Associations between polymorphisms at microRNA-binding sites in TYMS and breast cancer risk among Chinese women

Abstract

Studies have suggested that thymidylate (TYMS) polymorphisms are associated with breast cancer. However, inconsistent results were obtained and data from Asian populations are largely lacking. In this study, the relationships between two common TYMS polymorphisms (rs2790 and rs1059394) and the breast cancer risk were evaluated. We also studied the TYMS expression between tumor and para-carcinoma tissues, and the association between TYMS levels and prognosis of breast cancer. This hospital-based study included 434 patients and 450 cancer-free individuals. Genotying was performed using Sequenom Mass-ARRAY. The microarray dataset GSE115144 was downloaded to compare the differences in TYMS expression between tumor and para-carcinoma tissues. The microarray dataset GSE20685 was used to analysis the metastasis free survival (MFS) and overall survival (OS) of patients. The rs2790 polymorphism was related to a higher risk of breast cancer (recessive model: OR=1.50, 95%CI=1.02-2.21, P=0.038) and the C allele of rs1059394 was overrepresented in patients with tumor stage III-IV (heterozygote model: OR=0.60, 95%CI=0.39-0.94, P=0.025; dominant model: OR=0.59, 95%CI=0.39-0.89, P=0.013). The tumor tissues had a higher TYMS expression levels and patients with higher TYMS expression levels had worse OS. Overall, TYMS polymorphism may increase susceptibility to breast cancer in Chinese Han women and TYMS expression levels may be a predictive factor for breast cancer patients.