CASP8 variants D302H and -652 6N ins/del do not influence the risk of colorectal cancer in the United Kingdom population

The Search for Cancer Biomarkers: Assessing the Distribution of INDEL Markers in Different Genetic Ancestries

Cancer is a multifactorial group of diseases, being highly incident and one of the leading causes of death worldwide. In Brazil, there is a great variation in cancer incidence and impact among the different geographic regions, partly due to the genetic heterogeneity of the population in this country, composed mainly by European (EUR), Native American (NAM), African (AFR), and Asian (ASN) ancestries. Among different populations, genetic markers commonly present diverse allelic frequencies, but in admixed populations, such as the Brazilian population, data is still limited, which is an issue that might influence cancer incidence. Therefore, we analyzed the allelic and genotypic distribution of 12 INDEL polymorphisms of interest in populations from the five Brazilian geographic regions and in populations representing EUR, NAM, AFR, and ASN, as well as tissue expression in silico. Genotypes were obtained by multiplex PCR and the statistical analyses were done using R, while data of tissue expression for each marker was extracted from GTEx portal. We highlight that all analyzed markers presented statistical differences in at least one of the population comparisons, and that we found 39 tissues to be differentially expressed depending on the genotype. Here, we point out the differences in genotype distribution and gene expression of potential biomarkers for risk of cancer development and we reinforce the importance of this type of study in populations with different genetic backgrounds.

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.

Genomic profiling of microRNA target genes in colorectal cancer

Colorectal cancer is the second and third most common cancer in men and women, respectively, worldwide. Alterations such as genetic and epigenetic are common in colorectal cancer and are the basis of tumor formation. The exploration of the molecular basis of colorectal cancer can drive a better understanding of the disease as well as guide the prognosis, therapeutics, and disease management. This study is aimed at investigating the genetic mutation profile of five candidate microRNAs (hsa-miR-513b-3p, hsa-miR-500b-3p, hsa-miR-500a-3p, hsa-miR-450b-3p, hsa-miR-193a-5p) targeted by seven genes (APC, KRAS, TCF7L2, EGFR, IGF1R, CASP8, and GNAS)) using in silico approaches. Two datasets (dataset 1 from our previous study and dataset two (The Cancer Genome Atlas, Nature 2012) were considered for this study. Protein-protein interaction, expression analysis, and genetic profiling were carried out using STRING, FireBrowse, and cBioPortal, respectively. Protein-protein interaction network showed that epidermal growth factor receptor has the highest connection among the target genes and this can be considered as the hub gene. Relative to other solid tumors, in colorectal cancer, six of the target genes were downregulated and only CASP8 was upregulated. Genes with protein tyrosine kinases domain were frequently altered in colorectal cancer and the most common alteration in these genes/domain are missense mutation. These results could serve as a lead in the identification of driver genes responsible for colorectal cancer initiation and progression. However, the intense mechanism of these results remains unclear and further experimental validation and molecular approaches are the focal points in the nearest future.

Cumulative evidence of relationships between multiple variants in 8q24 region and cancer incidence

Genome-wide association studies (GWAS) have identified multiple independent cancer susceptibility loci at chromosome 8q24. We aimed to evaluate the associations between variants in the 8q24 region and cancer susceptibility. A comprehensive research synopsis and meta-analysis was performed to evaluate associations between 28 variants in 8q24 and risk of 7 cancers using data from 103 eligible articles totaling 146,932 cancer cases and 219,724 controls. Results: 20 variants were significantly associated with risk of prostate cancer, colorectal cancer, thyroid cancer, breast cancer, bladder cancer, stomach cancer, and glioma, including 1 variant associated with prostate cancer, colorectal cancer, and thyroid cancer. Cumulative epidemiological evidence of an association was graded as strong for DG8S737 -8 allele, rs10090154, rs7000448 in prostate cancer, rs10808556 in colorectal cancer, rs55705857 in gliomas, rs9642880 in bladder cancer, moderate for rs16901979, rs1447295, rs6983267, rs7017300, rs7837688, rs1016343, rs620861, rs10086908 associated in prostate cancer, rs10505477, rs6983267 in colorectal cancer, rs6983267 in thyroid cancer, rs13281615 in breast cancer, and rs1447295 in stomach cancer, weak for rs6983561, rs13254738, rs7008482, rs4242384 in prostate cancer. Data from ENCODE suggested that these variants with strong evidence and other correlated variants might fall within putative functional regions. Our study provides summary evidence that common variants in the 8q24 are associated with risk of multiple cancers in this large-scale research synopsis and meta-analysis. Further studies are needed to explore the mechanisms underlying variants in the 8q24 involved in various human cancers.

A meta-analysis of caspase-8 -652 6N del polymorphism and digestive tract cancer risk

Caspase-8 (CASP8) is one key regulator of apoptosis of T lymphocytes and is encoded by the CASP8 gene. It has been reported that the six-nucleotide deletion polymorphism (-652 6N del) of the CASP8 gene had effect on some cancer risk. Few studies explored the association between CASP8 gene polymorphism and digestive tract cancer risk. To evaluate the association between the CASP8 -652 6N del polymorphism and the risk of digestive tract cancer, we conducted this meta-analysis. We found that CASP8-652 6N del polymorphism was associated with a significantly reduced risk of digestive tract cancer in the co-dominant model (del/del vs. ins/ins: OR= 0.82, 95%CI= 0.72-0.95; del/ins vs. ins/ins: OR= 0.92, 95%CI= 0.87-0.97; dominant model (del/ins+ del/del vs. ins/ins: OR= 0.91, 95%CI= 0.87-0.96, recessive model: del/del vs. del/ins+ ins/ins: OR= 0.85, 95%CI= 0.75-0.97). In the stratified analysis by cancer types, we found that all genetic models had protective effect on gastric cancer. Similar results were observed for colorectal cancer under heterozygote comparison and dominant model, but not under homozygote comparison or recessive model. In addition, a significantly decreased risk was found on esophageal cancer for most genetic models, except heterozygote comparison. When stratified by ethnicity and source of control, an evidently decreased risk was identified in the Asian populations and population-based studies. In conclusion, there exists an association between the CASP8 -652 6N del polymorphism and reduced digestive cancer risk, especially among Asians and population-based studies.

CASP8 rs3834129 (-652 6N insertion/deletion) Polymorphism and Colorectal Cancer Susceptibility: An Updated Meta-Analysis

CASP8 rs3834129 polymorphism (-652 6N insertion/deletion) is a genetic alteration which might affect the apoptosis pathway caspase enzyme. The impaired caspase enzyme would lead to the change of cancer risk. By now, the role of CASP8 rs3834129 polymorphism has been widely investigated. However, the relationship of this genetic variant on colorectal cancer (CRC) susceptibility still remains inconsistent. Therefore, we further investigated the role of rs3834129 polymorphism on CRC risk. Eligible published studies were retrieved from EMBASE, PubMed, CNKI and WANFANG database updates to March 2018. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the relationship strengths. In general, we successfully retrieved 13 studies (8 publications) involving 13058 cases and 14418 controls. The meta-analysis results demonstrated that rs3834129 polymorphism was associated with a decreased CRC risk in heterozygous model (ID vs. II: OR = 0.94, 95% CI = 0.88-0.99), but not the homozygous and allele models. Furthermore, significantly decreased risk was also found among Asian (ID vs. II: OR = 0.86, 95% CI = 0.76-0.98), and high quality score group (ID vs. II: OR = 0.90, 95% CI = 0.81-1.00) in the stratified analyses. Taken together, we showed that CASP8 rs3834129 polymorphism influences CRC susceptibility in a weak impact manner. More case-control studies are warranted to validate such relationship.

