title: DC-81-enediyne induces apoptosis of human melanoma A375 cells: involvement of the ROS, p38 MAPK, and AP-1 signaling pathways.
abstract: Melanoma is one of the most chemoresistant cancers in patient care. The remission rate of current therapy remains low. DC-81, an antitumor antibiotic produced by Streptomyces species, belongs to pyrrolo[2,1-c][1,4]benzodiazepine (PBD), which is a potent inhibitor of nucleic acid synthesis. An enediyne contains either DNA intercalating groups or DNA minor groove binding functions and these are potent DNA-damaging agents due to their ability to generate benzenoid diradicals. We have previously reported an efficient synthesis and antitumor activity of a series of novel PBD hybrids linked with enediyne. The purpose of this study was to examine the mechanism of the antiproliferative effect of DC-81-enediyne agent on human melanoma A375 cells. DC-81-enediyne induced an increase in Ca(2+) level and reactive oxygen species (ROS) generation as detected by flow cytometric assay. Western blot analysis showed that DC-81-enediyne induced the phosphorylation of p38 and activating transcription factor 2 (ATF-2). By using the luciferase reporter assay, activating protein-1 (AP-1) activity was further enhanced after A375 cells were treated with graded concentrations of DC-81-enediyne. DC-81-enediyne treatment-induced A375 cell apoptosis was significantly abrogated by the addition of Ca(2+), ROS, and p38 inhibitors. Collectively, our studies indicate that DC-81-enediyne induces A375 cell apoptosis through an increased Ca(2+) and ROS generation, which involves p38 phosphorylation and enhanced ATF-2/AP-1 expressions, leading to caspase-3 activity, poly(ADP-ribose)polymerase cleavage, M30 CytoDeath staining, and subsequent apoptotic cell death.
authors.affiliation: Graduate Institute of Pharmacy, Faculty of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chung-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Yin-Kai
authors.initials: YK
authors.lastname: Chen
authors.forename: Jeh-Jeng
authors.initials: JJ
authors.lastname: Wang
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Hsu
authors.forename: Feng-Yuan
authors.initials: FY
authors.lastname: Tsai
authors.forename: Ping-Jyun
authors.initials: PJ
authors.lastname: Sung
authors.forename: Hsien-Chang
authors.initials: HC
authors.lastname: Lin
authors.forename: Long-Sen
authors.initials: LS
authors.lastname: Chang
authors.forename: Wan-Ping
authors.initials: WP
authors.lastname: Hu
mesh_terms: D000880:Anthraquinones / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D053281:Enediynes / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000187:drug effects / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D053281:Enediynes; D004791:Enzyme Inhibitors; D007093:Imidazoles; D011725:Pyridines; D011758:Pyrroles; D017382:Reactive Oxygen Species; D018808:Transcription Factor AP-1; C525714:pyrrolo(2,1-c)(1,4)benzodiazepine-anthraquinone; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole