Ca2+-permeable AMPA receptors regulate growth of human glioblastoma via Akt activation

J Neurosci. 2007 Jul 25;27(30):7987-8001. doi: 10.1523/JNEUROSCI.2180-07.2007.

Abstract

Evidence has been accumulated that glioblastoma cells release and exploit glutamate for proliferation and migration by autocrine or paracrine loops through Ca2+-permeable AMPA-type glutamate receptors. Here, we show that Ca2+ signaling mediated by AMPA receptor regulates the growth and motility of glioblastoma cells via activation of Akt. Ca2+ supplied through Ca2+-permeable AMPA receptor phosphorylated Akt at Ser-473, thereby facilitating proliferation and mobility. A dominant-negative form of Akt inhibited cell proliferation and migration accelerated by overexpression of Ca2+-permeable AMPA receptor. In contrast, introduction of a constitutively active form of Akt rescued tumor cells from apoptosis induced by the conversion of Ca2+-permeable AMPA receptor to Ca2+-impermeable receptors by the delivery of GluR2 cDNA. Therefore, Akt functions as downstream effectors for Ca2+-signaling mediated by AMPA receptor in glioblastoma cells. The activation of the glutamate-AMPA receptor-Akt pathway may contribute to the high degree of anaplasia and invasive growth of human glioblastoma. This novel pathway might give an alternative therapeutic target.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology*
  • Calcium / metabolism*
  • Calcium Signaling / genetics
  • Cell Proliferation*
  • Glioblastoma / genetics
  • Glioblastoma / metabolism*
  • Glioblastoma / pathology*
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Invasiveness
  • Permeability
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Receptors, AMPA / genetics
  • Receptors, AMPA / metabolism
  • Receptors, AMPA / physiology*
  • Tumor Cells, Cultured

Substances

  • Receptors, AMPA
  • Proto-Oncogene Proteins c-akt
  • Calcium