title: WP-1034, a novel JAK-STAT inhibitor, with proapoptotic and antileukemic activity in acute myeloid leukemia (AML).
abstract: Cytokine stimulation induces proliferation and growth of acute myeloid leukemia (AML) blasts and high levels of cytokines have been associated with poor prognosis in AML. The Jak-Stat pathway constitutes a major mediator of cytokine activity. We investigated whether WP-1034, a novel Jak-Stat inhibitor, is active against AML blasts. OCIM2 and fresh AML cells were incubated with 1 to 6 microM WP-1034 to determine its effect on proliferation. WP-1034 effectively inhibited proliferation of OCIM2 cells and fresh AML samples. We then analyzed the expressions of Stat 1, 3, and 5, as well as Phospho-Stat 1, 3, and 5 by Western immunoblotting after incubation of OCIM2 cells without and with 1 to 10 microM WP-1034 for 2 hours, and at 5 microM from 20 minutes up to 4 hours and found that WP-1034 blocked Stat 3 and 5 activation. Analysis of cell cycle status by PI staining and flow cytometry showed that WP-1034 caused cell cycle arrest of OCIM2 cells in sub-Go phase. We then evaluated the induction of apoptosis of OCIM2 cells following incubation with WP-1034 at 3 to 6 microM by annexin V-CY5 assay and analyzed caspase 3 and PARP cleavage using Western immunoblotting. We found that WP-1034 induced apoptosis of OCIM2 cells and that induction of apoptosis involved cleavage of caspase 3 and the DNA repair enzyme poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP). Taken together, our data suggest that WP-1034 is a potent inhibitor of AML cell proliferation by inhibition of Stat 3 and 5 and induction of caspase-dependent apoptosis.
authors.affiliation: The Department of Leukemia of The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Faderl
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ferrajoli
authors.forename: David
authors.initials: D
authors.lastname: Harris
authors.forename: Quin
authors.initials: Q
authors.lastname: Van
authors.forename: Waldemar
authors.initials: W
authors.lastname: Priebe
authors.forename: Zeev
authors.initials: Z
authors.lastname: Estrov
mesh_terms: D000178:Acrylamides / Q000494:pharmacology*; D000208:Acute Disease; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D053613:Janus Kinase 1; D004915:Leukemia, Erythroblastic, Acute / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D007951:Leukemia, Myeloid / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D008297:Male; D008894:Milk Proteins / Q000037:antagonists & inhibitors*; D009570:Nitriles / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects; D015534:Trans-Activators / Q000037:antagonists & inhibitors*
chemical_list: D000178:Acrylamides; D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D008894:Milk Proteins; D009570:Nitriles; D047428:Protein Kinase Inhibitors; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; C505031:WP-1034; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; D053613:Janus Kinase 1; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases