title: Role for c-jun N-terminal kinase in treatment-refractory acute myeloid leukemia (AML): signaling to multidrug-efflux and hyperproliferation.
abstract: A relationship was proved between constitutive activity of leukemic cell c-jun-N-terminal kinase (JNK) and treatment failure in AML. Specifically, early treatment failure was predicted by the presence of constitutive JNK activity. The mechanistic origins of this association was sought. A multidrug resistant leukemic cell line, HL-60/ADR, characterized by hyperexpression of c-jun and JNK activity, was transfected with a mutant c-jun vector, whose substrate N-terminal c-jun serines were mutated. Down-regulated expression occurred of c-jun/AP-1-dependent genes, catalase and glutathione-S-transferase (GST) pi, which participate in cellular homeostasis to oxidative stress and xenobiotic exposure. MRP-efflux was abrogated in HL-60/ADR cells with dominant-negative c-jun, perhaps because MRP1 protein expression was also lost. Heightened sensitivity to daunorubicin resulted in cells subjected to this change. Biochemical analysis in 67 primary adult AML samples established a statistical correlation between cellular expression of c-jun and JNK activity, JNK activity with hyperleukocytosis at presentation of disease, and with exuberant MRP efflux. These findings reflect the survival role for c-jun/AP-1 and its regulatory kinase previously demonstrated for yeast in homeostatic response to oxidative stress and in operation of ATP-binding cassette efflux pumps, and may support evolutionary conservation of such function. Thus, JNK and c-jun may be salient drug targets in multidrug resistant AML.
authors: Department of Medicine, Division of Hematology/Oncology, Indiana University School of Medicine, 1044 W Walnut Street, Indianapolis, IN 46202, USA.
authors: L D
authors: LD
authors: Cripe
authors: V M
authors: VM
authors: Gelfanov
authors: E A
authors: EA
authors: Smith
authors: D R
authors: DR
authors: Spigel
authors: C A
authors: CA
authors: Phillips
authors: T G
authors: TG
authors: Gabig
authors: S-H
authors: SH
authors: Jung
authors: J
authors: J
authors: Fyffe
authors: A D
authors: AD
authors: Hartman
authors: P
authors: P
authors: Kneebone
authors: D
authors: D
authors: Mercola
authors: G S
authors: GS
authors: Burgess
authors: H S
authors: HS
authors: Boswell
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000208:Acute Disease; D001854:Bone Marrow Cells / Q000473:pathology; D002455:Cell Division; D003630:Daunorubicin; D018432:Drug Resistance, Multiple / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D018922:HL-60 Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D007951:Leukemia, Myeloid / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D016755:Proto-Oncogene Proteins c-jun; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D003630:Daunorubicin