Cumulative evidence for relationships between multiple variants in 8q24 and colorectal cancer incidence

Genome-wide association studies (GWAS) have identified multiple independent cancer susceptibility loci at chromosome 8q24.We conducted a comprehensive research synopsis and meta-analysis to evaluate associations between 6 variants in 8q24 and risk of colorectal cancer using data from 31 eligible articles totaling 41,942 cases and 49,968 controls.Of the 6 variants located in 8q24, 3 were significantly associated with risk of colorectal cancer. In particular, both homozygous TT and heterozygous CT genotypes of rs10505477, as well as the GG and TG genotypes of rs6983267, were associated with risk of colorectal cancer.Our study provides summary evidence that common variants in the 8q24 are associated with risk of colorectal cancer in this large-scale research synopsis and meta-analysis. Further studies are needed to explore the exact role of the variants in the 8q24 involved in the etiology of colorectal cancer.

A systematic analysis of the association studies between CASP8 D302H polymorphisms and breast cancer risk

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.

Caspase 8 polymorphisms contribute to the prognosis of advanced lung adenocarcinoma patients after platinum-based chemotherapy

Lung cancer is the leading cause of cancer deaths in China, and about 60% of the cases are diagnosed with histological adenocarcinoma. The caspase 8 (CASP8) gene is a critical initiator of the extrinsic apoptosis pathway. To explore the relationship between tagSNPs or haplotypes of CASP8 and the efficacy of platinum-based chemotherapy in advanced lung adenocarcinoma patients of China, we recruited 555 advanced adenocarcinoma patients. We extracted the genomic DNA from patients' peripheral blood samples and sequenced tagSNPs of CASP8. We calculated the individual haplotype of CASP8 frequencies using the PHASE 2.0 program. The association between CASP8 tagSNPs and overall survival (OS) was calculated by univariate and multivariate Cox regression analysis. A univariate logistic regression analysis was done to analyze the CASP8 tagSNPs and the toxicity of platinum-based chemotherapy. The same statistical methods were used for exploring haplotypes of CASP8. Rs3769821 and rs1045494 of CASP8 were independent prognosis factors for overall survival (OS) using multivariate Cox's regression models. For the haplotype of the 7 tagSNPs, haplotype AGGAAAGA was correlated with the efficacy of platinum-based chemotherapy. The polymorphisms of CASP8, rs7608692, and haplotype AGAACAG correlated with neutropenia toxicity. The haplotype GGGGAAA was associated with thrombocytopenia toxicity. We conclude that the polymorphisms of CASP8 contribute to the prognosis of advanced lung adenocarcinoma and influence the quality of life and survival.

Association between 8q24 rs6983267 polymorphism and cancer susceptibility: a meta-analysis involving 170,737 subjects

Published data on the association between 8q24 rs6983267 polymorphism and cancer risk are inconsistent. Thus, we conducted a meta-analysis to evaluate the relationship between rs6983267 polymorphism and cancer risk. We searched on PubMed, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI) up to November 1, 2016 for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of this association. We included 78 case-control studies with a total of 73,996 cases and 96,741 controls in this meta-analysis. The pooled results showed that rs6983267 polymorphism was significantly associated with increased risk of overall cancer in all genetic models (dominant model: OR = 1.19, 95% CI = 1.13–1.26; recessive model: OR = 1.19, 95% CI = 1.14–1.25; homozygous model: OR= 1.31, 95% CI = 1.23–1.40; heterozygous model: OR = 1.14, 95% CI = 1.10–1.19; allelic model: OR = 1.14, 95% CI = 1.11–1.18). Stratified analyses indicated that rs6983267 significantly increased the risk of colorectal cancer in Caucasians, prostate cancer in Caucasians and Asians, thyroid cancer in Caucasians and lung cancer in Asians. When studies were stratified by study quality, source of controls and genotyping method, significant associations were especially found in the high quality studies, the publication-based studies, the hospital-based studies, and the PCR-RFLP studies. Additional well-designed studies with large samples should be performed to validate our results.

CASP8 -652 6N insertion/deletion polymorphism and overall cancer risk: evidence from 49 studies

The CASP8 -652 6N insertion/deletion (I/D) polymorphism reduces expression of caspase 8. We conducted a meta-analysis to clarify the relationship between this polymorphism and cancer risk. Eligible articles were retrieved from PubMed, EMBASE, CNKI, and WANFANG databases through February 2017. A total of 33 articles with 49 studies, including 33,494 cases and 36,397 controls, were analyzed. We found that the CASP8 -652 6N ins/del polymorphism was associated with decreased overall cancer risk in five genetic models [DD vs. II: odds ratio (OR)=0.76, 95% confidence interval (CI)=0.69–0.84, ID vs. II: OR=0.87, 95% CI=0.83–0.92, DD vs. ID/II: OR=0.82, 95% CI=0.75–0.89, ID/DD vs. II: OR=0.85, 95% CI=0.80–0.90, and D vs. I: OR=0.87, 95% CI=0.83–0.91]. Stratified analyses showed that the polymorphism was associated with decreased risk of colorectal, breast, esophageal, renal cell, lung, cervical, bladder, gastric, and other cancers. Overall cancer risk was reduced in Asian and Caucasian patients, both hospital- and population-based studies, and both high and low quality studies. Our results highlight the role of the CASP8 -652 6N ins/del polymorphism in decreasing cancer risk. Further studies with large-cohort populations, especially for specific cancer types and ethnic groups, are needed to confirm our findings.

Prognostic relevance of caspase 8 -652 6N InsDel and Asp302His polymorphisms for breast cancer

Background

The minor allele of two caspase 8 polymorphisms, namely CASP8 -652 6N InsDel (rs3834129) and CASP8 Asp302His (rs1045485), were repeatedly associated with reduced breast cancer susceptibility. Contrarily, the presence of the -652 6N Del or the CASP8 302His variant was reported to be an unfavorable prognostic factor in colorectal cancer or neuroblastoma. However, prognostic relevance of these genetic variants for breast cancer is completely unknown and is therefore adressed by the current study.

Methods

Genotyping was performed by pyrosequencing. Caspase 8 mRNA expression was quantified by comparative RT-qPCR.

Results

We observed an allele-dose dependent association between CASP8 -652 6N InsDel and caspase 8 mRNA expression in breast cancer tissue, with homozygous deletion carriers showing lowest relative caspase 8 expression (p = 0.0131). Intriguingly, the presence of the -652 6N Del or the 302His variant was shown to be a negative prognostic factor for breast cancer in terms of an allele-dose dependent influence on overall survival (OS, p = 0.0018, p = 0.0150, respectively). Moreover, both polymorphisms were independent predictors of OS after adjusting for co-variats (p = 0.007, p = 0.037, respectively). Prognostic relevance of both polymorphisms were confirmed to be independent from each other and combined analysis of diplotypes revealed an additive influence upon OS (p = 0.0002).

Conclusion

This is the first report, showing negative and independent prognostic impact of the CASP8 -652 6N Del and the 302His variant for breast cancer. Our data provide rationale to further validate clinical utility of these polymorphisms for breast cancer and to extend this investigation to a broad scope of other malignancies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2662-x) contains supplementary material, which is available to authorized users.

Association of 8q23-24 region (8q23.3 loci and 8q24.21 loci) with susceptibility to colorectal cancer: a systematic and updated meta-analysis

BACKGROUND

Several single nucleotide polymorphisms (SNPs), rs16892766 in the 8q23.3 region and rs6983267, rs10505477, rs7014346 and rs7837328 in the 8q24.21 region, have been identified by genome-wide association studies (GWAS) and a number of case-control studies to be closely associated with risk of colorectal cancer (CRC). In the present study, a meta-analysis was performed to confirm if these loci are risk factors for susceptibility to CRC, taking heterogeneity of population into consideration.

