Coding polymorphisms in Casp5, Casp8 and DR4 genes may play a role in predisposition to lung cancer

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

Identification of a pyroptosis-based model for predicting clinical outcomes from immunotherapy in patients with metastatic melanoma

Immunotherapy has greatly improved outcomes for patients with advanced melanoma, but good predictive biomarkers remain lacking in clinical practice. Although increasing evidence has revealed a vital role of pyroptosis in the tumor microenvironment (TME), it remains unclear for pyroptosis as a predictive biomarker for immunotherapy in melanoma. RNA sequencing data and annotated clinical information of melanoma patients were obtained from four published immunotherapy datasets. LASSO regression analysis was conducted to develop a pyroptosis-based model for quantifying a pyroptosis score in each tumor. Based on four clinical cohorts, we evaluated the predictive capability of the model using multiple immunotherapeutic outcomes, including clinical benefits, overall survival (OS), and progression-free survival (PFS). Furthermore, we depicted the distinctive TME features associated with pyroptosis. Compared with the group with low pyroptosis scores, the group with high pyroptosis scores consistently achieved better durable clinical benefits in four independent cohorts and the meta-cohort. ROC analysis validated that the pyroptosis-based model was a reliable biomarker for predicting clinical benefits from immunotherapy in melanoma. Survival analyses showed that the group with high pyroptosis scores harbored more favorable OS and PFS than those with low pyroptosis scores. Molecular analysis revealed that tumors with high pyroptosis scores displayed a typical immune-inflamed phenotype in TME, including enrichment of immunostimulatory pathways, increased level of tumor-infiltrating lymphocytes, upregulation of immune effectors, and activation of the antitumor immune response. Our findings suggested that the pyroptosis-related model associated with multiple immune-inflamed characteristics might be a reliable tool for predicting clinical benefit and survival outcomes from immunotherapy in melanoma.

Relationship Between CASP9 and CASP10 Gene Polymorphisms and Cancer Susceptibility: Evidence from an Updated Meta-analysis

Caspase-9 (CASP9) and caspase-10 (CASP10) polymorphisms were associated with human cancers; however, the results remain controversial. In this meta-analysis, we aimed to estimate the relationship among CASP9 (rs1052576, rs1052571, rs4645978, rs4645981, rs4645982, rs2308950) and CASP10 (rs13006529, rs13010627, rs3900115) polymorphisms and the overall risk of cancers. Relevant studies were obtained from Web of Science, MEDLINE, PubMed, Scopus, and Google scholar databases (updated January 1, 2021). Odds ratio (OR) and 95% confidence intervals (CIs) were measured to estimate the strength of association. Our meta-analysis included 40 studies. The rs4645981 significantly enhanced the risk of cancer under TT vs. CC (OR = 2.42), TC vs. CC (OR = 1.55), TT+ TC vs. CC (OR = 1.66), TT vs. TC + CC (OR = 1.91), and T vs. C (OR = 1.57) inheritance models. As for the rs1052571 variant, increased risk of cancer was observed under TT vs. CC (OR =1.22), TC vs. CC (OR = 1.17), and TT+ TC vs. CC (OR = 1.18) models. The stratified analysis showed a significant correlation between rs4645978 or rs4645981 polymorphisms and cancer risk, while in Asians rs4645978 conferred an increased risk of colorectal, lung, and prostate cancer. Both rs4645981 and rs1052576 polymorphisms were correlated with an enhanced risk of lung cancer. In conclusion, our meta-analysis suggested that CASP9 rs4645981 and rs1052571 polymorphisms are associated with overall cancer risk. More studies on larger populations are warranted to validate these associations.

Polymorphisms in the Gene Encoding Caspase 8 May Predict the Response to First-Line Platinum-Based Chemotherapy in Locally Advanced or Advanced Non-Small-Cell Lung Cancer

