Abstract# 4206: Mutant EGFR signaling in glioma

Aberrant EGFR signaling is a major contributing force to glioma progression and treatment resistance. The most prevalent mutation, EGFRvIII, is an inframe deletion of the extracellular domain, which occurs in the about 40% of glioblastomas and promotes growth and survival of cancer cells. More recently, new point mutations in the extracellular domain of EGFR have been identified by The Cancer Genome Atlas. We are investigating the signaling of these abnormal receptors to identify the basis of their oncogenicity, and taking a systems-level approach at the mRNA and protein level. We have analyzed the EGFRvIII specific signal using shotgun phosphoproteomics based on recovery of tyrosine-phosphopeptides and mass spectrometry. Glioma cell lines expressing EGFRvIII and wild-type EGFR, and with different PTEN backgrounds were compared by this approach. Spectral intensity and count was used in a label …