TNF-β genetic variant contributes to the risk of non-small cell lung cancer

Abstract

To investigate the association of TNF-β 252A >G variant with the risk of non-small cell lung cancer (NSCLC). Total 956 patients with NSCLC were recruited between January 2000 and December 2008 at Cancer Hospital, Chinese Academy of Medical Science as the case group, and 994 frequency-matched controls were randomly selected from a pool of cancer-free subjects recruited from a nutritional group. All the participants were unrelated Han Chinese. There were no age, gender restrictions. Smoking status of the subjects was surveyed. Informed consent was obtained and 3 ml peripheral blood was collected from each subject. All samples were genotyped by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). The OR and 95%CI were estimated by logistic regression to evaluate the relationship between TNF-β 252 A/G variant and the risk of lung cancer. The frequencies of TNF-β 252 AA, AG and GG genotype were 30.9% (307/994) , 47.4% (471/994) and 21.7% (216/994) in lung cancer cases and 35.7% (341/956) , 48.1% (460/956) and 16.2% (155/956) in controls. Logistic regression analysis revealed that TNF-β 252 GG genotype contributed to a decreased risk of developing NSCLC (OR = 0.64, 95%CI: 0.49-0.83) compared with AA genotype. When stratified by smoking status, the individuals with 252 GG genotype had a significant increased risk of NSCLC (OR = 1.54, 95%CI:1.00-2.39) among smokers; which was less than those with AA genotype among smokers (OR = 2.88, 95%CI:1.91-2.24). When further stratified by smoking index, individuals with 252 GG genotype had a significant decreased risk of NSCLC among heavy smokers with OR (95%CI) of 2.24 (1.33-3.74), which was less than those with AA genotype (OR = 4.62, 95%CI:2.88-7.41). TNF-β genetic variant may interact with environment factor to contribute to the susceptibility to NSCLC.