RNA-seq of PC9 cells tolerant to gefitinib

EGFR inhibitors (EGFRi) are effective against EGFR mutant lung cancers. The efficacy of these drugs however is mitigated by the outgrowth of resistant cells, most often driven by a secondary acquired mutation in EGFR, T790M. We recently demonstrated that T790M can arise de novo during treatment (Hata et al., Nature Medicine 2016); it follows that one potential therapeutic strategy to thwart resistance would be identifying and eliminating these cells (referred to as drug tolerant cells (DTCs)) prior to acquiring secondary mutations like T790M. We have developed DTCs to EGFRi in EGFR mutant lung cancer cell lines. Subsequent analyses of DTCs included RNA-seq, high-content microscopy, and protein translational assays. Based on these results, we tested the ability of MCL-1 BH3 mimetics to combine with EGFR inhibitors to eliminate DTCs and shrink EGFR mutant lung cancer tumors in vivo. The NSCLC cell line PC9 was made tolerant to gefitinib over 6-days. Replicates were performed at a minimum of duplicates. EGFR inhibitors (EGFRi) are effective against EGFR mutant lung cancers. The efficacy of these drugs however is mitigated by the outgrowth of resistant cells, most often driven by a secondary acquired mutation in EGFR, T790M. We recently demonstrated that T790M can arise de novo during treatment (Hata et al., Nature Medicine 2016); it follows that one potential therapeutic strategy to thwart resistance would be identifying and eliminating these cells (referred to as drug tolerant cells (DTCs)) prior to acquiring secondary mutations like T790M. We have developed DTCs to EGFRi in EGFR mutant lung cancer cell lines. Subsequent analyses of DTCs included RNA-seq, high-content microscopy, and protein translational assays. Based on these results, we tested the ability of MCL-1 BH3 mimetics to combine with EGFR inhibitors to eliminate DTCs and shrink EGFR mutant lung cancer tumors in vivo.