title: Rapid human melanoma cell death induced by sanguinarine through oxidative stress.
abstract: Sanguinarine is a natural isoquinoline alkaloid derived from the root of Sanguinaria canadensis and from other poppy fumaria species, and is known to have a broad spectrum of pharmacological properties. Here we have found that sanguinarine, at low micromolar concentrations, showed a remarkably rapid killing activity against human melanoma cells. Time-lapse videomicroscopy showed rapid morphological changes compatible with an apoptotic cell death, which was further supported by biochemical markers, including caspase activation, poly(ADP-ribose) polymerase (PARP) cleavage and DNA breakdown. Pan-caspase inhibition blocked sanguinarine-induced cell death. Sanguinarine treatment also induced an increase in intracellular calcium concentration, which was inhibited by dantrolene, and promoted cleavage of BAP-31, thus suggesting a putative role for Ca(2+) release from endoplasmic reticulum and a cross-talk between endoplasmic reticulum and mitochondria in the anti-melanoma action of sanguinarine. Sanguinarine disrupted the mitochondrial transmembrane potential (ΔΨm), released cytochrome c and Smac/DIABLO from mitochondria to cytosol, and induced oxidative stress. Overexpression of Bcl-XL by gene transfer did not prevent sanguinarine-mediated cell death, oxidative stress or release of mitochondrial apoptogenic proteins. However, preincubation with N-acetyl-l-cysteine (NAC) prevented sanguinarine-induced oxidative stress, PARP cleavage, release of apoptogenic mitochondrial proteins, and cell death. Pretreatment with glutathione (GSH) also inhibited the anti-melanoma activity of sanguinarine. Thus, pretreatment with the thiol antioxidants NAC and GSH abrogated the killing activity of sanguinarine. Taking together, our data indicate that sanguinarine is a very rapid inducer of human melanoma caspase-dependent cell death that is mediated by oxidative stress.
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Burgeiro
authors.forename: Ana C
authors.initials: AC
authors.lastname: Bento
authors.forename: Consuelo
authors.initials: C
authors.lastname: Gajate
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Oliveira
authors.forename: Faustino
authors.initials: F
authors.lastname: Mollinedo
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D053119:Benzophenanthridines / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology*; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C091247:BCAP31 protein, human; C494811:BCL2L1 protein, human; D053119:Benzophenanthridines; D007546:Isoquinolines; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D051020:bcl-X Protein; C005705:sanguinarine; D053148:Caspase 3; D053179:Caspase 7; D005978:Glutathione; D002118:Calcium; D000111:Acetylcysteine