Background: Breast cancer is one of the most common worldwide malignancies among women. Biological data suggest that damage induced by endogenous and exogenous factors affects the integrity of DNA and associated with susceptibility to breast cancer. Single nucleotide polymorphisms (SNPs) in DNA repair genes can associated with differences in the repair efficiency of DNA damage and may affect breast cancer. The XRCC3 protein participates in DNA double-strand breaks and recombinational repair, in other words the product of XRCC3 gene, plays a key role in homologous recombination repair of DNA double-strand breaks. The polymorphism of FokI plays critical roles in breast cancer development. The aim of the present study was to evaluate associations between the risk of breast cancer and FokI polymorphism in the XRCC3 gene.
Methods: This case-control study was carried out on the women with breast cancer and healthy women located in Markazi province at Arak University Research, Iran, from October 2016 to March 2017. In the present study, the association of FokI polymorphisms and the risk of breast cancer was assessed by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques. In this method, genomic DNA was extracted from blood samples using the kit procedure. Then, PCR was performed and the SNP-containing DNA amplicons were subjected to digestion of enzymes. Following digestion, each sample was immediately analyzed by 3% agarose gel electrophoresis. Statistical analysis was done using SPSS and SNP Analyzer softwares and the final results were determined.
Results: No statistically significant difference was observed between the two groups of patients and controls for three genotypes the site rs1799794 (P=0.435). Genotype AG (P=0.384, OR=0.614, CI=95%, 0.205-1.840) and GG (P=0.867, OR=0.911, CI=95%; 0.308-2.699) had no significant associations with risk of breast cancer.
Conclusion: There was no significant association between FokI polymorphisms of the XRCC3 and risk of susceptibility to breast cancer, which was in accordance to some researchers. FokI polymorphisms of XRCC3 gene cannot be used as a biomarker in clinical predictive studies in relation to risk of breast cancer.
