title: The JAK kinase inhibitor CP-690,550 suppresses the growth of human polycythemia vera cells carrying the JAK2V617F mutation.
abstract: The somatic activating janus kinase 2 mutation (JAK2)(V617F) is detectable in most patients with polycythemia vera (PV). Here we report that CP-690,550 exerts greater antiproliferative and pro-apoptotic activity against cells harboring JAK2(V617F) compared with JAK2(WT). CP-690,550 treatment of murine factor-dependent cell Patersen-erythropoietin receptor (FDCP-EpoR) cells harboring human wild-type or V617F JAK2 resulted in inhibition of cell proliferation with a 50% inhibitory concentration (IC(50)) of 2.1 microM and 0.25 microM, respectively. Moreover, CP-690,550 induced a significant pro-apoptotic effect on murine FDCP-EpoR cells carrying JAK2(V617F), whereas a lesser effect was observed for cells carrying wild-type JAK2. This activity was coupled with inhibition of phosphorylation of the key JAK2(V617F)-dependent downstream signaling effectors signal transducer and activator of transcription (STAT)3, STAT5, and v-akt murine thymoma viral oncogene homolog (AKT). Furthermore, CP-690,550 treatment of ex-vivo-expanded erythroid progenitors from JAK2(V617F)-positive PV patients resulted in specific, antiproliferative (IC(50) = 0.2 microM) and pro-apoptotic activity. In contrast, expanded progenitors from healthy controls were less sensitive to CP-690,550 in proliferation (IC(50) > 1.0 microM), and apoptosis assays. The antiproliferative effect on expanded patient progenitors was paralleled by a decrease in JAK2(V617F) mutant allele frequency, particularly in a patient homozygous for JAK2(V617F). Flow cytometric analysis of expanded PV progenitor cells treated with CP-690,550 suggests a possible transition towards a pattern of erythroid differentiation resembling expanded cells from normal healthy controls.
authors.affiliation: Department of Leukemia, The University of Texas, M D Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Taghi
authors.initials: T
authors.lastname: Manshouri
authors.forename: Alfonso
authors.initials: A
authors.lastname: Quintás-Cardama
authors.forename: Roberto H
authors.initials: RH
authors.lastname: Nussenzveig
authors.forename: Amos
authors.initials: A
authors.lastname: Gaikwad
authors.forename: Zeev
authors.initials: Z
authors.lastname: Estrov
authors.forename: Josef
authors.initials: J
authors.lastname: Prchal
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Cortes
authors.forename: Hagop M
authors.initials: HM
authors.lastname: Kantarjian
authors.forename: Srdan
authors.initials: S
authors.lastname: Verstovsek
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D015672:Erythroid Precursor Cells / Q000187:drug effects / Q000378:metabolism; D004921:Erythropoietin / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D047468:Immunoprecipitation; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009154:Mutation / Q000235:genetics*; D010766:Phosphorylation / Q000187:drug effects; D010880:Piperidines; D011087:Polycythemia Vera / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D021381:Protein Transport; D011743:Pyrimidines / Q000627:therapeutic use*; D011758:Pyrroles / Q000627:therapeutic use*; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; D017467:Receptors, Erythropoietin; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D004921:Erythropoietin; C479163:tofacitinib; D053614:Janus Kinase 2