FIGURE 3.

PLAC1 is a 17β-estradiol-responsive gene. A, quantitative real time RT-PCR analysis of PLAC1 in breast cancers and matched normal breast tissues. Correlation of PLAC1 expression levels with ERα receptor status of breast cancer specimens (20 samples per group) was analyzed using unpaired t test. ER+, estrogen receptor positive; ER−, estrogen receptor negative. B, real time RT-PCR quantification of PLAC1 induction in MCF-7 cells treated with 100 nm E₂, 100 nm E₂, and 5 μm ER antagonist ICI 182,780 or 5 μm ICI 182,780 alone. Expression levels were normalized to untreated, estradiol-depleted control cells (c). Assay was done in triplicates and repeated twice; mean values ± STD are shown. C, Western blot analysis of PLAC1 expression in MCF-7 cells 12 h after treatment. D, luciferase activity was measured in MCF-7 cells transfected with the PLAC1 wild type promoter luciferase reporter gene 12 h after treatment. Luciferase activity was normalized to fluorescence obtained by co-transfection with eGFP reporter plasmid. Assay was done in triplicate; mean values ± S.D. are shown.