The present invention provides a TOP2A inhibition by temozolomide useful for predicting glioblastoma patient's survival. Glioblastoma (GBM) is the most common, malignant primary adult brain tumor. The conventional treatments for GBM, include surgery, radiation, and chemotherapy which have only modestly improved patient survival. The patients with GBM expressing higher TOP2A transcript levels had better prognosis. More interestingly, the present invention reports that temozolomide is an inhibitor of TOP2A activity in vitro. The present invention further shows that siRNA knock down of TOP2A rendered a glioma cell line resistant to temozolomide chemotherapy. Thus it is demonstrated for the first time that temozolomide is a TOP2A inhibitor and establishes that TOP2A transcript levels determines the chemosensitivity of glioblastoma to temozolomide therapy thus explaining the very high levels of TOP2A transcript being a good prognostic indicator in GBM patients receiving temozolomide chemotherapy.
