title: Mitochondrial production of reactive oxygen species mediate dicumarol-induced cytotoxicity in cancer cells.
abstract: Dicumarol is a naturally occurring anticoagulant derived from coumarin that induces cytotoxicity and oxidative stress in human pancreatic cancer cells (Cullen, J. J., Hinkhouse, M. M., Grady, M., Gaut, A. W., Liu, J., Zhang, Y., Weydert, C. J. D., Domann, F. E., and Oberley, L. W. (2003) Cancer Res. 63, 5513-5520). Although dicumarol has been used as an inhibitor of the two-electron reductase NAD(P)H:quinone oxidoreductase (NQO1), dicumarol is also thought to affect quinone-mediated electron transfer reactions in the mitochondria, leading to the production of superoxide (O2*-) and hydrogen peroxide (H(2)O(2)). We hypothesized that mitochondrial production of reactive oxygen species mediates the increased susceptibility of pancreatic cancer cells to dicumarol-induced metabolic oxidative stress. Dicumarol decreased clonogenic survival equally in both MDA-MB-468 NQO1(-) and MDA-MB-468 NQO1+ breast cancer cells. Dicumarol decreased clonogenic survival in the transformed fibroblast cell line IMRSV-90 compared with the IMR-90 cell line. Dicumarol, with the addition of mitochondrial electron transport chain blockers, decreased clonogenic cell survival in human pancreatic cancer cells and increased superoxide levels. Dicumarol with the mitochondrial electron transport chain blocker antimycin A decreased clonogenic survival and increased superoxide levels in cells with functional mitochondria but had little effect on cancer cells without functional mitochondria. Overexpression of manganese superoxide dismutase and mitochondrial-targeted catalase with adenoviral vectors reversed the dicumarol-induced cytotoxicity and reversed fluorescence of the oxidation-sensitive probe. We conclude mitochondrial production of reactive oxygen species mediates the increased susceptibility of cancer cells to dicumarol-induced cytotoxicity.
authors.affiliation: Department of Surgery and University of Iowa College of Medicine, Holden Comprehensive Cancer Center, and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.forename: David H
authors.initials: DH
authors.lastname: Daniels
authors.forename: Carla
authors.initials: C
authors.lastname: Asbury
authors.forename: Sujatha
authors.initials: S
authors.lastname: Venkataraman
authors.forename: Jingru
authors.initials: J
authors.lastname: Liu
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Spitz
authors.forename: Larry W
authors.initials: LW
authors.lastname: Oberley
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Cullen
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D001728:Dicumarol / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007700:Kinetics; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014410:Tumor Stem Cell Assay; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D014475:Uncoupling Agents; D001728:Dicumarol; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human