Figure 5

Vav3 activates ERα partially via PI3K-Akt signaling and potentiates EGF for ERα activation. (A) Hela cells were cotransfected with ERE-Luc (0.25 ug), expression vectors ERα (25 ng), Vav3* or empty vector pHEF (50 ng), p85+p110 or empty vector pCR3.1 (50 ng). (B) Hela cells were cotransfected with ERE-Luc reporter (0.25 ug/well in 12-well plate), expression vectors ERα (25 ng), dominant-negative Akt expression vector or empty vector pCR3.1 (0.1 ug), and Vav3* expression vector or empty vector pHEF (0.1 ug), respectively. (C) T47D cells were cotransfected with ERE-Luc (0.5 ug) and expression vector for Vav3 or empty vector pHEF (0.25 ug). Then, the cells were treated with Wortmannin (0.5 um). (D) T47D cells were cotransfected with pS2-Luc (0.5 ug) and expression vector for Vav3 or empty vector pHEF (0.25 ug). Then, the cells were treated with EGF (20 ng/ml). All transfection and drug treatment are in stripped medium for 24 hours, followed by luciferase assay. Renilla luciferase as an internal control was used to normalize the data. Data are presented as the mean (± SD) of duplicate values of a representative experiment that was independently repeated for five times.