Polymorphisms XRCC1-R399Q and XRCC3-T241M and the Risk of Breast Cancer at the Ontario Site of the Breast Cancer Family Registry

Association of RAD51, XRCC1, XRCC2, and XRCC3 Polymorphisms with Risk of Breast Cancer

Background: DNA repair genes are among the low-penetrance genes implicated in breast cancer. However variants of DNA repair genes may alter their protein function thus leading to carcinogenesis. Breast cancer is the most common cancer among women in India. The aim of the present study was to identify association, if any, of single nucleotide polymorphisms (SNP's) in four genes involved in DNA repair pathways including, RAD51 rs1801320, XRCC1 rs25487, XRCC2 rs3218536, and XRCC3 rs861539 with the risk of breast cancer. Materials and Methods: In this case-control study 611 female subjects (311 breast cancer patients and 300 healthy controls) were screened for four SNPs using polymerase chain reaction-restriction fragment length polymorphism analyses. Multifactor dimensionality reduction (MDR) analysis was performed to estimate the gene-gene interaction. Protein-protein interaction network analysis were studied using the STRING database. Results: The GC genotype (p = 0.018) and the combined GC+CC (p = 0.03) genotypes of RAD51 rs1801320 were significantly associated with reduced risk of breast cancer. The CT genotype (p = 0.0001), the combined CT+TT genotypes (p = 0.0002), and the T allele (p = 0.0019) of XRCC3 rs861539 polymorphism were associated with reduced risk of the breast cancer. No association of XRCC1 rs25487 and XRCC2 rs3218536 polymorphisms with breast cancer was observed. MDR analysis indicated a positive interaction between XRCC3 and XRCC2. String network analysis showed that the RAD51, XRCC1, XRCC2, and XRCC3 proteins are in strong interaction with each other and other breast cancer-related proteins such as BRCA2. Conclusion: RAD51 rs1801320 and XRCC3 rs861539 polymorphisms were associated with reduced risk of breast cancer. There is evidence of positive interactions among XRCC1, XRCC2, XRCC3, and RAD51.

Relationship between polymorphisms in homologous recombination repair genes RAD51 G172T、XRCC2 & XRCC3 and risk of breast cancer: A meta-analysis

Background

Genetic variability in DNA double-strand break repair genes such as RAD51 gene and its paralogs XRCC2、XRCC3 may contribute to the occurrence and progression of breast cancer. To obtain a complete evaluation of the above association, we performed a meta-analysis of published studies.

Methods

Electronic databases, including PubMed, EMBASE, Web of Science, and Cochrane Library, were comprehensively searched from inception to September 2022. The Newcastle-Ottawa Scale (NOS) checklist was used to assess all included non-randomized studies. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by STATA 16.0 to assess the strength of the association between single nucleotide polymorphisms (SNPs) in these genes and breast cancer risk. Subsequently, the heterogeneity between studies, sensitivity, and publication bias were performed. We downloaded data from The Cancer Genome Atlas (TCGA) and used univariate and multivariate Cox proportional hazard regression (CPH) models to validate the prognostic value of these related genes in the R software.

Results

The combined results showed that there was a significant correlation between the G172T polymorphism and the susceptibility to breast cancer in the homozygote model (OR= 1.841, 95% CI=1.06-3.21, P=0.03). Furthermore, ethnic analysis showed that SNP was associated with the risk of breast cancer in Arab populations in homozygous models (OR=3.52, 95% CI=1.13-11.0, P= 0.003). For the XRCC2 R188H polymorphism, no significant association was observed. Regarding polymorphism in XRCC3 T241M, a significantly increased cancer risk was only observed in the allelic genetic model (OR=1.05, 95% CI= 1.00-1.11, P=0.04).

Conclusions

In conclusion, this meta-analysis suggests that Rad51 G172T polymorphism is likely associated with an increased risk of breast cancer, significantly in the Arab population. The relationship between the XRCC2 R188H polymorphism and breast cancer was not obvious. And T241M in XRCC3 may be associated with breast cancer risk, especially in the Asian population.

