Association between X-ray repair cross-complementation group 1 rs25487 polymorphism and pancreatic cancer risk

Association between Polymorphisms of X-Ray Repair Cross Complementing Group 1 Gene and Pancreatic Cancer Risk: a Systematic Review with Meta-Analysis

Emerging evidences have shown that common genetic polymorphisms in X-ray repair cross complementing group 1 (XRCC1) gene may be associated with the development of pancreatic cancer, but individually published studies and previous meta-analyses revealed inconclusive results. The aim of our study was to investigate the association between polymorphisms in XRCC1 gene and pancreatic cancer risk. We conducted a search of PubMed, Embase, the Cochrane Library and Web of Science databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were determined as measures of the strength of association between polymorphisms of XRCC1 and pancreatic cancer risk. Sensitivity analysis and publication bias were evaluated. All analyses were undertaken using the STATA 13.0. A total of 10 studies were included in this systematic review. Five common functional single-nucleotide polymorphisms (SNPs) in XRCC1 gene were found, including Arg399Gln G > A (rs25487), Arg194Trp C > T (rs1799782), Arg280His G > A (rs25489), c.1517G > C, c.1471G > A. Results from our stratified analysis based on Hardy-Weinberg equilibrium (HWE) showed that there was a robust significant association between Arg280His polymorphism and pancreatic cancer risk (allelic model, OR 0.743, 95% CI 0.576-0.958, P = 0.022; heterozygous model, OR 0.701, 95% CI 0.525-0.936, P = 0.016; dominant model, OR 0.710, 95% CI 0.537-0.939, P = 0.016). We also found a statistically significant association between c.1517G > C polymorphism and pancreatic cancer risk (Allelic model, OR 1.252, 95% CI 1.064-1.473, P = 0.007). No significant results were obtained for Arg399Gln, Arg194Trp and c.1471G > A polymorphisms. The present meta-analysis suggested that Arg280His and c.1517G > C polymorphisms in XRCC1 gene were associated with pancreatic cancer risk.

Association and Intragenic Single-Nucleotide Polymorphism Interactions of the XRCC1 Polymorphisms for Pancreatic Cancer Susceptibility

OBJECTIVES

X-ray repair cross-complementing group 1 (XRCC1) gene is an important candidate gene for influencing human cancer risks. This study examined the main and interactive effect of 9 single-nucleotide polymorphisms (SNPs) (Arg194Trp, Arg280His, Arg399Gln, c.1254C>T, c.1517G>C, c.1471G>A, C310T, 539del542, and T1915C) of XRCC1 in contribution to pancreatic cancer (PC).

METHODS

A total of 298 PC patients and 298 healthy controls were enrolled. Selected SNPs in XRCC1 were genotyped. The generalized multifactor dimensionality reduction method investigated gene-gene interactions.

RESULTS

Single-locus analyses showed that, in the codominant model, the GO genotype of 539del542 might have a higher risk for PC (odds ratio [OR], 1.47; 95% confidence interval [95% CI], 1.05-2.08). For T1915C polymorphism, the TC and CC genotypes both had a higher risk for PC (OR, 1.76; 95% CI, 1.25-2.48; OR, 1.83; 95% CI, 1.05-3.19, respectively); and a similar result was observed in the dominant model (OR, 1.77; 95% CI, 1.28-2.46). A tendency of association between Arg280His and PC was also detected in the dominant model (OR, 0.70; 95% CI, 0.48-1.00). Furthermore, the generalized multifactor dimensionality reduction method showed that the 4-locus model was significant, involving Arg280His, 539del542, T1915C, and c.1517G>C (P < 0.05).

CONCLUSIONS

Thus, XRCC1 polymorphisms may contribute to the risk of PC independently or in an interactive manner.

Variants of Base Excision Repair Genes MUTYH , PARP1 and XRCC1 in Alzheimer's Disease Risk

BACKGROUND

Many clinical studies have shown that oxidative stress pathways and the efficiency of the oxidative DNA damage base excision repair (BER) system are associated with the pathogenesis of Alzheimer's disease (AD). Reduced BER efficiency may result from polymorphisms of BER-related genes. In the present study, we examine whether single nucleotide polymorphisms (SNPs) of BER genes are associated with increased risk of AD.

METHODS

SNP genotyping was carried out on DNA isolated from peripheral blood mononuclear cells obtained from 120 patients with AD and 110 healthy volunteers. Samples were genotyped for the presence of BER-related SNPs, i.e. XRCC1-rs1799782, rs25487; MUTYH-rs3219489, and PARP1-rs1136410.

RESULTS

We found a positive association between AD risk and the presence of G/A genotype variant of the XRCC1 rs25487 polymorphism [odds ratio (OR) = 3.762, 95% CI: 1.793-7.891]. The presence of the A/A genotype of this polymorphism reduced the risk of AD (OR = 0.485, 95% CI: 0.271-0.870). In cases of the PARP1 gene rs1136410 polymorphism, we observed that the T/C variant increases (OR = 4.159, 95% CI: 1.978-8.745) while the T/T variant reduces risk (OR = 0.240, 95% CI: 0.114-0.556) of AD.

CONCLUSIONS

We conclude that BER gene polymorphisms may play an important role in the etiology of AD. Diagnosing the presence or absence of particular genetic variants may be an important marker of AD. Further research on a larger population is needed. There is also a need to examine polymorphisms of other BER in the context of AD risk.

Genetic Polymorphisms in XRCC1, CD3EAP, PPP1R13L, XPB, XPC, and XPF and the Risk of Chronic Benzene Poisoning in a Chinese Occupational Population

Objectives

Individual variations in the capacity of DNA repair machinery to relieve benzene-induced DNA damage may be the key to developing chronic benzene poisoning (CBP), an increasingly prevalent occupational disease in China. ERCC1 (Excision repair cross complementation group 1) is located on chromosome 19q13.2–3 and participates in the crucial steps of Nucleotide Excision Repair (NER); moreover, we determined that one of its polymorphisms, ERCC1 rs11615, is a biomarker for CBP susceptibility in our previous report. Our aim is to further explore the deeper association between some genetic variations related to ERCC1 polymorphisms and CBP risk.

Methods

Nine single nucleotide polymorphisms (SNPs) of XRCC1 (X-ray repair cross-complementing 1), CD3EAP (CD3e molecule, epsilon associated protein), PPP1R13L (protein phosphatase 1, regulatory subunit 13 like), XPB (Xeroderma pigmentosum group B), XPC (Xeroderma pigmentosum group C) and XPF (Xeroderma pigmentosum group F) were genotyped by the Snapshot and TaqMan-MGB^® probe techniques, in a study involving 102 CBP patients and 204 controls. The potential interactions between these SNPs and lifestyle factors, such as smoking and drinking, were assessed using a stratified analysis.

Results

An XRCC1 allele, rs25487, was related to a higher risk of CBP (P<0.001) even after stratifying for potential confounders. Carriers of the TT genotype of XRCC1 rs1799782 who were alcohol drinkers (OR = 8.000; 95% CI: 1.316–48.645; P = 0.022), male (OR = 9.333; 95% CI: 1.593–54.672; P = 0.019), and had an exposure of ≤12 years (OR = 2.612; 95% CI: 1.048–6.510; P = 0.035) had an increased risk of CBP. However, the T allele in PPP1R13L rs1005165 (P<0.05) and the GA allele in CD3EAP rs967591 (OR = 0.162; 95% CI: 0039~0.666; P = 0.037) decreased the risk of CBP in men. The haplotype analysis of XRCC1 indicated that XRCC1 rs25487^A, rs25489^G and rs1799782^T (OR = 15.469; 95% CI: 5.536–43.225; P<0.001) were associated with a high risk of CBP.

Conclusions

The findings showed that the rs25487 and rs1799782 polymorphisms of XRCC1 may contribute to an individual’s susceptibility to CBP and may be used as valid biomarkers. Overall, the genes on chromosome 19q13.2–3 may have a special significance in the development of CBP in occupationally exposed Chinese populations.

Association between OGG1 gene single nucleotide polymorphisms and risk of pancreatic cancer in Chinese

Previous studies have suggested that the 8-oxoguanine DNA glycosylase gene (OGG1) has potentially influenced the risk of pancreatic cancer. The objective of this study was to assess the association between single nucleotide polymorphisms (SNPs) of OGG1 gene and risk of pancreatic cancer. A case-control study has been conducted in 370 pancreatic cancer patients and 395 healthy controls. Genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. The association analysis was evaluated by the unconditional logistic regression test. Our data suggested that the distributions of alleles and genotypes were statistically different between pancreatic cancer patients and healthy controls. The c.307G>C SNP was associated with the decreased risk of pancreatic cancer (C vs. G: OR 0.73, 95 % CI 0.59-0.91, P = 0.006). As for c.828A>G SNP, the significantly decreased risk of pancreatic cancer was detected (G vs. A: OR 0.74, 95 % CI 0.59-0.92, P = 0.006). The allele C of c.307G>C and allele G of c.828A>G SNPs might be associated with a protection from pancreatic cancer. Findings from this study indicate that OGG1 SNPs are associated with pancreatic cancer risk in Chinese Han population and could be useful molecular biomarkers for assessing the risk of pancreatic cancer.

Lack of association of XRCC1 rs1799782 genetic polymorphism with risk of pancreatic cancer: a meta-analysis

Emerging evidence suggests that genetic polymorphisms in X-ray repair cross-complementation group 1 (XRCC1) gene could be associated with pancreatic cancer risk. However, previous published studies on the association between XRCC1 rs1799782 genetic polymorphism and pancreatic cancer risk reported inconsistent results. For better understanding of the effects of XRCC1 rs1799782 genetic polymorphism on pancreatic cancer risk, we conducted a meta-analysis of previous published studies by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). A total of five eligible studies with 1,144 pancreatic cancer cases and 2,925 controls were eventually enrolled. Overall, we found that the XRCC1 rs1799782 genetic polymorphism was not associated with pancreatic cancer risk in total population under all genetic models (TT vs. CC: OR = 1.11, 95% CI 0.76-1.63, P = 0.583; CT vs. CC: OR = 1.39, 95% CI 0.92-2.10, P = 0.118; TT/CT vs. CC: OR = 1.39, 95% CI 0.92-2.10, P = 0.121; TT vs.

CT/CC

OR = 1.07, 95% CI 0.73-1.55, P = 0.743; T vs. C: OR = 1.31, 95% CI 0.93-1.86, P = 0.125). In the subgroup analysis based on ethnicity, there was no statistically significant association between XRCC1 rs1799782 genetic polymorphism and pancreatic cancer risk in Asians/Caucasians under all genetic models (all P values > 0.05). No publication bias was detected in this study. Our meta-analysis suggests that the XRCC1 rs1799782 genetic polymorphism is not significantly associated with pancreatic cancer risk. Considering the limited sample size and ethnicity enrolled in this meta-analysis, further larger scaled studies are needed to provide a more precise estimation on the association.