Fig. 3

Intercellular transfer of exosomal wtEGFR protein activates PI3K/AKT and MAPK pathways in mutEGFR cancer cells. a Western blot analysis of indicated proteins in H1975 cells pre-treated with CM of H460 cells or control H1975 cells for 36 h and various concentration of osimertinib for another 6 h. b Western blot analysis of indicated proteins in H1975 cells pre-treated with CM of A549 cells or control H1975 cells for 36 h and various concentration of osimertinib for another 6 h. c Western blot analysis of indicated proteins in H1975 cells pre-treated with CM of H1299 cells or control H1975 cells for 36 h and various concentration of osimertinib for another 6 h. d Western blot analysis of indicated proteins in H1975 cells pre-treated with H1299 cells-derived exosomes or PBS for 6 h and various concentration of osimertinib for another 6 h. e Western blot analysis of indicated proteins in PC9 cells pre-treated with H1299 cells-derived exosomes or PBS for 6 h and various concentration of osimertinib for another 6 h. f Western blot analysis of EGFR protein in H1975 cells and PC9 cells with or without ectopic overexpression of wtEGFR protein. g Representative images of membrane-anchored wtEGFR (Flag-tag) in H1975 cells. Labels: blue, nucleus; green, wtEGFR (Flag-tag). Scale bar: 20 μm. h Western blot analysis of indicated proteins in H1975 cells treated with various concentration of osimertinib with or without ectopic overexpression of wtEGFR protein. i MTT assay of H1975 cells and PC9 cells with or without ectopic overexpression of wtEGFR protein. j-k Colony formation assay of H1975 cells with or without ectopic overexpression of wtEGFR protein after treated by osimertinib (1 μM) for 24 h. All data are presented as means ± SEM. * P < 0.05, ** P < 0.01, *** P < 0.001