DNA repair genes polymorphisms and risk of colorectal cancer in Saudi patients

Abstract

Background and study aims Polymorphisms in the DNA repair genes may influence individual capacity to repair DNA damage, which may be associated with increased genetic instability and carcinogenesis. Our aim was to evaluate the relation of genetic polymorphisms in 2 DNA repair genes, XPD Lys751Gln and XRCC1 (A399G), with colorectal cancer (CRC) susceptibility. We further investigated the potential effect of these DNA repair variants on clinicopathological parameters of CRC patients. Patients and methods Both XPD and XRCC1 polymorphisms were characterised in one hundred CRC patients and one hundred healthy controls who had no history of any malignancy by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method and PCR with confronting two-pair primers (PCR–CTPP), using DNA from peripheral blood in a case control study. Results Our results revealed that the frequencies of GG genotype of XRCC1 399 polymorphism were significantly higher in the CRC patients than in the normal individuals (p ⩽ 0.03), and did not observe any association between the XPD Lys751Gln polymorphism and CRC risk. We found association between both XRCC1 A399G polymorphisms and histological grading of disease. Conclusion Our results suggested that, XRCC1 gene is an important candidate gene for susceptibility to colorectal carcinoma.