The effects of CypB overexpression and CypB knockdown on a Stat5-responsive reporter. (A) Luciferase assay using pGL4-CISH reporter. Cells were transfected with pGL4-CISH reporter, the renilla luciferase control (pGL4.73), and pcDNA3.1-CypB expression vector. Transfectants were cultured in the minimal defined medium for 24 h, followed by 24 h of PRL stimulation prior to luminescence assay. (B and C) CypB knockdown in T47D cells confirmed by real-time PCR and microarray (B), and transient transfection (C). (D and E) Luciferase assay using pGL4-CISH (D) and pGL4-LHRE (E). T47D parental cells (wt) or si-CypB cells were co-transfected with 100 ng pGL4-CISH (D) or pGL4-LHRE (E), along with 2 ng renilla luciferase control (pGL4.73) and 400 ng pcDNA3.1-CypB expression vector, and maintained in the FBS-containing growth medium overnight. Transfectants were then starved in the FBS-free minimal defined medium for 24 h, followed by 24 h of PRL (10 ng/ml for pGL4-CISH and 100 ng/ml for pGL4-LHRE) stimulation prior to luminescence assay. Statistical analysis was performed using two-way ANOVA. **P<0.01; ***P<0.001.