Fig. 2.

Rescue of oncogene dependence by exogenous DEL15 EGFR. (A) Schematic of rescue assay. (B) Lysates from PC9 cells stably expressing GFP or DEL15-delUTR EGFR were analyzed by immunoblot 48 h after transduction with the shEGFR vector that targets the 3′-UTR of the endogenous EGFR mRNA. (C) PC9 cells expressing GFP (blue) or DEL15-delUTR EGFR (red) were transduced with a dilution series of the shEGFR vector supernatant and then cultured in the absence (left) or presence (right) of puromycin. EGFR mutant activity was quantified by determining the amount of shRNA virus required to cause a 50% decrease in cell number (IC50) in the absence of puromycin or by calculating the AUC of virus concentration versus well intensity with puromycin. Data shown is the mean of four replicates ± 1 STDEV.