Toll-like receptor (TLR)-4 is a transmembrane receptor for lipopolysaccharide, a highly pro-inflammatory component of the outer membrane of Gram-negative bacteria. To date, molecules of the TLR-4 signaling pathway have not been well characterized in cattle. The goal of this study was to clone and sequence the full-length coding regions of bovine genes involved in TLR-4 signaling including CASP8, IRAK1, LY96 (MD-2), TICAM2, TIRAP, TOLLIP and TRAF 6 and to position these genes, as well as MyD88 and TICAM1, on the bovine genome using radiation hybrid mapping. Results of this work indicate differences with a previously published bovine sequence for LY96 and a predicted sequence in the GenBank database for TIRAP based on the most recent assembly of the bovine genome. In addition, discrepancies between actual and predicted chromosomal map positions based on the Btau_2.0 genome assembly release were identified, although map positions were consistent with predicted locations based on the current bovine-human comparative map. Alignment of the bovine amino acid sequences with human and murine sequences showed a broad range in conservation, from 52 to 93%. Overall, this work should assist in the assembly and annotation of the bovine genome sequence, the identification of variations in genes critically involved in host innate immunity, and facilitate the study of TLR-4 signaling pathways in cattle.

Human placental trophoblasts can be considered pseudomalignant, with tightly controlled proliferation, apoptosis, and invasiveness. Gestational trophoblastic disease (GTD) represents a family of heterogeneous trophoblastic lesions with aberrant apoptotic and proliferative activities and dysregulation of cell signaling pathways. We characterize the oncogenic effects of factor that binds to the inducer of short transcripts of HIV-1 [FBI-1, alias POZ and Krüppel erythroid myeloid ontogenic factor (POKEMON)/ZBTB7A] in GTD and its role in promoting cell aggressiveness in vitro and tumor growth in vivo. IHC studies showed increased nuclear expression of FBI-1, including hydatidiform moles, choriocarcinoma (CCA), and placental site trophoblastic tumor, in GTD. In JAR and JEG-3 CCA cells, ectopic FBI-1 expression opposed apoptosis through repression of proapoptotic genes (eg, BAK1, FAS, and CASP8). FBI-1 overexpression also promoted Akt activation, as indicated by Akt-pS473 phosphorylation. FBI-1 overexpression promoted mobility and invasiveness of JEG-3 and JAR, but not in the presence of the phosphoinositide 3-kinase inhibitor LY294002. These findings suggest that FBI-1 could promote cell migration and invasion via phosphoinositide 3-kinase/Akt signaling. In vivo, nude mice injected with CCA cells with stable FBI-1 knockdown demonstrated reduced tumor growth compared with that in control groups. These findings suggest that FBI-1 is clinically associated with the progression of, and may be a therapeutic target in, GTD, owing to its diverse oncogenic effects on dysregulated trophoblasts.

The last few decades observed an increasing interest in development and application of 1-dimensional (1D) descriptors of protein structure. These descriptors project 3D structural features onto 1D strings of residue-wise structural assignments. They cover a wide-range of structural aspects including conformation of the backbone, burying depth/solvent exposure and flexibility of residues, and inter-chain residue-residue contacts. We perform first-of-its-kind comprehensive comparative review of the existing 1D structural descriptors. We define, review and categorize ten structural descriptors and we also describe, summarize and contrast over eighty computational models that are used to predict these descriptors from the protein sequences. We show that the majority of the recent sequence-based predictors utilize machine learning models, with the most popular being neural networks, support vector machines, hidden Markov models, and support vector and linear regressions. These methods provide high-throughput predictions and most of them are accessible to a non-expert user via web servers and/or stand-alone software packages. We empirically evaluate several recent sequence-based predictors of secondary structure, disorder, and solvent accessibility descriptors using a benchmark set based on CASP8 targets. Our analysis shows that the secondary structure can be predicted with over 80% accuracy and segment overlap (SOV), disorder with over 0.9 AUC, 0.6 Matthews Correlation Coefficient (MCC), and 75% SOV, and relative solvent accessibility with PCC of 0.7 and MCC of 0.6 (0.86 when homology is used). We demonstrate that the secondary structure predicted from sequence without the use of homology modeling is as good as the structure extracted from the 3D folds predicted by top-performing template-based methods.

Responses of human neutrophils to TNF-α are complex and multifactorial. Exposure of human neutrophils to TNF-α in vitro primes the respiratory burst, delays apoptosis and induces the expression of several genes including chemokines, and TNF-α itself. This study aimed to determine the impact of TNF-α exposure on the expression of neutrophil genes and proteins that regulate apoptosis. Quantitative PCR and RNA-Seq, identified changes in expression of several apoptosis regulating genes in response to TNF-α exposure. Up-regulated genes included TNF-α itself, and several anti-apoptotic genes, including BCL2A1, CFLAR (cFLIP) and TNFAIP3, whose mRNA levels increased above control values by between 4-20 fold (n = 3, P < 0.05). In contrast, the expression of pro-apoptotic genes, including CASP8, FADD and TNFRSF1A and TNFRSF1B, were significantly down-regulated following TNF-α treatment. These changes in mRNA levels were paralleled by decreases in protein levels of caspases 8 and 10, TRADD, FADD, TNFRSF1A and TNFRSF1B, and increased cFLIP protein levels, as detected by western blotting. These data indicate that when neutrophils are triggered by TNF-α exposure, they undergo molecular changes in transcriptional expression to up-regulate expression of specific anti-apoptotic proteins and concomitantly decrease expression of specific proteins involved in death receptor signaling which will alter their function in TNF-α rich environments.

The aim of the study is to investigate the relevance of rs1056663 and rs2708861 HUS1 polymorphisms, and rs104548, rs2981582 and rs2910164 polymorphisms of CASP8, FGFR2 and micro RNA 146A genes, respectively, as risk modifiers in hereditary breast or ovarian cancer (BC/OC) and risk factors in sporadic BC. We performed a case-control study in 189 healthy controls (CG) and 538 BC/OC cases, 340 with familial history of BC/OC (130 carriers of BRCA1/2 mutations and 210 non-carriers) and 198 sporadic BC/OC. The polymorphisms were assessed by real-time PCR using primers and fluorescent-labelled hybridization probes. We found statistically significant differences between familial BC/OC and CG for rs1056663 and rs2708861 HSU1 polymorphisms and rs2981582 FGFR2 polymorphism, particularly in non-carriers of BRCA1/2 mutations. In this group we found statistical differences for rs1056663 HSU1 and rs2981582 FGFR2 polymorphisms (p-trend < 0.006). The logistic regression confirmed that rs2981582 FGFR2 polymorphism (OR = 2.09; 95 % CI 1.35, 3.20) and the interaction between rs1056663 and rs2708861 HUS1 polymorphisms increased the risk of cancer (OR = 1.87; 95 % CI 1.19, 2.92). Furthermore, we found that the presence of rs1056663 and rs2708861 HUS1 polymorphisms is associated with early age of presentation of BC (p = 0.015) in the group of non-carriers of BRCA1/2 mutations. In addition, no association of the polymorphisms studied in sporadic BC was observed. In conclusion, the HUS1 and FGFR2 polymorphisms act as risk BC modifiers in familial BC/OC, particularly in the group of non-carriers of BRCA1/2 mutations.

BACKGROUND

Human papillomavirus-related (HPV-related) oropharyngeal squamous cell carcinomas (OPSCCs) have an excellent response rate to platinum-based chemoradiotherapy. Genomic differences between primary HPV-related OPSCCs that do or do not recur are unknown. Furthermore, it is unclear if HPV-related OPSCCs that recur share a genomic landscape with HPV-negative head and neck cancers (HNCs).

METHODS

We utilized whole exome sequencing to analyze somatic nucleotide (SNVs) and copy number variants (CNVs) among a unique set of 51 primary HPV-related OPSCCs, including 35 that did not recur and 16 that recurred. We evaluated 12 metachronous recurrent OPSCCs (7 with paired primary OPSCCs) and 33 primary HPV-unrelated oral cavity and OPSCCs.

RESULTS

KMT2D was the most frequently mutated gene among primary HPV-related OPSCCs (n = 51; 14%) and among metachronous recurrent OPSCCs (n = 12; 42%). Primary HPV-related OPSCCs that recurred shared a genomic landscape with primary HPV-related OPSCCs that did not recur. However, TSC2, BRIP1, NBN, and NFE2L2 mutations occurred in primary OPSCCs that recurred but not in those that did not recur. Moreover, primary HPV-related OPSCCs that recur harbor features of HPV-unrelated HNCs, notably including MAPK, JAK/STAT, and differentiation signaling pathway aberrations. Metachronous recurrent OPSCCs shared a genomic landscape with HPV-unrelated HNCs, including a high frequency of TP53, CASP8, FAT1, HLA-A, AJUBA, and NSD1 genomic alterations.

CONCLUSIONS

Overall, primary HPV-related OPSCCs that recur share a genomic landscape with nonrecurrent OPSCCs. Metachronous recurrent OPSCCs share genomic features with HPV-negative HNCs. These data aim to guide future deescalation endeavors and functional experiments.

BACKGROUND

This study is supported by the American Cancer Society (RSG TBG-123653), funding support for RAH (T32DC00018, Research Training in Otolaryngology, University of Washington), funds to EM from Seattle Translational Tumor Research (Fred Hutchinson Cancer Research Center), and center funds from the Fred Hutchinson Cancer Research Center to EM. UD is supported by the Department of Veterans Affairs, Biomedical Laboratory Research and Development (BLR&D), grant IO1-oo23456, and funds from the Pittsburgh Foundation and PNC Foundation.

OBJECTIVE

Cisplatin is an anti-neoplastic agent treatment with which causes many side effects including ototoxicity. The aim of this study was to investigate whether acetyl-L-carnitine would have protective effects on cisplatin-induced ototoxicity in vitro, and if present, to reveal roles of apoptotic gene expressions and pro-inflammatory cytokines.

METHODS

House Ear Institute-Organ of Corti 1 cell line was used for this study. Apoptotic genes were evaluated with an apoptosis PCR array and pro-inflammatory cytokine levels were measured using ELISA.

RESULTS

Apoptotic cell death reduced by around 22% with acetyl-L-carnitine-cisplatin treatment compared to cisplatin alone. Genes displaying increase in expression of apoptosis, related to cisplatin treatment, were Casp8, Bcl10, Bcl2, Bcl2l1, Bcl2l2, Bid, Naip1, Bnip3l, Card6, Pak7, Cd40, Trp 53inp1, Cideb and Cd70. The acetyl-L-carnitine-cisplatin combination caused reduced expression of genes Casp8, Fas, Casp1, Tnfrsf11b, Tnfrsf10b induced by cisplatin. Acetyl-L-carnitine-cisplatin also caused reduced levels of IL-6, IL-1β and TNF-α, pro-inflammatory cytokines, induced by cisplatin.

CONCLUSIONS

Protective mechanisms of aceytl-L-carnitine against cisplatin induced apoptosis, mainly due to activation of anti-apoptotic Bcl family members' genes, and in an Akt-related gene expression dependent manner. This is the first study to indicate that acetyl-L-carnitine can be an effective agent against cisplatin ototoxicity in auditory cells, with induction of anti-apoptotic gene expression and attenuating levels of pro-inflammatory cytokines.

BACKGROUND

Despite widespread activation of proapoptotic stimuli and mediators, the degree of apoptosis in failing hearts is not very high. Endogenous antiapoptotic mechanisms are thought to be triggered by the heart-failure process. We investigated whether activation of endogenous apoptosis inhibitors plays a part when death receptor and mitochondrial apoptotic pathways have been triggered.

METHODS

We evaluated various proapoptotic and antiapoptotic factors in myocardial tissue specimens obtained from normal and explanted end-stage ischemic and dilated cardiomyopathic hearts. Caspases (CASPs) 3, 8 and 9, total and activated Bcl-2 homology domain 3-interacting domain death agonist, the X-linked inhibitor of apoptosis (XIAP), and DNA fragmentation factor (DFF) proteins were analyzed by western blotting. Expression of messenger RNA was measured by reverse-transcription polymerase chain reaction for the XIAP, DIABLO, CFLAR and DFF genes. We also assessed CASP3, CASP8 and CASP9 and DFF activity. Cytochrome c1 localization in myocytes was analyzed by immunohistochemistry and immunoelectron microscopy.

RESULTS

We collected myocardial tissue from eight cardiomyopathic hearts and five normal hearts. Cytochrome c1 was released from mitochondria into the cytosol in the cardiomyopathic hearts but CASP9 was not activated. CASP8 activity was increased compared with that in normal myocardium. Although CASP3 was cleaved, activity was not greatly increased because of an increase in XIAP and decrease in DIABLO expression. DFF proteins were conspicuously absent.

CONCLUSIONS

Concurrent upregulation of endogenous antiapoptotic mechanisms can interrupt the apoptotic cascade and prevents cell loss despite the presence of multiple proapoptotic factors. This period might offer a therapeutic window for restoration of myocardial function in heart failure.

OBJECTIVE

In the current study, we analysised only the articles that investigate serum proteome profile of cirrhosis patients or HCC patients versus healthy controls.

BACKGROUND

Increased understanding of cancer biology has enabled identification of molecular events that lead to the discovery of numerous potential biomarkers in diseases. Protein-protein interaction networks is one of aspect that could elevate the understanding level of molecular events and protein connections that lead to the identification of genes and proteins associated with diseases.

METHODS

Gene expression data, including 63 gene or protein names for hepatocellular carcinoma and 29 gene or protein names for cirrhosis, were extracted from a number of previous investigations. The networks of related differentially expressed genes were explored using Cytoscape and the PPI analysis methods such as MCODE and ClueGO. Centrality and cluster screening identified hub genes, including APOE, TTR, CLU, and APOA1 in cirrhosis.

RESULTS

CLU and APOE belong to the regulation of positive regulation of neurofibrillary tangle assembly. HP and APOE involved in cellular oxidant detoxification. C4B and C4BP belong to the complement activation, classical pathway and acute inflammation response pathway. Also, it was reported TTR, TFRC, VWF, CLU, A2M, APOA1, CKAP5, ZNF648, CASP8, and HSP27 as hubs in HCC. In HCC, these include A2M that are corresponding to platelet degranulation, humoral immune response, and negative regulation of immune effector process. CLU belong to the reverse cholesterol transport, platelet degranulation and human immune response. APOA1 corresponds to the reverse cholesterol transport, platelet degranulation and humoral immune response, as well as negative regulation of immune effector process pathway.

CONCLUSIONS

In conclusion, this study suggests that there is a common molecular relationship between cirrhosis and hepatocellular cancer that may help with identification of target molecules for early treatment that is essential in cancer therapy.

BACKGROUND

Death receptors on the cell surface and the interacting cytosolic molecules, adaptors and initiator caspases, are essential as core components of the extrinsic apoptotic signaling pathway. While the apoptotic machinery governing the extrinsic signaling pathway is well characterized in mammals, it is not fully understood in fish.

RESULTS

We identified and characterized orthologs of mammalian Fas, FADD and caspase-8 that correspond to the death receptor, adaptor and initiator caspase, from the Medaka fish (Oryzias latipes). Medaka Fas, caspase-8 and FADD exhibited protein structures similar to that of their mammalian counterparts, containing a death domain (DD), a death effector domain (DED) or both. Functional analyses indicated that these molecules possess killing activity in mammalian cell lines upon overexpression or following activation by apoptotic stimuli, suggesting similar pro-apoptotic functions in the extrinsic pathway as those in mammals. Genomic sequence analysis revealed that the Medaka fas (tnfrsf6), fadd and caspase-8 (casp8) genes are organized in a similar genomic structure as the mammalian genes. Database search and phylogenetic analysis revealed that the fas gene, but not the fadd and casp8 genes, appear to be present only in vertebrates.

CONCLUSIONS

Our results indicate that the core components necessary for the extrinsic apoptotic pathway are evolutionarily conserved in function and structure across vertebrate species. Based on these results, we presume the mechanism of apoptosis induction via death receptors was evolutionarily established during the appearance of vertebrates.

BACKGROUND

Template-based modelling can approximate the unknown structure of a target protein using an homologous template structure. The core of the resulting prediction then comprises the structural regions conserved between template and target. Target prediction could be improved by rigidly repositioning such single template, structurally conserved fragment regions. The purpose of this article is to quantify the extent to which such improvements are possible and to relate this extent to properties of the target, the template and their alignment.

RESULTS

The improvement in accuracy achievable when rigid fragments from a single template are optimally positioned was calculated using structure pairs from the HOMSTRAD database, as well as CASP7 and CASP8 target/best template pairs. Over the union of the structurally conserved regions, improvements of 0.7 A in root mean squared deviation (RMSD) and 6% in GDT_HA were commonly observed. A generalized linear model revealed that the extent to which a template can be improved can be predicted using four variables. Templates with the greatest scope for improvement tend to have relatively more fragments, shorter fragments, higher percentage of helical secondary structure and lower sequence identity. Optimal positioning of the template fragments offers the potential for improving loop modelling. These results demonstrate that substantial improvement could be made on many templates if the conserved fragments were to be optimally positioned. They also provide a basis for identifying templates for which modification of fragment positions may yield such improvements.

