Co-expression of Survivin and Bcl-2 in Primary Brain Tumors: Their Potential Effect on Anti-apoptosis

ABSTRACT

OBJECTIVE: Survivin is an inhibitor of apoptosis protein(IAP), which inhibits apoptosis through a pathway distinct from the Bcl-2 family members. Overexpression of survivin and Bcl-2 have been commonly reported in human neoplasms. The authors investigate whether there is a synergistic effect on the anti-apoptosis rate of primary brain tumors "in situ" based on the co-expression of survivin and Bcl-2. METHODS: One hundred and two brain tumor patients who had been resected were included in this study. Survivin and Bcl-2 were detected by Western blotting analysis, while apoptosis was examined by DNA fragmentation analysis. An anti-apoptotic rate was assessed in these brain tumor samples based on the expression of survivin and Bcl-2 or co-expression of both. RESULTS: Survivin and Bcl-2 were expressed in 57(55.9%) and 53(52.0%) of 102 brain tumor samples studied respectively, and co-expressed in 31(30.4%). The percentage of astrocytic and meningeal tumors expressing survivin was significantly correlated with histological grades; however, Bcl-2 was not correlated (p=0.106). The anti-apoptotic rate in primary brain tumors with survivin, Bcl-2, and both was detected in 49(86.0%) of 57 samples, 42(79.9%) of 53 samples, and 27(87.1%) of 31 samples, respectively. Their difference in the frequency of anti-apoptosis was not significant. CONCLUSION: Survivin or Bcl-2 is involved in the anti-apoptosis. However, it suggests that co-expression of survivin and Bcl-2, together, have no synergistic effect on the anti-apoptotic properties of the primary brain tumors.