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

Polymorphism at codon 31 of CDKN1A (p21) as a predictive factor for bevacizumab therapy in glioblastoma multiforme

Glioblastoma (GBM), a prevalent and malignant brain tumor, poses a challenge in surgical resection due to its invasive nature within the brain parenchyma. CDKN1A (p21, Waf-1), a cyclin-dependent kinase inhibitor, plays a pivotal role in regulating cell growth arrest, terminal differentiation, and apoptosis. The existence of natural variants of CDKN1A has been associated with specific cancer types. In this retrospective study, our objective was to identify polymorphic variants of CDKN1A, specifically c.93C > A (codon 31 Ser31Arg), and investigate its potential impact within the scope of bevacizumab therapy for glioblastoma multiforme. This study involved a cohort of 139 unrelated adult Chinese GBM patients in Taiwan. Genomic DNA extracted from tumor samples was utilized for genotyping using the polymerase chain reaction (PCR) restriction fragment length polymorphism method (PCR-RFLP analysis). Through unconditional logistic regression analysis, odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Our findings unveiled that among these GBM patients, the distribution of codon 31 polymorphisms was as follows: 23.02% were Serine homozygotes (Ser/Ser), 27.34% were Arginine homozygotes (Arg/Arg), and 49.64% were Serine/Arginine heterozygotes (Ser/Arg). While CDKN1A c.93C > A polymorphisms did not exhibit a direct association with overall survival in GBM patients, noteworthy survival benefits emerged among individuals with Arg/Arg and Arg/Ser genotypes who received combined concurrent chemoradiotherapy (CCRT) and bevacizumab treatment compared to those who underwent CCRT alone. Our findings indicate a significant involvement of the CDKN1A c.93C > A polymorphism in the development and onset of GBM, offering potential implications for the early prognostication of bevacizumab therapy outcomes.

miR-466 Contributes to the Enhanced Antitumor Effect of Bortezomib on Non-Small-Cell Lung Cancer by Inhibiting CCND1

INTRODUCTION

Changes in microRNAs (miRs) contribute to the alternative chemo-resistance of cancers. Bortezomib (BTZ) is a well-characterized anticancer agent that inhibits proteasome, and its effect is associated with the function of miRs. Based on the data of microarray assay and comprehensive bioinformatics analyses, in the current study, we explored the role of miR-466 and its downstream effector CCND1 in the BTZ-resistance of non-small-cell lung cancer (NSCLC) cells.

METHODS

miR expression profiles in NSCLC tissues and paratumor tissues were determined with microarray assay. The potential miR involved in the chemo-resistance of NSCLC cells was explored via a series of bioinformatics analyses, and miR-466 was selected. Afterward, levels of miR-466 and CCND1 were investigated in NSCLC samples and analyzed by clinicopathologic parameters, including age, sex, stage of NSCLC, tumor size, tumor differentiation status, and lymphocytic infiltration status. The expression of CCND1 and miR-466 was then modulated in vitro to explore the influence on cell phenotypes, which was then verified with mouse models.

RESULTS

Based on microarray detection, 287 miRs were dysexpressed between NSCLC tissues and paratumor tissues, including 90 upregulated members and 197 downregulated members. After bioinformatics analyses and reverse transcription quantitative PCR validation, miR-466 and CCND1 were selected. Following clinical investigations, miR-466 was downregulated, while CCND1 was upregulated in NSCLC samples, contributing to the advanced cancer progression. The overexpression of CCND1 increased cell viability, suppressed cell apoptosis, decreased p21 and induced N-cadherin, CCND2, and CDK4 under BTZ treatment. The induced expression of miR-466 re-sensitized NSCLC cells to BTZ treatment. In the animal model, the overexpression of CCND1 impaired the inhibitory effect of BTZ on the growth and metastasis of solid tumor, which was restored by miR-466 induction.

CONCLUSION

The findings showed that the interaction between BTZ, miR-466, and CCND1 determined the antitumor effect of BTZ on NSCLC.

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.

