Association of thymidylate synthase gene 3'-untranslated region polymorphism with sensitivity of non-small cell lung cancer to pemetrexed treatment: TS gene polymorphism and pemetrexed sensitivity in NSCLC

Background Thymidylate synthase (TS) is a key enzyme responsible for DNA synthesis and repair. Altered expression of TS protein or TS gene polymorphisms has been associated with cancer progression and treatment response. This study investigated the expressions of TS and its gene SNPs in non-small cell lung cancer (NSCLC), and then its association with sensitivity to pemetrexed treatment. Immunohistochemistry and qRT-PCR were performed on 160 resected NSCLC specimens and corresponding normal tissues to assess the expressions of TS protein and TS mRNA, and for associations with clinicopathological data. Blood samples of 106 lung adenocarcinoma patients were examined for polymorphisms of the TS gene 3’-UTR 1494del 6 bp, which was then investigated for associations with responses of the patients to pemetrexed treatment and survival.