BACKGROUND

Despite evidence suggesting roles for caspase-8 (CASP8) -652 6N del and D302H polymorphisms in prostate cancer (PCa), the association of these polymorphisms with PCa risk remains inconclusive. Therefore, a meta-analysis was performed to more precisely estimate the association of CASP8 -652 6N del and D302H polymorphisms with PCa susceptibility.

METHODS

A comprehensive literature search was conducted to identify all case-control studies of CASP8 D302H and -652 6N del polymorphisms and PCa risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association and the precision of the estimate, respectively.

RESULTS

Nine -625 6N del studies and 4 D302H studies were included. CASP8 -652 6N del and D302H polymorphisms were not significantly associated with PCa risk in the overall analyses. However, in the subgroup analysis stratified by ethnicity, -625 6N del was significantly associated with PCa risk in the East Asian and Indian populations under the recessive model. Furthermore, the subgroup analysis strongly suggested that D302H was associated with lower PCa risk in the Non-Indian population under the dominant model.

CONCLUSIONS

In our meta-analysis, ethnic-specific differences were evident in the association of CASP8 -625 6N del and D302H polymorphisms with PCa risk.

To evaluate whether promoter methylation is related to responsiveness for chemotherapy or clinical outcome, we performed an association analysis between methylation and clinical outcomes. Patients with nodal diffuse large B-cell lymphomas (DLBCL) at a single institute (n=44) were studied for methylation of tumor-related genes, MGMT, p15(INK4B), p16(INK4A), p16(INK4A), Mad2, TMS1/ASC, CASP8, and GSTP1. The clinical behavior of DLBCL after chemotherapy was followed up and analyzed. Hypermethylation of promoters of MGMT, p15(INK4B), p16(INK4A), p16(INK4A), Mad2, and TMS1/ASC genes was observed in 52.3%, 31.8%, 54.5%, 47.7%, 50%, and 2.3% of the cases, respectively. Methylation of CASP8 and GSTP1 genes was not observed. Promoter methylation was not related to chemo-responsiveness, disease-free survival, and progress of disease after chemotherapy. However, in overall survival analyses, MGMT methylation (p<0.05) and responsiveness to chemotherapy (p<0.01) were significant prognostic factors in patients with DLBCL. In the low-risk group, patients with p57 methylation showed longer overall survival than patients without p57 methylation (p=0.02) and all patients with p57 methylation were alive during follow-up. Our results demonstrate that aberrant promoter methylation of MGMT and p57 is an additional biological marker for predicting increased overall survival in patients with DLBCL.

Gallbladder cancer (GBC) is a multifactorial disease with complex interplay between multiple genetic variants. We performed Classification and Regression Tree Analysis (CART) and Grade of Membership (GoM) analysis to identify combinations of alleles among the DNA repair, inflammatory and apoptotic pathway genetic variants in modifying the risk for GBC. We analyzed 16 polymorphisms in 8 genes involved in DNA repair, apoptotic and inflammatory pathways to find out combinations of genetic variants contributing to GBC risk. The genes included in the study were XRCC1, OGG1, ERCC2, MSH2, CASP8, TLR2, TLR4 and PTGS2. Single locus analysis by logistic regression showed association of MSH2 IVS1+9G>C (rs2303426), ERCC2 Asp312Asn (rs1799793), OGG1 Ser326Cys (rs1052133), OGG1 IVS4-15C>G (rs2072668), CASP8 -652 6N ins/del (rs3834129), PTGS2 -1195G>A (rs689466), PTGS2 -765G>C (rs20417), TLR4 Ex4+936C>T (rs4986791) and TLR2 -196 to -174del polymorphisms with GBC risk. The CART analysis revealed OGG1 Ser326Cys, and OGG1 IVS4-15C>G polymorphisms as the best polymorphic signature for discriminating between cases and controls. In the GoM analysis, the data was categorized into six sets representing risk for GBC with respect to the investigated polymorphisms. Sets I, II and III described low intrinsic risk (controls) characterized by multiple protective alleles while sets IV, V and VI represented high intrinsic risk groups (GBC cases) characterized by the presence of multiple risk alleles. The CART and GoM analyses also showed the importance of PTGS2 -1195G>A polymorphism in susceptibility to GBC risk. In conclusion, the present multigenic approach can be used to define individual risk profiles for gallbladder cancer in North Indian population.

