title: Stimulation of the mitogen-activated protein kinase pathway antagonizes TRAIL-induced apoptosis downstream of BID cleavage in human breast cancer MCF-7 cells.
abstract: We studied the role of the mitogen-activated protein kinase (MAPK) pathway in the regulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in breast tumor MCF-7 cells. We found that addition of a protein kinase C (PKC) activator to MCF-7 cultures prevented TRAIL-induced apoptosis, by inhibiting a step downstream of both caspase-8 activation and BID cleavage. TRAIL-induced translocation of Bax from cytosol to mitochondria, release of cytochrome c from mitochondria and activation of caspase-9 were all inhibited by PKC activation. PKC-mediated prevention of mitochondrial apoptotic events and apoptosis was found to be dependent on the MAPK pathway. Since TRAIL is a ligand of potential use in antineoplastic clinical trials, our findings may provide relevant information in cancer therapy.
authors.affiliation: Instituto de Parasitología y Biomedicina CSIC, calle Ventanilla 11, 18001 Granada, Spain.
authors.forename: Malabika
authors.initials: M
authors.lastname: Sarker
authors.forename: Carmen
authors.initials: C
authors.lastname: Ruiz-Ruiz
authors.forename: Gema
authors.initials: G
authors.lastname: Robledo
authors.forename: Abelardo
authors.initials: A
authors.lastname: López-Rivas
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D002352:Carrier Proteins / Q000378:metabolism*; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors*; D008928:Mitochondria / Q000378:metabolism; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D053221:TNF-Related Apoptosis-Inducing Ligand; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D051028:bcl-2-Associated X Protein
chemical_list: D051017:Apoptosis Regulatory Proteins; C494826:BAX protein, human; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D002352:Carrier Proteins; D003574:Cytochrome c Group; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; D011493:Protein Kinase C; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases