Fig. 4

Association between IKKε and EGFR expression. Representative photomicrographs of IKKε (a, c) and EGFR (b, d) immunohistochemical staining of tumor breast tissues are shown. Representative images of staining in IKKε⁻/EGFR⁻ (a and b) and IKKε⁺/EGFR⁺ (c and d) breast cancer tissues are shown. Scale Bars: 100 μm. In (e and f), control RNAi (non-targeting) or IKKε-specific RNAi were transfected into MCF-7 cells. Efficiency of IKKε silencing and the impact on EGFR expression were analyzed by immunoblot (IB) using specific antibodies. Actin was used as loading control (e). EGFR levels normalized over actin levels were quantified by densitometric analysis using the ImageQuant software. In (f), Quantification data are expressed as mean ± SEM from n = 4 independent experiments and analyzed using a t-test (**p < 0.01)