The rs3834129 polymorphism, in the promoter of CASP8 gene, has been recently reported as associated with breast cancer risk in the general population, with the minor allele del having a protective effect. Some of the genetic variants found associated with breast cancer risk were reported as risk modifiers in individuals with mutations in BRCA1 and BRCA2 genes. Here, we tested the effect of the rs3834129 del allele on breast cancer risk in BRCA mutation carriers. The rs3834129 was genotyped in a total of 1,207 Italian female BRCA mutation carriers. Of these, 740 carried a BRCA1 mutation and 467 a BRCA2 mutation. Overall, 699 were affected with breast cancer and 508 were unaffected. When considering class 1 (loss-of-function) BRCA mutations, hazard ratios estimated by weighted multivariable Cox regression model, for individuals with at least one copy of the del allele, were 1.46 (95% confidence interval (CI): 1.08-1.99) for BRCA1 and BRCA2 mutation carriers combined, 1.74 (95% CI: 1.24-2.46) for BRCA1 mutation carriers, and 1.09 (95% CI: 0.66-1.80) for BRCA2 mutation carriers. These results suggest that the minor allele del of rs3834129 is associated under a dominant model with increased breast cancer risk in carriers of BRCA1 mutations but not in carriers of BRCA2 mutations.

BACKGROUND

Wilms tumor (WT) has a survival rate of 90% following multimodality therapy. Nevertheless, there are some groups of patients with event-free survival rates less than 75%. In addition to clinical prognostic factors, loss of heterozygosity at 1p and/or 16q has been used to determine treatment intensity. However, the incidence of this abnormality is low, and new biomarkers are still needed.

METHODS

We analyzed methylation status of three tumor suppressor genes; Ras-association domain family 1 protein, isoform A (RASSF1A), DCR2, and CASP8, in 84 WTs using conventional methylation-specific PCR (cMSP), and the results were correlated with outcome. Furthermore, we analyzed the methylation status of RASSF1A by quantitative MSP (qMSP) in 171 WTs, and evaluated clinical and genetic differences between the methylated and unmethylated tumors.

RESULTS

RASSF1A was the most frequently methylated gene identified by cMSP, and associated with a poor outcome. Patients with a RASSF1A-methylated tumor had shorter overall and event-free survival periods (P = 0.043 and 0.018, respectively), when a cut-off value of 7% by qMSP was used. The methylation was more frequent in tumors of older children than younger children (P < 0.001), and in advanced-stage tumors than early stage tumors (P = 0.001). However, multivariate analysis could not confirm the prognostic significance of RASSF1A methylation, possibly because of a small number of advanced stage tumors examined. RASSF1A methylation was correlated with LOH at 1p and/or 16q (P = 0.017), but not with WT1 abnormality, suggesting the methylation and LOH to involve the same tumorigenic pathway.

CONCLUSIONS

The methylation status of RASSF1A might be a novel biomarker to predict outcome of WT patients.

OBJECTIVE

Caspase 8 (CASP8) plays a critical role in the apoptotic pathway and aberrant regulation of this pathway causes many diseases including cancers. Genetic variants rs3834129 (CTTACT/-) and rs3769821 (T/C) in the promoter region of the CASP8 gene were documented to be associated with multiple solid cancers and non-Hodgkin's lymphoma (NHL), respectively, despite of some controversies. We aimed to discern potential association of these two variants and rs113686495 (CTGTCATT/-), as well as CASP8 mRNA and protein expression levels with colorectal cancer (CRC) in Han Chinese.

METHODS

We genotyped CASP8 genetic variants in 305 CRC patients and 342 healthy individuals from Kunming, Southwest China. Expression levels of CASP8 mRNA and protein were quantified in paired cancerous and paracancerous normal tissues by using real-time quantitative PCR and western blot, respectively. We compared the frequencies of alleles, genotypes, and haplotypes between the cases and controls. Correlation of CASP8 mRNA and protein expression levels in paired cancerous and paracancerous normal tissues from patients with different genotypes and clinical expression were also evaluated.

RESULTS

There was no association of the CASP8 genetic variants with CRC in our case-control study. The CASP8 gene mRNA expression levels in cancerous and paracancerous normal tissues were similar and there was no significant difference between subjects with different genotypes and clinical features. However, we found that CASP8 protein level was significantly lower in cancerous tissues than in paired paracancerous normal tissues.

