RÉSUMÉ
OBJECTIVE: The objective of the present study was to explore the role of the inhibitor of apoptosis protein (IAP) Livin in radioresistance in nonsmall cell lung cancer (NSCLC). METHODS: Lung adenocarcinoma cell lines A549 and SPC-A1 were used for this study. Using the technique of molecular cloning and gene transfection, two Livin isoforms, Livinα and ß, respectively, were expressed in A549 cells with the purpose of exploring the role of Livin in radiation resistance of A549 cells. Moreover, a Livin-specific gene-silencing system was developed using SPC-A1 cell line with the purpose of increasing radiosensitivity of SPC-A1 cells. RESULTS: A549 cells were induced by radiation to express Livin isoforms, Livinα and ß. A549 cells expressed Livin isoforms stably after gene transfection and the transfected cells demonstrated characteristics of antiradiation. However, Livin gene-silenced SPC-A1 cells exhibited remarkably enhanced radiation sensitivity. CONCLUSION: The IAP Livin is an important molecule in antiradiotherapy of NSCLC. Livin-specific gene silencing is likely to be an effective means to enhance radiation sensitivity of lung cancer.