Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish
Resource
Blood Cancer J., 6,
Journal
Blood Cancer Journal
Pages
e481
Date Issued
2016
Date
2016
Author(s)
Lim K.-H.
Chang Y.-C.
Chiang Y.-H.
Lin H.-C.
Chang C.-Y.
Lin C.-S.
Huang, L.
Wang W.-T.
Chen, C. Gon-Shen
Abstract
CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.
SDGs
Other Subjects
calcium binding protein; calreticulin; calreticulin 3a; calreticulin 3b; colony stimulating factor 3 receptor; colony stimulating factor receptor; erythropoietin receptor; fedratinib; Janus kinase; ruxolitinib; STAT protein; thrombopoietin receptor; unclassified drug; calreticulin; fedratinib; JAK2 protein, human; Janus kinase 2; MPL protein, human; pyrazole derivative; pyrrolidine derivative; ruxolitinib; sulfonamide; thrombopoietin receptor; angiogenesis; animal cell; animal experiment; Article; attenuation; controlled study; drug effect; embryo; gene expression; gene mutation; hematopoiesis; hematopoietic stem cell; in vitro study; in vivo study; mutant; nonhuman; signal transduction; thrombocytopoiesis; thrombocytosis; wild type; zebra fish; animal; carcinogenesis; disease model; drug effects; gene expression regulation; genetics; hematopoiesis; human; metabolism; mutation; myeloid metaplasia; myeloproliferative disorder; pathology; thrombocythemia; thrombocytosis; Animals; Calreticulin; Carcinogenesis; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Hematopoiesis; Hematopoietic Stem Cells; Humans; Janus Kinase 2; Mutation; Myeloproliferative Disorders; Primary Myelofibrosis; Pyrazoles; Pyrrolidines; Receptors, Thrombopoietin; Signal Transduction; Sulfonamides; Thrombocythemia, Essential; Thrombocytosis; Zebrafish