Caspase 8 is a protein involved in the process of cell apoptosis, which may affect the efficacy of anti-cancer treatment. The aim of our study was to determine the impact of polymorphisms in the CASP-8 gene encoding caspase 8 on the prognosis in non-small-cell lung cancer (NSCLC). The study involved 99 patients with newly diagnosed locally advanced or metastatic NSCLC treated with platinum-based chemotherapy. The presence of the GG genotype was associated with distant metastases, smoking, and a family history of cancer. The higher risk of early progression was associated with weight loss and the CASP-8 genotype (GG vs. AG or AA: 20.51% vs. 2.86%). The higher risk of progression-free survival (PFS) shortening was associated with a higher stage of disease (hazard ratio (HR) = 2.50, 95% CI: 1.61–3.89, p < 0.0001), distant metastases (HR = 2.30, 95% CI: 1.42–3.72, p = 0.0016), and the GG genotype (HR = 1.68, 95% CI: 1.10–2.57, p = 0.0152). The influence of the GG genotype on the PFS was confirmed in a multivariate analysis (HR = 1.80, 95% CI: 1.06–3.05, p = 0.0317). We did not confirm the influence of CASP-8 genotypes on the overall survival (OS).

Computational Functional Genomics-Based AmpliSeq™ Panel for Next-Generation Sequencing of Key Genes of Pain

The genetic background of pain is becoming increasingly well understood, which opens up possibilities for predicting the individual risk of persistent pain and the use of tailored therapies adapted to the variant pattern of the patient's pain-relevant genes. The individual variant pattern of pain-relevant genes is accessible via next-generation sequencing, although the analysis of all "pain genes" would be expensive. Here, we report on the development of a cost-effective next generation sequencing-based pain-genotyping assay comprising the development of a customized AmpliSeq™ panel and bioinformatics approaches that condensate the genetic information of pain by identifying the most representative genes. The panel includes 29 key genes that have been shown to cover 70% of the biological functions exerted by a list of 540 so-called "pain genes" derived from transgenic mice experiments. These were supplemented by 43 additional genes that had been independently proposed as relevant for persistent pain. The functional genomics covered by the resulting 72 genes is particularly represented by mitogen-activated protein kinase of extracellular signal-regulated kinase and cytokine production and secretion. The present genotyping assay was established in 61 subjects of Caucasian ethnicity and investigates the functional role of the selected genes in the context of the known genetic architecture of pain without seeking functional associations for pain. The assay identified a total of 691 genetic variants, of which many have reports for a clinical relevance for pain or in another context. The assay is applicable for small to large-scale experimental setups at contemporary genotyping costs.

Association of CASP8 polymorphisms and cancer susceptibility: A meta-analysis

Caspase-8 plays is an essential enzyme in apoptosis pathway. Several investigation have been done to identify the relation between CASP8 polymorphisms and different human cancers, but, the findings are still debated. The aim of the current investigation is to assess if CASP8 rs3834129 (-652 6N insertion/deletion), rs1045485 G > C, rs3769818 G > A, rs6723097 A > C, rs3769821 T > C, rs13113 T > A, rs3769825 G > A, rs2293554 A > C, and rs10931936 C > T polymorphisms are linked to susceptibility of cancer. Our team has extracted the eligible studies up to July 4, 2019, from different sources. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were estimated to quantitatively evaluate the association between CASP8 polymorphisms and cancer susceptibility. Our results showed that the rs3834129 and rs1045485 polymorphisms meaningfully reduced the risk of cancer, while the rs3769818, rs3769821 and rs3769825 polymorphisms considerably increased cancer susceptibility. No association of rs6723097, rs13113, rs2293554 and rs10931936 polymorphisms was observed with cancer susceptibility. The CASP8 rs3834129 polymorphism reduced the risk of gastrointestinal, digestive tract, colorectal, breast and lung cancers. Furthermore, the cancer risk was decreased in Asian and Caucasian populations as well as population- and hospital-based studies due to this polymorphism. There was not any relation between this gene polymorphism and the risk of prostate and cervical cancer development. Regarding the CASP8 rs1045485 polymorphism, the reduced breast cancer risk along with the risk of cancer in Caucasians, population- and hospital-based studies were observed.

Distribution of Coding Apoptotic Gene Polymorphisms in Women with Extreme Phenotypes of Breast Cancer Predisposition and Tolerance

Aims and background

Comparison of subjects with extreme phenotypes of cancer susceptibility and tolerance allows to detect low-penetrance gene-disease interactions with a relatively small study size.

Methods and study design

We analyzed the distribution of 19 coding apoptotic gene polymorphisms (Bid Gly10Ser; Casp2 Leu141Val; Casp5 Ala90Thr and Val318Leu; Casp7 Glu255Asp; Casp8 His302Asp; Casp9 Val28Ala, His173Arg and Arg221Gln; Casp10 Ile479Leu; Faim Thr117Ala and Ser127Leu; DR4 Arg141His, Thr209Arg, Ala228Glu and Lys441Arg; Survivin Lys129Glu; TNFR1 Gln121Arg; XIAP Pro423Gln) in 121 breast cancer patients with clinical features of a hereditary predisposition (family history and/or early onset and/or bilaterality) and 142 elderly tumor-free women.

Results

None of the individual single nucleotide polymorphisms (SNPs) demonstrated an association with breast cancer risk. The analysis of gene interactions revealed that the combination of XIAP Pro423Gln (rs5956583) AA genotype with Casp7 Glu255Asp (rs2227310) CG genotype appeared to prevail in “supercases” relative to “supercontrols” (25/121 [21%] vs 11/142 [8%], P = 0.002). We attempted to validate this association in the second round of case-control analysis, which involved 519 randomly selected breast cancer patients and 509 age-matched healthy women, but no difference was detected upon this comparison.

Conclusions

Coding apoptotic gene polymorphisms do not play a major role in BC predisposition. The results of this investigation may be considered while designing future studies on breast cancer-associated candidate SNPs.

Genetic association between TRAIL-R1 Thr209Arg and cancer susceptibility

We aimed to determine the indecisive association between tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) Thr209Arg polymorphism and inherited susceptibility to cancer. A meta-analysis combining data on 9,517 individuals was performed to assess the association between TRAIL-R1 Thr209Arg and cancer incidence. The summary ORs with 95% CI calculated with the fixed effects model suggested that Thr209Arg was not significantly associated with cancer susceptibility (homozygous model: OR 0.98, 95% CI 0.88–1.09; heterozygous model: OR 0.95, 95% CI 0.87–1.04; allele frequency model: OR 0.99, 95% CI 0.94–1.05; dominant model: OR 0.98, 95% CI 0.91–1.05; recessive model: OR 1.01, 95% CI 0.92–1.10). Stratified analysis by ethnicity and cancer type yielded similar null associations. These statistical data suggest that Thr209Arg in exon 4 of the TRAIL-R1 gene may not represent a modifier of susceptibility to cancer.

Genetic variants in the tumor necrosis factor-related apoptosis-inducing ligand and death receptor genes contribute to susceptibility to bladder cancer

AIM

The aim of this study was to evaluate the role of polymorphisms of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and death receptor (DR4) genes in bladder cancer susceptibility in a Turkish population.

MATERIALS AND METHODS

The study group included 91 bladder cancer patients, while the control group comprised 139 individuals with no evidence of malignancy. Gene polymorphisms of TRAIL C1595T (rs1131580) and DR4 C626G (rs4871857) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

The frequency of the TRAIL 1595 TT genotype was significantly lower in patients with bladder cancer compared to controls (p<0.001; odds ratios [OR]=0.143; 95% confidence interval [CI]=0.045-0.454). A significantly increased risk for developing bladder cancer was found for the group bearing a C allele for TRAIL C1595T polymorphism (p<0.001; OR=1.256; 95% CI=1.138-1.386). The observed genotype and allele frequencies of DR4 626 C/G in all groups were in agreement with the Hardy-Weinberg equilibrium (p=0.540). However, the frequency of DR4 GG genotype was found to be 2.1-fold increased in the bladder cancer patients with high-grade tumor, when compared to those having low-grade tumor (p=0.036). Additionally, combined genotype analysis showed that the frequency of TRAILCT-DR4GG was significantly higher in patients with bladder cancer in comparison with those of controls (p=0.037; OR=2.240; 95% CI=1.138-1.386).

CONCLUSIONS

Our study provides new evidence that TRAIL 1595 C allele may be used as a low-penetrant risk factor for bladder cancer development in a Turkish population. Otherwise, gene-gene interaction analysis revealed that the DR4GG genotype may have a predominant effect on the increased risk of bladder cancer over the TRAIL CT genotype.

Death receptor (DR4) haplotypes are associated with increased susceptibility of gallbladder carcinoma in north Indian population

Background and Aim

Defective apoptosis is a hallmark of cancer development and progression. Death receptors (DR4, FAS) and their ligands (TRAIL, FASL) are thought to mediate the major extrinsic apoptotic pathway in the cell. SNPs in these genes may lead to defective apoptosis. Hence, the present study aimed to investigate the association of functional SNPs of DR4 (rs20575, rs20576 and rs6557634), FAS (rs2234767) and FASL (rs763110) with gallbladder cancer (GBC) risk.

