Figure 1. Expression of palmitoylation defective EGFR^C1025A mediates gefitinib-induced cytotoxicity.

(A) Gefitinib increases cytotoxicity in DHHC20 silenced Kras mutant cells MDA-MB-231. (B) MDA-MB-231 (Kras^G13D) cells stably expressing inducible EGFR^WT or EGFR^C1025A or empty vector control (EV) were treated with doxocycline (1µg/ml) for 15 hours. Immunoblotting with anti-FLAG shows induced expression of FLAG tagged EGFR^WT and EGFR^C1025A. (C) Cells were treated with doxocycline (1µg/ml) every 24 hours for 72 hours and with DMSO or 5 µM gefitinib at 24 hours post-seeding. Expression of EGFR^C1025A induced sensitivity to gefitinib. Cell viability was measured by Trypan Blue staining at 72 hours post-treatment (mean +/−StDev). (D) Induced expression of EGFR^C1025A in MDA-MB-231 cells reduces cell growth.