CONCLUSIONS

Our results suggest that the three CASP8 genetic variants may not be associated with CRC risk in Han Chinese from southwest China. Aberrant CASP8 protein expression may play a role in the pathogenesis of CRC.

In addition to its proapoptotic function, caspase-8 is also important for several other processes, including suppressing necroptosis, cell migration, and immune cell survival. In the present study, we report that the loss of caspase-8 in B lymphocytes leads to B-cell malignancies and that the risk for these tumors is further enhanced in the absence of p53. We also report that deficiency of caspase-8 results in impaired cytokinesis and that casp8(-/-) lymphomas display remarkably elevated levels of chromosomal aberrations. Our data support an important role for caspase-8 in the maintenance of genomic integrity and highlight its tumor-suppressive function.

Deletion of the Casp8 gene in epithelial tissues of mice results in severe inflammatory pathologies. Its ubiquitous deletion, or its specific deletion in endothelial cells, results in intrauterine death associated with capillary damage. These pathologies are all preventable by co-deletion of Casp8 and the genes encoding either the RIPK1 or the RIPK3 protein kinase. Since activation of RIPK3 in Caspase-8-deficient cells can trigger necroptotic cell death, and since RIPK1 can activate RIPK3, it is widely assumed that the inflammatory states resulting from Caspase-8 deficiency occur as a consequence of RIPK3-induced necroptosis. Here, we report that although on a Ripk3-null background Casp8 deletion in mice does not result in outright pathological changes, it triggers enhanced expression of a variety of inflammatory genes in utero, which gradually subsides after birth. Deletion of Ripk1, or even of only one of its two alleles, obliterates this activation. Resembling the embryonic pathology observed in RIPK3-expressing cells, the activation of inflammatory genes observed on a Ripk3-null background seems to be initiated in endothelial cells. Analysis of endothelial cells isolated from livers of Caspase-8-deficient embryos revealed neither an increase in the amount of RIPK1 in these cells after Casp8 deletion, nor triggering of RIPK1 phosphorylation. These findings indicate that the triggering of inflammation by Casp8 deletion in mice occurs, in part, independently of necroptosis or other functions of RIPK3, and rather reflects enhanced RIPK1-dependent signaling for activation of inflammatory genes.

Disruptions of normal apoptotic pathways, which are mainly mediated by caspases, play an essential role in cancer development. Caspase-8 (CASP8) is encoded by the CASP8 gene and is centrally involved in the apoptosis of T lymphocytes. The association between a six-nucleotide deletion polymorphism (-652 6N del) of the CASP8 gene and the risk of cancer is widely reported; however, study results have been inconsistent and contradictory. To evaluate the association between the CASP8 -652 6N del polymorphism and the risk of cancer and to overcome the limitations of any individual study, a meta-analysis based on a total of 23 700 cases and 26 412 controls from 30 case-control studies was conducted. The results of the overall analysis suggested that the CASP8 -652 6N del polymorphism is associated with decreased risk of cancer for the allele contrast [del versus ins: odd ratio (OR) = 0.86, 95% confidence interval (CI) = 0.80-0.92], the additive genetic model (del/del versus ins/ins: OR = 0.78, 95% CI = 0.69-0.88), the dominant genetic model (del/del+del/ins versus ins/ins: OR = 0.83, 95% CI = 0.78-0.89) and the recessive genetic model (del/del versus ins/ins+del/ins: OR = 0.84, 95% CI = 0.75-0.93). In addition, after stratification for ethnicity and cancer type, significantly reduced risk was found for Asians and Caucasians as well as for individuals in the colorectal cancer group and the 'other cancers' group. Accordingly, there is an association between the CASP8 -652 6N del polymorphism and reduced cancer risk, especially among Asians, Caucasians and those with colorectal cancer. However, further research, such as studies focusing on additional ethnic groups and cancer types, is needed to provide a more exact and comprehensive synthesis conclusion.

This study was designed to identify candidate single-nucleotide polymorphisms (SNPs) that may affect the susceptibility to esophageal squamous cell carcinoma (ESCC) and elucidate their potential mechanisms to generate SNP-to-gene-to-pathway hypotheses. A genome-wide association study (GWAS) dataset for ESCC, which included 453,852 SNPs from 1898 ESCC patients and 2100 control subjects of Chinese population, was reviewed. The identify candidate causal SNPs and pathways (ICSNPathway) analysis identified seven candidate SNPs, five genes, and seven pathways, which together revealed seven hypothetical biological mechanisms. The three strongest hypothetical biological mechanisms were as follows: rs4135113→TDG→BASE EXCISION REPAIR; rs1800450→MBL2→MONOSACCHARIDE BINDING; and rs3769823→CASP8→d4gdiPathway. The GWAS dataset was evaluated using the ICSNPathway, which showed seven candidate SNPs, five genes, and seven pathways that may contribute to the susceptibility of patients to ESCC.

