BACKGROUND AND OBJECTIVEThe transport of nucleoside transmembrane mediated by equilibrative nucleoside transporter (ENT) plays an important role in regulating various cellular functions, and the ENT gene may be candidate gene of tumors. The aim of this study is to investigate the association between the single nudcleotide polymorphism (SNP) of ENT3 and the hereditary susceptibility of lung cancer.

METHODSA case-control study was performed involved in 351 lung cancer patients and 207 cancer-free controls from Chinese population in Shanghai pulmonary hospital. The rs10999776 (C>T) polymorphism was determined by using Real-time PCR with AllGlo probes. The frequency distribution of genotypes and allele between lung cancer and controls groups was analyzed by chi-square test. The association between polymorphism in the ENT3 gene with the risk of lung cancer was estimated by computing odds ration (OR) and 95%CI.

RESULTSThe genotype (CC, TC, IT) and allele distribution of the ENT3 SNP in the patients with lung cancer was not significantly different compared with that in controls (P > 0.05). Compared with never-smokers with wild homozygous genotype, smokers with T allele (TC+TT) had increased risk of lung cancer (OR = 2.848, 95% CI: 1.536-4.879, P = 0.005), and those with pack-years of smoking more than 30 had higher risk (OR = 3.076, 95% CI: 2.308-6.741, P = 0.001). And the risk of squamous cell carcinoma significantly increased in smokers, especially those with T allele (TC+TI) genotype (OR = 6.066, 95% CI: 2.884-12.758, P < 0.001). The genotype with smoking conditions had no significant effect on adenocarcinoma (all P > 0.05).

CONCLUSIONThe results suggested rs10999776 polymorphism may implicate in the risk of squamous cell carcinoma in Chinese population which may interact with smoking-exposure.