Figure 4.

Higher EPHA2 and MET protein expression after progression. EFNA1 ligand downregulation leads to increased EPHA2/pEPHA2 protein expression. (a) EPHA2 and FLI1 protein expression downregulation after 48 h transfection with siRNA against EPHA2, FLI1 and negative sicontrol in A375VR4 cell line. (b) EPHA2 degradation in presence of 1 μg/ml of EFNA1 ligand (2 h) and rescue from degradation by adding 20 nM bafilomycin 1 h before ligand treatment in A375VR4 cells. (c) The impact of EFNA1 downregulation on EPHA2/pEPHA2 protein expression level after 48 h transfection using siRNA against EFNA1 and sicontrol in A375 and A375VR4 cell lines. RRAS protein was used as loading control (d). EPHA2 and MET protein expression in FFPE tumor samples excised before treatment and after progression from three melanoma patients, who recieved first line treatment with BRAFi using IHC. Images show staining of EPHA2 expression in tumors from one patient before treatment and after progression