title: Biologic sequelae of c-Jun NH(2)-terminal kinase (JNK) activation in multiple myeloma cell lines.
abstract: Although c-Jun NH(2)-terminal kinase (JNK) is activated by treatment with therapeutic agents, the biologic sequelae of inhibiting constitutive activation of JNK has not yet been clarified. In this study, we examine the biologic effect of JNK inhibition in multiple myeloma (MM) cell lines. JNK-specific inhibitor SP600125 induces growth inhibition via induction of G1 or G2/M arrest in U266 and MM.1S multiple myeloma cell lines, respectively. Neither exogenous IL-6 nor insulin-like growth factor-1 (IGF-1) overcome SP600125-induced growth inhibition, and IL-6 enhances SP600125-induced G2/M phase in MM.1S cells. Induction of growth arrest is mediated by upregulation of p27(Kip1), without alteration of p53 and JNK protein expression. Importantly, SP600125 inhibits growth of MM cells adherent to bone marrow stromal cells (BMSCs). SP600125 induces NF-kappaB activation in a dose-dependent fashion, associated with phosphorylation of IkappaB kinase alpha (IKKalpha) and degradation of IkappaBalpha. In contrast, SP600125 does not affect phosphorylation of STAT3, Akt, and/or ERK. IKK-specific inhibitor PS-1145 inhibits SP600125-induced NF-kappaB activation and blocks the protective effect of SP600125 against apoptosis. Our data therefore demonstrate for the first time that inhibiting JNK activity induces growth arrest and activates NF-kappaB in MM cells.
authors.affiliation: Jerome Lipper Multiple Myeloma Center, Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
authors.forename: Teru
authors.initials: T
authors.lastname: Hideshima
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hayashi
authors.forename: Dharminder
authors.initials: D
authors.lastname: Chauhan
authors.forename: Masaharu
authors.initials: M
authors.lastname: Akiyama
authors.forename: Paul
authors.initials: P
authors.lastname: Richardson
authors.forename: Kenneth
authors.initials: K
authors.lastname: Anderson
mesh_terms: D000873:Anthracenes / Q000494:pharmacology; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D009101:Multiple Myeloma / Q000201:enzymology* / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D050796:STAT3 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D000873:Anthracenes; D004268:DNA-Binding Proteins; D015850:Interleukin-6; D016328:NF-kappa B; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; C432165:pyrazolanthrone; D007334:Insulin-Like Growth Factor I; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases