The Contribution of DNA Apurinic/Apyrimidinic Endonuclease Genotype and Smoking Habit to Taiwan Lung Cancer Risk

To evaluate the association and interaction of genotypic polymorphism the gene for DNA- apurinic/apyrimidinic endonuclease (APEX1) with personal smoking habit and lung cancer risk in Taiwan, the polymorphic variants of APEX1, Asp 148 Glu (rs1130409), were analyzed in association with lung cancer risk, and their joint effect with personal smoking habits on lung cancer susceptibility was discussed. In this hospital-based case-control study, 358 patients with lung cancer and 716 cancer-free controls, frequency-matched by age and sex, were recruited and genotyped by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The results showed that the percentages of TT, TG and GG APEX1 Asp 148 Glu genotypes were not significantly different at 43.0%, 41.1% and 15.9% in the lung cancer patient group and 39.9%, 46.1% and 14.0% in non-cancer control group, respectively. We further analyzed the genetic-lifestyle effects on lung cancer risk and found the contribution of APEX1 Asp 148 Glu genotypes to lung cancer susceptibility was neither enhanced in the cigarette smokers nor in the non-smokers (p=0.3550 and 0.8019, respectively). Our results provide evidence that the non-synonymous polymorphism of APEX1 Asp 148 Glu may not be directly associated with lung cancer risk, nor enhance the effects of smoking habit on lung cancer development.