Figure 5.
(A, B) CO-1686 resistant NCI-H1975 cell clones, COR1-1 and COR10-1 display a reduced dependence on EGFR signaling for survival. (A) Effect of EGFR siRNA transfection on EGFR protein expression in CO-1686 resistant clones (COR 1-1 and COR 10-1) and NCI-H1975 parental as determined Western blotting. (B) Impact of EGFR siRNA knock-down on cell viability in NCI-H1975, COR1-1 and COR10-1 clones. Cell viability was determined 72-hours post-siRNA transfection and plotted relative to the siRNA control treated group (representing 100%). Data plotted as mean ± SEM. * indicates P < 0.05 and ** P < 0.005 comparing siCTRL and siEGFR groups. (C) qRT-PCR analysis of EMT-related and EGFR-related genes in COR1-1 and COR10-1 cell clones. Data plotted as fold change relative to parental NCI-H1975 cells ± SEM. All data shown P < 0.05 comparing COR clone to parental. (D) Inhibition of AKT restores partial sensitivity of COR cell clones to CO-1686. COR10-1 was exposed to CO-1686, the AKT-inhibitors MK-2206 (left panel) or GDC-0068 (right panel), or an equimolar combination of AKT inhibitor + CO-1686. 72 hours post-drug addition cell viability was determined by CellTiterGlo. Data plotted as % viability relative to DMSO (no drug) control.