The fusion oncoprotein BCR-ABL1 exhibits aberrant tyrosine kinase activity and it has been proposed that it deregulates signaling networks involving both transcription factors and non-coding microRNAs that result in chronic myeloid leukemia (CML). Previously, microRNA expression profiling showed deregulated expression of miR-150 and miR-155 in CML. In this study, we placed these findings into the broader context of the MYC/miR-150/MYB/miR-155/PU.1 oncogenic network. We propose that up-regulated MYC and miR-155 in CD34+ leukemic stem and progenitor cells, in concert with BCR-ABL1, impair the molecular mechanisms of myeloid differentiation associated with low miR-150 and PU.1 levels. We revealed that MYC directly occupied the -11.7 kb and -0.35 kb regulatory regions in the MIR150 gene. MYC occupancy was markedly increased through BCR-ABL1 activity, causing inhibition of MIR150 gene expression in CML CD34+ and CD34- cells. Furthermore, we found an association between reduced miR-150 levels in CML blast cells and their resistance to tyrosine kinase inhibitors (TKIs). Although TKIs successfully disrupted BCR-ABL1 kinase activity in proliferating CML cells, this treatment did not efficiently target quiescent leukemic stem cells. The study presents new evidence regarding the MYC/miR-150/MYB/miR-155/PU.1 leukemic network established by aberrant BCR-ABL1 activity. The key connecting nodes of this network may serve as potential druggable targets to overcome resistance of CML stem and progenitor cells.

BIOCEV 1st Medical Faculty Charles University Vestec Czech Republic

Department of Medicine Marlene and Stewart Greenebaum Comprehensive Cancer Center University of Maryland Baltimore MD USA

Department of Microbiology and Immunology Marlene and Stewart Greenebaum Comprehensive Cancer Center University of Maryland Baltimore MD USA

Institute of Clinical and Experimental Hematology 1st Medical Faculty Charles University Prague Czech Republic

Institute of Hematology and Blood Transfusion Prague Czech Republic

Institute of Pathological Physiology 1st Medical Faculty Charles University Prague Czech Republic

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Chereda B, Melo JV. Natural course and biology of CML. Ann Hematol. 2015;94(2S):107–121. PubMed

Pellicano F, Scott MT, Helgason GV, et al. The antiproliferative activity of kinase inhibitors in chronic myeloid leukemia cells is mediated by FOXO transcription factors. Stem Cells. 2014;32(9):2324–2337. PubMed PMC

Wagle M, Eiring AM, Wongchenko M, et al. A role for FOXO1 in BCR-ABL1-independent tyrosine kinase inhibitor resistance in chronic myeloid leukemia. Leukemia. 2016;30(7):1493–1501. PubMed PMC

Graham SM, Jorgensen HG, Allan E, et al. Primitive, quiescent, Philadelphia-positive stem cells from patients with chronic myeloid leukemia are insensitive to STI571 in vitro. Blood. 2002;99(1):319–325. PubMed

Bhatia R, Holtz M, Niu N, et al. Persistence of malignant hematopoietic progenitors in chronic myelogenous leukemia patients in complete cytogenetic remission following imatinib mesylate treatment. Blood. 2003;101(12):4701–4707. PubMed

Corbin AS, Agarwal A, Loriaux M, Cortes J, Deininger MW, Druker BJ. Human chronic myeloid leukemia stem cells are insensitive to imatinib despite inhibition of BCR-ABL activity. J Clin Invest. 2011;121(1):396–409. PubMed PMC

Agirre X, Jimenez-Velasco A, San Jose-Eneriz E, et al. Down-regulation of Hsa-miR-10a in chronic myeloid leukemia CD34+ cells increases USF2-mediated cell growth. Mol Cancer Res. 2008;6(12):1830–1840. PubMed

Flamant S, Ritchie W, Guilhot J, et al. Micro-RNA response to imatinib mesylate in patients with chronic myeloid leukemia. Haematologica. 2010;95(8):1325–1333. PubMed PMC

Morris VA, Zhang A, Yang T, et al. MicroRNA-150 expression induces myeloid differentiation of human acute leukemia cells and normal hematopoietic progenitors. PLoS One. 2013;8(9):e75815. PubMed PMC

Machová Poláková K, Lopotová T, Klamová H, et al. Expression patterns of microRNAs associated with CML phases and their disease related targets. Mol Cancer. 2011;10:41. PubMed PMC

Lin YC, Kuo MW, Yu J, et al. c-Myb is an evolutionary conserved miR-150 target and miR-150/c-Myb interaction is important for embryonic development. Mol Biol Evol. 2008;25(10):2189–2198. PubMed

Xiao C, Calado DP, Galler G, et al. MiR-150 controls B cell differentiation by targeting the transcription factor c-Myb. Cell. 2007;131(1):146–159. PubMed

Gonda TJ, Metcalf D. Expression of myb, myc and fos proto-oncogenes during the differentiation of a murine myeloid leukaemia. Nature. 1984;310(5974):249–251. PubMed

Lidonnici MR, Corradini F, Waldron T, Bender TP, Calabretta B. Requirement of c-Myb for p210(BCR/ABL)-dependent transformation of hematopoietic progenitors and leukemogenesis. Blood. 2008;111(9):4771–4779. PubMed PMC

Vigorito E, Perks KL, Abreu-Goodger C, et al. microRNA-155 regulates the generation of immunoglobulin class-switched plasma cells. Immunity. 2007;27(6):847–859. PubMed PMC

