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Article
Role of reactive oxygen species in proapoptotic ability of oncogenic H-Ras to increase human bladder cancer cell susceptibility to histone deacetylase inhibitor for caspase induction
Journal of Cancer Research and Clinical Oncology (2009)
  • Shambhunath Choudhary, University of Tennessee, Knoxville
  • Hwa-Chain Robert Wang, University of Tennessee, Knoxville
Abstract
PURPOSE: Reveal mechanisms for the novel proapoptotic ability of oncogenic H-Ras to increase cell susceptibility to a histone deacetylase inhibitor (HDACI) FR901228 for inducing caspase activation and selective apoptosis. METHODS: Human urinary bladder cancer J82 and oncogenic H-Ras-expressing J82 cells were used to reveal differential induction of intracellular reactive oxygen species (ROS), caspase activation, and apoptosis by HDACI FR901228. ROS levels and caspase-8, -9, and -3/7 activities were measured by flow cytometry and luminescence assays, respectively. Specific inhibitors were used to suppress caspases and ROS. Western blot analysis determined modulators of caspase pathways. RESULTS: ROS, caspase activity, and cell death was differentially increased by FR901228 in oncogenic H-Ras-expressing J82 versus parental cells. Blocking ROS resulted in reduced FR901228-induced cell death and caspase activation. Suppression of caspase-8 resulted in reduced FR901228-activated caspase-9 and -3/7. Suppression of caspase-9 resulted in reduced FR901228-activated caspase-3/7. Although FR901228 induced an ROS-dependent increase of FasL, FasL failed to induce caspase activation and cell death. CONCLUSION: Increased ROS played an important role in the activation of the extrinsic and intrinsic caspase pathways to cooperatively induce executioner caspase-3/7 through a novel FasL-independent pathway in FR901228-induced selective apoptosis of oncogenic H-Ras-expressing J82 versus parental cells.
Publication Date
2009
Citation Information
Shambhunath Choudhary and Hwa-Chain Robert Wang. "Role of reactive oxygen species in proapoptotic ability of oncogenic H-Ras to increase human bladder cancer cell susceptibility to histone deacetylase inhibitor for caspase induction" Journal of Cancer Research and Clinical Oncology Vol. 135 Iss. 11 (2009)
Available at: http://works.bepress.com/hwa-chain_wang/24/