Intrathymic Notch3 and CXCR4 combinatorial interplay facilitates T-cell leukemia propagation

Oncogene. 2018 Dec;37(49):6285-6298. doi: 10.1038/s41388-018-0401-2. Epub 2018 Jul 23.

Abstract

Notch hyperactivation dominates T-cell acute lymphoblastic leukemia development, but the mechanisms underlying "pre-leukemic" cell dissemination are still unclear. Here we describe how deregulated Notch3 signaling enhances CXCR4 cell-surface expression and migratory ability of CD4+CD8+ thymocytes, possibly contributing to "pre-leukemic" cell propagation, early in disease progression. In transgenic mice overexpressing the constitutively active Notch3 intracellular domain, we detect the progressive increase in circulating blood and bone marrow of CD4+CD8+ cells, characterized by high and combined surface expression of Notch3 and CXCR4. We report for the first time that transplantation of such CD4+CD8+ cells reveals their competence in infiltrating spleen and bone marrow of immunocompromised recipient mice. We also show that CXCR4 surface expression is central to the migratory ability of CD4+CD8+ cells and such an expression is regulated by Notch3 through β-arrestin in human leukemia cells. De novo, we propose that hyperactive Notch3 signaling by boosting CXCR4-dependent migration promotes anomalous egression of CD4+CD8+ cells from the thymus in early leukemia stages. In fact, in vivo CXCR4 antagonism prevents bone marrow colonization by such CD4+CD8+ cells in young Notch3 transgenic mice. Therefore, our data suggest that combined therapies precociously counteracting intrathymic Notch3/CXCR4 crosstalk may prevent dissemination of "pre-leukemic" CD4+CD8+ cells, by a "thymus-autonomous" mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / pathology*
  • CD8-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / pathology*
  • Cell Movement / physiology
  • Cell Transformation, Neoplastic / metabolism
  • Cell Transformation, Neoplastic / pathology
  • Humans
  • Mice
  • Mice, Transgenic
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / metabolism
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / pathology*
  • Receptor, Notch3 / metabolism*
  • Receptors, CXCR4 / metabolism*

Substances

  • Receptor, Notch3
  • Receptors, CXCR4