Abstract 1045: Enhancement of drug-induced apoptotic cell death in human hepatocellular carcinoma cells with knock-down of BNIP3

Although BNIP3 is known for its pro-apoptotic function by forming dimer to help the release of cytochrome c in apoptosis, its role in the cell death pathways was not yet well-defined. To investigate the role of BNIP3 in drug-induced apoptosis, stable transfectants were established from human hepatocarcinoma HepG2 cells transfected with pSilencer inserted with scramble oligos or BNIP3 siRNA. By MTT assay, knock-down of BNIP3 in HepG2 stable transfectant decreased cell survival towards vincristine, Taxol and doxorubicin. By DNA fragmentation assay and Annexin V binding assay, the level of drug-induced apoptosis in BNIP3i cells was elevated as compared with the control cells. Further analyses on caspases activation and mitochondrial cytochrome c release were done by Western blot analysis while the mitochondrial membrane depolarization was monitored by flow cytometry of JC-1 dye staining. By comparing with the control cells, the presence of vincristine or Taxol induced less cytochrome c release, mitochondrial membrane depolarization and activation of caspases-3, −8 and −9 in HepG2 BNIP3i cells. The results from present study indicated that BNIP3 might induce apoptosis by therapeutic drugs in HepG2 cells through a non-classical apoptotic pathway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1045.