Gastric carcinogenesis is associated with defects in DNA damage repair pathways, in which the XRCC gene family (XRCC1, XRCC5, and XRCC6) play an important role in DNA repair. It is also well known that the CDH1 gene, as a tumor suppressor, influences the development of gastric cancer.

We recruited 484 gastric cancer patients and 471 controls. DNA genotyping and Helicobacter pylori infection were determined by commercial kits. Association between polymorphisms and gastric cancer risk and survival was evaluated through SPSS 26.0.

Stratified analysis revealed that XRCC1 rs25487 TC/TT was associated with increased gastric cancer risk in the following four subgroups of males (adjusted OR = 1.40, 95% CI: 1.03-1.90, p = 0.031), positive Helicobacter pylori (adjusted OR = 1.58, 95% CI: 1.09-2.28, p = 0.015), tumor stage III-IV (adjusted OR = 1.42, 95% CI: 1.06-1.89, p = 0.017), and non-gastric cardiac adenocarcinoma (adjusted OR = 1.36, 95% CI: 1.02-1.82, p = 0.034). Additionally, survival analysis indicated that XRCC1 rs25487 TC/TT genotype (HR = 1.35, 95% CI: 1.08-1.69, p = 0.010) was associated with unfavorable survival in gastric cancer patients.

XRCC1 rs25487 CC genotype decreased the risk of gastric cancer, and predicted a favorable survival prognosis.

To identify potential Single Nucleotide Polymorphisms (SNPs) of susceptibility for the development of acute radiation dermatitis in head and neck cancer patients, and also to verify the association between SNPs and the severity of RD.

This systematic review was reported according to the PRISMA guideline. The proportion meta-analysis was performed to identify the prevalence of genetic markers by geographical region and radiation dermatitis severity. The meta-analysis was performed to verify the association between genetic markers and RD severity. The certainty of the evidence was assessed by GRADE.

Thirteen studies were included. The most prevalent SNPs were XRCC3 (rs861639) (36%), TGFβ1 (rs1800469) (35%), and RAD51 (rs1801321) (34%). There are prevalence studies in Europe and Asia, with a similar prevalence for all SNPs (29-40%). The prevalence was higher in patients who developed radiation dermatitis ≤2 for any subtype of genes (75-76%). No SNP showed a statistically significant association with very low certainty of evidence.

The most prevalent SNPs may be predictors of acute RD. The analysis of SNP before starting radiation therapy may be a promising method to predict the risk of developing radiation dermatitis and allow radiosensitive patients to have a customized treatment. This current review provides new research directions.

At present very little information is available on combined effects of DNA repair genes with tumor suppressor gene polymorphisms and their association with cancer susceptibility. No such association studies have been carried out with breast cancer or any other cancer from India. Present study was conducted to study the combined effects of SNPs of XRCC1, XRCC2, XRCC3 with Arg72Pro and Arg249Ser SNPs of TP53 gene in risk of BC in rural parts of India.

The polymorphisms of Arg194Trp, Arg280His, Arg399Gln of XRCC1, Arg188His of XRCC2 and Thr241Met of  XRCC3 with Arg72Pro and Arg249Ser of TP53 gene polymorphisms was studied by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method. The association among the polymorphisms with breast cancer risk was studied by Odds ratio within 95% confidence interval and SNP-SNP interaction were confirmed by logistic regression analysis.

The results of genotype frequency distribution of XRCC1, XRCC2, XRCC3 genotypes showed positive association between XRCC1 Arg280His polymorphism and BC risk (OR=4.54; 95% CI: 3.36- 6.15; p<0.0001).  Also the heterozygous genotypes Arg188His of XRCC2 (OR=1.58; 95% CI: 1.13- 2.21; p=0.007) and Thr241Met genotype of XRCC3 (OR=2.13; 95% CI: 1.44- 3.13; p=0.0001) were associated with BC risk. The combination of heterozygous Arg280His genotype of XRCC1 along with Arg72Pro genotype of TP53 increased the risk of BC (OR=4.53; 95% CI: 2.85-7.20); p<0.0001). Similarly,  the combined effect of heterozygous Arg/His genotype of XRCC1 with heterozygous Arg/Ser genotype of TP53 at codon 249 showed significant association with increased BC risk (OR=5.08; 95% CI: 2.86-9.04); p<0.0001).

The findings derived from our study concluded that the heterozygous variant Arg280His genotype of XRCC1 and Thr241Met polymorphism of XRCC3 in combination with heterozygous arginine72proline genotype and heterozygous Arg249Ser polymorphism of TP53 showed significant association with breast cancer risk in Maharashtrian women.

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.

The base excision repair (BER) pathway is essential for maintaining the stability of DNA in all organisms and defects in this process are associated with life-threatening diseases. It is involved in removing specific types of DNA lesions that are induced by both exogenous and endogenous genotoxic substances. BER is a multi-step mechanism that is often initiated by the removal of a damaged base leading to a genotoxic intermediate that is further processed before the reinsertion of the correct nucleotide and the restoration of the genome to a stable structure. Studies in human and yeast cells, as well as fruit fly and nematode worms, have played important roles in identifying the components of this conserved DNA repair pathway that maintains the integrity of the eukaryotic genome. This review will focus on the components of base excision repair, namely, the DNA glycosylases, the apurinic/apyrimidinic endonucleases, the DNA polymerase, and the ligases, as well as other protein cofactors. Functional insights into these conserved proteins will be provided from humans, Saccharomyces cerevisiae, Drosophila melanogaster, and Caenorhabditis elegans, and the implications of genetic polymorphisms and knockouts of the corresponding genes.

Cervical cancer (CC) is one of the leading cause of death in women worldwide, HPV infection is the major risk factor in the disease development, 0and however other risk factor such as chemical carcinogens, genetic susceptibility and altered immune system are also a cause of the disease progression. In the light of the above statement we studied the base excision repair pathway (BER).

We identified and studied the association of Single Nucleotide polymorphisms in the DNA repair genes of XRCC1 (Arg194Trp, Arg399G,) and APE-1Asp/148Glu to the susceptibility of cervical cancer (CC) in North Indian population. In our study of cases (n=102). Controls (n=109) were recruited from among women without cervical abnormalities. Genotypes were determined by PCR-CTPP method, Taking DNA from peripheral blood in a case control study.

A positive association was observed between the polymorphisms of XRCC1 genes, that is, in codons 194 (P=0.03, odds ratio (OR) =2.39, 95% confidence interval (CI)=5.2-1.1), 280 (P=0.01, OR=4.1, 95% CI=11.5-1.3) and 399 (P=0.01, OR=3.4, 95% CI=8.6-1.3) while APE-1 genotype GG (p=0.03,odds ratio(OR)=0.2,95% confidence interval (CI)=0.97-0.004) we observed a statistically significant protective role in developing cervical cancer.

Our results suggested that, XRCC1 gene is an important candidate gene for susceptibility to cervical cancer. Although the sample size was small, the present study indicate a statistical association between cervical cancer and XRCC1 SNPs. Future studies are needed that may provide a better understanding of the association between gene polymorphism and cervical carcinoma risk.
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