MicroRNA-binding site polymorphisms and risk of colorectal cancer: A systematic review and meta-analysis

Genetic variations in miRNAs binding site might participate in cancer risk. This study aimed to systematically review the association between miRNA-binding site polymorphisms and colorectal cancer (CRC). Electronic literature search was carried out on PubMed, Web of Science (WOS), Scopus, and Embase. All types of observational studies till 30 November 2018 were included. Overall 85 studies (21 SNPs) from two systematic searches were included analysis. The results showed that in the Middle East population, the minor allele of rs731236 was associated with decreased risk of CRC (heterozygote model: 0.76 [0.61-0.95]). The minor allele of rs3025039 was related to increased risk of CRC in East Asian population (allelic model: 1.25 [1.01-1.54]). Results for rs3212986 were significant in overall and subgroup analysis (P < .05). For rs1801157 in subgroup analysis the association was significant in Asian populations (including allelic model: 2.28 [1.11-4.69]). For rs712, subgroup analysis revealed a significant (allelic model: 1.41 [1.23-1.61]) and borderline (allelic model: 0.92 [0.84-1.00]) association in Chinese and Czech populations, respectively. The minor allele of rs17281995 increased risk of CRC in different genetic models (P < .05). Finally, rs5275, rs4648298, and rs61764370 did not show significant associations. In conclusion, minor allele of rs3025039, rs3212986, and rs712 polymorphisms increases the risk of CRC in the East Asian population, and heterozygote model of rs731236 polymorphism shows protective effect in the Middle East population. In Europeans, the minor allele of rs17281995 may increase the risk of CRC, while rs712 may have a protective effect. Further analysis based on population stratifications should be considered in future studies.

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.

The association between CCND1 G870A polymorphism and colorectal cancer risk: A meta-analysis

BACKGROUND

CyclinD1 (CCND1) is a key cell cycle regulatory protein. A large number of epidemiological studies have assessed the potential correlation between the CCND1 G870A polymorphism and the risk of colorectal cancer (CRC), but their findings have been inconsistent. To obtain a more precise understanding of the association between the G870A polymorphism in the CCND1 gene and the CRC risk, we conducted a more comprehensive meta-analysis.

METHODOLOGY

We searched PubMed, Ovid, Springer, Weipu, China National Knowledge Infrastructure (CNKI), and Wanfang databases, covering all publications (the last search was updated on January 10, 2017). The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. Statistical analyses were performed using Review Manager 5.3 and STATA 10.0 software.

RESULTS

A total of 7276 CRC patients and 9667 controls from 27 publications were included in this meta-analysis. We found that compared with GG homozygote genetic model, AA, AG, AA + AG genetic models of the CCND1 G870A polymorphism were significantly associated with overall CRC risk (AA homozygote genetic model: OR = 1.28, 95% CI = 1.10-1.49; AG heterozygote genetic model: OR = 1.15, 95% CI = 1.06-1.25; AA homozygote + AG heterozygote genetic model: OR = 1.19, 95% CI = 1.07-1.33). Subgroup analyses by ethnicity and cancer location showed that A carriers were consistently associated with a significantly increased risk of CRC in all subsets of participants (Asian and Caucasian; colon cancer and rectal cancer). When stratified by study design, we found a significant association in hospital-based studies (HB), but no significant associations were found in either population-based studies (PB) or family-based studies (FB). According to subgroup analysis by cancer type, the risk of sporadic colorectal cancer (sCRC) and hereditary nonpolyposis colorectal cancer (HNPCC) were not correlated with the CCND1 G870A polymorphism, except AG (AG vs GG: OR = 1.30, 95% CI = 1.11-1.53).

CONCLUSIONS

This meta-analysis suggests that the CCND1 G870A polymorphism is associated with an increased risk of CRC, especially that A carriers may be a major risk factor for CRC.

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.

Investigation of cyclin D1 rs9344 G>A polymorphism in colorectal cancer: a meta-analysis involving 13,642 subjects

The relationship between cyclin D1 (CCND1) rs9344 G>A polymorphism and colorectal cancer (CRC) risk is still ambiguous. To obtain a precise estimation of the relationship, we performed an extensive meta-analysis based on the eligible studies. Crude odds ratios with their 95% confidence intervals were harnessed to determine the strength of correlation between CCND1 rs9344 G>A polymorphism and CRC risk under the allele, the homozygote, the dominant, and the recessive genetic models, respectively (28 studies with 5,784 CRC cases and 7,858 controls). Our results indicated evidence of the association between CCND1 rs9344 G>A polymorphism and the increased risk of CRC in four genetic models: A vs G, AA vs GG, AA+GA vs GG, and AA vs GA+GG. In a stratified analysis by cancer type of CRC, there was an increased risk of sporadic CRC found in three genetic models: A vs G, AA vs GG, and AA+GA vs GG. In a stratified analysis by ethnicity, there was an increased CRC risk found among Asians in allele comparison genetic models, as well as Caucasians in two genetic models: AA+GA vs GG and A vs T. In summary, this meta-analysis demonstrates that CCND1 rs9344 G>A polymorphism may be a risk factor for CRC.

CCND1 G870A polymorphism and colorectal cancer risk: An updated meta-analysis

Molecular epidemiological studies have revealed a closer association between cyclin D1 (CCND1) polymorphism and the risk of colorectal cancer; however, the results were inconsistent. The aim of the present meta-analysis was to investigate the association between CCND1 G870A polymorphism and colorectal cancer risk. Online electronic databases (PubMed and Embase) were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between CCND1 G870A polymorphism and the risk of colorectal cancer. In addition, heterogeneity, publication bias and sensitivity analysis were performed to guarantee the statistical power. In total, 23 published case-control studies with 6,320 patients and 8,252 controls were selected. Significantly increased risks were observed in four genetic models (A vs. G: OR=1.09, 95% CI=1.00-1.18, I²=54.3%; GA vs. GG: OR=1.13, 95% CI=1.04-1.24, I²=18.2%; AA vs. GG, OR=1.17: 95% CI=1.00-1.38, I²=52.5%; GA+AA vs. GG: OR=1.14, 95% CI=1.05-1.24, I²=33.8%). Similarly, significant associations were also identified in the stratified analysis in the cancer subtype of sporadic colorectal cancer (GA vs. GG: OR=1.21, 95% CI=1.04-1.42, I²=24.1%; GA+AA vs. GG: OR=1.18, 95% CI=1.02-1.37, I²=35.0%), Caucasian population (GA vs. GG, OR=1.14, 95% CI=1.02-1.28, I²=19.8%; GA+AA vs. GG, OR=1.14, 95% CI=1.02-1.27, I²=37.5%) and other subgroups of control design and genotyping type. The present updated meta-analysis suggested that CCND1 G870A may present an increased risk for developing colorectal cancer, particularly in sporadic colorectal cancer and a Caucasian population.

Association of p21 3' UTR gene polymorphism with cancer risk: Evidence from a meta-analysis

Numerous studies have investigated the risk of cancer associated with the polymorphism of p21 3' UTR (rs1059234 C > T), but results have been inconsistent. We performed this meta-analysis to drive a more precise estimation of the association between this polymorphism and risk of cancer. A comprehensive search was conducted to identify all case-control studies of the rs1059234 C > T polymorphism of p21 3' UTR and cancer susceptibility. A total of eleven eligible studies, including 3,099 cases and 4,354 controls, relating to the rs1059234 polymorphism of p21 3' UTR to the risk of cancer were identified. Multivariate and univariate methods revealed no association between this polymorphism and cancer risk. However, subgroup analysis by cancer type suggested that rs1059234 C > T polymorphism was associated with increased risk of squamous cell carcinoma of the head and neck (SCCHN) (dominant model CT + TT vs. CC: OR = 1.51, 95% CI = 1.17-1.94). No significant association was found in other subgroup analyses. This meta-analysis suggested that rs1059234 polymorphism of p21 3' UTR may be associated with increased SCCHN risk. And larger scale primary studies are required to further evaluate the interaction of p21 3' UTR rs1059234 polymorphism and cancer risk in specific populations.

Quantitative Assessment the Relationship between p21 rs1059234 Polymorphism and Cancer Risk

p21 is a cyclin-dependent kinase inhibitor, which can arrest cell proliferation and serve as a tumor suppressor. Though many studies were published to assess the relationship between p21 rs1059234 polymorphism and various cancer risks, there was no definite conclusion on this association. To derive a more precise quantitative assessment of the relationship, a large scale meta-analysis of 5,963 cases and 8,405 controls from 16 eligible published case-control studies was performed. Our analysis suggested that rs1059234 was not associated with the integral cancer risk for both dominant model [(T/T+C/T) vs C/C, OR=1.00, 95% CI: 0.84-1.18] and recessive model [T/T vs (C/C+C/T), OR=1.03, 95% CI: 0.93-1.15)]. However, further stratified analysis showed rs1059234 was greatly associated with the risk of squamous cell carcinoma of head and neck (SCCHN). Thus, larger scale primary studies are still required to further evaluate the interaction of p21 rs1059234 polymorphism and cancer risk in specific cancer subtypes.

