Both environmental and genetic factors participate in the pathogenesis of lung cancer. The aim of this study was to explore the association between CHRNA3 polymorphisms of the nicotinic acetylcholine receptor gene and lung cancer risk in a hospital-based, case-controlled study. Single nucleotide polymorphisms (SNPs) in CHRNA3 rs3743073 (A>G) were determined using the TaqMan-MGB probe technique in 600 lung cancer cases and 600 normal controls. The differences in genotype and allele frequency were compared between groups and their association with lung cancer. The genotype frequency of rs3743073 (A>G) demonstrated Hardy-Weinberg equilibrium (P<0.05). The genotype and allele frequencies were significantly different between the cancer and control groups (P<0.05). Compared with patients with the TT genotype, lung cancer incidence was increased in patients with the TG and GG genotypes (OR=1.68; 95% CI, 1.30-2.19; P<0.05; OR=1.30; 95% CI, 1.05-1.61; P<0.05, respectively). Patients with rs3743073G variant alleles (TG and GG) were at greater risk (OR=0.65; 95% CI, 0.50-0.84; P<0.05) of developing lung cancer. Increased risk associated with rs3743073G variant alleles was observed in male smokers over the age of 60 (P<0.05). In this cohort, the CHRNA3 gene rs3743073G variant genotype significantly increased lung cancer risk, especially in male smokers over the age of 60.
Keywords: lung cancer; nicotinic acetylcholine receptors; CHRNA3 gene; single nucleotide polymorphisms.