Compound 10 as a transcriptional regulator of HER2 by inhibiting ELF3-MED23 PPI.
(A) Effect of compound 10 on the FP (mP) induced by the binding of FITC-ELF3129-145 peptide to (His)6-MED23391-582 protein was evaluated in cell-free system. Unlabeled ELF3137-144 peptide was used as positive control. IC50 and Ki values were calculated from the FP assay results (n = 3, mean ± S.D.).
(B) Intracellular PPI inhibitory effect of compound 10 (5 μM, 12 h treatment) against ELF3-MED23 was evaluated through GST-pull down assay using GST-ELF3WT and 3xFLAG-MED23. (C) Impact of compound 10 on the relative luciferase activity generated by Nluc-ELF3WT and Cluc-MED23391-582 interaction was evaluated (20 h treatment at indicated concentrations, n = 3, mean ± S.D., ANOVA, ***p < 0.001). (D) Effect of compound 10 on the overall HER2 promoter activity was assessed (20 h treatment at indicated concentrations, n = 3, mean ± S.D., ANOVA, *p < 0.05, **p < 0.01, and ***p < 0.001). (E) Changes in the HER2 and its downstream signaling pathway were evaluated by treating compound 10 in dose– and time-dependent manner.