Gerloff D, Grundler R, Wurm AA, et al. NF-kappaB/STAT5/miR-155 network targets PU.1 in FLT3-ITD-driven acute myeloid leukemia. Leukemia. 2015;29(3):535–547. PubMed PMC

Wolff L, Schmidt M, Koller R, et al. Three genes with different functions in transformation are regulated by c-Myb in myeloid cells. Blood Cells Mol Dis. 2001;27(2):483–488. PubMed

Sharma N, Magistroni V, Piazza R, et al. BCR/ABL1 and BCR are under the transcriptional control of the MYC oncogene. Mol Cancer. 2015;14:132. PubMed PMC

Baccarani M, Deininger MW, Rosti G, et al. European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013. Blood. 2013;122(6):872–884. PubMed PMC

Saeed AI, Sharov V, White J, et al. TM4: a free, open-source system for microarray data management and analysis. Biotechniques. 2003;34(2):374–378. PubMed

Lehár J, Zimmermann GR, Krueger AS, et al. Chemical combination effects predict connectivity in biological systems. Mol Syst Biol. 2007;3:80. PubMed PMC

Yuan H, Wang Z, Gao C, et al. BCR-ABL gene expression is required for its mutations in a novel KCL-22 cell culture model for acquired resistance of chronic myelogenous leukemia. J Biol Chem. 2010;285(7):5085–5096. PubMed PMC

Delmore JE, Issa GC, Lemieux ME, et al. BET bromodomain inhibition as a therapeutic strategy to target c-Myc. Cell. 2011;146(6):904–917. PubMed PMC

Kihara-Negishi F, Yamamoto H, Suzuki M, et al. In vivo complex formation of PU.1 with HDAC1 associated with PU.1-mediated transcriptional repression. Oncogene. 2001;20(42):6039–6047. PubMed

Bellon T, Perrotti D, Calabretta B. Granulocytic differentiation of normal hematopoietic precursor cells induced by transcription factor PU.1 correlates with negative regulation of the c-myb promoter. Blood. 1997;90(5):1828–1839. PubMed

Dahl R, Simon MC. The importance of PU.1 concentration in hematopoietic lineage commitment and maturation. Blood Cells Mol Dis. 2003;31(2):229–233. PubMed

Hornick NI, Doron B, Abdelhamed S, et al. AML suppresses hematopoiesis by releasing exosomes that contain microRNAs targeting c-MYB. Sci Signal. 2016;9(444):ra88. PubMed

Chang TC, Yu D, Lee YS, et al. Widespread microRNA repression by Myc contributes to tumorigenesis. Nat Genet. 2008;40(1):43–50. PubMed PMC

Jiang X, Huang H, Li Z, et al. Blockade of miR-150 maturation by MLL-fusion/MYC/LIN-28 is required for MLL-associated leukemia. Cancer Cell. 2012;22(4):524–535. PubMed PMC

Adams CM, Hiebert SW, Eischen CM. Myc Induces miRNA-Mediated Apoptosis in Response to HDAC Inhibition in Hematologic Malignancies. Cancer Res. 2016;76(3):736–748. PubMed PMC

Abraham SA, Hopcroft LE, Carrick E, et al. Dual targeting of p53 and c-MYC selective ly eliminates leukaemic stem cells. Nature. 2016;534(7607):341–346. PubMed PMC

Albajar M, Gutierrez P, Richard C, et al. PU.1 expression is restored upon treatment of chronic myeloid leukemia patients. Cancer Lett. 2008;270(2):328–336. PubMed

Yang H, Liang H, Yan JS, Tao R, Hao SG, Ma LY. Down-regulation of hematopoiesis master regulator PU.1 via aberrant methylation in chronic myeloid leukemia. Int J Hematol. 2012;96(1):65–73. PubMed

Stopka T, Amanatullah DF, Papetti M, Skoultchi AI. PU.1 inhibits the erythroid program by binding to GATA-1 on DNA and creating a repressive chromatin structure. EMBO J. 2005;24(21):3712–3723. PubMed PMC

Kluiver J, Poppema S, de Jong D, et al. BIC and miR-155 are highly expressed in Hodgkin, primary mediastinal and diffuse large B cell lymphomas. J Pathol. 2005;207(2):243–249. PubMed

Calin GA, Croce CM. Chronic lymphocytic leukemia: interplay between noncoding RNAs and protein-coding genes. Blood. 2009;114(23):4761–4770. PubMed PMC

Volinia S, Calin GA, Liu CG, et al. A microRNA expression signature of human solid tumors defines cancer gene targets. Proc Natl Acad Sci USA. 2006;103(7):2257–2261. PubMed PMC

O’Connell RM, Rao DS, Chaudhuri AA, et al. Sustained expression of microRNA-155 in hematopoietic stem cells causes a myelo-proliferative disorder. J Exp Med. 2008;205(3):585–594. PubMed PMC

Rokah OH, Granot G, Ovcharenko A, et al. Downregulation of miR-31, miR-155, and miR-564 in chronic myeloid leukemia cells. PLoS One. 2012;7(4):e35501. PubMed PMC

Narayan N, Morenos L, Phipson B, et al. Functionally distinct roles for different miR-155 expression levels through contrasting effects on gene expression, in acute myeloid leukaemia. Leukemia. 2017;31(4):808–820. PubMed

Somatic Mutations in Oncogenes Are in Chronic Myeloid Leukemia Acquired De Novo via Deregulated Base-Excision Repair and Alternative Non-Homologous End Joining