Selective reduction of JAK2V617F-dependent cell growth by siRNA/shRNA and its reversal by cytokines
Open Access
- 27 August 2009
- journal article
- Published by American Society of Hematology in Blood
- Vol. 114 (9), 1842-1851
- https://doi.org/10.1182/blood-2008-09-176875
Abstract
The JAKV617F mutation is responsible for the majority of breakpoint cluster region (BCR)/Abelson (ABL)–negative myeloproliferative disorders. Ongoing clinical trials of Janus kinase 2 (JAK2) inhibitors in myeloproliferative disorder patients use small molecules targeting both wild-type and mutated JAK2. To selectively target malignant cells, we developed JAK2V617F-specific small interfering RNAs or short hairpin RNAs. Expression of these RNAs in cell lines or CD34+ cells from patients reduced JAK2V617F-driven autonomous cell proliferation. Mechanisms of inhibition involved selective JAK2V617F protein down-regulation, and consequently, decrease in signal transducer and activator of transcription 5 phosphorylation, cell-cycle progression, and cell survival. However, the addition of high concentrations of cytokines to cell lines or erythropoietin to patient cells greatly reduced growth inhibition. Similarly, the efficacy of a JAK2 small molecule inhibitor on cell line and patient cell proliferation dose dependently decreased with the addition of cytokines. Our results demonstrate that it is possible to specifically target JAK2V617F by RNA interference (RNAi) strategies. In addition, cytokines partially reverse the inhibition induced by both RNAi and small molecule approaches. This strongly suggests that patient cytokine levels in current JAK2 inhibitor clinical trials modulate the outcome of these therapies.Keywords
This publication has 36 references indexed in Scilit:
- JAK2Exon 12 Mutations in Polycythemia Vera and Idiopathic ErythrocytosisNew England Journal of Medicine, 2007
- MPLW515L Is a Novel Somatic Activating Mutation in Myelofibrosis with Myeloid MetaplasiaPLoS Medicine, 2006
- New Insights into the Pathogenesis of JAK2 V617F-Positive Myeloproliferative Disorders and Consequences for the Management of PatientsSeminars in Thrombosis and Hemostasis, 2006
- A Gain-of-Function Mutation ofJAK2in Myeloproliferative DisordersNew England Journal of Medicine, 2005
- Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosisCancer Cell, 2005
- A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia veraNature, 2005
- Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disordersThe Lancet, 2005
- The chronic myeloproliferative disorders: Clonality and clinical heterogeneitySeminars in Hematology, 2004
- Chronic Myeloproliferative DisordersHematology-American Society Hematology Education Program, 2003
- Bone-Marrow Responses in Polycythemia VeraNew England Journal of Medicine, 1974