The significant association of CCND1 genotypes with colorectal cancer in Taiwan

Colorectal cancer, one million cases of diagnosis worldwide annually, is one of the most common malignant tumors and 20 % incidence caused by low penetrance susceptibility genes. Cyclin D1 (CCND1) regulating cell cycle transition may determine the susceptible individuals to genomic instability and carcinogenesis. The study aimed at examining the contribution of CCND1 genotypes to colorectal cancer risk in Taiwan. The genotypes of CCND1 A870G (rs9344) and G1722C (rs678653) were determined among 362 colorectal cancer patients and 362 age- and gender-matched cancer-free controls. Significant differences were observed between colorectal cancer and control groups in the distributions of genotypic (P = 9.71 × 10(-4)) and allelic (P = 0.0017) frequencies at CCND1 A870G. Additionally, individuals carried AG or GG genotype had 0.56- or 0.51-fold higher of odds ratios for developing colorectal cancer than the AA genotype (95 % confidence intervals = 0.40-0.78 and 0.32-0.81, respectively). Furthermore, G allele of CCND1 A870G performed a protective effects for nonsmokers and nonalcohol drinkers (P = 0.0012 and 0.0007, respectively) on colorectal cancer risk. These findings support the concept that the cell cycle regulation may play a role in colorectal cancer initiation and development and CCND1 A870G genotyping maybe a feasible technology for colorectal cancer early detection.

Association Between p21 Ser31Arg Polymorphism and Gastrointestinal Tract Tumor Risk: A Meta-analysis

Human p21 gene is characterized by a polymorphism at codon 31 leading to a Serine-to- Arginine (S/R), two different alleles of p21 Ser31Arg (rs 1801270) polymorphism have been shown to differ significantly in their transcriptional efficiency. More and more investigations are now being carried out to examine a possible link between the p21 Ser31Arg polymorphism and cancer. However, the results were inconclusive. Therefore, we carried out a systematic review and meta-analysis to examine whether this polymorphism is associated with gastrointestinal tract tumor in Asian. Seven studies (n = 2690), comprising 967 cases and 1723 controls in Asian population, were included in our study. The meta-analysis showed significant association between Ser-allele or Ser/Ser genotype and the susceptibility to gastrointestinal tract tumor in overall studies (Ser-allele vs. Arg-allele: OR = 1.17, 95% CI: 1.04-1.31; Ser/Ser vs. Arg/Arg: OR = 1.38, 95% CI: 1.09-1.75; Ser/Ser vs. Arg/Ser: OR = 1.27, 95% CI: 1.05-1.53; Ser/Ser vs. Arg/Ser + Arg/Arg: OR = 1.29, 95% CI: 1.07-1.54). Despite the limitations, the results of the present meta-analysis suggested that, in the p21 Ser31Arg polymorphism, Ser-allele and Ser/Ser genotype might be risk factors for gastrointestinal tract tumor in Asian populations.

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.

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.

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.

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.

Genetic variants of p21 and p27 and hepatocellular cancer risk in a Chinese Han population: a case-control study

The p21 (Cip1/CDKN1A) and p27 (Kip1/CDKN1B) are members of the Cip/Kip family of cyclin-dependent kinase inhibitors, which can arrest cell proliferation and serve as tumour suppressors. We hypothesized that genetic variants in p21 and p27 may modify individual susceptibility to hepatocellular carcinoma (HCC). To test this hypothesis, we evaluated the associations of the polymorphisms of Ser31Arg and C+20T in p21 and C-79T and Gly109Val in p27, as well as their combinations, with HCC risk in a case-control study of 476 HCC cases and 526 cancer-free controls in a Chinese population. The matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry method was performed to detect these polymorphisms. We found that the variant genotypes of p21 Ser31Arg and p27 C-79T were individually associated with a significantly increased risk of HCC, but no associations were observed for other variant genotypes. Moreover, the combined variant genotypes of the four loci were associated with a significantly increased HCC risk (adjusted OR = 2.24, 95% CI = 1.72, 2.91 among subjects carrying 3 or more variant alleles), especially among HbsAg-positive individuals (adjusted OR = 3.09, 95% CI = 1.86, 5.14). Furthermore, the combined variant genotypes of the four loci (carrying three or more variant alleles) increased a 1.93-fold (95% CI = 1.20, 3.09) and 1.76-fold (95% CI = 1.17, 2.64) risk of HCC among smokers and nonsmokers. The variant genotypes of the two genes in this study have negative correlation with the clinicopathologicals observed. These results suggest that p21 polymorphisms individually or in combination with p27 polymorphisms increases risk of HCC, particularly among HbsAg-positive individuals.

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.

