Fig. 6

Defactinib and osimertinib co-treatment inhibited cell proliferation in various EGFR-TKI-resistant cell lines. a Immunoblots of phosphorylated and total PTK2 in PC-9 and PC-9/ER-1-6 cells. b Viabilities of PC-9 and PC-9/ER-4 cells treated with osimertinib at the indicated concentrations for 72 h. Data are means (SD), n = 3. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Data for treated and untreated cells were compared by Student’s t-test. c Immunoblots of the phosphorylated and total levels of the indicated proteins in PC-9/ER-4 cells treated with defactinib at the indicated concentration for 96 h. d-f Viability of PC-9/ER-4 cells with or without defactinib and osimertinib at the indicated concentrations for 96 h. Data are means (SD), n = 3. **, P < 0.01; ***, P < 0.001, ****, P < 0.0001. Data for untreated cells were compared with those for cells treated with defactinib by one-way ANOVA and Tukey’s HSD multiple comparisons test. Viabilities of PC-9/ER-1 (e) and PC-9/ER-2 (f) cells with or without 1 μM defactinib and osimertinib at the indicated concentrations for 96 h. Data are means (SD), n = 3. *, P < 0.05; **, P < 0.01; ***, P < 0.001 by Student’s t-test