The Expression Of MGMT Protein In Lung Cancer And Its Relationship With Cigarette Smoking

Objective Lung cancer is one of the leading causes of the cancer-related death in recent years. Much progress has been made in the diognosis and treatment of lung cancer, but the prognosis is still disappointing. MGMT (O6-methylguanine-DNA methyltransferase) is the most important enzyme in the DNA repairing system, and it play an important role in defencing cell damage from alkylating agents. To evaluate the relationship between expression of MGMT protein in lung neoplasm and cigarette smoking by detecting the expression of MGMT protein in lung neoplasm. Methods Immunohistochemical methods (S-P) was used to detect the expression of MGMT protein,after the previously established methods, in 62 cases of lung cancer, 8 cases of histological normal lung tissue from lung cancer patients, and 32 cases of lung benign pathological changes. Results The MGMT expression was detected in 28 of 62 lung cancer (45.2%), 28 of 32(87.5%) lung benign pathological change , 6 of 8(75%) histological normal lung tissue and the average score of expression was 1.85±1.906,3.31±1.554,2.75±2.550,respectively. The difference of the positive rate and score was significant (P<0.05) in 3 groups. The MGMT expression had no correlation with patients'histological types, grades, age, sex and lymph nodes metastasis(P=0.708). The average score of MGMT expression was higher in lung tissue (including histological normal lung tissue, lung benign pathological tissue and lung cancer) of smoking patients than un-smoking patients(P<0.05). Conclusion The expression of MGMT protein is related to cigarette smoking, and had no correlation with patients'histological types, grades, age, sex and lymph nodes metastasis.