Immature CML cells implement a BMP autocrine loop to escape TKI treatment

Blood. 2017 Dec 28;130(26):2860-2871. doi: 10.1182/blood-2017-08-801019. Epub 2017 Nov 14.


The BCR-ABL specific tyrosine kinase inhibitors (TKI) changed the outcome of chronic myeloid leukemia (CML), turning a life-threatening disease into a chronic illness. However, TKI are not yet curative, because most patients retain leukemic stem cells (LSC) and their progenitors in bone marrow and relapse following treatment cessation. At diagnosis, deregulation of the bone morphogenetic protein (BMP) pathway is involved in LSC and progenitor expansion. Here, we report that BMP pathway alterations persist in TKI-resistant patients. In comparison with patients in complete cytogenetic remission, TKI-resistant LSC and progenitors display high levels of BMPR1b expression and alterations of its cellular localization. In vitro treatment of immature chronic phase CML cells with TKI alone, or in combination with interferon-α, results in the preferential survival of BMPR1b+ cells. We demonstrated persistent and increasing BMP4 production by patients' mesenchymal cells with resistance. Patient follow-up revealed an increase of BMPR1b expression and in BMP4 expression in LSC from TKI-resistant patients in comparison with diagnosis, while remaining unchanged in sensitive patients. Both leukemic and nonleukemic cells exhibit higher BMP4 levels in the bone marrow of TKI-resistant patients. Exposure to BMP2/BMP4 does not alter BCR-ABL transcript expression but is accompanied by the overexpression of TWIST-1, a transcription factor highly expressed in resistant LSC. By modulating BMP4 or BMPR1b expression, we show that these elements are involved in TKI resistance. In summary, we reveal that persistence of BMP alterations and existence of an autocrine loop promote CML-primitive cells' TKI resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autocrine Communication*
  • Bone Morphogenetic Protein 4 / analysis
  • Bone Morphogenetic Protein 4 / metabolism
  • Bone Morphogenetic Protein Receptors, Type I / analysis
  • Bone Morphogenetic Protein Receptors, Type I / metabolism
  • Bone Morphogenetic Proteins / analysis
  • Bone Morphogenetic Proteins / metabolism*
  • Drug Resistance, Neoplasm*
  • Humans
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology*
  • Neoplastic Stem Cells / metabolism
  • Nuclear Proteins / analysis
  • Nuclear Proteins / metabolism
  • Protein Binding
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use*
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Twist-Related Protein 1 / analysis
  • Twist-Related Protein 1 / metabolism


  • BMP4 protein, human
  • Bone Morphogenetic Protein 4
  • Bone Morphogenetic Proteins
  • Nuclear Proteins
  • Protein Kinase Inhibitors
  • TWIST1 protein, human
  • Twist-Related Protein 1
  • Protein-Tyrosine Kinases
  • BMPR1B protein, human
  • Bone Morphogenetic Protein Receptors, Type I