Methods

This case-control study included 400 GBC and 246 healthy controls (HC). Genotyping was carried out by Taqman genotyping assays. Statistical analysis was performed by using SPSS ver16. Meta-analysis was performed using Comprehensive Meta-analysis software (Version 2.0, BIOSTAT, Englewood, NJ) to systematically summarize the possible association of SNP with cancer risk. Functional prediction of these variants was carried out using Bioinformatics tools (FAST-SNP, F-SNP). False discovery rate (FDR test) was used in multiple comparisons.

Results

The DR4 C_rs20575A_rs20576A_rs6557634, G_rs20575A_rs20576G_rs6557634 and G_rs20575C_rs20576G_rs6557634 haplotypes conferred two-fold increased risk for GBC. Among these, the DR4 C_rs20575A_rs20576A_rs6557634 haplotype emerged as main factor influencing GBC susceptibility as the risk was not modulated by gender or gallstone stratification. Our meta-analysis results showed significant association of DR4 rs6557634 with overall cancer risk, GI cancers as well as in Caucasians. We didn't find any association of FAS and FASL SNPs with GBC susceptibility.

Conclusions

The DR4 haplotype C_rs20575A_rs20576A_rs6557634 represents an important factor accounting the patients susceptibility to GBC probably due to decreased apoptosis. However, additional well-designed studies with larger sample size focusing on different ethnicities are required to further validate the results.

Association of CASP9, CASP10 gene polymorphisms and tea drinking with colorectal cancer risk in the Han Chinese population

The initiators caspase-9 (CASP9) and caspase-10 (CASP10) are two key controllers of apoptosis and play important roles in carcinogenesis. This study aims to explore the association between CASPs gene polymorphisms and colorectal cancer (CRC) susceptibility in a population-based study. A two-stage designed population-based case-control study was carried out, including a testing set with 300 cases and 296 controls and a validation set with 206 cases and 845 controls. A total of eight tag selected single nucleotide polymorphisms (SNPs) in CASP9 and CASP10 were chosen based on HapMap and the National Center of Biotechnology Information (NCBI) datasets and genotyped by restriction fragment length polymorphism (RFLP) assay. Multivariate logistic regression models were applied to evaluate the association of SNPs with CRC risk. In the first stage, from eight tag SNPs, three polymorphisms rs4646077 (odds ratio (OR)(AA+AG): 0.654, 95% confidence interval (CI): 0.406-1.055; P=0.082), rs4233532 (OR(CC): 1.667, 95% CI: 0.967-2.876; OR(CT): 1.435, 95% CI: 0.998-2.063; P=0.077), and rs2881930 (OR(CC): 0.263, 95% CI: 0.095-0.728, P=0.036) showed possible association with CRC risk. However, none of the three SNPs, rs4646077 (OR(AA+AG): 1.233, 95% CI: 0.903-1.683), rs4233532 (OR(CC): 0.892, 95% CI: 0.640-1.243; OR(CT): 1.134, 95% CI: 0.897-1.433), and rs2881930 (OR(CC): 1.096, 95% CI: 0.620-1.938; OR(CT): 1.009, 95% CI: 0.801-1.271), remained significant with CRC risk in the validation set, even after stratification for different tumor locations (colon or rectum). In addition, never tea drinking was associated with a significantly increased risk of CRC in testing set together with validation set (OR: 1.755, 95% CI: 1.319-2.334). Our results found that polymorphisms of CASP9 and CASP10 genes may not contribute to CRC risk in Chinese population and thereby the large-scale case-control studies might be in consideration. In addition, tea drinking was a protective factor for CRC.

Influence of survivin (BIRC5) and caspase-9 (CASP9) functional polymorphisms in renal cell carcinoma development: a study in a southern European population

Renal cell carcinoma (RCC) is the most common cancer of the adult kidney and its incidence and mortality has increase in the last 20 years. The disruption of cellular death is one the mechanism involved in cancer development. This process is precise regulated by apoptotic and anti-apoptotic molecules. Survivin (BIRC5) is a member of the inhibitor of apoptosis protein family and has the ability to inhibit the activation of the pro-apoptotic caspase-9 (CASP9). Thus BIRC5 and CASP9 functional polymorphisms might modulate the apoptosis and consequently RCC development. Our purpose was to investigate the potential role of BIRC5-31G/C and CASP9+83C/T functional polymorphisms in the risk for the development of RCC and metastatic disease. We studied the BIRC5-31G/C and CASP9+83C/T functional polymorphisms by PCR-RFLP and allelic discrimination using the 7300 real-time polymerase chain reaction system, respectively, in 178 RCC patients and in 305 healthy individuals. Regarding the BIRC5-31G/C polymorphism, there is a trend to an overrepresentation of CC genotype in RCC group compared with normal controls (aOR, 1.94; P=0.053). We observed, after gender stratification and age-adjustment, that BIRC5-31CC and CASP9+83CT/TT genotypes were associated with an increased risk for RCC development in the female group of our southern European study population (aOR=3.85; P=0.019; aOR=2.98; P=0.028; respectively). Concerning the waiting time for onset of metastatic disease, we observed that BIRC5-31CC homozygous developed metastasis 8 years earlier than the G carriers using a Cox proportional hazard model with gender as covariate (HR=4.9, P=0.038, P bootstrap=0.009). The Cox regression proportional hazard model was validated using bootstrap statistic with 1,000 samples of the same number of patients as the original dataset. Our results suggest that individual differences influence the susceptibility to RCC and tumor behavior. This genetic profile may help to define higher risk groups that would benefit from individualized chemoprevention strategies and therapies.

CASP-1, -2 and -5 gene polymorphisms and cancer risk: A review and meta-analysis

Accumulating evidence suggests the CASP gene family is important in the development of carcinogenesis. These genetic polymorphisms have been extensively investigated as a potential risk factor for cancer, but results have been inconclusive. This Human Genome Epidemiology (HuGE) review and meta-analysis was performed to investigate the associations between CASP-1, -2 and -5 and cancer risk. A literature search of Pubmed, Embase, Web of Science and CBM databases was conducted from inception through September 1st, 2012. Four case-control studies with a total of 1,592 cancer cases and 1,833 healthy controls were included in the present meta-analysis. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. Five polymorphisms were examined, including rs501192 (G>A), rs4647297 (C>G), rs507879 (T>C), rs3181320 (G>C) and rs523104 (G>C). Meta-analysis results showed that the rs3181320*C allele/carrier were associated with increased risk of various types of cancers (OR=1.26; 95% CI, 1.04-1.54; P=0.020 and OR=1.33; 95% CI, 1.00-1.75; P=0.047, respectively). However, similar associations were not found in the rs501192, rs4647297, rs507879 and rs523104 polymorphisms (all P>0.05). Results from the current meta-analysis suggest that the rs3181320*C allele/carrier in CASP-5 gene are potential risk factors for cancer.

Role of the CASP-9 Ex5+32 G>A polymorphism in susceptibility to cancer: A meta-analysis

Failure of apoptosis is one of the hallmarks of cancer. As an execution-phase caspase, caspase-9 plays a crucial role during apoptosis. To examine whether the Ex5+32 G>A (rs1052576) polymorphism in the CASP-9 gene alters cancer risk, we conducted a comprehensive meta-analysis of 7 case-control studies consisting of a total of 1668 cancer cases and 2294 healthy controls. All studies considered, A allele and A allele carriers of Ex5+32 G>A in the CASP-9 gene had significant associations with cancer risk (OR=0.72, 95% CI, 0.58–0.89, P= 0.003; OR= 0.76, 95% CI, 0.63–0.92, P= 0.004; respectively). In the subgroup analysis, we found that the A allele of Ex5+32 G>A was a protective factor for cancer risk in Chinese and American populations (OR=0.60, 95% CI, 0.44–0.81, P<0.001; OR= 0.80, 95% CI, 0.69–0.94, P= 0.005; respectively). Similarly, we also found positive associations between A allele carriers of Ex5+32 G>A and cancer risk in Chinese and American populations (OR=0.63, 95% CI, 0.44–0.90, P= 0.01; OR= 0.78, 95% CI, 0.62–0.98, P=0.03; respectively). In addition, we identified that A allele and A allele carriers of Ex5+32 G>A may decrease the risk of cancer in the Asian population (OR=0.60, 95% CI, 0.44–0.81, P<0.001; OR= 0.63, 95% CI, 0.44–0.90, P= 0.01; respectively). In conclusion, this meta-analysis demonstrated that A allele and A allele carriers of the Ex5+32 G>A polymorphism in the CASP-9 gene may be protective factors for cancer risk.

