title: The oxygen radicals involved in the toxicity induced by parthenolide in MDA-MB-231 cells.
abstract: It has been shown that the sesquiterpene lactone parthenolide lowers the viability of MDA-MB-231 breast cancer cells, in correlation with oxidative stress. The present report examined the different radical species produced during parthenolide treatment and their possible role in the toxicity caused by the drug. Time course experiments showed that in the first phase of treatment (0-8 h), and in particular in the first 3 h, parthenolide induced dichlorofluorescein (DCF) signal in a large percentage of cells, while dihydroethidium (DHE) signal was not stimulated. Since the effect on DCF signal was suppressed by apocynin and diphenyleneiodonium (DPI), two inhibitors of NADPH oxidase (NOX), we suggest that parthenolide rapidly stimulated NOX activity with production of superoxide anion (O2•-), which was converted by superoxide dismutase 1 (SOD1) into hydrogen peroxide (H2O2). In the second phase of treatment (8-16 h), parthenolide increased the number of positive cells to DHE signal. Since this event was not prevented by apocynin and DPI and was associated with positivity of cells to MitoSox Red, a fluorochrome used to detect mitochondrial production of O2•-, we suggest that parthenolide induced production of O2•- at the mitochondrial level independently by NOX activity in the second phase of treatment. Finally, in this phase, most cells became positive to hydroxyphenyl fluorescein (HPF) signal, a fluorescent probe to detect highly reactive oxygen species (hROS), such as hydroxyl radical and peroxynitrite. Therefore, parthenolide between 8-16 h of treatment induced generation of O2•- and hROS, in close correlation with a marked reduction in cell viability.
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Carlisi
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: D'Anneo
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Martinez
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Emanuele
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Buttitta
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Di Fiore
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Renza
authors.initials: R
authors.lastname: Vento
authors.affiliation: Laboratory of Biochemistry, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tesoriere
authors.affiliation: Laboratory of Biochemistry, Department of Experimental Biomedicine and Clinical Neurosciences, Polyclinic, University of Palermo, 90127 Palermo, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Lauricella
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism; D012717:Sesquiterpenes / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D013481:Superoxides / Q000378:metabolism*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C000606290:SOD1 protein, human; D012717:Sesquiterpenes; D013481:Superoxides; C002669:parthenolide; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D019255:NADPH Oxidases