Fig. 4

Mig-6 inhibition restores sensitivity to EGFR-tyrosine kinase inhibitors (TKIs) in PC9/GR cells. a Cell viability was assessed using the CCK-8 assay after transfection with Mig-6 siRNA or scrambled siRNA and treatment with various doses of gefitinib. Data are shown as the mean ± SD; *P < 0.05, **P < 0.01, ***P < 0.001, Student’s t-test. b PC9 and PC9/GR cells were incubated with medium alone (control) or various concentrations of gefitinib for 24 h with or without siMig-6, and cleaved PARP/PARP expression was assessed by western blot analysis. β-actin was used as a loading control. c Apoptotic cells were evaluated by TUNEL assays. The number of apoptotic cells (TUNEL-stained) and the total number of cells (DAPI-stained) were counted to determine the percentage of apoptotic cells in the tumor sections. An apparent increase in the number of apoptotic PC9/GR cells was observed when cells were simultaneously treated with the EGFR-TKI and siMig-6. Data are shown as the mean ± SD; *P < 0.05, **P < 0.01, ***P < 0.001, Student’s t-test. Uncropped blots were shown in Additional file 1: Fig. S4