title: Resistance to cisplatin and adriamycin is associated with the inhibition of glutathione efflux in MCF-7-derived cells.
abstract: The impact of the anti-cancer drugs cisplatin (CDDP) and adriamycin (ADR) was investigated on sensitive and resistant MCF-7-derived human breast cancer cells. Cytotoxicity was evaluated by MTT assay, reactive oxygen species (ROS), apoptosis and necrosis by flow cytometry, glutathione (GSH) by HPLC, and Bcl-2, Bax and PARP expression by Western blot. A perturbation of ROS and intracellular GSH levels, and the enhancement of both apoptosis and necrosis were observed in sensitive cells. Transfected MCF-7 cells overexpressing the anti-apoptotic Bcl-2 protein, as well as MCF-7-derived vincristine-resistant cell line (Vcr-R) were resistant to both drugs. This resistance was clearly associated with an unaltered GSH level and with the inhibition of an early GSH efflux. Vcr-R cell resistance seemed to rely on a different mechanism, since it was found to be independent of Bcl-2 expression. Since Bcl-2 overexpression confers the strongest degree of resistance of MCF-7-derived cells, our observations further highlight Bcl-2 as a prime pharmacological target to sensitize cancer cells to chemotherapeutic agents.
authors.affiliation: Laboratoire d'Ingénierie Moléculaire et Biochimie Pharmacologique, UFR SciFA, Université Paul Verlaine-Metz, Campus Bridoux, rue du Général Delestraint, 57070 Metz, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Osbild
authors.forename: Laurent
authors.initials: L
authors.lastname: Brault
authors.forename: Eric
authors.initials: E
authors.lastname: Battaglia
authors.forename: Denyse
authors.initials: D
authors.lastname: Bagrel
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D004317:Doxorubicin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005434:Flow Cytometry; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D009336:Necrosis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000903:Antibiotics, Antineoplastic; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D014750:Vincristine; D004317:Doxorubicin; D011065:Poly(ADP-ribose) Polymerases; D005978:Glutathione