Figure 4.

Estetrol modulates the activation of the actin-binding protein, moesin. T47-D ER+ breast cancer cells were treated for 10 min with different amounts of E4, E2, or the combination (A,B). Other cells were treated with E4 (10⁻⁷ M) for different times (C). Lastly, T47-D cells were treated with E4 (10⁻⁷ M) in the presence or absence of the pure ER antagonist ICI 182,780 (D) or of siRNAs toward ERβ (E). Protein extracts were assayed with western analysis for their overall content of wild type moesin (moesin), Thr⁵⁵⁸-phosphorylated moesin (P-moesin), and ERβ. Images are representative of triplicate experiments. The bar graphs show the mean ± SD WB band intensity out of the three independent experiments. *p < 0.05 vs. control. **p < 0.05 vs. E2.