title: Actinomycin D enhances TRAIL-induced caspase-dependent and -independent apoptosis in SH-SY5Y neuroblastoma cells.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has attracted great attention as a promising anti-cancer reagent. Recombinant soluble TRAIL (rsTRAIL) derivatives induce apoptosis in various cancer cells, but not in most normal cells. However, a number of cancerous cell types are resistant to TRAIL cytotoxicity, limiting its application in cancer therapy. In the present study, we report that actinomycin D (Act D) pretreatment increases apoptosis in human neuroblastoma SH-SY5Y cells treated with rsTRAIL. Both caspase-9 and caspase-7, but not caspase-3, were activated during the apoptosis process. z-VAD-fmk, a pan-caspase inhibitor, only partially suppressed apoptosis of the cells, suggesting that the Act D-enhanced apoptosis of SH-SY5Y occurred via caspase-dependent and -independent manners. In cells pretreated with Act D, we found decreased mitochondrial transmembrane potential, high levels of reactive oxygen species (ROS), and up-regulated apoptotic-inducing factor (AIF). Cell death was blocked in cells stably transfected with AIF-siRNA plasmid. Taken together, these data indicate that Act D sensitizes SH-SY5Y cells to rsTRAIL-induced apoptosis via caspase activation, impairment of the mitochondrial membrane, release of ROS, and up-regulation of AIF expression. This study provides a novel strategy for the therapy of malignant neuroblastoma resistant to rsTRAIL cytotoxicity.
authors: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005, China.
authors: Ming-Jie
authors: MJ
authors: Wang
authors: Shilian
authors: S
authors: Liu
authors: Yanxin
authors: Y
authors: Liu
authors: Dexian
authors: D
authors: Zheng
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D003609:Dactinomycin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009447:Neuroblastoma / Q000473:pathology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D014162:Transfection
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D004791:Enzyme Inhibitors; D011500:Protein Synthesis Inhibitors; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D003609:Dactinomycin; D020169:Caspases