METHODS

The whole literature search was conducted via database of MEDLINE and Embase, through which 33 articles with 49 studies (141,899 cases and 157,536 controls) were finally included in this meta-analysis to evaluate the association between the 5 polymorphisms and risk of CRC under allelic model.

RESULTS

A meta-analysis of the pooled data showed that the G allele of rs6983267, the A allele of rs7014346, the T allele of rs10505477, the C allele of rs16892766 and the A allele of rs7837328 were associated with significantly increased risk of CRC under allelic model. Additionally, subgroup analyses of four SNPs (rs7837328 excluded) by ethnicity witnessed a notable association between the G allele of rs6983267 and increased risk of CRC among Caucasians, Asians and Africans. Furthermore, the C allele of rs16892766 was strongly linked with elevated risk of CRC among Caucasians and Africans. However, the A allele of rs7014346 and T allele of rs10505477 only heightened risk for CRC among Caucasians and showed no effects among Asians.

CONCLUSION

In summary, rs6983267 is a risk factor for CRC among Caucasians, Asians and Africans; rs7014346 and rs10505477 are risky genetic polymorphisms only among Caucasians; rs16892766 is a hazardous element among populations with Caucasian and African ancestry; and rs7837328 could elevate the susceptibility to CRC in a multinational group. However, more potential factors related with CRC risk should be investigated in further studies.

The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa

Background

Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (−1377G > A and -670A > G), FasL (−844 T > C) and CASP8 (−652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins.

In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection.

Methods

Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2.

Results

CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = −2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = −2.28) of HSV-2 infection in both black African and mixed-ancestry population.

Conclusions

Our results show that the combined risks of variants in cell death pathway genes are associated with the cervical cancer as well as the HSV-2 infection in the black African and mixed-ancestry population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1678-y) contains supplementary material, which is available to authorized users.

Identification of a secondary promoter of CASP8 and its related transcription factor PURα

Caspase-8 (CASP8) is an essential initiator of apoptosis and is associated with many diseases in humans including esophageal squamous cell carcinoma. CASP8 produces a variety of transcripts, which might perform distinct functions. However, the cis and trans transcriptional determinants that control CASP8 expression remain poorly defined. Using a series of luciferase reporter assays, we identified a novel secondary promoter of CASP8 within chr2: 202,122,236 to 202,123,227 and 25 kb downstream of the previously described CASP8 promoter. ENCODE ChIP-seq data for this novel promoter region revealed several epigenetic features, including high levels of histone H3 lysine 27 acetylation and lysine 4 methylation, as well as low levels of CpG island methylation. We developed a mass spectrometry based strategy to identify transcription factors that contribute to the function of the secondary promoter. We found that the transcription activator protein PURα is specifically involved in the transcriptional activation of the secondary promoter and may exert its function by forming a complex with E2F-1 and RNA polymerase II. PURα can bind to both DNA and RNA, and functions in the initiation of DNA replication, regulation of transcription. We observed that knockdown of PURα expression decreased the transcriptional activity of the secondary promoter and mRNA expression of CASP8 isoform G. Although the physiologic roles of this secondary promoter remain unclear, our data may help explain the complexity of CASP8 transcription and suggest that the various caspase 8 isoforms may have distinct regulations and functions.

CASP8 -652 6N del polymorphism contributes to colorectal cancer susceptibility: evidence from a meta-analysis

Objective

Caspase-8 (CASP8) plays a central role in the apoptotic pathway and aberrant regulation of this pathway may cause cancers. Previous studies investigating the association between CASP8 -652 6N ins/del polymorphism and colorectal cancer (CRC) risk showed inconclusive results. We performed a meta-analysis of all available studies to investigate this association.

Methods

All studies published up to October 2013 on the association between CASP8 -652 6N ins/del polymorphism and CRC risk were identified by searching electronic databases PubMed, EMBASE, and Cochrane library. The association between CASP8 -652 6N ins/del polymorphism and CRC risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

Six studies with 6,325 cases and 6,842 controls were included in the meta-analysis. We observed that the CASP8 -652 6N ins/del polymorphism was significantly correlated with CRC risk when all studies were pooled into the meta-analysis (ins/del vs. ins/ins: OR = 0.890, 95%CI 0.821–0.964, P = 0.004; del/del + ins/del vs. ins/ins: OR = 0.899, 95%CI 0.833–0.970, P = 0.006). In stratified analyses by ethnicity, source of control, and quality score, significant association was observed in Asians (ins/del vs. ins/ins: OR = 0.862, 95%CI 0.761–0.977, P = 0.020; del/del + ins/del vs. ins/ins: OR = 0.845, 95%CI 0.749–0.953, P = 0.006), population-based studies (ins/del vs. ins/ins: OR = 0.890, 95%CI 0.813–0.975, P = 0.012; del/del + ins/del vs. ins/ins: OR = 0.901, 95%CI 0.827–0.982, P = 0.018), and high quality studies. However, in subgroup analysis according to cancer location, no significant association was detected.

Conclusions

The present meta-analysis suggests that the CASP8 is a candidate gene for CRC susceptibility. The CASP8 -652 6N ins/del polymorphism may play a protective role in CRC development especially among Asians. Further large and well-designed studies are needed to confirm this association.

Association between CASP8 -652 6N del polymorphism (rs3834129) and colorectal cancer risk: results from a multi-centric study

The common −652 6N del variant in the CASP8 promoter (rs3834129) has been described as a putative low-penetrance risk factor for different cancer types. In particular, some studies suggested that the deleted allele (del) was inversely associated with CRC risk while other analyses failed to confirm this. Hence, to better understand the role of this variant in the risk of developing CRC, we performed a multi-centric case-control study. In the study, the variant −652 6N del was genotyped in a total of 6,733 CRC cases and 7,576 controls recruited by six different centers located in Spain, Italy, USA, England, Czech Republic and the Netherlands collaborating to the international consortium COGENT (COlorectal cancer GENeTics). Our analysis indicated that rs3834129 was not associated with CRC risk in the full data set. However, the del allele was under-represented in one set of cases with a family history of CRC (per allele model OR = 0.79, 95% CI = 0.69–0.90) suggesting this allele might be a protective factor versus familial CRC. Since this multi-centric case-control study was performed on a very large sample size, it provided robust clarification of the effect of rs3834129 on the risk of developing CRC in Caucasians.

Common variation rs6983267 at 8q24.1 and risk of colorectal adenoma and cancer: evidence based on 31 studies

Genome-wide association studies have identified 8q24.21-rs6983267 as a new colorectal cancer (CRC) and colorectal adenoma (CRA) susceptibility locus in populations of European descent. Since then, the relationship between 8q24.21-rs6983267 and CRC/CRA has been reported in various ethnic groups; however, these studies have yielded inconsistent results. To investigate this inconsistency and derive a more precise estimation of the relationship, we conducted a meta-analysis of 31 studies, including 51,293 cases and 58,962 controls for CRC, and 8,148 cases and 17,065 controls for CRA. Potential sources of heterogeneity and publication bias were also systematically explored. Overall, the summary odds ratio of G variant for CRC was 1.18 (95% CI, 1.16-1.21; P < 10(-5)) and 1.17 (95% CI, 1.11-1.23; P < 10(-5)) for CRA. Significant results were observed using dominant or recessive genetic model for the polymorphism. In the subgroup analysis by ethnicity, significantly increased risks were found in East Asians and Caucasian populations; while no significant associations were detected among African Americans. After stratifying by sample size and control source, significant associations were also obtained. This meta-analysis suggests that the 8q24.21-rs6983267 polymorphism is associated with CRC/CRA susceptibility, but these associations vary in different ethnic populations.

