BACKGROUNDSurvivin, a member of inhibitor of apoptosis protein (IAP) family, can directly inhibit caspase-3 and caspase-7 activity and plays an important role in oncogenesis. The aim of this study is to investigate the expressions of survivin and caspase-3 in human non-small cell lung cancer (NSCLC), and to evaluate their relationship with cell apoptosis.

METHODSThe expressions of survivin and caspase-3 in 88 patients with NSCLC were examined by using immunohistochemical SP methods, and TNUEL method was used to detect the cell apoptosis simultaneously.

RESULTSThe positive expression rates of survivin in NSCLC tissues and normal lung tissues were 61.4% (54/88) and 13.8% (4/29) respectively, there was a significant difference between them (P < 0.01). Survivin expression in NSCLC was not related to the histologic type, pathological grade and lymph node metastasis (P > 0.05), but correlated with TNM stage (P < 0.05). The positive expression rate of caspase-3 was 89.7% (26/29) in normal lung tissues, which was higher than that in NSCLC tissues (73.9%, 65/88), but there was no significant difference (P > 0.05). Caspase-3 expression in NSCLC was associated with pathological grade (P < 0.05). The average apoptosis index (AI) of survivin-positive cases was significantly higher than that of surviving-negative ones (1.63±0.58 vs 3.29±0.76)(P < 0.05). The average AI of the caspase-3 positive cases was significantly higher than that of the caspase23 negative cases (2.42±0.59vs1.28±0.65)(P < 0.05). Expression of survivin was negatively correlated with caspase-3 (P < 0.05).

CONCLUSIONSSurvivin may play an important role in the process of carcinogenesis of NSCLC by inhibiting cell apoptosis. Moreover, survivin may prevent cell apoptosis by inhibiting caspase-3 activation.