Associations between XRCC3 Thr241Met polymorphisms and breast cancer risk: systematic-review and meta-analysis of 55 case-control studies

BACKGROUND

The X-ray repair cross-complementing group 3 (XRCC3) is an efficient component of homologous recombination and is required for the preservation of chromosomal integrity in mammalian cells. The association between Thr241Met single-nucleotide polymorphism (SNP) in this gene and susceptibility to breast cancer has been assessed in several studies. Yet, reports are controversial. The present meta-analysis has been designed to identify whether this SNP is associated with susceptibility to breast cancer.

METHODS

We performed a systematic review and meta-analysis for retrieving the case-control studies on the associations between T241 M SNP and the risk of breast cancer. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to verify the association in dominant, recessive, and homozygote inheritance models.

RESULTS

We included 55 studies containing 30,966 sporadic breast cancer cases, 1174 familial breast cancer cases and 32,890 controls in the meta-analysis. In crude analyses, no association was detected between the mentioned SNP and breast cancer risk in recessive, homozygote or dominant models. However, ethnic based analysis showed that in sporadic breast cancer, the SNP was associated with breast cancer risk in Arab populations in homozygous (OR (95% CI) = 3.649 (2.029-6.563), p = 0.0001) and recessive models (OR (95% CI) = 4.092 (1.806-9.271), p = 0.001). The association was significant in Asian population in dominant model (OR (95% CI) = 1.296, p = 0.029). However, the associations was significant in familial breast cancer in mixed ethnic-based subgroup in homozygote and recessive models (OR (95% CI) = 0.451 (0.309-0.659), p = 0.0001, OR (95% CI) = 0.462 (0.298-0.716), p = 0.001 respectively).

CONCLUSIONS

Taken together, our results in a large sample of both sporadic and familial cases of breast cancer showed insignificant role of Thr241Met in the pathogenesis of this type of malignancy. Such results were more conclusive in sporadic cases. In familial cases, future studies are needed to verify our results.

DNA Repair Mechanism Gene, XRCC1A ( Arg194Trp) but not XRCC3 ( Thr241Met) Polymorphism Increased the Risk of Breast Cancer in Premenopausal Females: A Case-Control Study in Northeastern Region of India

X-ray repair cross complementary group gene is one of the most studied candidate gene involved in different types of cancers. Studies have shown that X-ray repair cross complementary genes are significantly associated with increased risk of breast cancer in females. Moreover, studies have revealed that X-ray repair cross complementary gene polymorphism significantly varies between and within different ethnic groups globally. The present case–control study was aimed to investigate the association of X-ray repair cross complementary 1A (Arg194Trp) and X-ray repair cross complementary 3 (Thr241Met) polymorphism with the risk of breast cancer in females from northeastern region of India. The present case–control study includes histopathologically confirmed and newly diagnosed 464 cases with breast cancer and 534 apparently healthy neighborhood community controls. Information on sociodemographic factors and putative risk factors were collected from each study participant by conducting face-to-face interviews. Genotyping of X-ray repair cross complementary 1A (Arg194Trp) and X-ray repair cross complementary 3 (Thr241Met) was carried out by polymerase chain reaction-restriction fragment length polymorphism. For statistical analysis, both univariate and multivariate logistic regression analyses were performed. We also performed stratified analysis to find out the association of X-ray repair cross complementary genes with the risk of breast cancer stratified based on menstrual status. This study revealed that tryptophan allele (R/W-W/W genotype) in X-ray repair cross complementary 1A (Arg194Trp) gene significantly increased the risk of breast cancer (adjusted odds ratio = 1.44, 95% confidence interval = 1.06-1.97, P < .05 for R/W-W/W genotype). Moreover, it was found that tryptophan allele (W/W genotype) at codon 194 of X-ray repair cross complementary 1A (Arg194Trp) gene significantly increased the risk of breast cancer in premenopausal females (crude odds ratio = 1.66, 95% confidence interval = 1.11-2.46, P < .05 for R/W-W/W genotype). The present study did not reveal any significant association of X-ray repair cross complementary 3 (Thr241Met) polymorphism with the risk of breast cancer. The present study has explored that X-ray repair cross complementary 1A (Arg194Trp) gene polymorphism is significantly associated with the increased risk of breast cancer in premenopausal females from northeastern region of India which may be beneficial for prognostic purposes.

