CHRNA5 and CHRNA3 polymorphism and lung cancer susceptibility in Palestinian population

Abstract

Objective: The genetic polymorphism (rs16969968 in CHRNA5, and rs1051730 in CHRNA3 genes) were recently shown to be associated with risk of LC. The aim of this study is to elucidate whether they predispose Palestinian individuals to lung cancer, and how is this related to smoking.

Results: Frequency of the rs16969968-A allele was significantly higher in the case group (36.7%) than in normal controls (17.5%; P = 0.022; OR = 6.83 for AA and 2.81 for AG genotypes). The frequency of rs1051730-T allele was also significantly higher in the case group (46.7%) than in the control group (22.5%; P = 0.001; OR = 2.20 for TC and 13.22 for TT genotypes). Frequency of rs16969968-A allele was higher in smokers (29.1%) than nonsmokers (15.7%) regardless of lung cancer; similarly, frequency of rs1051730-T allele was also higher in smokers than in smokers (46.7% vs 22.5%, respectively). The higher the proportion of the risk allele (rs16969968-A and rs1051730-T), the higher the mean number of daily consumed cigarettes (P = 0.006). Carrying rs16969968-A and/or rs1051730-T alleles results in an increased risk to lung cancer probably by increasing the individual's tendency for heavy smoking. The allelic frequency of the rs16969968-A and rs1051730-T alleles among normal Palestinian controls is similar to different populations worldwide.

Keywords: ASP-PCR; CHRNA3; CHRNA5; Gaza strip; Lung cancer; nAChR; rs1051730; s16969968.

Fig. 1

A representative agarose gel electrophoresis of ASP-PCR. a The SNP rs16969968 and b the SNP rs1051730 were genotyped with two separate reactions for each sample: one using wildtype-specific primer (wt) and the other using mutant-specific primers (mt). L 100 bp DNA ladder and B blank water sample. Samples (S30, S31, and S33) are wildtype homozygous and sample S32 is heterozygous for both SNPs