title: Cisplatin overcomes Bcl-2-mediated resistance to apoptosis via preferential engagement of Bak: critical role of Noxa-mediated lipid peroxidation.
abstract: Increased expression of antiapoptotic Bcl-2 proteins confers therapeutic resistance in various cancer types. Targeting Bcl-2 proteins by small molecules or activating alternative pathways to bypass Bcl-2-mediated protection to promote apoptosis are two approaches to overcoming therapeutic resistance. Here, we show that cisplatin triggers a Bak-dependent pathway to induce apoptosis in Bcl-2-overexpressing MCF-7 cells. p53-mediated induction of Noxa expression, generation of lipid peroxidation end products and induction of Noxa-Mcl-1 interaction are necessary for this pathway to function. Although Puma is also induced by cisplatin treatment, it is not required for apoptosis. Similarly, reactive oxygen species production by cisplatin did not have any effect on cisplatin-induced apoptosis in MCF-7 Bcl-2 cells. Furthermore, p53 promotes cisplatin-induced apoptosis by directly binding and counteracting Bcl-x(L) antiapoptotic function. In conclusion, our findings suggest a novel mode of action for cisplatin to overcome Bcl-2-mediated protection against apoptosis, which requires preferential activation of Bak and p53-mediated upregulation of Noxa protein levels and lipid peroxidation.
authors: Biological Sciences and Bioengineering Program, Sabanci University, 34956 Tuzla, Istanbul, Turkey.
authors: Ozgur
authors: O
authors: Kutuk
authors: Elif Damla
authors: ED
authors: Arisan
authors: Tugsan
authors: T
authors: Tezil
authors: Maria C
authors: MC
authors: Shoshan
authors: Huveyda
authors: H
authors: Basaga
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000502:physiology*; D051028:bcl-2-Associated X Protein / Q000502:physiology; D051020:bcl-X Protein / Q000502:physiology
chemical_list: D000970:Antineoplastic Agents; C494772:BAK1 protein, human; C494826:BAX protein, human; C494811:BCL2L1 protein, human; D064549:Myeloid Cell Leukemia Sequence 1 Protein; C498702:PMAIP1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D002945:Cisplatin