Oncogenic EGFR signaling cooperates with loss of tumor suppressor gene functions in gliomagenesis.
Glioblastoma multiforme (GBM) is a highly lethal brain tumor for which little treatment is available. The epidermal growth factor receptor (EGFR) signaling pathway is thought to play a crucial role in GBM pathogenesis, initiating the early stages of tumor development, sustaining tumor growth, promoting infiltration, and mediating resistance to therapy. The importance of this pathway is highlighted in the fact that EGFR is mutationally activated in over 50% of GBM tumors. Consistent with this, we show here that concomitant activation of wild-type and/or mutant (vIII) EGFR and ablation of Ink4A/Arf and PTEN tumor suppressor gene function in the adult mouse central nervous system generates a fully penetrant, rapid-onset high-grade malignant glioma phenotype with prominent pathological and molecular resemblance to GBM in humans. Studies of the activation of signaling events in these GBM tumor cells revealed notable differences between wild-type and vIII EGFR-expressing cells. We show that wild-type EGF receptor signals through its canonical pathways, whereas tumors arising from expression of mutant EGFR(vIII) do not use these same pathways. Our findings provide critical insights into the role of mutant EGFR signaling function in GBM tumor biology and set the stage for testing of targeted therapeutic agents in the preclinical models described herein.
Zhu
Haihao
H
Molecular Oncology Research Institute, Department of Neurosurgery, Tufts University School of Medicine, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA.
Acquaviva
Jaime
J
Ramachandran
Pranatartiharan
P
Boskovitz
Abraham
A
Woolfenden
Steve
S
Pfannl
Rolf
R
Bronson
Roderick T
RT
Chen
John W
JW
Weissleder
Ralph
R
Housman
David E
DE
Charest
Al
A
D000818:Animals; D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D016147:Genes, Tumor Suppressor; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D015398:Signal Transduction
D019941:Cyclin-Dependent Kinase Inhibitor p16; D066246:ErbB Receptors; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human