Email updates

Keep up to date with the latest news and content from Journal of Biomedical Science and BioMed Central.

Journal App

google play app store

MST logoThe cost of publication in Journal of Biomedical Science is borne by the Ministry of Science and Technology, Taiwan.

Open Access Highly Accessed Research

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

Xia Wang1, Yadi Wang2, Yue Wang1, Jian Cheng1, Yanyun Wang1 and Minwen Ha1*

Author Affiliations

1 Department of Oncology, First Affiliated Hospital of Liaoning Medical College, Jinzhou, China

2 Department of Oncology, Third Affiliated Hospital of Liaoning Medical College, Jinzhou, China

For all author emails, please log on.

Journal of Biomedical Science 2013, 20:5  doi:10.1186/1423-0127-20-5

Published: 25 January 2013

Abstract

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.

Results

Expression of both TS protein and its mRNA was elevated in NSCLC tissues compared with matched normal tissues, and significantly higher in lung squamous cell carcinoma than in lung adenocarcinoma. TS expression was associated with poor tumor differentiation. Furthermore, the genotyping data showed that 56% of lung adenocarcinoma patients had the TS gene 3’-UTR 1494 bp (−6 bp/-6 bp) genotype and the rest had TS gene 3’-UTR 1494 bp (−6 bp/+6 bp). There was no TS 3’-UTR 1494 bp (+6 bp/+6 bp) genotype in any patients. Statistical analysis revealed that gender, tumor stage, and TS 3’-UTR 1494del 6 bp polymorphism were significant prognostic factors after short-term pemetrexed treatment. Log-rank analysis revealed that patients with the (−6 bp/-6 bp) genotype had significantly better progression-free and overall survival than patients with (−6 bp/+6 bp).

Conclusions

This study showed that TS protein is highly expressed in NSCLC and that polymorphisms of TS 3’-UTR 1494del 6 bp are associated with sensitivity of lung adenocarcinoma patients to pemetrexed treatment. This suggests that TS gene polymorphisms should be further evaluated as prognostic markers for personalized therapy in lung adenocarcinoma.

Keywords:
Lung adenocarcinoma; Non-small cell lung cancer; Pemetrexed treatment; Thymidylate synthase; TS gene polymorphism