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.

Genetic polymorphisms of the CASP8 gene promoter may not be associated with colorectal cancer in Han Chinese from southwest China

PURPOSE

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.

Association between main Caspase gene polymorphisms and the susceptibility and prognosis of colorectal cancer

Caspase (CASP) 3, 8, 9 are important caspases in the apoptosis pathway and play important roles in development and progression of cancer. A case-control study with 451 colorectal cancer (CRC) patients and 631 cancer-free controls were carried out, and CRC patients followed up, to investigate the associations between three main polymorphisms and colorectal cancer risk and prognosis, and their potential interactions with environmental factors on CRC risk among Chinese people. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-single strand conformation polymorphism sequencing. Odds ratio (OR), hazard ratio (HR) and their 95 % confidence intervals (CIs) were estimated with unconditional logistic-regression and Cox proportion hazard model. Individuals harboring the CASP8 -652 6N ins/del plus del/del genotype had a slightly lower risk for CRC compared those with ins/ins genotype (adjusted OR = 0.77, 95 % CI 0.59-0.99, P = 0.04). Significant associations between CASP3 -928 GG genotype and CASP9 -1263 GG genotype and reduced risk of rectal cancer were observed (adjusted OR = 0.56, 95 % CI 0.34-0.92, P = 0.02; adjusted OR = 0.59, 95 % CI 0.36-0.95, P = 0.03, respectively). There was a marginal significant association between CASP8 -652 6N ins/del polymorphism and CRC prognosis (ins/del versus ins/ins, adjusted HR = 0.69, 95 % CI 0.48-0.99, P = 0.04). These findings suggested these polymorphisms and their combinations with dietary factors may be associated with the development of CRC. CASP8 -652 6N ins/del polymorphism may be an independent survival predictor for CRC.

CASP8 promoter polymorphism, mRNA expression and risk of prostate cancer among Chinese men

Caspase-8 (CASP8) plays a key role in apoptosis. We examined by genotyping whether the -652 six-nucleotide insertion-deletion (6N ins/del) polymorphism in the CASP8 promoter region was associated with prostate cancer risk in a hospital-based case-control study of 406 Chinese prostate cancer patients and 408 age-matched cancer-free controls. Additionally, 23 prostate cancer tissues were analyzed for CASP8 mRNA expression. We found a significantly decreased prostate cancer risk for the 6N ins/del genotype [adjusted odds ratio (OR)=0.68; 95% confidence interval (CI)=0.51-0.92] and del/del genotype (OR=0.34; 95% CI=0.19-0.63) compared with the ins/ins genotype. The 6N del allele was associated dose-dependently with decreased prostate cancer risk (P_trend = 0.001). RT-PCR showed that individuals with the 6N del allele had lower CASP8 mRNA levels than those with the ins/ins genotype (P = 0.024). These findings suggested that the CASP8-652 6N ins/del polymorphism may affect the susceptibility to prostate cancer and reduce prostate cancer risk among Chinese men.

The CASP8 -652 6N insertion/deletion promoter polymorphism is associated with renal cell carcinoma risk and metastasis

PURPOSE

Caspase-8 is a key regulator of apoptosis. Its cancer cell antigen induced cell death activity is strongly impacted by the insertion/deletion promoter polymorphism CASP8 -652 6N ins/del (rs3834129). We studied the association of this polymorphism with renal cell carcinoma risk and pathology.

MATERIALS AND METHODS

In this hospital based case-control study 500 Austrian patients were genotyped, including 250 with renal cell carcinoma, and 250 age and gender matched healthy controls. Polymerase chain reaction amplified genomic DNA was evaluated by restriction fragment length polymorphism analysis and automatic sequencing. We assessed associations with renal cell carcinoma risk and pathological factors, and performed a meta-analysis of the literature.

RESULTS

The CASP8 -652 6N ins/del polymorphism was significantly linked to renal cell carcinoma (chi-square for trend = 9.50, p = 0.002). Compared with ins/ins, del/del was associated with a 57% decreased risk of the disease (OR 0.43, 95% CI 0.26-0.73, p = 0.002). Furthermore, del/del was associated with a lower risk of distant metastases (p <0.05) but not with T stage, N stage or grade. On meta-analysis the CASP8 -652 6N ins/del polymorphism was associated with renal cell carcinoma risk (p <0.001).

CONCLUSIONS

The del/del genotype of the CASP8 -652 6N ins/del promoter polymorphism decreases the overall risk of renal cell carcinoma. It may be associated with a decreased risk of metastasis. Larger studies are warranted to validate our findings.

Insertion/deletion polymorphisms in the ΔNp63 promoter are a risk factor for bladder exstrophy epispadias complex

Bladder exstrophy epispadias complex (BEEC) is a severe congenital anomaly; however, the genetic and molecular mechanisms underlying the formation of BEEC remain unclear. TP63, a member of TP53 tumor suppressor gene family, is expressed in bladder urothelium and skin over the external genitalia during mammalian development. It plays a role in bladder development. We have previously shown that p63^−/− mouse embryos developed a bladder exstrophy phenotype identical to human BEEC. We hypothesised that TP63 is involved in human BEEC pathogenesis. RNA was extracted from BEEC foreskin specimens and, as in mice, ΔNp63 was the predominant p63 isoform. ΔNp63 expression in the foreskin and bladder epithelium of BEEC patients was reduced. DNA was sequenced from 163 BEEC patients and 285 ethnicity-matched controls. No exon mutations were detected. Sequencing of the ΔNp63 promoter showed 7 single nucleotide polymorphisms and 4 insertion/deletion (indel) polymorphisms. Indel polymorphisms were associated with an increased risk of BEEC. Significantly the sites of indel polymorphisms differed between Caucasian and non-Caucasian populations. A 12-base-pair deletion was associated with an increased risk with only Caucasian patients (p = 0.0052 Odds Ratio (OR) = 18.33), whereas a 4-base-pair insertion was only associated with non-Caucasian patients (p = 0.0259 OR = 4.583). We found a consistent and statistically significant reduction in transcriptional efficiencies of the promoter sequences containing indel polymorphisms in luciferase assays. These findings suggest that indel polymorphisms of the ΔNp63 promoter lead to a reduction in p63 expression, which could lead to BEEC.

Bladder exstrophy epispadias complex is a severe congenital abnormality. The affected babies' bladders are born open, leaking urine constantly. Treatment involves multiple major reconstructive surgeries and the need for lifelong care for the complications of the disease. Although a number of studies have suggested a genetic cause of the disease, the genetic and molecular mechanism underlying the formation of BEEC remains unknown. One gene, TP63, plays a crucial role in the early bladder development. Two different genetic promoters of TP63 produce different forms of the protein with opposing properties. We have shown mice lacking p63 displayed a deformity complex identical to human BEEC. There are no genetic mutations in the p63 protein in BEEC, so genetic variants in the promoter could alter protein expression. Our hypothesis was that loss of p63 expression due to sequence polymorphisms in a promoter is a risk factor for BEEC. We found promoter sequence variants that were statistically associated with the disease and the sequence variant location varied between Caucasian and non-Caucasian patients. This is particularly important as Caucasian populations have a higher risk of BEEC. These findings provide an explanation of BECC and a base for further study of TP63 related genes in this disease.

