The Cholesterol Metabolite 25-Hydroxycholesterol Activates Estrogen Receptor α-Mediated Signaling in Cancer Cells and in Cardiomyocytes
Figure 1
(A) MCF7 cells were transfected with an ER luciferase reporter gene along with the internal transfection control Renilla Luciferase and treated with increasing concentrations (logarithmic scale) of E2 and 25HC. Moreover, cells were treated simultaneously with similar doses of each compound. The normalized luciferase activity values of cells treated with vehicle (-) were set as 1-fold induction, upon which the activity induced by treatments was calculated. (B) MCF7 cells transfected with the ER reporter gene were treated with 10nM E2 or 1µM 25HC alone and in combination with increasing concentration of the ER antagonist ICI, as indicated. Each data point represents the mean ± SD of three experiments performed in triplicate. (C–F) Hek293 cells were transfected with ER luciferase reporter gene (EREluc) and ERα (C) or ERβ (D) expression plasmids, with Gal4 reporter gene GK1 and the Gal4 fusion proteins encoding the Ligand Binding Domain (LBD) of ERα (GalERα) (E) or ERβ (GalERβ) (F) and treated with 10nM E2 or 1µM 25HC alone and in combination with 10µM ER antagonist ICI, as indicated. Each data point represents the mean ± SD of three experiments performed in triplicate.