Polymorphisms and mutations in GSTP1, RAD51, XRCC1 and XRCC3 genes in breast cancer patients

BACKGROUND

Genotoxic factors, including ionizing radiation and oxidative stress, are associated with genomic instability and development of breast cancer (BC). The homologous recombination DNA repair (HRR) pathway, base excision repair (BER) mechanism, and antioxidative enzymes are required as defense mechanisms against these DNA damaging agents. GSTP1, XRCC1, XRCC3 and RAD51 proteins are essential components of antioxidation, BER and HRR of DNA, respectively. Deficiencies in BER, HRR and antioxidation pathways are involved in the progression of cancer.

METHODS

Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue and blood samples of BC patients of an Italian population. Genomic DNA was also extracted from blood specimens of a control group. DNA sequencing was performed for six single-nucleotide polymorphisms (SNPs) in the GSTP1, RAD51, XRCC1 and XRCC3 genes in BC patients and the control group.

RESULTS

Two variants in the 5'-UTR of the XRCC3 (rs1799794 A/G) and RAD51 (rs1801321) genes showed a significant association with susceptibility to BC (OR = 4.125; 95% CI 1.057-16.102; p = 0.03 and OR = 2.04; 95% CI 0.4925-8.449; p = 0.007, respectively). Additionally, we reported 2 mutations in intron 7 of the XRCC3 gene, CTdel (rs543072564) and A/G (rs369703243).

CONCLUSIONS

Our results underscored the existence of an association between XRCC3-5'-UTR-A/G (rs1799794) and RAD51-5'-UTR G172T (rs1801321) genotypes and BC risk in an Italian population. The presence of mutations in the intronic region of the XRCC3 gene highlights the importance of more sequence screening of DNA repair genes for possible genetic penetrance in BC.

XRCC1 Arg399Gln Gene Polymorphism and Hepatocellular Carcinoma Risk in the Italian Population

Background

The human X-ray repair cross-complementing protein 1 ( XRCC1) gene encodes for one of the major repair factors involved in base excision repair (BER), which is reported to be associated with the risk of several cancers. A few studies have explored the association between risk of hepatocellular carcinoma (HCC) and single-nucleotide polymorphisms (SNPs) in different DNA repair genes, with contradictory results. The purpose of this study was to evaluate the association between XRCC1 Arg399Gln polymorphism and susceptibility to HCC.

Methods

A total of 89 HCC patients and 99 randomly selected healthy controls were enrolled. Genotyping of XRCC1 rs25487 was performed by high-resolution melting analysis and Sanger sequencing.

Results

On univariate analysis, a statistically significant association was found between risk of HCC and XRCC1 399Arg/Gln genotype (odd ratio [OR] = 1.88; 95% CI, 1.04-3.43), which was confirmed after adjusting by sex (OR = 1.94; 95% CI, 1.04-3.63). Although not significant, Kaplan-Meier analysis showed a decreased median survival in Arg/Gln genotype carriers in comparison with Arg/Arg carriers.

Conclusions

To our knowledge, this is the first study reporting an association between BER SNP and HCC risk in a population of central-southern Italy.

Polymorphisms in Cancer Susceptibility Genes XRCC1, RAD51 and TP53 and the Risk of Breast Cancer in Serbian Women

Background

Thanks to immense improvements in technology over the past few decades, we have witnessed a major shift towards the idea that breast cancer results from a combined effect of multiple common alleles conferring low risk. This study investigates the role of 3 nonsynonymous SNPs in the DNA repair genes XRCC1 (R399Q), RAD51 (G135C) and TP53 (Arg72Pro) in breast cancer in Serbian women.

Patients and Methods

Cases of BRCA1/2-negative hereditary breast cancer (n = 52), sporadic breast cancer (n = 106) and age-matched cancer-free female controls (n = 104) were obtained from the Institute for Oncology and Radiology of Serbia's blood bank. Restriction fragment length polymorphism analysis was used for genotyping. Descriptive analyses included genotype and allelic frequencies; the odds ratio and 95% confidence interval were calculated as an estimate of the relative risk.