CASP-8 -652 6N ins/del polymorphism and cancer risk: A literature-based systematic HuGE review and meta-analysis

Caspase-8 (encoded by the CASP-8 gene) is crucial in generating cell death signals and eliminating potentially malignant cells. Genetic variation in CASP8 may affect susceptibility to cancer. The CASP-8 −652 6N ins/del (rs3834129) polymorphism has been previously reported to influence the progression to several cancers. However, the overall reported studies have shown inconsistent conclusions. In this human genome epidemiology (HuGE) review and meta-analysis, the aim was to identify the association between CASP-8 −652 6N ins/del polymorphism and cancer risk. According to the inclusion criteria, 19 case-control studies with a total of 23,172 cancer cases and 26,532 healthy controls were retrieved. Meta-analysis results showed that the del allele, del allele carrier and ins/del genotype of −652 6N ins/del in the CASP-8 gene were negatively associated with cancer risk (OR=0.91, 95% CI=0.84–0.98, P=0.01; OR=0.88, 95% CI=0.80–0.96, P=0.005; OR=0.91, 95% CI=0.85–0.98, P<0.001; respectively, while no significant correlation was observed between the del/del genotype of −652 6N ins/del and cancer risk (OR=0.89, 95% CI=0.79–1.01, P=0.08). In the subgroup analysis by ethnicity, the meta-analysis indicated that Caucasian populations harboring the del allele, del allele carriers and ins/del genotype had a lower cancer risk (OR=0.96, 95% CI=0.93–1.00, P=0.05; OR=0.86, 95% CI=0.75–1.00, P=0.05; OR=0.91, 95% CI=0.84–0.98, P=0.01; respectively). In addition, a negative association was found between the del allele of −652 6N ins/del in the CASP-8 gene and cancer risk in the Asian population (OR=0.89, 95% CI=0.83–0.97, P=0.005). In conclusion, this meta-analysis suggests that the del allele, del allele carrier and ins/del geno-type of the −652 6N ins/del polymorphism in the CASP-8 gene may be protective factors for cancer risk.

The role of TNF and Fas dependent signaling in animal models of inflammatory liver injury and liver cancer

Tumor Necrosis Factor (TNF) alpha is a pleiotropic cytokine triggering either pro-inflammatory effects via NF-κB related pathways or apoptosis through activation of caspase-8. The related death ligands Fas and TRAIL use homologous receptors and similar signaling cascades but predominantly induce apoptosis. Here, we summarize our experimental approaches to analyze the mechanisms and consequences of TNF and Fas signaling with the ultimate aim to define molecular targets for the treatment of inflammatory liver disease and liver cancer. By using conditional knockout technology in mice we genetically dissected the I-kappa B kinase (IKK) complex consisting of IKK1/IKKα, IKK2/IKKβ and IKKγ/NEMO. We demonstrated that IKK2/IKKβ, but not IKKγ/NEMO might be a promising target for the prevention of liver injury after ischemia and reperfusion or treating steatohepatitis. Genetic inactivation of IKKγ/NEMO defined a new animal model of spontaneous hepatitis and hepatocarcinogenesis involving constitutive activation of caspase-8 and basal apoptosis. We further show that caspase-8 is not only regulated by post-translational modifications as suggested earlier, but also by complex transcriptional regulation. Targeted stimulation of the caspase-8 promoter by interferons alpha and gamma, cytotoxic drugs or p53 can substantially sensitize hepatoma cells for apoptosis, whereas hepatocellular carcinoma frequently present an inactive caspase-8 gene promoter. In conclusion, our work demonstrates that therapeutic intervention in the TNF-NF-κB-caspase-8 network is technically feasible and could be of potential benefit in inflammatory liver disease.

Role of Caspase 8, Caspase 9 and Bcl-2 polymorphisms in papillary thyroid carcinoma risk in Han Chinese population

Dysregulation of apoptosis plays a key role in carcinogenesis. This study was designed to investigate the association of apoptosis-related gene Caspase 8, Caspase 9 and Bcl-2 polymorphisms with papillary thyroid carcinoma (PTC) susceptibility. We undertook a case-control study of 118 patients and 213 controls to investigate the association between Caspase 8 (-652 6 N ins/del), Caspase 9 (-1263 A>G) and Bcl-2 (-938 C>A) polymorphisms and PTC susceptibility by polymerase chain reaction restriction-fragment length polymorphism and DNA sequencing methods. We further analyzed the distribution of genotype frequency, as well as the association of genotype with clinicopathological characteristics. Overall, no statistically significant association was observed in Caspase 8 (-652 6 N ins/del). Nevertheless, Caspase 9 -1263 GG genotype was at increased risk of PTC (P=0.045; odds ratio (OR)=1.12). Furthermore, GG genotype thyroid cancers were significantly more common in older patients than AA or AG genotypes PTC and in cases of advanced pathological stages. However, Bcl-2 -938 AA genotype demonstrated a protective effect in PTCs (P=0.004; OR=0.35). Polymorphism in Caspase 9 (-1263 A>G) was observed to be associated with susceptibility of PTC. However, Bcl-2 (-938 C>A) polymorphism indicated to play a protective role in susceptibility to PTC. Nevertheless, further investigation with a larger sample size is needed to support our results.

Linkage to chromosome 2q32.2-q33.3 in familial serrated neoplasia (Jass syndrome)

Causative genetic variants have to date been identified for only a small proportion of familial colorectal cancer (CRC). While conditions such as Familial Adenomatous Polyposis and Lynch syndrome have well defined genetic causes, the search for variants underlying the remainder of familial CRC is plagued by genetic heterogeneity. The recent identification of families with a heritable predisposition to malignancies arising through the serrated pathway (familial serrated neoplasia or Jass syndrome) provides an opportunity to study a subset of familial CRC in which heterogeneity may be greatly reduced. A genome-wide linkage screen was performed on a large family displaying a dominantly-inherited predisposition to serrated neoplasia genotyped using the Affymetrix GeneChip Human Mapping 10 K SNP Array. Parametric and nonparametric analyses were performed and resulting regions of interest, as well as previously reported CRC susceptibility loci at 3q22, 7q31 and 9q22, were followed up by finemapping in 10 serrated neoplasia families. Genome-wide linkage analysis revealed regions of interest at 2p25.2-p25.1, 2q24.3-q37.1 and 8p21.2-q12.1. Finemapping linkage and haplotype analyses identified 2q32.2-q33.3 as the region most likely to harbour linkage, with heterogeneity logarithm of the odds (HLOD) 2.09 and nonparametric linkage (NPL) score 2.36 (P = 0.004). Five primary candidate genes (CFLAR, CASP10, CASP8, FZD7 and BMPR2) were sequenced and no segregating variants identified. There was no evidence of linkage to previously reported loci on chromosomes 3, 7 and 9.

Association of 8q24.21 loci with the risk of colorectal cancer: a systematic review and meta-analysis

BACKGROUND AND AIM

Recent genome-wide association studies of colorectal cancer (CRC) have identified rs6983267 and trs10505477 polymorphisms as key loci in the 8q24 region to be associated with CRC. In the present study, we performed a meta-analysis to determine whether these loci are risk factors for susceptibility to CRC.

METHODS

We meta-analyzed the 22 included studies (47 003 cases and 45 754 controls) that evaluated the association of rs6983267 and trs10505477 with CRC under alternative genetic models.

RESULTS

A meta-analysis of the pooled data showed allelic and genotypic association of the rs6983267 polymorphism with CRC risk in Asians, Europeans, and European-Americans. A subanalysis of the US studies showed negative results in the studies with non-identified ethnicity of the patients. A meta-analysis of included studies of rs10505477 polymorphisms identified allelic and genotypic associations with CRC risk in the US patients. A further meta-analysis of the US studies demonstrated positive results in the studies with non-identified ethnicity of the samples.

