WP-1034, a novel JAK-STAT inhibitor, with proapoptotic and antileukemic activity in acute myeloid leukemia (AML).
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.
Faderl
Stefan
S
The Department of Leukemia of The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA.
Ferrajoli
Alessandra
A
Harris
David
D
Van
Quin
Q
Priebe
Waldemar
W
Estrov
Zeev
Z
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*
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