Correspondence
JAK2 Mutations in Myeloproliferative Disorders
N Engl J Med 2005; 353:1416-1417September 29, 2005
- Article
To the Editor:
An activating somatic mutation involving the JH2 pseudokinase domain of Janus kinase 2 (JAK2 [V617F]) has been associated with myeloproliferative disorders. The mutation is detectable in 65 percent1 to 97 percent2 of cases of polycythemia vera. Kralovics and colleagues (April 28 issue)1 report a significant association between homozygosity for the JAK2 (V617F) mutation, which occurred in approximately one quarter of the patients with polycythemia vera, and increased duration of disease in polycythemia vera, essential thrombocythemia, and myelofibrosis with myeloid metaplasia. A similar observation was made by others,3 raising the possibility that homozygosity for the mutant allele is a time-dependent clonal evolution.
We tested this hypothesis by performing mutational analysis in archived bone marrow cells from patients showing homozygosity in DNA derived from peripheral-blood granulocytes. Among 220 patients with either polycythemia vera or myelofibrosis with myeloid metaplasia who were seen at the Mayo Clinic and not included in previous publications,3 granulocyte-based mutation screening identified 21 patients who were homozygous for JAK2 (V617F) — 13 who had polycythemia vera and 8 who had myelofibrosis with myeloid metaplasia. In the case of 5 of these 21 patients, including 2 with polycythemia vera, the study was performed at the time of diagnosis. However, laboratory records in the two patients with polycythemia vera revealed a preexisting increase in the hematocrit from baseline that had been unrecognized for at least two years. Stored bone marrow from six patients, collected 1.5 to 9.5 years before the current analysis, showed variable degrees of heterozygosity in four patients at different times during their clinical course (Figure 1Figure 1
Mutational Analysis of JAK2 (V617F) in Serial Bone Marrow Specimens from Six Patients with Myeloproliferative Disorders.). The pattern of change over time, especially as depicted in Patient 3, favors a time-dependent increase in clonal dominance rather than a two-step molecular event. This possibility is consistent with the occurrence of a mixed-clonality pattern in purified CD34+ cell fractions in patients whose granulocytes show homozygosity4 and the in vitro demonstration of a JAK2 (V617F)–induced proliferative advantage in cell lines.1,5 Furthermore, as noted above, the occurrence of subclinical clonal myelopoiesis might partly explain why heterozygosity is not always documented at the time of clinical diagnosis.5 ReferencesAyalew Tefferi, M.D.
Terra L. Lasho, M.T.
Mayo Clinic, Rochester, MN 55905
tefferi.ayalew@mayo. edu Gary Gilliland, M.D., Ph.D.
Harvard Medical School, Boston, MA 021151
Kralovics R ,Passamonti F ,Buser AS , et al. A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med 2005;352:1779-1790
Full Text | Web of Science | Medline2
Baxter EJ ,Hochhaus A ,Bolufer P , et al. The t(4;22)(q12;q11) in atypical chronic myeloid leukaemia fuses BCR to PDGFRA. Hum Mol Genet 2002;11:1391-1397
CrossRef | Web of Science | Medline3
Levine RL ,Wadleigh M ,Cools J , et al. Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell 2005;7:387-397
CrossRef | Web of Science | Medline4
Lasho TL ,Mesa R ,Gilliland DG ,Tefferi A . Mutation studies in CD3, CD19 and CD34 cell fractions in myeloproliferative disorders with homozygous JAK2 in granulocytes. Br J Haematol 2005;130:797-799
CrossRef | Web of Science | Medline5
James C ,Ugo V ,Le Couedic JP , et al. A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera. Nature 2005;434:1144-1148
CrossRef | Web of Science | Medline
Author/Editor Response
We proposed a two-step model for the role of JAK2 (V617F) in the clonal evolution of myeloproliferative disorders. The first step consists of a G-to-T mutation in one allele of the JAK2 gene that is acquired as a somatic mutation in a hematopoietic progenitor cell or stem cell. This cell gives rise to a clone that is heterozygous for JAK2 (V617F) and expands to replace hematopoietic cells without the JAK2 mutation. The second step consists of a mitotic recombination in one of the progenitor cells or stem cells heterozygous for the JAK2 mutation that generates uniparental disomy and homozygosity for JAK2 (V617F) in one of the two daughter cells. This daughter cell gives rise to a clone that is homozygous for JAK2 (V617F) and expands to replace heterozygous hematopoietic cells. The results of the test described by Tefferi and colleagues provide evidence that confirms the predictions of our model. A strict two-step process applies at the level of individual cells (i.e., each cell can be either heterozygous or homozygous, provided that gene amplification at the JAK2 locus is not involved). In contrast, when cell populations are analyzed, the transition from heterozygosity to homozygosity will be a continuous process, since the proportion of homozygous cells in this mixed population of cells will gradually increase until the homozygous cells fully dominate hematopoiesis. Analyses of mixed-cell populations, such as those of bone marrow or blood, taken during this transition period are expected to show a time-dependent increase of clonal dominance rather than a two-step transition. Thus, the data from Tefferi and colleagues do not contradict our model but instead confirm its predictions. We have applied a quantitative allele-specific polymerase-chain-reaction technique to determine the ratios of wild-type and mutant JAK2 alleles, and we obtained very similar results to those reported here by Tefferi and colleagues.
