FIGURE 1. EGFR-knockdown induces cell death in GBM cells with EGFR EC mutations.
A. EGFR domain structure. Mutations indicated in red have been documented in glioblastoma (GBM) but not in lung cancer, while those indicated in blue are seen in non-small cell lung cancer (NSCLC) and not in GBM. Roman numerals indicate subdomains within the EC domain. B. EGFR-mutant GBM lines are sensitive to EGFR knockdown. The indicated cell lines were acutely transduced with control or two different EGFR-targeted shRNAs. The extent of EGFR knockdown was assessed by immunoblot (left panel). The effects of the hairpins on cell death was assessed by trypan blue exclusion 5 days post-infection (right panel). (NHA, normal human astrocytes). C. HER2 knockdown only induces minimal cell death in EGFR mutant SF268 GBM cells. Cells were acutely transduced with control, EGFR-targeted, or HER2-targeted shRNAs. The extent of EGFR and HER2 knockdown was evaluated by immunoblot (inset). Cell death was assessed as in B. Confer Suppl. Figure 2 for results of HER2 knockdown in EGFR mutant SKMG3 GBM cells.