The expression of melanoma antigen encoding gene in lung cancer

Background : Because melanoma antigen gene (MAGE) was expressed in many kinds of cancers and MAGE expression is highly specific to cancer cells, MAGE has been studied as an important marker for cancer diagnosis. The purpose of this study was to evaluate the expression rates of MAGE-A1 to A6 by common MAGE primer and to evaluate the difference of expression rates of MAGE according to the clinical stages and the cell types in lung cancer tissues. Methods : 114 cancer tissues (53 tissues surgically removed, 61 tissues bronchoscopically biopsied), 18 benign lung tissues and 45 normal lung tissues sampled from surgically removed lung cancer were investigated. The MAGE assay was performed by nested reverse transcription polymerase chain reaction (nested RT-PCR) using common MAGE primer. Results : The expression rate of MAGE was 83.0% in surgically removed lung cancer tissues and was 70.5% in bronchoscopically biopsied lung cancer tissues. But MAGE was not detected in 18 benign lesions. In surgically removed lung cancer tissues, the positive rate of MAGE expression was 86.1% in squamous cell carcinoma, 69.2% in adenocarcinoma, and 100% in small cell carcinoma and in lung cancer tissues obtained by bronchoscopy 77.5%, 71.4%, and 50.0%, respectively. The detection rates of MAGE assay were increased according to clinical stage, stage I (57.1%), II (60.0%), III (80.0%) and IV (85.7%) (p>0.05). Conclusion : Common MAGE RT-PCR method is highly sensitive and specific for lung cancer detection. It may be useful method for the diagnosis of lung cancer and could be effectively utilized for early lung cancer screening method.