Unliganded PRA induces continuously elevated AREG mRNA levels.

(A) Cells were incubated with DMSO vehicle or RSL1 (0.5 µM) in steroid-free medium for indicated time periods and qRT-PCR analysis was performed for AREG or cyclin D1 transcript levels as indicated. Data (mean ± SEM) from three independent cell cultures measured in duplicate are presented as fold change with respect to transcript levels at 1 h time period in uninduced cells. Star (*) represents statistical difference with uninduced (PR−) cells for the corresponding time point. (B) Following 24 h exposure to DMSO vehicle or RSL1 (0.5 µM), cells were incubated with actinomycin D (4 µM) during indicated time periods and qRT-PCR analysis of AREG mRNA expression was performed. Star (*) represents statistical difference with uninduced (PR−) cells for the corresponding time point. (C) Cells were induced or not for 24 h as in B and then treated with vehicle or antiprogestin RU486 (10 nM) during 6 h. AREG mRNA was quantified by qRT-PCR and data (mean ± SEM) from three independent cell cultures in duplicate are presented as fold change with respect to vehicle-treated uninduced cells (PR−). Statistical differences with either uninduced PR− cells (*) or vehicle-treated PRA-induced cells (x).