Fig. 6
Effect of combined treatment with g-PPT and Gefitinib on apoptosis in acquired resistant cell lines a The indicated NSCLC cell lines were exposed to various concentrations of Gefitinib and Gefitinib + g-PPT (20 μM) for 2 days. Cell proliferation was determined by the CCK-8 assay. Data represent the mean ± SD of three replicate determinations. b Relative OD value at 12, 24, 48 and 72 h after vehicle (DMSO, NT), g-PPT (20 μM), Gefitinib (2 μM) or g-PPT (20 μM) + Gefitinib (2 μM) treatment. Data are expressed as cell viability from three independent experiments. c Morphology of the indicated NSCLC cell lines after exposure to vehicle, g-PPT, Gefitinib or g-PPT + Gefitinib was assessed. For each experiment, five images of random fields were acquired. A representative image is shown. d Upper panel, 800 surviving cells per well were incubated in 6-well plates, followed by incubation for 10 days until a mass of cells was visible to the naked eye. The synchronized cell masses were exposed to vehicle, g-PPT, Gefitinib or g-PPT + Gefitinib for 48 h and stained with crystal violet. Lower panel, the colony numbers were assessed with ImageJ software. p values were determined by one-way ANOVA. *p < 0.05, **p < 0.01, ***p < 0.001. e Upper panel, apoptotic rate of the indicated NSCLC cell lines were assessed by flow cytometry after vehicle, g-PPT, Gefitinib or g-PPT + Gefitinib treatment for 48 h. Down panel, apoptotic rates were quantified. p values calculated as above. f Up panel, cell lines were exposed to vehicle, g-PPT, Gefitinib or g-PPT + Gefitinib for 48 h. The cells were harvested for Western blotting to detect the indicated apoptotic proteins. A representative blot is shown from three independent experiments. Down panel, the quantitation of western bolt. g Up panel, western bolt detect intracellular signal change in TKI-resistant cell lines. The cells were then harvested for Western blotting to detect the indicated signaling proteins. A representative blot is shown from three independent experiments. Down panel, the quantitation of western bolt