Cisplatin-Induced Apoptosis by Cisplatin in Human Glioblastoma Cell Line

ABSTRACT

OBJECTIVE: This study is designed to evaluate the apoptotic signaling pathway of anticancer agent (cisplatin) on human malignant glioblastoma A172 and T98G cells, bearing wild type p53 and mutated p53, respectively. METHODS: The A172 and T98G glioblastoma cells were exposed to cisplatin and we investigated the cytotoxic effect in two different cell lines with cell viability(MTT assay), morphological study(agarose-gel electroporesis and Hoechst staining), and biochemical study(PCR, RT-PCR, Western blotting, caspase activity assay, and flow cytometry). RESULTS: Cisplatin had cytotoxicity of A172 cells in a time and dose-dependent manner. The nature of cytotoxicity by cisplatin was revealed as an apoptosis characterized by genomic DNA fragmentation in agarose electrophoresis as well as nuclear condensation by Hoechst staining in A172 cells. Cisplatin also resulted in the activation of caspase-9 and caspase 3-like proteases significantly, which eventually cleaved poly(ADP-ribose) polymerase(PARP) in A172 cells, but not in T98G cells. Interestingly, treatment with cisplatin was accumulated p21 and arrested cell cycle in A172 cells with time dependency. Furthermore, cisplatin-treated A172 cells resulted in change of membrane potential transition(MPT) of mitochondria and followed by cytosolic release of cytochrome c in time-dependent manner. In addition, transduction of ad-p53 significantly increased the cytotoxicity of cisplatin in T98G cells. CONCLUSION: Cisplatin induced apoptotic death of human glioblastoma A172 cells in p53 dependent manner. Furthermore, resistance of cisplatin in T98G cells, bearing mutated p53, was abolished by p53 protein expression and resulted in the apoptotic cell death.