title: Mitochondria are direct targets of the lipoxygenase inhibitor MK886. A strategy for cell killing by combined treatment with MK886 and cyclooxygenase inhibitors.
abstract: We have investigated the mitochondrial and cellular effects of the lipoxygenase inhibitor MK886. Low concentrations (1 microM) of MK886 selectively sensitized the permeability transition pore (PTP) to opening, whereas higher concentrations of MK886 (10 microM) caused depolarization through combination of an ionophoretic effect with inhibition of respiration. MK886 killed prostate cancer PC3 cells only at the higher, toxic concentration (10 microM), whereas the lower concentration (1 microM) had no major effect on cell survival. However, 1 microM MK886 alone demonstrably induced PTP-dependent mitochondrial dysfunction; and it caused cell death through the mitochondrial pathway when it was used in combination with the cyclooxygenase inhibitor, indomethacin, which had no effects per se. Treatment with 1 microM MK886 plus indomethacin sensitized cells to killing by exogenous arachidonic acid, which induces PTP opening and cytochrome c release (Scorrano, L., Penzo, D., Petronilli, V., Pagano, F., and Bernardi, P. (2001) J. Biol. Chem. 276, 12035-12040). Combination of MK886 and cyclooxygenase inhibitors may represent a viable therapeutic strategy to force cell death through the mitochondrial pathway. This approach should be specifically useful to kill cells possessing a high flux of arachidonic acid and its metabolites like prostate and colon cancer cells.
authors.affiliation: Venetian Institute of Molecular Medicine, I-35129 Padova, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Gugliucci
authors.forename: Laura
authors.initials: L
authors.lastname: Ranzato
authors.forename: Luca
authors.initials: L
authors.lastname: Scorrano
authors.forename: Raffaele
authors.initials: R
authors.lastname: Colonna
authors.forename: Valeria
authors.initials: V
authors.lastname: Petronilli
authors.forename: Claudia
authors.initials: C
authors.lastname: Cusan
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
authors.forename: Mariangela
authors.initials: M
authors.lastname: Mancini
authors.forename: Francesco
authors.initials: F
authors.lastname: Pagano
authors.forename: Paolo
authors.initials: P
authors.lastname: Bernardi
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology*; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D008099:Liver / Q000166:cytology* / Q000187:drug effects; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000502:physiology*; D010101:Oxygen Consumption / Q000187:drug effects; D010539:Permeability; D011471:Prostatic Neoplasms; D051381:Rats; D017208:Rats, Wistar; D014407:Tumor Cells, Cultured; D002722:Chlorobenzenes
chemical_list: D016718:Arachidonic Acid; D007211:Indoles; D007213:Indomethacin; D016859:Lipoxygenase Inhibitors; C060893:MK-886; D002722:Chlorobenzenes