Polymorphisms of the XRCC1 and XPD Genes and Breast Cancer Risk: A Case-Control Study

Associations of mRNA expression of DNA repair genes and genetic polymorphisms with cancer risk: a bioinformatics analysis and meta-analysis

A systematical bioinformatics and meta-analysis were carried out to establish our understanding of possible relationships between DNA repair genes and the development of cancer. The bioinformatics analysis confirmed that lower XPA and XPC levels and higher XPD, XPF, and WRN levels were observed in 19 types of cancer, and subsequently results indicated that elevated XPA and XPC had a better impact on overall survival, however, higher XPD, XPF, and WRN showed worse influence on cancer prognosis. The meta-analysis included 58 eligible studies demonstrated that harboring XPA rs10817938, XPD rs238406 increased overall cancer risk, however, XPA rs2808668 SNP in overall cancer analysis and XPF rs3136038 in the digestive system remarkably reduced the cancer risk. Moreover, no correlation was investigated for XPC rs1870134, WRN rs1346044 and rs1801195. These suggest that the DNA repair gene was associated with carcinogenesis, and contribute to the prognosis, and the critical SNPs further involved in affecting cancer risk.

Polymorphisms in BER genes and risk of breast cancer: evidences from 69 studies with 33760 cases and 33252 controls

Recently, numerous studies have reported an association between single nucleotide polymorphisms in base-excision repair genes and the risk of developing breast cancer, however there is no consensus. The aim of this meta-analysis was to review and quantitatively assess the relationship between single nucleotide polymorphisms in base-excision repair genes and breast cancer risk. The results suggested that a mutation of T to G in rs1760944 may lead to a higher risk of developing breast cancer in the Mongoloid population, and G to A of rs25487 significantly reduced the risk of breast cancer in Mongoloid and Caucasoid populations. In contrast to the CC and CG genotypes, the GG genotype of rs1052133 located on theOGG1 gene appeared to be a protective factor against developing breast cancer in both Mongoloid and Caucasoid populations. There was no evidence to suggest that rs25489, rs1799782, rs1130409, rs1805414 and rs1136410 were associated with breast cancer risk. In conclusion, this study provides evidence to support the theory that DNA repair genes are associated with breast cancer risk, providing information to further understand breast cancer etiology. and The potential biological pathways linking DNA repair, ethnic background, environment and breast cancer require further investigation.

XRCC1 and OGG1 Gene Polymorphisms and Breast Cancer: A Systematic Review of Literature

Context:

Known polymorphisms of DNA repair genes can be associated with the risk of many types of cancer. There is no consensus regarding association between XRCC1 and OGG1 with breast cancer (BC).

Objectives:

The aim of this study is to collect relevant published studies systematically.

Data Sources:

Sixty-two publications were identified through searching PubMed, PubMed Central, ISI web of knowledge, and reference list of related articles.

Study Selection:

We performed a systematic review according MOOSE guideline criteria. All longitudinal cohort and case-control studies investigating association of any type and grade of breast cancer with XRCC1 and OGG1 gene and their polymorphisms were eligible for initial inclusion.

Data Extraction:

Two authors screened titles and abstracts and extracted all needed information from eligible studies. Four research methodological components causing bias for the association between gene polymorphisms and breast cancer risk, including source of controls sampling, population ethnicity, sample size of studies and menopausal status of cases and controls was used for assessment of quality of studies

Results:

A total of 14,793 breast cancer cases and 15,409 controls were included in assessment of XRCC1 Arg194Trp. Four studies showed significant association and one study showed protective effect of XRCC1 Arg194Trp and BC. A total of 7,716 cases and 7,370 controls were included for XRCC1 Arg280His. Only one study showed significant association of XRCC1 Arg280His and breast cancer (OR = 1.82 (1.06 - 3.15). A total of 27,167 cases and 31,998 controls were included to estimate association between XRCC1 Arg399Gln polymorphism and breast cancer. Seven studies showed significant association and one showed protective effect of XRCC1 Arg399Gln and BC. A total of 9,417 cases and 11,087 controls were included for OGG1 Ser326Cys. Among studies focused on OGG1 Ser326Cys, none showed significant association with breast cancer.

Conclusions:

Systematic search of major databases identify many studies addressing the relationship between BC and susceptible alleles in the base excision repair genes and the fact that there are many variations in the magnitude of association depending on inheritance model and the population of the study.

XPD Asp312Asn and Lys751Gln polymorphisms and breast cancer susceptibility: a meta-analysis

