Fig. 3.

Unliganded ERα is sufficient to activate the basal expression of E-cadherin in sfRON-T47D. (A and B) Reversion of the morphological penotype in sfRON-T47D cells by a kinase inhibitor. Cells were grown in estrogen-free medium for 72 h and then treated with K252a (B) or control vehicle (A) for 48 h. Images were taken at 40× magnification. (C) Quantitative real-time PCR was used to evaluate changes in E-cadherin and ERα mRNA level in sfRON-T47D cells in the presence of K252a or control vehicle. (D) K252a treatment induces ERα recruitment at the E-cadherin promoter. ChIP with quantitative real-time PCR was performed by using antibodies against ERα. (E) Induction of E-cadherin mRNA by K252a depends on ERα. sfRON-T47D cells were transfected with a control siRNA or a siRNA against ERα, grown in estrogen-free medium for 72 h, and treated with K252a or control vehicle. (F) The same experiment as in E demonstrates that ERα is required for morphological reversal in the presence of K252a. The images were taken at 40× magnification. (G) ERα expression induces E-cadherin-Luc reporter activity. Cells were grown in estrogen-free medium for 24 h then were transiently transfected with E-cadherin promoter-Luc vector, ERα-expressing vector, or empty vector. After 48 h luciferase activity was measured and normalized to β-gal activity.