Here, we have further studied the interactions between these two proteins, including two variants of XRCC1 (R194W and R280H) arising from single-nucleotide polymorphisms (SNPs) that have been associated with elevated cancer risk in some reports.
DNA repair genes is a key factor for cancer susceptibility, and we conducted a case-control study to investigate the association of XRCC1 codons 194 (Arg to Trp), 280 (Arg to His) and 399 (Arg to Gln) with risk of NSCLC.
Despite accumulating evidence of an important role that XRCC1 plays in maintaining genomic stability, the relationship between one of its most predominant variants, R280H (rs25489), and cancer prevalence remains ambiguous.
The meta-analysis results suggest that the XRCC1 Arg399Gln and Arg280His polymorphisms are probably not associated with the risk of HNC, but the XRCC1 Arg194Trp polymorphism was associated with increased risk of HNC in the subgroup analysis of studies adjusted for smoking and alcohol and with increased risk of oral cancer in the stratified analyses based on cancer site.
Polymorphisms of the DNA repair gene X-ray repair cross-complementing protein 1 (XRCC1) Arg194Trp, Arg280His, and Arg399Gln have been shown to alter the DNA repair activity and to be associated with genetic susceptibility to several types of cancer.
The analyses suggest that XRCC1 Arg194Trp, Arg280His polymorphisms may be biomarkers of cancer susceptibility and a single larger study with thousands of subjects and tissue-specific biochemical and biological characterization is warranted to further evaluate potential gene-to-gene and gene-to-environment interactions on XRCC1 polymorphisms and cancer risk.
In this study, we have shown that three nsSNPs, which were predicted to have functional consequences (XRCC1-R399Q, XRCC3-T241M, XRCC1-R280H), were already found to be associated with cancer risk.