CBIO-16: NON-STEROIDAL ANTI-INFLAMMATORY DRUGS ENHANCE THE THERAPEUTIC EFFECTS OF TEMOZOLOMIDE AND RADIATION AGAINST MALIGNANT ASTROCYTIC TUMOR CELLS IN VITRO

BACKGROUND: The present study aimed to define the anti-tumor effects of aspirin (ASA) and celecoxib (CXB) alone or combined with temozolomide (TMZ) and/or irradiation (XRT), against C6, U87MG and T98G malignant astrocytic tumor cell lines in vitro. METHODS: Cell viability, cell cycles and apoptosis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry and terminal deoxynucleotidyl transferase-mediated nick end-labeling assays, respectively. RESULTS: Aspirin and CXB exerted similar anti-tumor effects by inducing cell cycle arrest and apoptosis. Aspirin and CXB induced the G0/G1 and G2/M phases of cell cycle arrest respectively, in all three malignant astrocytic tumor cell lines, whereas ASA with TMZ induced G2/M cell cycle arrest in the C6 and U87MG lines. The viability of malignant astrocytic tumor cell lines was reduced more effectively by ASA or CXB when combined with TMZ and XRT than by any of these agents alone or by a combination of any two modalities in the C6 and T98G cell lines. CONCLUSIONS: Both ASA and CXB enhance the therapeutic effects of concomitant XRT and TMZ and thus might serve as a novel strategy for treating malignant astrocytic tumors.