Polymorphisms of DNA Repair Genes in Endometrial Cancer

Abstract

Endometrial cancer belongs to the commonest malignancy in females. Its development may be associated with the high exposure of endometrium to exo- and endogenous estrogens. Estrogens produce DNA bulky adducts and oxidative base damages which are removed in nucleotide excision repair (NER) and base excision repair (BER) pathways. The reaction of endometrial cells to DNA damage may be crucial for their susceptibility to cancer transformation. This reaction is executed mainly by DNA repair, which can be modulated by the variability in the genes encoding DNA repair proteins. In this report we genotyped 4 polymorphisms of 3 DNA repair genes in 94 endometrial cancer patients and 114 age-matched cancer-free women using RFLP-PCR. The following polymorphisms were studied: p.Arg194Trp, p.Arg399Gln of the XRCC1 gene, p.Ser326Cys of the hOGG1 gene and p.Lys751Gln of the ERCC2 gene. We found an association between the ERCC2 751Gln variant and endometrial cancer occurrence (OR 3.95; 95 % CI 1.88-8.31). Gene-gene interaction between the ERCC2 751Gln and XRCC1 194Trp variants also increased the risk of endometrial cancer (OR 4.41; 95 % CI 2.01-9.67). The risk in the carriers of the ERCC2 751Gln variant was increased by a positive cancer history in first degree relatives (OR 4.97; 95 % CI 1.98-12.48). The risk of endometrial cancer was not alter by polymorphism p.Ser326Cys of the hOGG1 gene. The 751 Lys/Gln polymorphism of the ERCC2 gene may be linked with endometrial cancer occurrence and its effect can be potentiated by variants of the XRCC1 gene or first degree relatives positive cancer history.