CONCLUSION

Our data suggested that the rs6983267 G > T polymorphism is a risk factor for CRC in Asians, Europeans, and Americans with European ancestry.

Caspase 8 and caspase 9 gene polymorphisms and susceptibility to gastric cancer

BACKGROUND

Caspase-8 (CASP8) and caspase-9 (CASP9) play crucial roles in regulating apoptosis, and their functional polymorphisms may alter cancer risk. Our aim was to investigate the association of CASP8 and CASP9 gene polymorphisms with gastric cancer (GC) susceptibility.

METHODS

We undertook a case-control study of 88 GC cases and 480 controls to investigate the association between CASP8 -652 6N ins/del and CASP9 -1263 A>G polymorphisms and GC susceptibility by a polymerase chain reaction (PCR)-restriction fragment length polymorphism method.

RESULTS

CASP8 -652 6N ins/del polymorphism and CASP9 -1263 GG genotype were observed to be significantly associated with a reduced risk of GC. No significant association was observed between CASP8 -652 6N ins/del and CASP9 -1263 A>G polymorphisms and tumor characteristics. However, both CASP8 del/del and CASP9 -1263 GG genotypes were associated with increased overall survival in GC patients.

CONCLUSIONS

The CASP8 -652 6N ins/del and the CASP9 -1263 A>G polymorphisms were observed to play a protective role in GC predisposition.

Polymorphisms of caspase 8 and caspase 9 gene and colorectal cancer susceptibility and prognosis

PURPOSE

Caspase-8 (CASP8) and caspase-9 (CASP9) play crucial roles in regulating apoptosis, and their functional polymorphisms may alter cancer risk. Our aim was to investigate the association between CASP8 and CASP9 gene polymorphisms and colorectal cancer (CRC) susceptibility.

METHODS

A case-control study at 402 CRC patients and 480 healthy controls was undertaken in order to investigate the association between the genotype and allelic frequencies of CASP8 -652 6N ins/del and CASP9 -1263 A>G polymorphisms and the CRC susceptibility. The polymerase chain reaction (PCR) restriction fragment length polymorphism method was used and the incidence of polymorphisms on messenger RNA (mRNA) expression levels was detected by quantitative reverse-transcriptase PCR in CRC tissues.

RESULTS

No statistical significant association was observed between CASP8 -652 6N ins/del polymorphism frequencies and CRC susceptibility. CASP9 -1263 G allele was observed to be significant associated with reduced risk of CRC. Homozygotes for the -1263 GG CASP9 genotype, and hetrozygotes for the -1263 AG genotype expressed 6.64- and 3.69-fold higher mRNA levels of Caspase-9, respectively compared to the -1263 AA genotype cases. No significant association was observed between CASP9 -1263 A>G polymorphism and tumor characteristics. The CASP9 -1263 GG genotype was associated with increased overall survival in CRC patients.

CONCLUSION

The CASP9 -1263 A>G polymorphism was observed to play a protective role in CRC predisposition, while the CASP9 -1263 GG genotype may confer a better prognosis at CRC patients.

Polymorphisms in the CASP8 gene and the risk of epithelial ovarian cancer

OBJECTIVE

The CASP8 gene plays a central role in the apoptotic pathway and is therefore a plausible cancer susceptibility gene. However, the precise role of the CASP8 gene in epithelial ovarian cancer carcinogenesis is unclear. Therefore, we analyzed the correlation between single nucleotide polymorphisms (SNPs) and haplotypes in CASP8 and the risk and clinical characteristics of epithelial ovarian cancer (EOC) in the Chinese population.

SUBJECTS AND METHODS

Eight tag SNPs were identified using the MassARRAY system to genotype 37 genetic polymorphisms around and in the CASP8 gene in 100 unrelated, healthy females. Then, a case-control study of 218 EOC patients and 285 controls who were matched on residence, age and race was conducted using these 8 tag SNPs.

RESULTS

The risk of developing EOC was significantly decreased in association with CASP8 rs3834129 ins>del (odds ratio (OR)(del/del)=0.129, 95% confidence interval (95% CI): 0.038-0.439; OR(ins/del)=0.769, 95% CI, 0.534-1.108), rs3769827 T>C (OR(C/C)=0.187, 95% CI: 0.070-0.500; OR(T/C)=0.729, 95% CI: 0.505-1.052), rs6704688 C>T (OR(T/T)=0.344, 95% CI, 0.168-0.707; OR(C/T)=0.802, 95% CI, 0.552-1.166), and with the del-C-T haplotype of these 3 SNPs (OR=0.615, 95% CI: 0.453-0.8363). Moreover, a notably later onset was significantly associated with the rs3834129 ins/del+del/del and the rs3769827 T/C+C/C genotypes (p<0.0001).

CONCLUSIONS

Genetic variants of the CASP8 gene protect against EOC carcinogenesis and delay the age of EOC onset. Furthermore, these protective effects may be due to the dysfunctional expression of caspase-8 caused by the -652 6N del variant in the promoter.

CASP8 promoter polymorphism is associated with high-risk HPV types and abnormal cytology but not with cervical cancer

Only a small fraction of women infected with human papillomavirus (HPV) progress to cervical cancer pointing to additional risk factors including host genetics that might play a role in development of cervical cancer. Caspase-8 (encoded by CASP8 gene) is crucial in generating cell death signals to eliminate potentially malignant cells. Genetic variation in CASP8 might influence the susceptibility to cancer. CASP8 -652 6N ins/del polymorphism has been previously reported to influence the progression to several cancers including cervical cancer. This polymorphism was investigated in 445 women of black African and Mixed Ancestry origin with invasive cervical cancer and 1,221 controls matched (1:3) by age, ethnicity, and domicile status. Genotyping for CASP8 -652 6N ins/del was done by PCR-RFLP. In the control women cervical disease was detected by cervical cytology. The CASP8 -652 6N del/del genotype did not show any significant association (P=0.948) with cervical cancer. Further analysis within the controls showed a weak association (P=0.048) of this polymorphism with abnormal cytology in both ethnicities and high-risk HPV infection (P=0.030) only in the black Africans. This is the first study of the role of CASP8 -652 6N ins/del polymorphism in cervical cancer in an African population. These results show that CASP8 -652 6N del/del genotype increases the risk of abnormal cytology and high-risk HPV infection but does not show an association with cervical cancer. This result points towards an important role of CASP8 in HPV infection and in the development of pre-cancers.

Genetic variants on chromosome 8q24 and colorectal neoplasia risk: a case-control study in China and a meta-analysis of the published literature

Previous studies have found that common genetic variants on chromosome 8q24 are associated with the risk of developing colorectal neoplasia. We conducted a hospital-based case-control study, including 435 cases and 788 unrelated controls to investigate the associations between common variants on 8q24 and the risk of colorectal cancer in a Chinese population. We also evaluated the association of rs6983267 with colorectal neoplasia in the published literature via a meta-analysis study. We found that rs6983267 was significantly associated with the risk of colorectal cancer in the Chinese population, with an adjusted odds-ratio (OR) for the GT heterozygotes and GG homozygotes of 1.30 (95% CI  = 0.98–1.71, P = 0.069) and 1.66 (95% CI  = 1.18–2.34, P = 0.004), respectively, compared to the TT homozygotes, with a P-trend value of 0.003. No association was found for the other three loci (rs16901979, rs1447295 and rs7837688). In the meta-analysis of the published genetic association studies, the rs6983267 variant was found to be associated with an increased risk of colorectal neoplasia. The heterozygous GT carriers showed a 20% increased risk of colorectal neoplasia (OR  = 1.20, 95% CI  = 1.16–1.25; random effects model) with a summary OR for homozygous GG carriers of 1.39 (95% CI  = 1.32–1.48; random effects model) compared to the TT genotype carriers. We found no significant differences between the association of rs6983267 and colorectal cancer and colorectal adenomas. In summary, our study confirms that the variant rs6983267 is a risk factor for colorectal neoplasia in various populations, including the Chinese population.