Systematic evaluation of apoptotic pathway gene polymorphisms and lung cancer risk

We adopted a two-stage study design to screen 927 single nucleotide polymorphisms (SNPs) located in 73 apoptotic-pathway genes in a case-control study and then performed a fast-track validation of the significant SNPs in a replication population to identify sequence variations in the apoptotic pathway modulating lung cancer risk. Fifty-five SNPs showed significant associations in the discovery population comprised of 661 lung cancer cases and 959 controls. Six of these SNPs located in three genes (Bcl-2, CASP9 and ANKS1B) were validated in a replication population with 1154 cases and 1373 controls. Additive model was the best-fitting model for five SNPs (rs1462129 and rs255102 of Bcl-2, rs6685648 of CASP9 and rs1549102, rs11110099 of ANKS1B) and recessive model was the best fit for one SNP (rs10745877 of ANKS1B). In the analysis of joint effects with subjects carrying no unfavorable genotypes as the reference group, those carrying one, two, and three or more unfavorable genotypes had an odds ratio (OR) of 2.22 [95% confidence interval (CI) = 1.08-4.57, P = 0.03], 2.70 (95% CI = 1.33-5.49; P = 0.006) and 4.13 (95% CI = 2.00-8.57; P = 0.0001), respectively (P for trend = 6.05E-06). The joint effect of unfavorable genotypes was also validated in the replication population. The SNPs identified are located in or near key genes known to play important roles in apoptosis regulation, supporting the strong biological relevance of our findings. Future studies are needed to identify the causal SNPs and elucidate the underlying molecular mechanisms.

TRAIL receptor I (DR4) polymorphisms C626G and A683C are associated with an increased risk for hepatocellular carcinoma (HCC) in HCV-infected patients

Background

Tumour surveillance via induction of TRAIL-mediated apoptosis is a key mechanism, how the immune system prevents malignancy. To determine if gene variants in the TRAIL receptor I (DR4) gene affect the risk of hepatitis C virus (HCV)-induced liver cancer (HCC), we analysed DR4 mutations C626G (rs20575) and A683C (rs20576) in HCV-infected patients with and without HCC.

Methods

Frequencies of DR4 gene polymorphisms were determined by LightSNiP assays in 159 and 234 HCV-infected patients with HCC and without HCC, respectively. 359 healthy controls served as reference population.

Results

Distribution of C626G and A683C genotypes were not significantly different between healthy controls and HCV-positive patients without HCC. DR4 variants 626C and 683A occurred at increased frequencies in patients with HCC. The risk of HCC was linked to carriage of the 626C allele and the homozygous 683AA genotype, and the simultaneous presence of the two risk variants was confirmed as independent HCC risk factor by Cox regression analysis (Odds ratio 1.975, 95% CI 1.205-3.236; p = 0.007). Furthermore HCV viral loads were significantly increased in patients who simultaneously carried both genetic risk factors (2.69 ± 0.36 × 10⁶ IU/ml vs. 1.81 ± 0.23 × 10⁶ IU/ml, p = 0.049).

Conclusions

The increased prevalence of patients with a 626C allele and the homozygous 683AA genotype in HCV-infected patients with HCC suggests that these genetic variants are a risk factor for HCC in chronic hepatitis C.

Association of death receptor 4, Caspase 3 and 5 gene polymorphism with increased risk to bladder cancer in North Indians

PURPOSE

Perturbed apoptosis due to missense alterations in candidate tumor suppressor gene Death receptor 4 (DR4) and in caspases (Casp) lead to deregulated cell proliferation and cancer predisposition. Some data indicate that normal variations within the sequence of apoptotic genes may lead to suboptimal apoptotic capacity and therefore increased cancer risk. To test our proposal we examined whether six single nucleotide polymorphisms (SNPs) of the DR4 and Casp3, 5 genes contrive the risk of bladder cancer (BC) in a North Indian population.

