High-throughput screening in niche-based assay identifies compounds to target preleukemic stem cells

J Clin Invest. 2016 Dec 1;126(12):4569-4584. doi: 10.1172/JCI86489. Epub 2016 Oct 31.

Abstract

Current chemotherapies for T cell acute lymphoblastic leukemia (T-ALL) efficiently reduce tumor mass. Nonetheless, disease relapse attributed to survival of preleukemic stem cells (pre-LSCs) is associated with poor prognosis. Herein, we provide direct evidence that pre-LSCs are much less chemosensitive to existing chemotherapy drugs than leukemic blasts because of a distinctive lower proliferative state. Improving therapies for T-ALL requires the development of strategies to target pre-LSCs that are absolutely dependent on their microenvironment. Therefore, we designed a robust protocol for high-throughput screening of compounds that target primary pre-LSCs maintained in a niche-like environment, on stromal cells that were engineered for optimal NOTCH1 activation. The multiparametric readout takes into account the intrinsic complexity of primary cells in order to specifically monitor pre-LSCs, which were induced here by the SCL/TAL1 and LMO1 oncogenes. We screened a targeted library of compounds and determined that the estrogen derivative 2-methoxyestradiol (2-ME2) disrupted both cell-autonomous and non-cell-autonomous pathways. Specifically, 2-ME2 abrogated pre-LSC viability and self-renewal activity in vivo by inhibiting translation of MYC, a downstream effector of NOTCH1, and preventing SCL/TAL1 activity. In contrast, normal hematopoietic stem/progenitor cells remained functional. These results illustrate how recapitulating tissue-like properties of primary cells in high-throughput screening is a promising avenue for innovation in cancer chemotherapy.

MeSH terms

  • 2-Methoxyestradiol
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Estradiol / analogs & derivatives*
  • Estradiol / pharmacology
  • Humans
  • Jurkat Cells
  • LIM Domain Proteins / genetics
  • LIM Domain Proteins / metabolism
  • Mice
  • Neoplastic Stem Cells / metabolism*
  • Neoplastic Stem Cells / pathology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / drug therapy*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / metabolism*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / pathology
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Receptor, Notch1 / genetics
  • Receptor, Notch1 / metabolism
  • T-Cell Acute Lymphocytic Leukemia Protein 1
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Tumor Microenvironment / drug effects*
  • Tumor Microenvironment / genetics
  • Tumor Stem Cell Assay
  • Xenograft Model Antitumor Assays

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • DNA-Binding Proteins
  • LIM Domain Proteins
  • LMO1 protein, human
  • NOTCH1 protein, human
  • Proto-Oncogene Proteins
  • Receptor, Notch1
  • T-Cell Acute Lymphocytic Leukemia Protein 1
  • Transcription Factors
  • TAL1 protein, human
  • Estradiol
  • 2-Methoxyestradiol