Polymorphisms and haplotypes in caspases 8 and 9 genes and risk for prostate cancer: a case-control study in cohort of North India

OBJECTIVE

Despite the potential importance of apoptosis pathways in prostate tumor etiology, little has been published regarding prostate tumor risk associated with common gene variants in caspases (CASP). Normal variations within the sequence of apoptotic genes may lead to suboptimal apoptotic capacity and therefore increased cancer risk.

MATERIALS AND METHODS

Using data from a hospital-based case-control study conducted by Sanjay Gandhi Post Graduate Institute of Medical Science, India, from 2007 to 2009, we evaluated risk of prostate cancer (CaP) in 165 patients and age-matched 205 healthy controls. We genotyped the functional IVS12-19G/A, D302H, -678del, and -652 6N ins/del polymorphisms in the promoter of CASP 8 and -293del, -1263A/G in CASP 9 genes.

RESULTS

A significant increased risk for CaP was found for the CASP 8 IVS12-19G/A heterozygous genotype (P = 0.02; OR = 1.69) as well as for the variant allele carriers (P = 0.04; OR = 1.56). Also the CASP 9 -1263A/G showed lower risk for both heterozygous and variant allele carrier genotypes (P = 0.002; OR = 0.45 and P = 0.05; OR = 0.66 respectively). CASP 9 -1263A/G was also found to be associated with increased risk with bone metastasis. Furthermore, a significant additive interaction between CASP 8 IVS12-19G/A polymorphism and tobacco smoking was observed with CaP risk.

CONCLUSION

These results suggested that the CASP 8 IVS12-19G/A and CASP 9 -1263 polymorphism may be involved in etiology of CaP and thus could be implicated as a marker for genetic susceptibility in North Indian population.

CASP8 -652 6N del and CASP8 IVS12-19G>A gene polymorphisms and susceptibility/prognosis of ESCC: a case control study in northern Indian population

BACKGROUND

Caspase8 influences carcinogenesis through regulation of apoptosis, hyperproliferation, and metastasis. Role of genetic variations in caspase8 has been explored in various cancers; however, their predictive and prognostic role in esophageal cancer is poorly understood.

METHODS

We investigated the association of two potential caspase8 polymorphisms: CASP8 -652 6N del and CASP8 IVS12-19 G>A polymorphisms with susceptibility and survival of 259 esophageal squamous cell carcinoma (ESCC) cases and 259 cancer-free controls from northern Indian population using PCR/PCR RFLP method.

RESULTS

CASP8 IVS12-19 AA genotype was found to be associated with significant increased risk of ESCC (odds ratio (OR) 3.28, 95% confidence interval (CI) 1.04-10.29) specifically in male subjects (OR 3.71, 95% CI 1.01-13.35) with lower third tumor anatomical location (OR 6.00, 95% CI 1.60-22.55). Kaplan-Meier and Cox Regression analysis showed lower median survival (7.13 months vs. 25.21 months) and greater hazard of death (HR 3.40, 95% CI 1.38-7.90) with CASP8 IVS12-19 AA genotype in ESCC cases compared to IVS12-19 GG genotype. However, no association of CASP8 -652 6N del polymorphism with susceptibility and prognosis of ESCC was observed.

CONCLUSION

CASP8 IVS12-19 G>A but not CASP8 -652 6N del polymorphism may modulate risk of ESCC and its survival outcome in northern Indian population.

Generalizability and epidemiologic characterization of eleven colorectal cancer GWAS hits in multiple populations

BACKGROUND

Genome-wide association studies (GWAS) in populations of European ancestry have identified several loci that confer an increased risk of colorectal cancer (CRC).

METHODS

We studied the generalizability of the associations with 11 risk variants for CRC on 8q23 (rs16892766), 8q24 (rs6983267), 9p24 (rs719725), 10p14 (rs10795668), 11q23 (rs3802842), 14q22 (rs4444235), 15q13 (rs4779584), 16q22 (rs9929218), 18q21 (rs4939827), 19q13 (rs10411210), and 20p12 (rs961253) in a multiethnic sample of 2,472 CRC cases, 839 adenoma cases and 4,466 controls comprised of European American, African American, Native Hawaiian, Japanese American, and Latino men and women. Because findings for CRC and adenoma were similar, we combined both groups in the analyses.

RESULTS

We confirmed the associations with an increased risk of CRC/adenoma for the 8q24, 11q23 and 15q13 loci in European Americans, and observed significant associations between the 8q24 and 20p12 loci with CRC/adenoma risk in African Americans. Moreover, we found statistically significant cumulative effects of risk alleles on CRC/adenoma risk in all populations (odds ratio [OR] per allele = 1.07-1.09, P ≤ 0.039) except in Japanese Americans (OR = 1.01, P = 0.52). We found heterogeneity in the associations by tumor subsite, age of CRC/adenoma onset, sex, body mass index (BMI), and smoking status for some of the variants.

CONCLUSIONS

These results provide evidence that the known variants are in aggregate significantly associated with CRC/adenoma risk in multiple populations except Japanese Americans, and the influences may differ across groups defined by clinicopathological characteristics for some variants.

IMPACT

These results underline the importance of studying the epidemiologic architecture of these genetic effects in large and diverse populations.

Association of CASP8 D302H polymorphism with reduced risk of aggressive prostate carcinoma

BACKGROUND

Because of the dramatically different clinical course of aggressive and indolent prostate carcinoma (PCa), markers that distinguish between these phenotypes are of critical importance. Apoptosis is an important protective mechanism for unrestrained cellular growth and metastasis. Therefore, dysfunction in this pathway is a key step in cancer progression. As such, genetic variants in apoptosis genes are potential markers of aggressive PCa. Recent work in breast carcinoma has implicated the histidine variant of CASP8 D302H (rs1045485) as a protective risk allele.

METHODS

We tested the hypothesis that the H variant was protective for aggressive PCa in a pooled analysis of 796 aggressive cases and 2,060 controls.

RESULTS

The H allele was associated with a reduced risk of aggressive PCa (OR(per allele) = 0.67, 95% CI: 0.54-0.83, P(trend) = 0.0003). The results were similar for European-Americans (OR(per allele) = 0.68; 95% CI: 0.54-0.86) and African-Americans (OR(per allele) = 0.61; 95% CI: 0.34-1.10). We further determined from the full series of 1,160 cases and 1,166 controls in the Prostate, Lung, Colorectal, Ovarian (PLCO) population that the protective effect of the H allele tended to be limited to high-grade and advanced PCa (all cases OR(per allele) = 0.94; 95% CI: 0.79-1.11; localized, low-grade disease OR(per allele) = 0.98; 95% CI: 0.79-1.23; and aggressive disease OR(per allele) = 0.73; 95% CI: 0.50-1.07).

CONCLUSION

These results suggest that histidine variant of CASP8 D302H is a protective allele for aggressive PCa with potential utility for identification of patients at differential risk for this clinically significant phenotype.

