Figure 1.

Comparison of Responses to EGFR and ALK Inhibitors Measured Using CK8/18-Positive Cell Count and CellTiter-Glo in EGFR-Mutant and ALK-Translocated Cancer Cells

(A–H) Patient-derived EGFR-mutant (A–E) or ALK-translocated (F–H) lung cancer cells growing in 384-well plates in R10 or D10 media were treated with nine doses of the EGFR inhibitor osimertinib or the ALK inhibitor lorlatinib for 4–7 days. (A) MGH121-1. (B) MGH141-1. (C) MGH134-1. (D) MGH121-1R. (E) MGH707-1. (F) MGH021-2. (G) MGH045-1. (H) MGH051-1. (MGH121-1R cells were made resistant in vitro to the third-generation EGFR inhibitor WZ4002 by increasing its concentration over time.) Plates were either fixed and stained with Hoechst 33342 and the anti-CK8/18 antibody to determine the change in CK8/18-positive cells (red curves, left y-axes) or treated with CellTiter-Glo to determine the change in ATP concentration (green curves, right y-axes). Circles indicate CK8/18-positive cell number (red) or CellTiter-Glo measurement (green) at the day of treatment initiation. Nonlinear regression curves fit to the data points are shown, and data are represented as mean ± SD with n = 4 replicates and experiments performed twice.