Significance of MGMT hypermethylation in serum DNA of non-small cell lung cancer patients

Abstract

Objective To detect the promoter methylation status of O6-methylguanine-DNA-methyhransferase(MGMT) gene in the serum of non-small cell lung cancer(NSCLC) patients and to discuss its clinical significance.Methods Serum DNA was extracted from 62 patients with NSCLC,30 patients with benign pulmonary disease and 16 health subjects with medical check-up.The methylation status of MGMT gene was detected by bisulfite genomic sequence and the correlation of methylation profiles with clinical characteristics was analyzed.Results Aberrant promoter methylation of MGMT was detected in 17 of 62 (27.42%) NSCLC patients,but in none of patients with benign pulmonary disease and health subjects with medical check-up(Fisher exact test,P＜0.01).The promoter hypermethylation of MGMT correlated with late stage(P＜0.05),but not with age,gender,histopathology or differentiation in NSCLC patients,The smoking index in methylated patients was higher than that in unmethylated patients(P＜0.01).Conclusions The promoter hypermethylation of MGMT may play an important role in the tumorigenesis and progression,and it is hopeful to become a biomarker for auxiliary diagnosis in NSCLC. Key words: Lung neoplasms/non-small-cell; O6-methylguanine-DNA-methyltransferase; DNA Methylation; DNA Sequence Analysis; Serum