title: Cytochrome c-dependent and -independent induction of apoptosis in multiple myeloma cells.
abstract: Cytochrome c is a mitochondrial protein that induces apoptosis when accumulated in the cytosol in response to diverse stress inducers. This protein has also been shown to cause apoptosis when added to cell free extracts. In this report, we studied the role of cytochrome c (cyto-c) in dexamethasone (Dex), anti-Fas monoclonal antibody (mAb), and ionizing radiation-induced apoptosis in multiple myeloma cells. The results demonstrate that ionizing radiation-induced apoptosis is associated with an increase in cytosolic cyto-c levels, whereas apoptosis induced by Dex or anti-Fas mAb has no detectable effect on cyto-c release. By contrast, caspase-3 was activated in response to all of these agents. Thus, our findings suggest that Dex or anti-Fas mAb-induced apoptosis is not accompanied by cyto-c release and that there are at least two different pathways leading to activation of caspases and induction of apoptosis in multiple myeloma cells that can be distinguished by accumulation of cytosolic cyto-c.
authors.affiliation: Hematologic Malignancy, Department of Adult Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: D
authors.initials: D
authors.lastname: Chauhan
authors.forename: P
authors.initials: P
authors.lastname: Pandey
authors.forename: A
authors.initials: A
authors.lastname: Ogata
authors.forename: G
authors.initials: G
authors.lastname: Teoh
authors.forename: N
authors.initials: N
authors.lastname: Krett
authors.forename: R
authors.initials: R
authors.lastname: Halgren
authors.forename: S
authors.initials: S
authors.lastname: Rosen
authors.forename: D
authors.initials: D
authors.lastname: Kufe
authors.forename: S
authors.initials: S
authors.lastname: Kharbanda
authors.forename: K
authors.initials: K
authors.lastname: Anderson
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003574:Cytochrome c Group / Q000502:physiology*; D003593:Cytoplasm / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009101:Multiple Myeloma; D011493:Protein Kinase C / Q000378:metabolism; D051745:Protein Kinase C-delta; D011839:Radiation, Ionizing; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000502:physiology
chemical_list: D003574:Cytochrome c Group; D007527:Isoenzymes; D019014:fas Receptor; D003907:Dexamethasone; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases