Fig. 1. Overexpression of AXL is observed in EGFR-TKI resistant NSCLC cells.

NSCLC cells (PC9, PC9-gef, HCC827, HCC827-gef, and HCC827-osi) were treated with gefitinib or osimertinib for 72 h. Cell viability was measured by MTT assay as described in Methods (a). IC₅₀ values and subculture conditions were stated (b). The protein expressions of major RTKs, p-AKT, and p-ERK were determined by Western blotting (c). Cells were incubated on the confocal dish for 24 h, fixed, and stained with C-term AXL (red) and DAPI (blue) for visualization of cellular localization (d). Data are presented as the mean fold changes ± SD of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.005 by t-test