Fig. 3

Estrogen up-regulates the transcription of PIWIL1. a A schematic of three PIWIL1 promoter-luciferase reporter constructs (wild type, WT; Mutation of the half-ERE, MUT; Deletion of the half-ERE, DEL) was shown. b and c Luciferase activities of the WT reporter in endometrial cancer cell lines. d and e Luciferase activities of the WUT reporter in endometrial cancer cell lines. f and g Luciferase activities of the DEL reporter in endometrial cancer cell lines. The expression construct of ERα was co-transfected into ERα-negative cell lines. All experiments were performed at three times. **p < 0.01 and ns, not significant versus control group