Background:
DNA repair genes are the genes that protect cellular genome from carcinogenic exposures such as uv radiation, ionizing radiation, nicotine and etc. Any dysfunction in this repair system does significantly increase the risk of cancer induction. XRRC1 (X-ray repair Cross Complementing 1) gene is one of the important DNA repair genes. In this study we aimed to investigate the polymorphism in XRCC1 gene and relationship between the polymorphic genotypes and development of non melanoma skin cancer.
Material and Methods:
XRCC1 gene polymorphism was evaluated in a total of 138 patients. Seventyfive healty individuals were used as the control group and 63 patients with a histopahologic diagnosis of skin cancer as the risk group. Polymerase chain reaction – restriction fragment length poymorphism (PCR-RFLP) method was used to define Arg194Arg (Cytosin to Thymidine conversion on exon 6) and Arg399Gln (Guanine to Adenine conversion on exon 10) polymorphisms in XRCC1 gene.
Results:
There was no significant difference between the groups with respect to the distribution of XRC194 polymorphism (p=0.901). However, there was a significant increase in the number of XRC399 polymorphism in the skin cancer group (p=0.048). The genotypes of this polymorphism were Arg/Arg, Gln/Gln and Arg/Gln. Among these Arg/Arg genotype (homozygot Arg) was associated with a higher incidence of skin cancer (2.32 x higher) when compared to heterozygotes (Arg/Gln) (p=0.022). There was also no significant relationship between the distribution of polymorphisms and clinical risk factors of age, sex, positive family history, age of tumor detection, tumor type, primary vs recurrent tumor and skin type.
Conclusion:
In conclusion, the results of this study suggested that homozygotous Arg XRC399 polymorphism was associated with an increased susceptibility to non melanoma skin cancers.
Keywords: Skin cancer, DNA repair gene, XRCC1, polymorphism