Inhibition of Farnesyltransferase Potentiates NOTCH-Targeted Therapy against Glioblastoma Stem Cells

Stem Cell Reports. 2017 Dec 12;9(6):1948-1960. doi: 10.1016/j.stemcr.2017.10.028. Epub 2017 Nov 30.

Abstract

Accumulating evidence suggests that cancer cells with stem cell-like phenotypes drive disease progression and therapeutic resistance in glioblastoma (GBM). NOTCH regulates self-renewal and resistance to chemoradiotherapy in GBM stem cells. However, NOTCH-targeted γ-secretase inhibitors (GSIs) exhibited limited efficacy in GBM patients. We found that farnesyltransferase inhibitors (FTIs) significantly improved sensitivity to GSIs. This combination showed significant antineoplastic and radiosensitizing activities in GBM stem cells, whereas non-stem GBM cells were resistant. These combinatorial effects were mediated, at least partially, through inhibition of AKT and cell-cycle progression. Using subcutaneous and orthotopic GBM models, we showed that the combination of FTIs and GSIs, but not either agent alone, significantly reduced tumor growth. With concurrent radiation, this combination induced a durable response in a subset of orthotopic tumors. These findings collectively suggest that the combination of FTIs and GSIs is a promising therapeutic strategy for GBM through selectively targeting the cancer stem cell subpopulation.

Keywords: Notch; farnesyltransferase inhibitors; glioblastoma stem cells; γ-secretase inhibitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / antagonists & inhibitors
  • Amyloid Precursor Protein Secretases / genetics*
  • Animals
  • Cell Line, Tumor
  • Cell Self Renewal / drug effects
  • Disease Progression
  • Drug Resistance, Neoplasm / genetics
  • Enzyme Inhibitors / administration & dosage*
  • Farnesyltranstransferase / antagonists & inhibitors
  • Farnesyltranstransferase / genetics*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glioblastoma / drug therapy*
  • Glioblastoma / genetics
  • Glioblastoma / pathology
  • Glioblastoma / radiotherapy
  • Humans
  • Mice
  • Molecular Targeted Therapy
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / pathology
  • Radiation Tolerance / drug effects
  • Receptors, Notch / antagonists & inhibitors
  • Receptors, Notch / genetics
  • Xenograft Model Antitumor Assays

Substances

  • Enzyme Inhibitors
  • Receptors, Notch
  • Farnesyltranstransferase
  • Amyloid Precursor Protein Secretases