DNA topoisomerase II-alpha as a proliferation marker in human gliomas: correlation with PCNA expression and patient survival.

OBJECTIVE

DNA topoisomerase II-alpha (Topo-IIalpha) is the inducible form of the enzyme responsible for the first step in the modification of DNA topology. Topo-IIalpha upregulation has been demonstrated in different tumors. Topo-IIalpha products may modulate tumoral growth, metastasis and immunosuppression, inhibit apoptosis and cause resistance to chemotherapy. Moreover, the antitumoral effect ofTopo-IIalpha inhibitors has been documented.

MATERIAL AND METHODS

We studied the immunohistochemical expression and the prognostic value of Topo-IIalpha on 57 surgical specimens ofglioma. Furthermore, we evaluated the correlation between the immunohistochemical expression of Topo-IIalpha and proliferating cell nuclear antigen (PCNA).

RESULTS

A statistically significant correlation with survival time was found, there was no statistically significant difference in survival between patients receiving or not receiving carmustine-based combined chemotherapy (p > 0.05), regardless of histological type. A significant correlation between Topo-IIalpha and PCNA was documented (r = 0.9245, p < 0.001).

CONCLUSIONS

Our findings show that gliomas immunohistochemically express Topo-IIalpha that is correlated with PCNA expression, and which is significantly less frequent in long survivors. The presence of a statistical correlation with survival time and tumor histological grade encourages further studies on a larger series to verify the prognostic value of Topo-IIalpha expression in gliomas.