Differential effect of leukaemogenic tyrosine kinases on cell motility is governed by subcellular localisation

Br J Haematol. 2006 May;133(3):345-52. doi: 10.1111/j.1365-2141.2006.06015.x.

Abstract

The chemokine, stromal cell-derived factor-1 (SDF-1) is a crucial regulator of stem cell homing and tethering, and potentiation of this pathway in leukaemias may contribute to the pathogenesis of the disease. A key second messenger in SDF-1 signal/response coupling is phosphatidylinositol 3,4,5-triphosphate [PtdIns(3,4,5)P3]. SDF-1 elevated PtdIns(3,4,5)P3 levels markedly in the multipotent FDCP-mix stem cell line. Similarly, transfection with BCR/ABL or TEL/PDGFRbeta leukaemogenic tyrosine kinases chronically elevated PtdIns(3,4,5)P3 levels. However, whilst an SDF-1 chemotactic response was observed in TEL/PDGFRbeta-transfected cells, in BCR/ABL cells this was markedly decreased, which was not due to Ras-pathway activation. Thus, multipotent cells can respond to SDF-1, despite chronic increases in this second messenger indicating that a discrete pool of SDF-1-stimulated PtdIns(3,4,5)P3 production drives the chemotactic response. To discern the mechanism for the differential effects of these oncogenes we considered subcellular localisation. As TEL/PDGFRbeta has a cytosolic location whilst BCR/ABL associates with actin, we removed the actin-binding domain from BCR/ABL. We observed relocation of BCR/ABL to the cytosol and increased SDF-1 responses. We conclude that the localisation of BCR/ABL to the cytoskeleton is essential for effects on motility and moderating SDF-1 responses is not essential in tyrosine kinase-mediated leukaemic transformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Cell Line
  • Cell Transformation, Neoplastic / metabolism*
  • Chemokine CXCL12
  • Chemokines, CXC / pharmacology*
  • Chemotaxis / drug effects
  • Chemotaxis / physiology*
  • Cytoskeleton / metabolism
  • Dose-Response Relationship, Drug
  • Fusion Proteins, bcr-abl / analysis
  • Fusion Proteins, bcr-abl / physiology*
  • Hematopoietic Stem Cells / drug effects
  • Hematopoietic Stem Cells / physiology
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / metabolism
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology*
  • Mice
  • Oncogene Proteins, Fusion / metabolism
  • Phosphatidylinositol 3-Kinases / physiology
  • Phosphatidylinositol Phosphates / biosynthesis
  • Signal Transduction
  • Transfection

Substances

  • Actins
  • CXCL12 protein, human
  • Chemokine CXCL12
  • Chemokines, CXC
  • Cxcl12 protein, mouse
  • Oncogene Proteins, Fusion
  • Phosphatidylinositol Phosphates
  • TEL-PDGFRbeta fusion protein, human
  • phosphatidylinositol 3,4,5-triphosphate
  • Phosphatidylinositol 3-Kinases
  • Fusion Proteins, bcr-abl