Single-nucleotide polymorphisms in the p53 signaling pathway

The p53 tumor suppressor pathway is central both in reducing cancer frequency in vertebrates and in mediating the response of commonly used cancer therapies. This article aims to summarize and discuss a large body of evidence suggesting that the p53 pathway harbors functional inherited single-nucleotide polymorphisms (SNPs) that affect p53 signaling in cells, resulting in differences in cancer risk and clinical outcome in humans. The insights gained through these studies into how the functional p53 pathway SNPs could help in the tailoring of cancer therapies to the individual are discussed. Moreover, recent work is discussed that suggests that many more functional p53 pathway SNPs are yet to be fully characterized and that a thorough analysis of the functional human genetics of this important tumor suppressor pathway is required.

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.

Association of selected polymorphisms of CCND1, p21, and caspase8 with colorectal cancer risk

It has been well elucidated that the signal transduction of cell-cycle control pathway and apoptosis pathway plays an important role in the normal growth and differentiation of organisms. To test the hypothesis that mutants of key genes involved in cell-cycle regulation and apoptosis might contribute to the increased risk of colorectal cancer (CRC), a population-based case-control study was carried out in Jiashan County, Zhejiang Province. The study population was composed of 373 CRC cases and 838 controls. Five genetic variants including CCND1 G870A, p21 codon31 C/A, p21 3'UTR C/T, caspase8 IVS12-19G/A, and caspase8 6n del/ins were genotyped. The associations of the polymorphisms with CRC were estimated by logistical regression model after adjustment for the important covariates. The interactive effect among the five selected genetic polymorphisms on CRC was explored by multifactor dimensionality reduction (MDR) software. The significant association between five single-nucleotide polymorphisms (SNPs) and CRC risk was not observed, respectively. However, caspase8 del/del showed a marginally significant association with the increased risk of rectum cancer [adjusted odds ratio (OR) (95% confidence interval, CI) = 1.92 (0.97-3.79); P = 0.06]. Furthermore, the MDR analysis indicated that the best interactive model for CRC included three factors-CCND1 G870A, caspase8 IVS12-19G/A, and caspase8 6 n del/ins-with 53.44% testing balanced accuracy and 10/10 cross-validation consistency, but the model was no longer significant after the 1000 times permutation test (P = 0.25). Our findings suggest that the selected polymorphisms of p21, CCND1, and caspase8 may not contribute to the risk of colorectal cancer.

Polymorphisms and haplotypes in the caspase-3, caspase-7, and caspase-8 genes and risk for endometrial cancer: a population-based, case-control study in a Chinese population

Caspase-3, caspase-7, and caspase-8 are important caspases in the apoptosis pathway and play an important role in the development and progression of cancer. We examined the association between genetic variants in the caspase-3, caspase-7, and caspase-8 genes and risk for endometrial cancer among Chinese women. Genotypes for 1,028 women with endometrial cancer and 1,003 healthy controls were determined with the Affymetrix MegAllele Targeted Genotyping System and Molecular Inversion Probe method. Of 35 selected single-nucleotide polymorphisms, four in the caspase-7 gene were in high linkage disequilibrium (rs11593766, rs3124740, rs11196445, and rs11196418) and associated with the risk for endometrial cancer. The AA genotype of rs11196418 [odds ratio, 0.36; 95% confidence interval (95% CI), 0.14-0.94] and the G allele of rs11593766 were associated with reduced risk (odds ratio of 0.75 and 95% CI of 0.59-0.96 for carriers of one G allele; odds ratio of 0.70 and 95% CI of 0.24-2.03 for carriers of two G alleles). The AA genotype of rs11196445 (odds ratio, 1.74; 95% CI, 0.99-3.05), the CC genotype of rs3124740 (odds ratio, 1.36; 95% CI, 1.06-1.75), and the GG genotype of rs10787498 in the caspase-7 gene (odds ratio, 1.90; 95% CI, 1.16-3.11) were associated with increased risk compared with homozygotes of the major alleles. The gene-disease association seemed to be more pronounced among premenopausal women, although tests for multiplicative interaction between genes and menopausal status failed to reach statistical significance. The GG genotype of rs2705901 in the caspase-3 gene was significantly associated with increased cancer risk compared with the CC genotype (odds ratio, 2.25; 95% CI, 1.03-4.95). No association was observed between polymorphisms of the caspase-8 gene and risk for endometrial cancer. These findings suggest that genetic variants in caspase-3 and caspase-7 may play a role in endometrial cancer susceptibility.

Caspase 9 and caspase 8 gene polymorphisms and susceptibility to bladder cancer in north Indian population

BACKGROUND

Dysregulation of apoptosis plays a crucial role in carcinogenesis. Our aim was to investigate the association of Caspase 9 and Caspase 8 gene polymorphism with bladder cancer (BC) susceptibility.

METHODS

We undertook a case-control study of 212 (BC) cases and 250 controls to investigate the association between Caspase 9-1263A > G, Caspase 9-293del, and Caspase 8-6 N ins/del polymorphism and BC susceptibility by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method, and further to study the influence on recurrence in patients after Bacillus Calmette-Guerin (BCG) immunotherapy.

RESULTS

Overall, no statistically significant association was observed in Caspase 9-293del and Caspase 8. Nevertheless, Caspase 9-1263GG genotype was at reduced risk of BC [p = 0.010; odds ratio (OR) = 0.487]. Caspase 9-1263AG genotype was also observed to be significantly associated with reduced risk with high-risk non-muscle-invasive bladder cancer (NMIBC) (TaG(2-3), T1G(1-3)) and invasive tumors (T2 +) of BC (P = 0.042, OR = 0.39 and P = 0.013, OR = 0.028 respectively). Caspase 9-293del, heterozygous (-/+) genotype, too, demonstrated protective effect in high-risk NMIBC (P = 0.017; OR = 0.205). Haplotype analysis revealed variant genotypes Caspase 9AG + GG/Caspase 8 DI + II to be at reduced risk of BC (= 0P.014, OR = 0.47). The GG genotype of Caspase 9-1263 was associated with reduced risk for recurrence in BCG-treated patients [hazard ratio (HR) = 0.217, P = 0.005], thus showing increased recurrence-free survival (log-rank P = 0.024).

CONCLUSION

Polymorphism in Caspase 9-1263 was observed to play a protective role in susceptibility to BC risk. Caspase 9 gene variants were also associated with reduced risk of NMBIC stages. The variant G allele at Caspase 9-1263 may be responsible for increased recurrence-free survival in BCG-treated patients.

A six-nucleotide insertion-deletion polymorphism in the CASP8 promoter associated with risk and progression of bladder cancer

PURPOSE

Caspase-8 (CASP8) is a key regulator of apoptosis or programmed cell death, an essential defense mechanism against hyperproliferation and malignancy. We hypothesized that the variants in the CASP8 gene are associated with risk of bladder cancer.

EXPERIMENTAL DESIGN

In a hospital-based case-control study of 365 case patients with newly diagnosed bladder transitional cell carcinoma and 368 cancer-free controls frequency-matched by age and sex, we genotyped the functional -652 6N ins/del polymorphism (rs3834129) in the promoter of CASP8 and assessed its associations with risk of bladder cancer and interaction with tobacco smoking.

RESULTS

A significant decreased risk of bladder cancer was found for the CASP8 -652 6N ins/del (adjusted odds ratio, 0.72; 95% confidence interval, 0.53-0.99) and del/del (odds ratio, 0.37; 95% confidence interval, 0.18-0.77) genotypes. Furthermore, a significant additive interaction between CASP8 polymorphism and tobacco smoking on bladder cancer risk was observed.

CONCLUSIONS

These results suggested that the CASP8 -652 6N ins/del polymorphism is involved in etiology of bladder cancer and thus may be a marker for genetic susceptibility to bladder cancer in Chinese populations. Larger studies are warranted to validate our findings.