Robert Kralovics, Ph.D.
University Hospital Basel, 4031 Basel, SwitzerlandMario Cazzola, M.D.
University of Pavia Medical School, 27100 Pavia, ItalyRadek C. Skoda, M.D.
University Hospital Basel, 4031 Basel, Switzerland
radek.skoda@unibas. ch - Citing Articles (27)
Citing Articles
1
Cui-Juan Qian, Jun Yao, Jian-Min Si. (2011) Nuclear JAK2: Form and Function in Cancer. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 294:9, 1446-1459
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Brady L. Stein, Donna M. Williams, Ophelia Rogers, Mary Ann Isaacs, Jerry L. Spivak, Alison R. Moliterno. (2011) Disease burden at the progenitor level is a feature of primary myelofibrosis: a multivariable analysis of 164 JAK2 V617F-positive myeloproliferative neoplasm patients. Experimental Hematology 39:1, 95-101
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Wolfgang Kern, Torsten Haferlach, Susanne Schnittger, Claudia Haferlach, Ulrike Bacher. 2010. Presentation and Diagnosis: Novel Molecular Markers and their Role in the Prognosis and Therapy of Acute Myeloid Leukemia. , 115-124.
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J. He, Y. Zhang. (2010) Janus Kinase 2: An Epigenetic 'Writer' that Activates Leukemogenic Genes. Journal of Molecular Cell Biology 2:5, 231-233
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Nicolaus Kröger, Ulrike Bacher, Peter Bader, Sebastian Böttcher, Michael J. Borowitz, Peter Dreger, Issa Khouri, Eduardo Olavarria, Jerald Radich, Wendy Stock, Julie M. Vose, Daniel Weisdorf, Andre Willasch, Sergio Giralt, Michael R. Bishop, Alan S. Wayne. (2010) NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: Report from the Committee on Disease-Specific Methods and Strategies for Monitoring Relapse Following Allogeneic Stem Cell Transplantation. Part II: Chronic Leukemias, Myeloproliferative Neoplasms, and Lymphoid Malignancies. Biology of Blood and Marrow Transplantation 16:10, 1325-1346
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Ulrike Bacher, Svetlana Asenova, Anita Badbaran, Axel Rolf Zander, Haefaa Alchalby, Boris Fehse, Nicolaus Kröger, Claudia Lange, Francis Ayuk. (2010) Bone marrow mesenchymal stromal cells remain of recipient origin after allogeneic SCT and do not harbor the JAK2V617F mutation in patients with myelofibrosis. Clinical and Experimental Medicine 10:3, 205-208
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Zhaohui Ye, Linzhao Cheng. (2010) Potential of human induced pluripotent stem cells derived from blood and other postnatal cell types. Regenerative Medicine 5:4, 521-530
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Ulrike Bacher, Claudia Haferlach, Susanne Schnittger, Alexander Kohlmann, Wolfgang Kern, Torsten Haferlach. (2010) Mutations of the TET2 and CBL genes: novel molecular markers in myeloid malignancies. Annals of Hematology 89:7, 643-652
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A Tefferi. (2010) Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms: JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1. Leukemia 24:6, 1128-1138
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Andrea Hoelbl, Christian Schuster, Boris Kovacic, Bingmei Zhu, Mark Wickre, Maria A. Hoelzl, Sabine Fajmann, Florian Grebien, Wolfgang Warsch, Gabriele Stengl, Lothar Hennighausen, Valeria Poli, Hartmut Beug, Richard Moriggl, Veronika Sexl. (2010) Stat5 is indispensable for the maintenance of bcr/abl-positive leukaemia. EMBO Molecular Medicine 2:3, 98-110
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Ulrike Bacher, Susanne Schnittger, Wolfgang Kern, Tamara Weiss, Torsten Haferlach, Claudia Haferlach. (2009) Distribution of cytogenetic abnormalities in myelodysplastic syndromes, Philadelphia negative myeloproliferative neoplasms, and the overlap MDS/MPN category. Annals of Hematology 88:12, 1207-1213
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J. W. Vardiman, J. Thiele, D. A. Arber, R. D. Brunning, M. J. Borowitz, A. Porwit, N. L. Harris, M. M. Le Beau, E. Hellstrom-Lindberg, A. Tefferi, C. D. Bloomfield. (2009) The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood 114:5, 937-951
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Ayalew Tefferi. (2009) Molecular drug targets in myeloproliferative neoplasms: mutant ABL1, JAK2, MPL, KIT, PDGFRA, PDGFRB and FGFR1. Journal of Cellular and Molecular Medicine 13:2, 215-237
