title: Molecular mechanisms mediating antimyeloma activity of proteasome inhibitor PS-341.
abstract: We have recently shown that proteasome inhibitor PS-341 induces apoptosis in drug-resistant multiple myeloma (MM) cells, inhibits binding of MM cells in the bone marrow microenvironment, and inhibits cytokines mediating MM cell growth, survival, drug resistance, and migration in vitro. PS-341 also inhibits human MM cell growth and prolongs survival in a SCID mouse model. Importantly, PS-341 has achieved remarkable clinical responses in patients with refractory relapsed MM. We here demonstrate molecular mechanisms whereby PS-341 mediates anti-MM activity by inducing p53 and MDM2 protein expression; inducing the phosphorylation (Ser15) of p53 protein; activating c-Jun NH(2)-terminal kinase (JNK), caspase-8, and caspase-3; and cleaving the DNA protein kinase catalytic subunit, ATM, and MDM2. Inhibition of JNK activity abrogates PS-341-induced MM cell death. These studies identify molecular targets of PS-341 and provide the rationale for the development of second-generation, more targeted therapies.
authors.affiliation: Jerome Lipper Multiple Myeloma Center, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Teru
authors.initials: T
authors.lastname: Hideshima
authors.forename: Constantine
authors.initials: C
authors.lastname: Mitsiades
authors.forename: Masaharu
authors.initials: M
authors.lastname: Akiyama
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hayashi
authors.forename: Dharminder
authors.initials: D
authors.lastname: Chauhan
authors.forename: Paul
authors.initials: P
authors.lastname: Richardson
authors.forename: Robert
authors.initials: R
authors.lastname: Schlossman
authors.forename: Klaus
authors.initials: K
authors.lastname: Podar
authors.forename: Nikhil C
authors.initials: NC
authors.lastname: Munshi
authors.forename: Nicholas
authors.initials: N
authors.lastname: Mitsiades
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Anderson
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D064007:Ataxia Telangiectasia Mutated Proteins; D001897:Boronic Acids / Q000494:pharmacology* / Q000627:therapeutic use; D000069286:Bortezomib; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D018797:Cell Cycle Proteins; D016923:Cell Death / Q000187:drug effects; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2; D011719:Pyrazines / Q000494:pharmacology* / Q000627:therapeutic use; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011480:Protease Inhibitors; D011518:Proto-Oncogene Proteins; D011719:Pyrazines; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D010768:Phosphoserine; D000069286:Bortezomib; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; C505409:Casp3 protein, mouse; C505526:Casp8 protein, mouse; C506434:Casp9 protein, mouse; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases