title: Cotreatment with 17-allylamino-demethoxygeldanamycin and FLT-3 kinase inhibitor PKC412 is highly effective against human acute myelogenous leukemia cells with mutant FLT-3.
abstract: Presence of the activating length mutation (LM) in the juxtamembrane domain or point mutation in the kinase domain of FMS-like tyrosine kinase-3 (FLT-3) mediates ligand-independent progrowth and prosurvival signaling in approximately one-third of acute myelogenous leukemia (AML). PKC412, an inhibitor of FLT-3 kinase activity, is being clinically evaluated in AML. Present studies demonstrate that treatment of human acute leukemia MV4-11 cells (containing a FLT-3 LM) with the heat shock protein 90 inhibitor 17-allylamino-demethoxy geldanamycin (17-AAG) attenuated the levels of FLT-3 by inhibiting its chaperone association with heat shock protein 90, which induced the poly-ubiquitylation and proteasomal degradation of FLT-3. Treatment with 17-AAG induced cell cycle G(1) phase accumulation and apoptosis of MV4-11 cells. 17-AAG-mediated attenuation of FLT-3 and p-FLT-3 in MV4-11 cells was associated with decrease in the levels of p-AKT, p-ERK1/2, and p-STAT5, as well as attenuation of the DNA binding activity of STAT-5. Treatment with 17-AAG, downstream of STAT5, reduced the levels of c-Myc and oncostatin M, which are transactivated by STAT5. Cotreatment with 17-AAG and PKC412 markedly down-regulated the levels of FLT-3, p-FLT-3, p-AKT, p-ERK1/2, and p-STAT5, as well as induced more apoptosis of MV4-11 cells than either agent alone. Furthermore, the combination of 17-AAG and PKC412 exerted synergistic cytotoxic effects against MV4-11 cells. Importantly, 17-AAG and PKC412 induced more loss of cell viability of primary AML blasts containing FLT-3 LM, as compared with those that contained wild-type FLT-3. Collectively, these in vitro findings indicate that the combination of 17-AAG and PKC412 has high level of activity against AML cells with FLT-3 mutations.
authors.affiliation: Department of Interdisciplinary Oncology, Moffitt Cancer Center and Research Institute University of South Florida, Tampa, Florida 33612, USA.
authors.forename: Prince
authors.initials: P
authors.lastname: George
authors.forename: Purva
authors.initials: P
authors.lastname: Bali
authors.forename: Pamela
authors.initials: P
authors.lastname: Cohen
authors.forename: Jianguo
authors.initials: J
authors.lastname: Tao
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.forename: Celia
authors.initials: C
authors.lastname: Sigua
authors.forename: Anasuya
authors.initials: A
authors.lastname: Vishvanath
authors.forename: Warren
authors.initials: W
authors.lastname: Fiskus
authors.forename: Anna
authors.initials: A
authors.lastname: Scuto
authors.forename: Srinivas
authors.initials: S
authors.lastname: Annavarapu
authors.forename: Lynn
authors.initials: L
authors.lastname: Moscinski
authors.forename: Kapil
authors.initials: K
authors.lastname: Bhalla
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016227:Benzoquinones; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004273:DNA, Neoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D016193:G1 Phase / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D047029:Lactams, Macrocyclic; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D008894:Milk Proteins; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D017828:Rifabutin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D050799:STAT5 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects; D019311:Staurosporine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015534:Trans-Activators / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D051941:fms-Like Tyrosine Kinase 3
chemical_list: D016227:Benzoquinones; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D008894:Milk Proteins; D009097:Multienzyme Complexes; D011518:Proto-Oncogene Proteins; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D025801:Ubiquitin; D017828:Rifabutin; C112765:tanespimycin; C497970:FLT3 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D051941:fms-Like Tyrosine Kinase 3; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D019311:Staurosporine; C059539:midostaurin