Abstract: Objective To investigate the status and diagnostic value of aberrant phosphatase and tensin homology deleted on chromosometen(PTEN) gene promoter in tissues, peripheral plasma and BALF of lung cancer patients. Methods We analyzed the methylation of PTEN gene in tissues, peripheral plasma and BALF by methylation specific-PCR. Results The frequency of methylation of Promoter of PTEN gene was 26.67%(12/45) in lung cancer tissues , 15.56%(7/45) in peripheral plasma, 22.22%(10/45) in BALF, no methylation product was detected in lung tissues without cancer, normal plasma and BALF controls (ρ< 0. 01); there were significantly coincident in patients tumor tissues, plasma and BALF.Conclusions Detection of aberrant methylation of PTEN promoter in plasma and/or BALF may contribute to a definite value in early prognostic in lung cancer.

Key words: Lung carcinoma, CpG islands methylation, methylation-specific PCR, PTEN