Results

A significant difference in QQ+RQ versus RR genotype distribution of XRCC1 was observed between hereditary breast cancer patients and cancer-free controls. The association was confirmed among young breast cancer patients from these high-risk families. The existence of 3 recessive alleles in the RAD51 and XRCC1 genotype combination showed an association with hereditary breast cancer. Odds ratio analysis indicated a strong protective role of the RAD51 GG + TP53 ArgArg + XRCC1 RR combined genotype against hereditary breast cancer negative for BRCA1/2 mutations.

Conclusions

The XRCC1 R399Q polymorphism showed an association with increased breast cancer risk in Serbia, especially in the hereditary form of the disease and in young breast cancer patients. Dominant alleles of RAD51, TP53 and XRCC1 combined genotypes indicated a strong protective role against hereditary breast cancer.

Association between hospital discharge rate for female breast cancer and residence in a zip code containing hazardous waste sites

BACKGROUND

Exposure to chemicals plays a role in risk of breast cancer. However, possible associations between risk of breast cancer and residential proximity to hazardous waste sites (HWSs) have not been reported.

METHODS

We determined rates of hospital discharge with a diagnosis of female breast cancer in relation to residence in a zip code containing HWSs in New York State (NYS) after adjustment for ethnicity, age, income and urbanicity. Waste exposure was assessed by both the number of waste sites and the type of contaminants. Negative binomial regression was used to test the associations.

RESULTS

After controlling for confounders, the hospital discharge rate of breast cancer for women living in zip codes having four or more HWSs or in zip codes having one HWS increased significantly (at the 0.05 level) by 9.1% and 6.4%, as compared to those living in a zip code with no HWS. The association for women living in zip codes having two or three HWSs was not significant. This indicates that the extent of exposure cannot be assessed solely by the number of waste sites. The discharge rate for women living in zip codes containing at least one volatile organic compound (VOC) waste site was significantly increased 5.6% as compared to those living in a zip code without any HWS, while the increases were not significant for women living in zip codes containing waste sites with persistent organic pollutants (POPs) or other contaminants. The significant associations were stronger for African American than Caucasian women and stronger in more urbanized than in rural areas.

CONCLUSIONS

Residence within a geographic area (defined by zip codes) that includes a hazardous waste site with VOCs is significantly associated with an increased rate of hospitalization for breast cancer, and the association is stronger for African American than Caucasian women and stronger in more urbanized than in rural areas after adjustment for the confounders.

XRCC1 Genotype and Breast Cancer: Functional Studies and Epidemiologic Data Show Interactions between XRCC1 Codon 280 His and Smoking

Tobacco smoke produces oxidative and alkylative DNA damage that necessitates repair by base excision repair coordinated by X-ray cross-complementing gene 1 (XRCC1). We investigated whether polymorphisms in XRCC1 alter DNA repair capacity and modify breast cancer risk associated with smoking. To show the functionality of the 280His variant, we evaluated single-strand break (SSB) repair capacity of isogenic Chinese hamster ovary cells expressing human forms of XRCC1 after exposure to hydrogen peroxide (H(2)O(2)), methyl methanesulfonate (MMS), or camptothecin by monitoring NAD(P)H. We used data from the Carolina Breast Cancer Study (CBCS), a population-based, case-control study that included 2,077 cases (786 African Americans and 1,281 Whites) and 1,818 controls (681 African Americans and 1,137 Whites), to examine associations among XRCC1 codon 194, 280, and 399 genotypes, breast cancer, and smoking. Odds ratios and 95% confidence intervals (95% CI) were calculated by unconditional logistic regression. Only cells expressing the 280His protein accumulated SSB, indicated by NAD(P)H depletion, from both H(2)O(2) and MMS exposures. In the CBCS, positive associations were observed between breast cancer and smoking dose for participants with XRCC1 codon 194 Arg/Arg (P(trend) = 0.046), 399 Arg/Arg (P(trend) = 0.012), and 280 His/His or His/Arg (P(trend) = 0.047) genotypes. The 280His allele was in strong linkage disequilibrium with 194Arg (Lewontin's D' = 1.0) and 399Arg (D' = 1.0). These data suggest that less common, functional polymorphisms may lie within common haplotypes and drive gene-environment interactions.