[Expressions of survivin and caspase-3 in human non-small cell lung cancer and their relationship with cell apoptosis].

BACKGROUND: Survivin, 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.

METHODS: The 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.

RESULTS: The 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).

CONCLUSIONS: Survivin 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.