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Ayalew Tefferi, Ross L. Levine, Hagop Kantarjian. (2009) Oncogenic Signals as Treatment Targets in Classic Myeloproliferative Neoplasms. Biology of Blood and Marrow Transplantation 15:1, 114-119
CrossRef15
U Bacher, A R Zander, T Haferlach, S Schnittger, B Fehse, N Kröger. (2008) Minimal residual disease diagnostics in myeloid malignancies in the post transplant period. Bone Marrow Transplantation 42:3, 145-157
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Ayalew Tefferi. (2008) JAK and MPL mutations in myeloid malignancies. Leukemia & Lymphoma 49:3, 388-397
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Ciro R. Rinaldi, Vincenzo Martinelli, Paola Rinaldi, Rosanna Ciancia, Luigi del Vecchio, Fabrizio Pane, Giuseppina Nucifora, Bruno Rotoli. (2008) GATA1 is overexpressed in patients with essential thrombocythemia and polycythemia vera but not in patients with primary myelofibrosis or chronic myelogenous leukemia. Leukemia & Lymphoma 49:7, 1416-1419
CrossRef18
Torsten Haferlach, Ulrike Bacher, Wolfgang Kern, Susanne Schnittger, Claudia Haferlach. (2008) The diagnosis of BCR/ABL-negative chronic myeloproliferative diseases (CMPD): a comprehensive approach based on morphology, cytogenetics, and molecular markers. Annals of Hematology 87:1, 1-10
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Takefumi Ishii, Yan Zhao, Selcuk Sozer, Jun Shi, Wei Zhang, Ronald Hoffman, Mingjiang Xu. (2007) Behavior of CD34+ cells isolated from patients with polycythemia vera in NOD/SCID mice. Experimental Hematology 35:11, 1633-1640
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Amos Gaikwad, Roberto Nussenzveig, Enli Liu, Stephen Gottshalk, KoTung Chang, Josef T. Prchal. (2007) In vitro expansion of erythroid progenitors from polycythemia vera patients leads to decrease in JAK2V617F allele. Experimental Hematology 35:4, 587-595
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E Jost, N do Ó, E Dahl, C E Maintz, P Jousten, L Habets, S Wilop, J G Herman, R Osieka, O Galm. (2007) Epigenetic alterations complement mutation of JAK2 tyrosine kinase in patients with BCR/ABL-negative myeloproliferative disorders. Leukemia 21:3, 505-510
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Kais Hussein, Kai Brakensiek, Guntram Buesche, Thomas Buhr, Birgitt Wiese, Hans Kreipe, Oliver Bock. (2007) Different involvement of the megakaryocytic lineage by the JAK2V617F mutation in Polycythemia vera, essential thrombocythemia and chronic idiopathic myelofibrosis. Annals of Hematology 86:4, 245-253
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Terra L. Lasho, Animesh Pardanani, Rebecca F. McClure, Ruben A. Mesa, Ross L. Levine, D. Gary Gilliland, Ayalew Tefferi. (2006) Concurrent MPL515 and JAK2V617F mutations in myelofibrosis: chronology of clonal emergence and changes in mutant allele burden over time. British Journal of Haematology 135:5, 683-687
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Ruben A. Mesa, Heather Powell, Terra Lasho, Gordon DeWald, Rebecca McClure, Ayalew Tefferi. (2006) JAK2V617F and leukemic transformation in myelofibrosis with myeloid metaplasia. Leukemia Research 30:11, 1457-1460
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R A Mesa, A Tefferi, T S Lasho, D Loegering, R F McClure, H L Powell, N T Dai, D P Steensma, S H Kaufmann. (2006) Janus kinase 2 (V617F) mutation status, signal transducer and activator of transcription-3 phosphorylation and impaired neutrophil apoptosis in myelofibrosis with myeloid metaplasia. Leukemia 20:10, 1800-1808
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Marla Lay, Rajan Mariappan, Jason Gotlib, Lisa Dietz, Siby Sebastian, Iris Schrijver, James L. Zehnder. (2006) Detection of the JAK2 V617F Mutation by LightCycler PCR and Probe Dissociation Analysis. The Journal of Molecular Diagnostics 8:3, 330-334
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Ayalew Tefferi, Jacob J. Strand, Terra L. Lasho, Michelle A. Elliott, Chin-Yang Li, Ruben A. Mesa, Gordon W. Dewald. (2006) Respective clustering of unfavorable and favorable cytogenetic clones in myelofibrosis with myeloid metaplasia with homozygosity for JAK2V617F and response to erythropoietin therapy. Cancer 106:8, 1739-1743
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