Fig. 4

HER2 assessment in scrambled- and HER2-silenced SKBR3 cells. (A) Western blot analysis of HER2 on extracts from single clones isolated upon selection of SKBR3 stably transfected with a scrambled control (SCR) or with an shRNA directed against HER2 (HER2 shRNA Clones 1–3). α-Tubulin was used as loading control for each sample. (B) Flow cytometry analysis of HER2 cell surface exposure in the scrambled transfected SKBR3 (SCR) or in clone 3 (Clone 3). The cell counts are reported on the y axis, while the Fluorescence Intensity on the x axis. The histogram shows the relative quantification expressed as Mean Fluorescence Intensity (MFI). Statistical significance is considered when **** p < 0.0001 (t-test). (C) Western blot analysis of HER2, AKT and the phosphorylated form levels in extracts from SKBR3 transfected with a scrambled control and from the HER2-silenced clone 3. The first histogram illustrates the quantification of HER2 relative to α-Tubulin and the second the AKT phosphorylation level to total AKT compared to the SCR control. Statistical significance is considered when *** p < 0.001 and **** p < 0.0001 (t-test). (D) Brightfield images and SERS intensity maps of a selected cell for the peaks at 1080 and 1580 cm^− 1 for scrambled- and HER2-silenced SKBR3 cells. Scale bar = 10 μm. (E) Relative quantification of HER2 biomarker on cell membrane of the analysed cell lines