Fig. 1

Osimertinib induces cell surface expression of HER-2. a PC9 and PC9-T790M cells were treated with the indicated concentrations of osimertinib for 24 h, then cell lysates were immunoblotted to detect the indicated proteins. The immunoreactive spots were quantified by densitometric analysis, ratios of EGFR/Actin and HER2/Actin were calculated and values, expressed as fold increase versus control (control value = 1), are reported. Results are representative of two independent experiments. PC9 and PC9-T790M cell lines were treated with the indicated concentrations of osimertinib for 24 h (b) or with 30 nM osimertinib for 24 and 48 h (c), then HER-2 protein levels on cell surface was evaluated by flow-cytometry, quantified as MEF, and expressed as fold increase versus control (control value = 1). Mean values of three independent measurements (±SD) are shown (**p < 0.01, ***p < 0.001 versus control; one-way analysis of variance followed by Bonferroni’s post-test)