MATERIALS AND METHODS

Genotyping was performed in 200 BC patients and 225 controls by Allele-specific PCR and by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In DR4 Arg141His, BC patients having AA genotype (p = 0.036; OR = 2.51. In Casp5Leu13Phe G > C, significant association was observed with GC (p = 0.025; OR = 1.78) and also in GC + CC (p = 0.026; OR = 1.68). C allele carriers in Casp5Ala90Thr T > C showed low risk of BC (p = 0.036; OR = 0.83). While in Casp3 G > A, AG (p = 0.003; OR = 2.11), GG (p = 0.050; OR = 2.18), G allele (p < 0.001; OR = 1.85) and its carrier AG + GG (p = 0.001; OR = 2.12) have shown significant BC risk. Significant association between DR4 Ala228Glu polymorphism and smoking was observed in BC risk. Haplotype analysis demonstrated that DR4 (Thr209Arg-Arg141His-Ala228Glu) C-G-C is associated with 1.8 folds (OR = 1.85; p = 0.033) risk. GG genotype of Casp3 G > A polymorphism showed increased risk of recurrence (p = 0.009; HR = 5.20).

CONCLUSION

This study provided new support for the association of DR4 and Casp3, 5 in BC development, the tumorigenic effect of which was observed to be more enhanced in case of smoking exposure.

Association of caspases with an increased prostate cancer risk in north Indian population

Dysregulation of apoptosis plays a crucial role in carcinogenesis. Thus, genetic alterations within caspase genes would be expected to provoke a deficient apoptotic signaling thereby facilitating the development of prostate cancer (PCa). In the present study we investigated whether three different polymorphisms in the caspase-5 and -3 genes are differentially expressed in PCa. In a hospital-based case control study in northern India, we genotyped 192 PCa patients and 225 unrelated healthy controls for caspase-5 (G>C) (T>C) and caspase-3 (G>A) polymorphisms using amplification refractory mutation system and polymerase chain restriction fragment length polymorphism methods. Data were statistically analyzed and variant genotype GG of caspase-3 demonstrated increased risk for PCa (odds ratio [OR]=2.72, p=0.005). Similarly variant allele carrier (AG+GG) (OR=1.53, p=0.034) and G allele (OR=1.54, p=0.005) were also statistically associated with PCa risk. High risk for PCa was also observed with respect to caspase-5 (CC) diplotypes (OR=21.67, p=0.012, Pc=0.048). We observed significantly enhanced risk for PCa due to interaction between caspase-3 and -5 gene polymorphisms. In association of genotypes with clinical characteristics, heterozygous TC genotype of caspase-5 (T>C) conferred risk with high Gleason grade tumor (OR=2.35, p=0.042). In case-only analysis, interaction of environmental risk factors and genotypes did not further modulate the risk for PCa. Our observations suggested positive association of caspase-3 and diplotype analysis of caspase-5 to be associated with PCa risk. Interaction of caspase-3 and -5 genotypes also modulated the PCa risk.

CASP8 polymorphisms contribute to cancer susceptibility: evidence from a meta-analysis of 23 publications with 55 individual studies

Several potentially functional polymorphisms of CASP8 encoding an apoptotic enzyme, caspase 8, have been implicated in cancer risk, but individually published studies showed inconclusive results. We performed a meta-analysis of 23 publications with a total of 55 174 cancer cases and 59 336 controls from 55 individual studies. We summarized the data on the associations between three studied CASP8 polymorphisms (G>C D302H, -652 6N del and Ex14-271A>T) and cancer risk and performed subgroup analysis by ethnicity, cancer type, study design and etiology. We found that D302H CC and CG variant genotypes were associated with significantly reduced overall risk of cancers using conservative random genetic models [homozygote comparison: odds ratios (OR) = 0.79; 95% confidence interval (CI): 0.69-0.92; dominant comparison: OR = 0.93, 95% CI: 0.89-0.98; recessive comparison: OR = 0.81, 95% CI: 0.71-0.93). In further stratified analyses, the reduced cancer risk remained for subgroups of Caucasians, breast or estrogen-related cancers, and hospital- or population-based studies, except for an elevated risk for brain tumors. Similarly, the -652 6N del polymorphism was also associated with significantly reduced overall risk of cancers (homozygote comparison: OR = 0.84, 95% CI: 0.75-0.94; dominant comparison: OR = 0.88, 95% CI: 0.81-0.96; recessive comparison: OR = 0.90, 95% CI: 0.82-0.99) and all subgroups analyzed. However, the Ex14-271A>T polymorphism did not appear to have an effect on cancer risk. These results suggest that CASP8 D302H and -652 6N del polymorphisms are potential biomarkers for cancer risk.