Polymorphism Of GSTM1 And CYP1A1 Gene And Methylation Of P16 Gene Related With Lung Cancer

Objective To investigate the relations between the methylation of p16 gene, genetic polymorphism of GSTM1 gene and CYP1A1 gene, environment exposure and lung cancer risk,and to explore the mechanism of lung cancer and offer an effective means for the earlier diagnosis of the malignancy.Methods The case-control study was conducted among 158 lung cancer cases and 455 healthy controls, data of environment exposure were collected by uniform questionnaire,the GSTM1 gene and CYP1A1 gene genetic polymorphisms were genotyped with method of PCR-RFLP, methylation of P16 gene was tested in DNA from158 lung cancer tissues and adjacent nomalignant tissues by MS-PCR technique.Results There was a significantly high frequency of smoking and dust exposure in cases than in controls (P<0.01), by contrary, frequency of eating vegetables, fruits and drinking sanitized water frequently was lower in cases(P<0.01), there was a statistical significance between SCC and smoking (P<0.05). In lung cancer tissues, the frequency of P16 methylation was 48.1% , while, in the nomalignant tissue it was 9.5%(P<0.01). Methylation of P16 was significantly correlated with smoking(P<0.01). There was no statistical difference in each genotype of GSTM1 and CYP1A1 frequency between case and control (P>0.05), there was a synergistic interaction between tobacco exposure and GSTM1 null genotype,as well as CYP1A1 mutant genotype. Methylation of P16 did not correlate with polymorphism of GSTM1 and CYP1A1 gene.Conclusions This investigation revealed that smoking ,dust exposure significantly increase the risk of lung cancer , consumption of vegetables, fruits, and sanitized water frequently was associated with the decreased risk of lung cancer. Methylation of P16 gene owing to smoking was involved in the progress of lung cancer ,perhaps there was an elevated risk of lung cancer in GSTM1 null genotype with exposure to tobacco, as well as CYP1A1 mutant genotype. This study did not reveal the interaction between polymorphism of GSTM1and CYP1A1 gene and methylation of P16 in lung cancer.