Association between p21 Ser31Arg polymorphism and cancer risk: a meta-analysis

P21 (CDKN1A), a key cell cycle regulatory protein that governs cell cycle progression from G1 to S phase, can regulate cell proliferation, growth arrest, and apoptosis. The Ser31Arg polymorphism is located in the highly conserved region of p21 and may encode functionally distinct proteins. Although many epidemiological studies have been conducted to evaluate the association between the p21 Ser31Arg polymorphism and cancer risk, the findings remain conflicting. This meta-analysis with 33 077 cases and 45 013 controls from 44 published case-control studies showed that the variant homozygous 31Arg/Arg genotype was associated with an increased risk of numerous types of cancers in a random-effect model (homozygote comparison: OR = 1.17, 95% CI = 0.99 to 1.37, P = 0.0002 for the heterogeneity test; recessive model comparison: OR = 1.16, 95% CI = 1.01 to 1.33, P = 0.0001 for the heterogeneity test). Stratified analysis revealed that increased cancer risk associated with the 31Arg/Arg genotype remained significant in subgroups of colorectal cancer, estrogen-related cancer, Caucasians, population-based studies, studies with matching information or a larger sample size. Heterogeneity analysis showed that tumor type contributed to substantial between-study heterogeneity (recessive model comparison: Χ(2) = 21.83, df = 7, P = 0.003). The results from this large-sample sized meta-analysis suggest that the p21 31Arg/Arg genotype may serve as a potential marker for increased cancer risk.

Bi-directional PCR allele-specific amplification (bi-PASA) for detection of caspase-8 -652 6N ins/del promoter polymorphism (rs3834129) in breast cancer

Caspase-8 (CASP8) plays a critical role in regulating apoptosis, and its functional polymorphisms may modify cancer risk. We investigated the possible association between CASP8 -652 6N ins/del (rs3834129) and the risk of breast cancer in a sample of Iranian population. This case-control study was done on 236 breast cancer patients and 203 cancer free healthy female. We designed a rapid and simple bi-directional PCR allele-specific amplification (bi-PASA) for detection of CASP8 -652 6N ins/del polymorphism. The results showed that the CASP8 -652 6N del/dl genotype was inversely associated with breast cancer risk (OR=0.33, 95% CI=0.17-0.65, p=0.001). The frequencies of the del allele in cases and controls were 29.1% and 38.6%, respectively. An inverse association between CASP8 6N del variant and the risk of breast cancer (OR=0.66, 95% CI=0.66-0.87, p=0.002) was found. In conclusion, the result suggests that the CASP8 -652 6N del polymorphism plays a protective role in susceptibility to breast cancer in our population. Further studies in other populations with larger samples are needed to confirm these findings.

Cyclin D1 G870A polymorphism contributes to colorectal cancer susceptibility: evidence from a systematic review of 22 case-control studies

Background

Cyclin D1 (CCND1) plays a vital role in cancer cell cycle progression. Numerous epidemiological studies have evaluated the association between the CCND1 G870A polymorphism and the risk of colorectal cancer. However, these studies have yielded conflicting results. To derive a more precise estimation of this association, we conducted a meta-analysis and systematic review.

Methodology/Principal Findings

A comprehensive search was conducted to identify eligible studies of the CCND1 G870A polymorphism and colorectal cancer risk. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. We applied a grading system (Venice criteria) that assessed the epidemiological strength of the association. A total of 22 publications that included 6157 cases and 8198 controls were identified. We found that the CCND1 G870A polymorphism was significantly associated with overall colorectal cancer risk (homozygote genetic model: OR = 1.130, 95% CI = 1.023–1.248, P = 0.016; heterozygote genetic model: OR = 1.124, 95% CI = 1.030–1.226, P = 0.009; dominant genetic model: OR = 1.127, 95% CI = 1.037–1.224, P = 0.005). After further stratified analyses, the increased risk was observed only in the subgroups of hospital-based studies, PCR-RFLP genotyping methods, sporadic colorectal cancer, and Caucasian ethnicity.

Conclusions

The available evidence demonstrates that the CCND1 870A allele might be a low-penetrant risk factor for colorectal cancer.

CCND1 G870A polymorphism is associated with increased risk of colorectal cancer, especially for sporadic colorectal cancer and in Caucasians: a meta-analysis

AIMS

To detect the association between G870A polymorphism of cyclin D1 (CCND1) gene and colorectal cancer.

