastatic prostate cancer patients. Although paclitaxel exhibits a wide spectrum of antitumor activity, its therapeutic application is limited, in part, due to its low water solubility that necessitates the use of Cremophor EL, which is known to induce hypersensitivity reactions. Therefore, the objective of this present study was to assess the efficiency of paclitaxel palmitate-loaded anti-HER2 immunoemulsions, a targeted drug delivery system based on cationic emulsion covalently linked to anti-HER2 monoclonal antibody (Herceptin), in a well-established in vivo pharmacologic model of metastatic prostate cancer that overexpresses the HER2 receptor. It was clearly noted that the cationic emulsion and immunoemulsion did not activate the complement compared with the commercial and paclitaxel palmitate hydroalcoholic formulations. In addition, 10 mg/kg of paclitaxel palmitate-loaded immunoemulsion once weekly over 3 weeks inhibits the tumor growth in severe combined immunodeficient mice much more than the cationic emulsion (P < 0.05) and the paclitaxel palmitate formulation (P < 0.01). The histopathologic analysis suggested a therapeutic improvement trend in favor of the immunoemulsion. However, there was no significant difference in antimetastatic activity between the emulsion and the immunoemulsion despite the affinity of the immunoemulsion towards the HER2 receptor. Although the tumor growth was not fully inhibited, the actual results are encouraging and may lead to an improved therapeutic strategy of metastatic prostate cancer treatment. Antitumour activity of docetaxel (Taxotere) in hormone-dependent (HD) and hormone-independent (HID) prostate cancer PAC120 xenograft model was previously reported, and its level was associated with HER2 protein expression. In the present study, we evaluate the antitumour effects of docetaxel combined with trastuzumab (Herceptin), an anti-HER2 antibody. Although trastuzumab alone had no effect on tumour growth, it potentiated the antitumour activity of docetaxel in HD tumours and more strongly in HID variants. Using the HID28 variant, we show that docetaxel treatment of tumour-bearing mice induces an increased HER2 mRNA expression of the tyrosine kinase receptor of 25-fold 24 h after docetaxel treatment, while HER2 protein and p-AKT decreased. This was followed by an increase of HER2 protein 3 days (two-fold) after docetaxel treatment and by a strong HER2 release in the serum of treated mice; expression of phospho-ERK, p27, BCL2 and HSP70 concomitantly increased. Similar molecular alterations were induced by docetaxel plus trastuzumab combination, except for that there was a transient and complete disappearance of AR and HSP90 proteins 24 h after treatment. We show that in addition to its known effects on tubulin and mitotic spindles, docetaxel induces complex signalisation pathway mechanisms in surviving cells, including HER2, which can be pharmacologically targeted. This study suggests that the docetaxel/trastuzumab combination may prove an effective therapeutic approach for HER2-expressing hormone-refractory prostate cancer. BACKGROUND/AIMS: Evaluation of Her2/neu expression in the peripheral blood mononuclear cell fraction of prostate cancer patients by RT-PCR may afford an opportunity for the detection of circulating tumor cells and thus serve as a marker of micrometastatic disease. METHODS: We studied Her2/neu expression by reverse transcriptase-polymerase chain reaction in peripheral blood mononuclear cell fraction samples of 21 controls and serially in 43 patients with prostate cancer. RESULTS: None of the 21 controls expressed Her2/neu whereas 23.25% (95% CI, 11.75-38.63) of the patients were positive at entry into the study, and 65.11% (95% CI, 49.07-78.99) of them had at least one positive result during the follow-up period. Her2/neu positivity at study entry did not correlate significantly with PSA level, Gleason score, clinical stage or time to PSA progression. When we analyzed only patients with advanced disease, we observed a trend towards a shorter time to PSA progression in patients with at least one positive Her2/neu result during the follow-up (log-rank test, P = 0.08). CONCLUSIONS: We conclude that Her2/neu expression in the peripheral blood mononuclear cell fraction of prostate cancer patients is frequent and therefore this assay may potentially be useful to detect the presence of micrometastatic disease in men with prostate cancer and for monitoring patients enrolled in trastuzumab-based therapeutic protocols. The potential of the HER2-targeting antibody trastuzumab as a radioimmunoconjugate useful for both imaging and therapy was investigated. Conjugation of trastuzumab with the acyclic bifunctional chelator CHX-A"-DTPA yielded a chelate:protein ratio of 3.4 ± 0.3; the immunoreactivity of the antibody unaffected. Radiolabeling was efficient, routinely