title: Imatinib mesylate induction of ROS-dependent apoptosis in melanoma B16F0 cells.
abstract: BACKGROUND
  Imatinib mesylate (STI571), a protein tyrosine kinase inhibitor, was shown to reduce the viability of several cancer cell lines via apoptosis induction; however, the role of reactive oxygen species (ROS) in STI571-induced melanoma cell apoptosis is still undefined.
  
  
  OBJECTIVE
  In this study, we investigated the contribution of ROS to STI571-induced apoptosis in melanoma B16F0 cells, and the apoptotic mechanism elicited by STI571 was illustrated.
  
  
  METHODS
  Using an in vitro cell culture system, the effects of STI571 on ROS production, cell cycle progression, caspase activation, and mitochondrial functions were examined via Western blotting, a flow cytometric analysis, an enzyme activity assay, and a DNA integrity assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, dipheylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (PD98059, SP600125, and SB203580) were applied to investigate the mechanism.
  
  
  RESULTS
  STI571 reduced the viability of melanoma cells B16F0, but not human skin fibroblasts WS1, via apoptosis induction. Besides, apoptosis induced by STI571 was inhibited by the addition of NAC and DPI, and an increase in the intracellular peroxide level by STI571 was identified in melanoma B16F0 cells. Activation of caspases 3 and 9 enzyme activities accompanied by disrupting the mitochondria membrane potential in according with stimulating JNK and p38 protein phosphorylation was identified in STI571-treated B16F0 cells. STI571-mediated a ROS-dependent apoptosis potentiated by JNK inhibitor SP600125 was first identified in melanoma B16F0 cells.
  
  
  CONCLUSIONS
  Our results support the idea that ROS-dependent apoptosis in STI571-treated melanoma cells B16F0. The combination of a JNK inhibitor with STI571 for treating melanomas is suggested for further in vivo studies.
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Chang
authors.forename: Shing-Chuan
authors.initials: SC
authors.lastname: Shen
authors.forename: Woan-Rouh
authors.initials: WR
authors.lastname: Lee
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Yang
authors.forename: Yen-Chou
authors.initials: YC
authors.lastname: Chen
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D001549:Benzamides; D005419:Flavonoids / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods; D000068877:Imatinib Mesylate; D007093:Imidazoles / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000378:metabolism*; D008564:Membrane Potentials; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D017382:Reactive Oxygen Species
chemical_list: D000873:Anthracenes; D000970:Antineoplastic Agents; D001549:Benzamides; D005419:Flavonoids; D007093:Imidazoles; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D011743:Pyrimidines; D017382:Reactive Oxygen Species; C432165:pyrazolanthrone; D000068877:Imatinib Mesylate; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one