METHODS

We performed a systematic literature and abstract search using PubMed, EMBase digital database. Keywords included CCND1, cyclin D1, polymorphism, SNP, colon cancer, rectal cancer and colorectal cancer. "And", "OR" and "NOT" were used as conjunction to narrow and widen the search. Data were extracted by two investigators independently, and meta-analysis was carried out by using Review Manager 4.2.8. The following pairwised combinations of genotypes for the CCND1 G870A polymorphism were evaluated: AA vs. GG, AG vs. GG, AA+AG vs. GG. Subsequently, sub-group analyses for cancer type, ethnicity, and the family history were performed. Sensitivity analysis was conducted by excluding the articles deviated from Hardy-Weinberg equilibrium.

RESULTS

Using GG genotype as a reference, A carriers were associated with a significantly increased cancer risk (OR=1.15, 95%CI=1.06-1.25, P=0.001, P(heterogeneity)=0.130), especially with rectal cancer (OR=1.24, 95%CI=1.02-1.51, P=0.030, P(heterogeneity)=0.570) and sporadic colorectal cancer (OR=1.26, 95%CI=1.08-1.46, P=0.003, P(heterogeneity)=0.730). The effect of A carriers on cancer also existed in Caucasians (OR=1.19, 95%CI=1.06-1.32, P=0.002, P(heterogeneity)=0.100).

CONCLUSIONS

CCND1 G870A polymorphism is associated with the increased risk of colorectal cancer, especially for sporadic colorectal cancer and in Caucasians.

Prognostic Impact of Polymorphisms in the CASPASE Genes on Survival of Patients with Colorectal Cancer

Purpose

This study analyzed potentially functional polymorphisms in CASPASE (CASP) genes and their impact on the prognosis for Korean colorectal cancer patients.

Materials and Methods

A total of 397 consecutive patients with curatively resected colorectal adenocarcinoma were enrolled in this study. Genomic DNA from these patients was extracted from fresh colorectal tissue, and the 10 polymorphisms in the CASP3, CASP6, CASP7, CASP8, CASP9, and CASP10 genes were determined using a reverse transcription polymerase chain reaction genotyping assay.

Results

The median patient age was 63 years, and 218 (54.9%) patients had colon cancer, while 179 (45.1%) patients had rectal cancer. Univariate and multivariate survival analysis including pathologic stage, patient age, differentiation, and carcinoembryonic antigen level demonstrated that these polymorphisms were not associated with either disease-free or overall survival.

Conclusion

None of the 10 polymorphisms in the CASP genes investigated in this study was found to be an independent prognostic marker for Korean patients with curatively resected colorectal cancer.

Associations of miRNA polymorphisms and female physiological characteristics with breast cancer risk in Chinese population

mircoRNAs (miRNAs) play important roles on regulation of gene expressions. Aberrant expression of miRNAs was involved in various biological and pathological processes, including tumorigenesis of breast cancer. Single-nucleotide polymorphisms (SNPs) were implicated in altered expression or biological functions of mature miRNAs. To explore the relevance of miRNA polymorphisms and female physiological characteristics to breast cancer risk, SNPs located within hsa-miR-605 (rs2043556), hsa-miR-149 (rs2292832), hsa-miR-27a (rs895819), hsa-miR-196a-2 (rs11614913) and hsa-miR-618 (rs2682818) were selected, and their associations with breast cancer risk were analysed. In addition, associations between physiological characteristics-related factors and breast cancer risk were estimated too. We found that the ones with menarche age less than 16 years had increased breast cancer risk (OR = 2.10, 95% CI: 1.23-3.60). Marginally significant association between rs11614913 CT/CC genotypes and reduced breast cancer risk was observed (OR = 0.65, 95% CI: 0.40-1.06), while no significance was detected about the other miRNA polymorphisms. We concluded that menarche at less than 16 years old increased breast cancer risk, while the genetic variants in miR-196-a-2 might decrease the risk.

Associations of lifestyle-related factors, hsa-miR-149 and hsa-miR-605 gene polymorphisms with gastrointestinal cancer risk

