[Expression of livin protein in lung cancer and its relation with the expression of pro-caspase3 protein.].

BACKGROUND: Livin is a novel inhibitor of apoptosis protein (IAP), recent studies showed it overexpresses in a variety of carcinomas including lung cancer and contributes much to the cancerous development. The objective of this study is to explore the expression of livin in tissues of lung cancer and its relationship with histological types, chemotherapy, Lymph node metastasis and to study its correlation with the expression of pro-caspase3 as well. METHODS: Expressions of Livin and caspase3 were detected by Western blot assay in lung cancer tissues as well as in controls. RESULTS: Livin was expressed in 15 of 27 lung cancer, significantly more than those in lung para-cancerous (1/5) or benign disease lung tissues (2/12) (P <0.01). Moreover, it showed expression in 10 of 13 lung adenocarcinoma and in 5 of 13 squamocellular and large cell carcinoma respectively, but not detected in one small cell carcinoma. The levels of livin protein in lung cancer were significantly higher than those in controls by Gel Imaging System (P <0.05). Meanwhile, the levels of pro-caspase3 protein in lung cancer were significantly higher than those in controls (P <0.05), the levels of livin tended to be positively associated with that of pro-caspase3. Livin expression seemed to increase after chemotherapy but not related to lymph node metastasis (P >0.05). CONCLUSIONS: Livin are differently expressed in different histological types of lung cancer; High levels of livin expression do not relate to chemotherapy, lymph node metastasis (P >0.05). The levels of livin tends to be positively associated with those of accordingly pro-caspase3, it is presumed that livin could bind pro-caspase3 and suppress its activation.