DNA REPAIR GENE XRCC3 241MET VARIANT AND BREAST CANCER SUSCEPTIBILITY OF AZERI POPULATIONIN IRANIAN

Abstract

DNA-repair systems are essential for repairing damage that occurs when there is recombination between homologous chromosomes. The gene XRCC3 (X-ray cross complementing group 3) encodes a member of the RecA/Rad51-related protein family that participates in homologous recombination to maintain chromosome stability and repair DNA damage. The Thr241Met (XRCC3-18067C>T, rs861539) substitution, a C to T transition at codon 241 in exon7, thus plays critical roles in cancer development. The aim of this study was association between XRCC3 Thr241Met polymorphism and risk of sporadic breast cancer in Azari population. We analysed DNA samples from 100 sporadic breast cancer patients and 100 healthy women, for XRCC3 Thr241Met polymorphism using PCR-RFLP. Genotype specific risks were tested using chi -test with 95% confident intervals. Frequency of Thr/Thr at codon 241 was 69% in controls and 70% in patients, Thr/Met frequency was 22% in controls and 13 % in patients, the Met/Met genotype was 9% incontrols and 17% in patients. No correlation between the genotype and allele distribution and increased susceptibility for breast Cancer. Our results suggested that in premenopausal women, breast cancer riskis not significantly associated with rs861539 in Azari population.