yielding a product with high specific activity. Tumor targeting was evaluated in mice bearing subcutaneous (s.c.) xenografts of colorectal, pancreatic, ovarian, and prostate carcinomas. High uptake of the radioimmunoconjugate, injected intravenously (i.v.), was observed in each of the models, and the highest tumor %ID/g (51.18 ± 13.58) was obtained with the ovarian (SKOV-3) tumor xenograft. Specificity was demonstrated by the absence of uptake of 111In-trastuzumab by melanoma (A375) s.c. xenografts and 111In-HuIgG by s.c. LS-174T xenografts. Minimal uptake of i.v. injected 111In-trastuzumab in normal organs was confirmed in non-tumor-bearing mice. The in vivo behavior of 111In-trastuzumab in mice bearing intraperitoneal (i.p.) LS-174T tumors resulted in a tumor %ID/g of 130.85 ± 273.34 at 24 h. Visualization of tumor, s.c. and i.p. xenografts, was achieved by γ-scintigraphy and PET imaging. Blood pool was evident as expected, but cleared over time. The blood pharmacokinetics of i.v. and i.p. injected 111In-trastuzumab was determined in mice with and without tumors. The data from these in vitro and in vivo studies supported advancement of radiolabeled trastuzumab into two clinical studies, a Phase 0 imaging study in the Molecular Imaging Program of the National Cancer Institute and a Phase 1 radioimmunotherapy study at the University of Alabama. The type I receptor tyrosine kinases (RTKs) are involved in various aspects of cell growth, survival, and differentiation. Among the known RTKs, the epidermal growth factor receptor (EGFR) and ErbB-2 (HER-2) are two widely studied proteins that are prototypic members of the ErbB family which also includes ErbB-3 (Her-3) and ErbB-4 (Her-4). Overexpression of ErbB-2 and EGFR has been associated with aggressive disease and poor patient prognosis in a range of human tumour types (e.g. breast, lung, ovarian, prostate, and squamous carcinoma of head and neck). Disruption of signal transduction of these kinases has been shown to have an antiproliferative effect. Various approaches have been developed to target the ErbB signalling pathways including monoclonal antibodies (trastuzumab/Herceptin™ and cetuximab/Erbitux™) directed against the receptor, and synthetic tyrosine kinase inhibitors (gefitinib/Iressa™ and erlotinib/Tarceva™). Since many tumours overexpress ErbB receptors, simultaneous targeting of multiple ErbB receptors therefore becomes a promising approach to cancer treatment. Lapatinib (Tykerb™), a potent dual EGFR/ErbB-2 inhibitor, was approved for the treatment of ErbB-2-positive breast cancer. Despite years of intensive research on EGFR inhibitors, there is a surprising dearth of chemically distinct small inhibitors with a high degree of selectivity. There is also a need for new scaffolds due to the recent finding of EGFR mutations which render the kinase resistant to gefinitib and erlotinib. The structures under study will be quinazolines with different substituents. The structure-activity relationships and biological evaluation of compounds published during the last four years will be reviewed herein. PURPOSE: Patients with recurrent prostate cancer are commonly treated with androgen withdrawal therapy (AWT); however, almost all patients eventually progress to castration resistant prostate cancer (CRPC), indicating failure of AWT to eliminate androgen-sensitive prostate cancer. The overall goal of these studies is to determine whether dual inhibition of the receptor tyrosine kinases epidermal growth factor receptor (EGFR) and HER2 would prolong the effectiveness of this treatment in prostate cancer. EXPERIMENTAL DESIGN: We used androgen-dependent LNCaP cells and its CRPC sublines LNCaP-AI and C4-2. Additional data were collected in pRNS-1-1 cells stably expressing a mutant androgen receptor (AR-T877A), and in nude mice harboring CWR22 tumors. Studies utilized EGFR inhibitors erlotinib and AG1478, and HER2 inhibitors trastuzumab and AG879. RESULTS: Dual EGFR/HER2 inhibition induced apoptosis selectively in androgen-sensitive prostate cancer cells undergoing AWT, but not in the presence of androgens, or in CRPC cells. We show that AWT alone failed to induce significant apoptosis in androgen-dependent cells, due to AWT-induced increase in HER2 and ErbB3, which promoted survival by increasing Akt phosphorylation. AWT-induced ErbB3 stabilized the AR and stimulated PSA, while it was inactivated only by inhibition of both its dimerization partners EGFR and HER2 (prostate cancer cells do not express ErbB4); but not the inhibition of any one receptor alone, explaining the success of dual EGFR/HER2 inhibition in sensitizing androgen-dependent cells to AWT. The effectiveness of the inhibitors in suppressing growth correlated with its ability to prevent Akt phosphorylation. CONCLUSION: These studies indicate that dual EGFR/HER2 inhibition, administered