To explore the associations of SNPs within hsa-miR-605 (rs2043556) and hsa-miR-149 (rs2292832) and lifestyle-related factors with gastrointestinal cancer, a case-control study including 762 cases and 757 controls was conducted. Marginally significant associations were found both for hsa-miR-149 rs2292832 with gastric cancer risk (TC + CC vs. TT, OR = 0.68, 95% CI: 0.44-1.04) and for hsa-miR-605 rs2043556 with colorectal cancer risk (AG + GG vs. AA, OR = 0.70, 95% CI: 0.48-1.02) in males. Tea drinking showed a protective effect on gastric cancer risk (OR = 0.28, 95% CI: 0.13-0.60), while smoke inhalation increased the risk of gastric cancer (OR = 1.94, 95% CI: 1.08-3.47). Irritability was found to be a risk factor for both colorectal cancer (OR = 1.61, 95% CI: 1.02-2.53) and gastric cancer (OR = 1.96, 95% CI: 1.17-3.29). Among those that engaged in smoke inhalation, miR-149 CT/CC and miR-605 AG/GG genotype carriers had increased susceptibilities to colorectal cancer (OR = 1.90, 95% CI: 1.11-3.25) and gastric cancer (OR = 1.87, 95% CI: 1.03-3.42), respectively. Among the tea drinkers, there exists a marginally protective effect of miR-605 AG/GG genotypes on colorectal cancer incidence (OR = 0.71, 95% CI: 0.47-1.06) and a significantly protective effect of miR-149 CT/CC on gastric cancer incidence (OR = 0.47, 95% CI: 0.29-0.77). The SNPs of rs2292832 and rs2043556 might be able to modify the susceptibility to male gastric and colorectal cancers, respectively. Tea drinking is a protective factor, while smoke inhalation is a risk factor for gastric cancer, and they might have the potential to modify the associations between miR-149 and miR-605 polymorphisms with gastrointestinal cancer risk. In addition, irritability was shown to be a risk factor for both gastric and colorectal cancers.

Cyclin D1 G870A polymorphism and colorectal cancer susceptibility: a meta-analysis of 20 populations

PURPOSE

Studies investigating the association between genetic polymorphism of cyclin D1 (CCND1) G870A and risk of colorectal cancer (CRC) reported conflicting results. In order to derive a more precise estimation of the relationship, a meta-analysis was performed.

MATERIALS AND METHODS

We performed an extensive search of relevant studies and carried out a meta-analysis, including 20 studies with 5,975 cases and 8,333 controls, to obtain a more precise estimate.

RESULTS

Overall, significantly elevated colorectal cancer risk was associated with variant allele 870A when all studies were pooled (AA vs. GG: OR = 1.23, 95% CI = 1.04-1.44; GA vs. GG: OR = 1.13, 95% CI = 1.01-1.26; dominant model: OR = 1.16, 95% CI = 1.03-1.31). In the subgroup analysis by ethnicity, significantly increased risks were detected among Caucasians (AA vs. GG: OR = 1.27, 95% CI = 1.04-1.44; dominant model: OR = 1.17, 95% CI = 1.02-1.34).We also observed sporadic CRC with an increased cancer susceptibility (AA vs. GG: OR = 1.24, 95% CI = 1.04-1.48; dominant model: OR = 1.17, 95% CI = 1.04-1.33), when colorectal cancer was stratified into sporadic CRC and hereditary nonpolyposis colorectal cancer (HNPCC). However, no significant associations were found in both Asians and HNPCC patients for all genetic models.

CONCLUSION

Result suggests that the cyclin D1 870A allele is a low-penetrant risk factor for developing sporadic colorectal cancer, especially among Caucasians.

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.

Cyclin D1 (CCND1) G870A gene polymorphism is an ethnicity-dependent risk factor for digestive tract cancers: a meta-analysis comprising 20,271 subjects

Published data on the association between Cyclin D1 (CCND1) G870A gene polymorphism and digestive tract cancers (DTC) are inconclusive. We carried out a meta-analysis of published case-control studies to derive a more precise estimation of the association. Relevant studies were identified from PubMed, EMBASE, and China National Knowledge Infrastructure up to February 1st, 2011. Crude odds ratios (OR) and 95% confidence intervals (CI) were used to investigate the strength of the association. Data were available from a total of 33 case-control studies with 8534 cases and 11,737 controls. The combined results based on all studies showed that there was a statistically significant link between CCND1 G870A polymorphism and DTC risk (GG vs. AA: OR=0.83, 95%CI=0.71-0.96). In the analysis of ethnic groups, we found the A allele carriers had a significantly increased DTC susceptibility among Caucasians, but not among Asians. When stratified for tumor location, the results based on all studies only showed the variant allele 870A might have a significantly increased risk of colorectal cancer (CRC), especially of rectal cancer (GG vs. AA: OR=0.71, 95%CI=0.58-0.89). When stratifying by the stage and histological differentiation of CRC, we only observed that patients had a significantly higher frequency of CCND1 870 AA than non-cancer patients among Caucasians. The A allele carriers (hetero- or homozygotes) were significantly more common in cases with a family history of CRC than in controls. There was no evidence of publication bias for CCND1 G870A polymorphism with DTC risk. In summary, this meta-analysis demonstrates that the CCND1 G870A polymorphism may be an ethnicity-dependent risk factor for DTC. And this genetic variant may increase the risk of rectal cancer, but not colon cancer.