The association between xeroderma pigmentosum complementation group D (XPD) Asp312Asn and Lys751Gln gene polymorphisms and breast cancer risk has been widely reported, but the results were inconsistent. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. A comprehensive search strategy was conducted towards the electronic databases including Medline, PubMed, Web of Science, Embase, and Chinese Biomedical Literature Database (Chinese). The association between the XPD polymorphism and breast cancer risk was conducted by odds ratios (ORs) and 95 % confidence intervals (95 % CIs). A total of 22 studies with 18,136 cases and 18,351 controls were included in our meta-analysis. Among these, 12 studies with 7,667 cases and 7,480 controls for Asp312Asn polymorphism and 20 studies with 10,469 cases and 10,871 controls for Lys751Gln polymorphism. With regard to Asp312Asn polymorphism, no significantly associated was found with breast cancer risk. However, significant association was found between Lys751Gln polymorphism and breast cancer risk under all genetic models in overall populations (C vs. A—OR = 1.10, 95 % CI = 1.04–1.17, P = 0.002; CC vs. AA—OR = 1.17, 95 % CI = 1.06–1.30, P = 0.003; AC vs. AA—OR = 1.06, 95 % CI = 1.01–1.12, P = 0.032; CC vs. AC/AA—OR = 1.17, 95 % CI = 1.04–1.32, P = 0.009; CC/AC vs. AA—OR = 1.07, 95 % CI = 1.02–1.12, P = 0.005). In subgroup analysis base on ethnicity, significance was found in Caucasians and mix. The results suggest that XPD Asp312Asn polymorphism was not associated with breast cancer. The XPD Lys751Gln polymorphism significantly increased breast cancer risk, especially for Caucasian and mix.

XPD Lys751Gln increases the risk of breast cancer

Breast cancer incidence has been on the increase in south Indian women. Polymorphisms in DNA repair genes modify an individual's risk to cancer. XPD (Xeroderma pigmentosum D), a DNA helicase gene involved in nucleotide excision repair and transcription coupled repair, may affect an individual's DNA repair capacity, particularly that of bulky adducts. This case-control study (250 breast cancer cases and 500 healthy controls) aimed to investigate the role of the XPD Lys751Gln polymorphism as a risk factor in the development of breast cancer. Genotyping was performed using the Taq Man allelic discrimination assay. Immunohisto-chemistry was used to quantitate the level of polycyclic aromatic hydrocarbon (PAH) adducts in biopsy samples obtained from the breast cancer patients. Results showed that the XPD Gln/Gln genotype was significantly associated with an increased risk of breast cancer (OR, 1.75; 95% CI 1.02-2.80), particularly in premenopausal female patients (OR, 2.6; 95% CI 1.33-4.79). PAH adduct levels were significantly higher in the cases with breast cancer as compared to the normal breast tissue. This study reveals that XPD may play a role in increasing breast cancer risk particularly in premenopausal females.

Meta-analysis of two ERCC2 (XPD) polymorphisms, Asp312Asn and Lys751Gln, in breast cancer

The excision repair cross-complementing group 2 gene (ERCC2) plays a key role in DNA repair. Several polymorphisms in the ERCC2 gene have been described, including the commonly occurring Lys751Gln and Asp312Asn polymorphisms. Studies investigating the association of these polymorphisms with breast cancer risk produced controversial results. To evaluate these associations presented in diverse populations, we have conducted a meta-analysis based on 40 studies from 33 publications in PubMed which included analyses of Lys751Gln (14,545 cases, 15,352 controls) and Asp312Asn polymorphisms (16,254 cases, 14,006 controls). Overall findings of both polymorphisms have implicated null effects (OR = 1.01-1.03) when the analyses were limited to the statistically powerful (≥80%) studies. Although modestly increased statistically significant breast cancer risk was detected in the underpowered studies (≤80%), removal of outliers resulted in null associations. Ethnic stratification showed non-significant and relatively null associations for both polymorphisms with breast cancer risk for the overall Caucasians as well as North American and the European sub-populations. Although statistically increased and decreased risks were observed for the homogenous populations of African-Americans (Lys751Gln, OR 1.25, 95% CI 1.03-1.53, P = 0.03) and Asians (Asp312Asn, ORs: 0.53-0.55, P values: 0.02-0.03), respectively, this may be the result of small sample size. Analyses of the homogeneous adduct studies, with relatively large sample size, exhibited increased risk for Lys751Gln (OR 1.20, 95% CI (1.02-1.41), P = 0.03) and Asp312Asn (OR 1.17 95% CI 1.02-1.34, P = 0.03) under the dominant genetic model. In conclusion, our results suggest null associations of both polymorphisms in the overall and the Caucasian subgroups, although some effects can be suggested for relatively smaller minority studies. Increased risk effect was more visible when the adduct studies are considered, suggesting the role of these polymorphisms in the presence of exposure to DNA damaging agents.

XRCC1 gene polymorphisms and breast cancer risk in different populations: a meta-analysis

We performed a meta-analysis to investigate the role of XRCC1 polymorphisms Arg194Trp, Arg280His and Arg399Gln in breast cancer. The results were pooled in a manner that appropriately reflects a biological model of gene effect using a random effects logistic regression model without multiple comparisons. Forty studies from 31 reports were included with 10 465 cases and 10 888 controls at Arg194Trp, 6156 cases and 5806 controls at Arg280His, and 21 467 cases and 22 766 controls at Arg399Gln. Our analysis found a tendency towards a recessive effect of Arg280His variant in Asian population only (His/His vs. Arg/Arg+Arg/His: OR=2.27, 95% CI=0.82, 6.31). An increased breast cancer risk with a recessive effect was also suggested for Arg399Gln variant in Asian population (Gln/Gln vs. Arg/Arg+Arg/Gln: OR=1.59, 95% CI=1.22, 2.09) only. These findings suggest that polymorphisms Arg280His and Arg399Gln may modify breast cancer risk differently in Caucasian and Asian populations.