Serine/Threonine Kinase MLK4 Determines Mesenchymal Identity in Glioma Stem Cells in an NF-κB-dependent Manner

Cancer Cell. 2016 Feb 8;29(2):201-13. doi: 10.1016/j.ccell.2016.01.005.

Abstract

Activation of nuclear factor κB (NF-κB) induces mesenchymal (MES) transdifferentiation and radioresistance in glioma stem cells (GSCs), but molecular mechanisms for NF-κB activation in GSCs are currently unknown. Here, we report that mixed lineage kinase 4 (MLK4) is overexpressed in MES but not proneural (PN) GSCs. Silencing MLK4 suppresses self-renewal, motility, tumorigenesis, and radioresistance of MES GSCs via a loss of the MES signature. MLK4 binds and phosphorylates the NF-κB regulator IKKα, leading to activation of NF-κB signaling in GSCs. MLK4 expression is inversely correlated with patient prognosis in MES, but not PN high-grade gliomas. Collectively, our results uncover MLK4 as an upstream regulator of NF-κB signaling and a potential molecular target for the MES subtype of glioblastomas.

Keywords: cancer stem cell; epithelial-to-mesenchymal transition; glioblastoma; proneural-mesenchymal transition.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Brain Neoplasms / enzymology*
  • Brain Neoplasms / pathology
  • Gene Silencing
  • Glioma / enzymology*
  • Glioma / pathology
  • Humans
  • MAP Kinase Kinase Kinases / genetics
  • MAP Kinase Kinase Kinases / metabolism*
  • Mesenchymal Stem Cells / enzymology*
  • Mesenchymal Stem Cells / pathology
  • Mice
  • NF-kappa B / metabolism
  • Neoplastic Stem Cells / enzymology*
  • Neoplastic Stem Cells / pathology
  • Phosphorylation
  • Signal Transduction

Substances

  • NF-kappa B
  • MAP Kinase Kinase Kinases
  • MAP3K21 protein, human