Figure 1

Stat6 enhances p21 and p27 promoter activities induced by progesterone. T47D cells were transiently cotransfected with the reporter constructs containing the indicated p21 (A) or p27 (B) promoter fragments. Twelve hours after transfection, cells were incubated with progesterone (30 nM) or vehicle (ethanol) for 24 h and then harvested for the luciferase activity assay. Results are expressed as increase (mean ± SD) over luciferase activity levels in control (-) p21Luc or p27Luc, arbitrarily set as 1. The arrows represent the transcription start sites; the crosses indicate the mutated Sp1-binding sites. For each promoter construct, columns followed by different symbols are statistically significantly different from each other.