Fig. 5. Effects of 1z on HSP90 and its client proteins in MCF-7 and SKBr3 cells. (A) Western blotting analysis of HER2, pAKT, AKT, CDK4, HSP70, and HSP90 protein expression in MCF-7 and SKBr3 cells after treatments with CTL (DMSO), GA (1.25 μM), NB (700 μM), and compound 1z (5, 10, and 20 μM) for 48 h. GAPDH was used as a loading control. (B) Unlike GA, 1z cannot compete the binding of FITC-GA (5 nM) with HSP90 in fluorescence polarization. (C) AlphaScreen-based HSP90 C-terminal inhibitory activities of 1z, GA, and NB (the results were determined by two dependent experiments).