together with AWT, sensitize prostate cancer cells to apoptosis during AWT. The purpose of this study was to determine therapeutic effects and systemic toxicity of 212Pb-trastuzumab in an orthotopic model of human prostate cancer cells in nude mice. TCMC-Trastuzumab was radiolabeled with 212Pb. The 212Pb-trastuzumab generated from the procedure was intact and had high binding affinity with a dissociation constant (of 3.9±0.99 nM. PC-3MM2 cells, which expressed a lower level of HER2 both in culture and in tumors, were used in therapy studies. A single intravenous injection of 212Pb-trastuzumab reduced tumor growth by 60-80%, reduced aortic lymph node metastasis, and prolonged the survival of tumor-bearing mice. Treatment with 212Pb-trastuzumab did not cause significant changes in body weight, serum glutamic pyruvic transaminase (SGPT), blood urea nitrogen (BUN), hematological profiles, and histological morphology of several major organs of tumor-bearing mice. These findings suggest that a systemic delivery of 212Pb-trastuzumab could be an effective modality for management of advanced human prostate cancer. The treatment of disseminated prostate cancer remains a great challenge in current oncology practice. The proliferation of prostate cancer cells is testosterone-driven, but clonal selection during androgen deprivation therapy promotes the development of androgen-independent (hormone-refractory) cells, which become phenotypically domit. Human epidermal growth factor receptor type 2 (HER2) is capable of activating the androgen receptor pathway, even in the absence of the ligand. The detection of phenotypic changes associated with the development of androgen independence may influence patient management, suggesting the initiation of a second-line therapy. This study aimed to establish the level of HER2 expression in a number of prostate cancer cell lines (LNCaP, PC3 and DU145) in order that they be used as models in further studies, and to evaluate the binding and cellular processing of [(111)In]-labeled trastuzumab and the anti-HER2 synthetic Affibody molecule ABY-025 in these cell lines. The expression of HER2 was demonstrated and quantified in all three tested prostate cancer cell-lines. Studies on cellular processing demonstrated that internalization of both conjugates increased continuously during the whole incubation. The internalization rate was approximately equal for both monoclonal antibodies and Affibody molecules. In both cases, internalization was moderately rapid. Such features would definitely favor the use of radiometal labels for trastuzumab and, most likely, for affibody molecules. The level of HER2 expression in these cell lines is sufficient for in vivo molecular imaging. The epidermal growth factor receptor (EGFR) family members are potential targets for therapy using extra-cellular domain receptor binding agents, such as the antibodies trastuzumab and cetuximab, or antibodies labeled with therapeutically useful radionuclides or toxins. This is especially the case when the tumor cells are resistant to chemotherapy and tyrosine kinase inhibitors. Studies concerning the expression of these receptors in prostate cancer vary in the literature, possibly due to differences in patient inclusion, sample preparations and scoring criteria. In our study, EGFR, HER2 and HER3 expression was analyzed in prostate cancer samples from primary tumors and corresponding lymph node metastases from 12 patients. The expression of HER2 and EGFR was scored from immunohistochemical preparations and the HercepTest criteria (0, 1+, 2+ or 3+), while HER3 expression was scored as no, weak or strong staining. There were 5 EGFR-positive (2+ or 3+) primary tumors and 6 EGFR-positive lymph node metastases, and there was EGFR upregulation in one metastasis. Only 4 of the 12 patients had marked HER2 expression (2+ or 3+) in their primary tumors and there was one downregulation and 5 cases of upregulation in the metastases. Thus, a total of 8 out of 12 analyzed metastases were HER2-positive. Of the 12 primary tumors, 9 expressed HER3 while only 2 of the lymph node metastases expressed recognizable HER3 staining, so 7 metastases appeared to have downregulated HER3 expression. In one of the primary tumors there was positive co-expression of EGFR and HER2, while this co-expression was observed in 4 of the metastases. Thus, there were tendencies for upregulation of HER2, increased co-expression of EGFR and HER2 and downregulation of HER3 in the prostate cancer lymph node metastases in comparison to the primary tumors. The results are encouraging for studies involving more patients. Possible strategies for EGFR- and HER2-targeted therapy are briefly discussed in the present study, especially with regard to the expression and co-expression of EGFR and HER2 in metastases.
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