Pathology & Oncology Research

, Volume 16, Issue 2, pp 285–293

Glutamate Promotes Cell Growth by EGFR Signaling on U-87MG Human Glioblastoma Cell Line

  • Daniel Pretto Schunemann
  • Ivana Grivicich
  • Andréa Regner
  • Lisiane Freitas Leal
  • Daniela Romani de Araújo
  • Geraldo Pereira Jotz
  • Carlos Alexandre Fedrigo
  • Daniel Simon
  • Adriana Brondani da Rocha
Article

DOI: 10.1007/s12253-009-9223-4

Cite this article as:
Schunemann, D.P., Grivicich, I., Regner, A. et al. Pathol. Oncol. Res. (2010) 16: 285. doi:10.1007/s12253-009-9223-4

Abstract

Accumulating evidences suggest that glutamate plays a key role in the proliferation and invasion of malignant glioblastoma (GBM) tumors. It has been shown that GBM cells release and exploit glutamate for proliferation and invasion through AMPA glutamate receptors. Additionally, amplification of the epidermal growth factor receptor (EGFR) gene occurs in 40–50% of GBM. Since, PI3K/Akt is considered one of the main intracellular pathways involved in EGFR activation, AKT functions could trigger EGFR signaling. Thus, we investigated whether EGFR-phospho-Akt pathway is involved on the glutamate inducing U-87MG human GBM cell line proliferation. For these purpose, we treated the U-87MG cell line with 5 to 200 mM of glutamate and assessed the number of viable cells by trypan blue dye exclusion test. An increase in cell number (50%) was found at 5 mM glutamate, while the addition of DNQX (500 µM), an antagonist of AMPA receptor, inhibited the effect of glutamate on the U87-MG cells proliferation. Also, at 5 mM glutamate we observed an increase on the EGFR and phospho-Akt contents evaluated by immunohistochemistry. Moreover, U-87MG cells treated with glutamate exhibited an increase about 2 times in the EGFR mRNA expression. While, in the presence of the anti-EGFR gefitinib (50 μM) or the PI3K inhibitor wortmannin (5 μM), the U-87MG proliferation was restored to control levels. Together, our data suggest that glutamate signaling mediated by AMPA receptor induces U-87MG human GBM cell line proliferation via EGFR-phospho-Akt pathway.

Keywords

Glioblastoma multiforme Glutamate EGFR Phospho-Akt Cell proliferation 

Abbreviations

CNS

central nervous system

DMEM

Dulbecco’s modified essential medium

DNQX

6,7-Dinitroquinoxaline-2,3-dione

EGFR

epidermal growth factor receptor

FCS

fetal calf serum

GBM

malignant glioblastoma

PI3K

Phosphatidylinositol 3-kinase

PIP2

Phosphatidylinositol 4,5-biphosphate

PIP3

Phosphatidylinositol 3,4,5-triphosphate

Copyright information

© Arányi Lajos Foundation 2009

Authors and Affiliations

  • Daniel Pretto Schunemann
    • 1
    • 2
  • Ivana Grivicich
    • 1
    • 2
    • 3
  • Andréa Regner
    • 1
    • 2
    • 3
  • Lisiane Freitas Leal
    • 1
  • Daniela Romani de Araújo
    • 1
  • Geraldo Pereira Jotz
    • 2
  • Carlos Alexandre Fedrigo
    • 1
    • 3
  • Daniel Simon
    • 2
    • 3
  • Adriana Brondani da Rocha
    • 1
    • 2
    • 3
  1. 1.Laboratório de Marcadores de Estresse Celular, Centro de Pesquisas em Ciências MédicasUniversidade Luterana do BrasilCanoasBrazil
  2. 2.Programa de Pós Graduação em Diagnóstico Genético e MolecularUniversidade Luterana do BrasilCanoasBrazil
  3. 3.Programa de Pós Graduação em Genética e Toxicologia AplicadaUniversidade Luterana do BrasilCanoasBrazil

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