Fig. 3

Biological or chemical inhibition of ERα or/and HER2 regulate CBP expression in ERα-positive cells. a–c Representative western blot analysis and relative bar graph quantification of CBP protein extracted from a MCF7, b T47D and c BT-474 cells transfected with negative control (NC) or ERα siRNA for 24–96 h. Fold change of CBP expression was done over cells transfected NC siRNA for each time point. d-f Upper panel: Representative western blot for CBP expression in d MCF7, e T47D and f BT-474 cells treated with 5 μM of the selective ER modulator Tamoxifen or with DMSO (control cells) for 24–96 h. Lower panel: Relative bar graph quantification of CBP protein after normalization to β-actin. g Western blot analysis of ERα, HER2 and CBP proteins in BT-474 cells transfected with negative control (NC) or ERα and HER2 siRNAs for 24–96 h. h Western blot analysis of CBP expression in BT-474 treated with Tamoxifen and Trastuzumab combination or with DMSO (control cells) for 24–96 h. The graphs show the densitometric quantification of CBP bands normalized to β-actin. Fold change of CBP expression was done over untreated control or cells transfected with NC siRNA for each time point. Full blots images are available in Additional file 1: Fig. S7, Additional file 1: Fig. S8 and Additional file 1: Fig. S9. Average present as mean ± SEM (n = 3). *p < 0.05 versus untreated control, unpaired t test