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.

Caspase 8 gene variants in healthy North Indian population and comparison with worldwide ethnic group variations

BACKGROUND:

Many strategies are being used for the quest for the disease causing genes. Inter-individual variations in several genes exist. Thus, even if they share the same disease-associated allele, the genomic backgrounds – and hence potential interacting alleles at other loci – of people with different regional ancestries may differ, with a consequent variation in the severity of their disease.

MATERIALS AND METHOD:

The present study was conducted to determine the distribution of Caspase 8 IVS12-19G/A, Caspase 8D302H, Caspase 8 -652del and Caspase 8 -678del polymorphisms (as frequency distribution of caspases in Indians generally is not yet known), which was then compared with different populations globally. Polymerase chain reaction (PCR)-based analysis was conducted in 205 normal healthy individuals of similar ethnicity.

RESULTS:

The variant allele frequencies were 17.6% (A) in Caspase 8 IVS12-19G/A, 13.2% (H) in Caspase 8D302H, 23.2% (Del) in Caspase 8 -652del and 24.6% (Del) in Caspase 8 -678del. Further, comparison of frequency distribution of these genes was done with various published studies of different ethnic groups globally.

CONCLUSION:

It is anticipated from our results that the frequency of these caspase genes exhibits distinctive patterns in India, which could perhaps be attributed to ethnic variation. This study is important as it can form a baseline for screening individuals who are at high risk due to exposure to environmental carcinogens and cancer predisposition, and therefore, might help in investigating linked polymorphisms in a way that will not obscure potential associations between genotype and phenotype.

Single nucleotide polymorphisms in the Wnt and BMP pathways and colorectal cancer risk in a Spanish cohort

Background

Colorectal cancer (CRC) is considered a complex disease, and thus the majority of the genetic susceptibility is thought to lie in the form of low-penetrance variants following a polygenic model of inheritance. Candidate-gene studies have so far been one of the basic approaches taken to identify these susceptibility variants. The consistent involvement of some signaling routes in carcinogenesis provided support for pathway-based studies as a natural strategy to select genes that could potentially harbour new susceptibility loci.

Methodology/Principal Findings

We selected two main carcinogenesis-related pathways: Wnt and BMP, in order to screen the implicated genes for new risk variants. We then conducted a case-control association study in 933 CRC cases and 969 controls based on coding and regulatory SNPs. We also included rs4444235 and rs9929218, which did not fulfill our selection criteria but belonged to two genes in the BMP pathway and had consistently been linked to CRC in previous studies. Neither allelic, nor genotypic or haplotypic analyses showed any signs of association between the 37 screened variants and CRC risk. Adjustments for sex and age, and stratified analysis between sporadic and control groups did not yield any positive results either.

Conclusions/Significance

Despite the relevance of both pathways in the pathogenesis of the disease, and the fact that this is indeed the first study that considers these pathways as a candidate-gene selection approach, our study does not present any evidence of the presence of low-penetrance variants for the selected markers in any of the considered genes in our cohort.

Are cell cycle and apoptosis genes associated with prostate cancer risk in North Indian population?

OBJECTIVE

Prostate cancer (CaP) is a heterogeneous, multifactorial, and multifocal disease. Therefore, the search for a combination of functional polymorphisms using cell cycle and apoptotic genes as tumor markers is fundamental for a more precise and reliable diagnosis. In the present study, we investigated the diagnostic value of 3 different genes associated with CaP carcinogenesis, encoding for cell cycle (MDM2, CCND1) and apoptotic (Fas) genes that are differentially expressed in CaP.

METHODS

In a hospital-based case control study of northern India, blood samples were obtained from 192 CaP patients and 224 cancer-free age matched unrelated healthy controls of similar ethnicity. They were genotyped for MDM2 G309T, CCND1 G870A, Fas A670G, and G1377A polymorphisms using polymerase chain restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

MDM2 309GG variant was at reduced risk for developing CaP (P = 0.041; OR, 0.59). Whereas CCND1 AA genotype demonstrated increased risk (P = 0.018; OR, 1.86). The diplotype analysis of Fas G670A and G1377A (G-A) was observed to be associated with a significant increase in CaP risk (P = 0.024; OR, 1.63).

CONCLUSION

Findings based on current sample size our results suggested a positive association of CCND1AA genotype and diplotype analysis of Fas G670A and G1377A (G-A) to be associated with CaP risk that could influence the pathophysiology, thereby modulating the risk of CaP.