OBJECTIVE

Hepatic stellate cell apoptosis may play a key role in inhibition of fibrotic hepatic injury. To understand the gene expression profiles of human hepatic stellate cell apoptosis, the global transcript levels in curcumin-induced apoptotic human telomerase reverse transcriptase hepatic stellate cells were analyzed with microarrays.

METHODS

19K human oligonucleotide microarrays were performed to obtain the gene expression profiles associated with apoptosis in human hepatic stellate cells. The microarray data were verified by real time quantitative PCR and expression of the components of apoptosis and Wnt signaling was analyzed by Western blot.

RESULTS

The apoptosis pathway components, BAX (BCL2-associated X protein) and FLIP (CASP8 and FADD-like apoptosis regulator), had increased or decreased expression in the microarray data, the findings of which the protein levels were consistent. The Wnt signaling pathway components, AXIN2 and FRA1 (FOS-like antigen 1), showed a decreasing expression in the time course microarrays at the protein level.

CONCLUSIONS

Our data show various gene expression profiles during apoptosis of human telomerase reverse transcriptase hepatic stellate cells, especially those involved in the apoptosis and Wnt signaling pathways, and demonstrate that the activation of the Wnt signaling pathway is inhibited in curcumin-induced apoptotic human telomerase reverse transcriptase hepatic stellate cells.

Oral tongue squamous cell carcinomas (OTSCC) are a homogeneous group of tumors characterized by aggressive behavior, early spread to lymph nodes and a higher rate of regional failure. Additionally, the incidence of OTSCC among younger population (<50yrs) is on the rise; many of whom lack the typical associated risk factors of alcohol and/or tobacco exposure. We present data on single nucleotide variations (SNVs), indels, regions with loss of heterozygosity (LOH), and copy number variations (CNVs) from fifty-paired oral tongue primary tumors and link the significant somatic variants with clinical parameters, epidemiological factors including human papilloma virus (HPV) infection and tumor recurrence. Apart from the frequent somatic variants harbored in TP53, CASP8, RASA1, NOTCH and CDKN2A genes, significant amplifications and/or deletions were detected in chromosomes 6-9, and 11 in the tumors. Variants in CASP8 and CDKN2A were mutually exclusive. CDKN2A, PIK3CA, RASA1 and DMD variants were exclusively linked to smoking, chewing, HPV infection and tumor stage. We also performed a whole-genome gene expression study that identified matrix metalloproteases to be highly expressed in tumors and linked pathways involving arachidonic acid and NF-k-B to habits and distant metastasis, respectively. Functional knockdown studies in cell lines demonstrated the role of CASP8 in a HPV-negative OTSCC cell line. Finally, we identified a 38-gene minimal signature that predicts tumor recurrence using an ensemble machine-learning method. Taken together, this study links molecular signatures to various clinical and epidemiological factors in a homogeneous tumor population with a relatively high HPV prevalence.

Caspase 8 (CASP8) is a regulator of apoptosis, whose genetic variation has been reported to be associated with the risk of various cancers. Especially, the single-nucleotide polymorphism (SNP) rs1045485, which generates the substitution D302H in CASP8, is likely to be associated with breast cancer. Several previous studies have reported the association of CASP8 D302H polymorphism with breast cancer; however, the results are inconsistent. To validate the association between CASP8 D302H polymorphism and breast cancer risk, we performed an updated meta-analysis of 18 studies including 27,807 cases and 32,332 controls. We tested the overall association between this SNP and breast cancer susceptibility and stratified subgroups based on countries where cases are from. We confirmed a significant correlation between CASP8 D302H polymorphism and the reduced breast cancer susceptibility in population from UK, Germany and Poland, but no significant association was observed in other countries, such as Finland or USA. Our findings indicate the relationship of SNP CASP8 D302H and breast cancer would not be universal but only be sensitive in some particular European countries. The genetic difference for diverse countries may be useful in individual and precision medicine or health.