Genetic Polymorphism of Epoxide Hydrolase and GSTM1 in Lung Cancer Susceptibility of Korean Population

Although 80~90% of patients with lung cancer are smokers, only 11% of smokers develop lung cancer. Genetic susceptibility according to the polymorphism of the epoxide hydrolase (mEPHX) gene and homozygous deletion of GSTM1 (M1 subunit of Glutathione S transferase) was studied in this case control study. Genomic DNA from 76 subjects with lung cancer (40 squamous cell carcinoma, 13 adenocarcinoma, 10 subtype undetermined non-small cell lung cancer, and 13 small cell lung carcinoma) and 62 age- matched controls were extracted from peripheral white blood cells. PCR and RFLP (restriction fragments length polymorphism) with restriction enzyme (RsaI) and automatic sequencing were used for mEPHX genotyping (T-->C, Tyr113His) in exon 3 and (A-->G, His139Arg) in exon 4. Looking for homozygous deletions of GSTM1, multiplex PCR with primers for the GSTM1 gene and coagulation factor V gene (as positive control) were performed. The age distribution between the cancer and control groups were similar (63.6 7.2 vs. 61.1 7.9 years). The lung cancer group, however, had more smokers (73.3%, 44/60) than the control group (21/54, 38.9%, p