Figure 1

ERβ decreases HIF-1α mediated gene transcription. (a) HEK293 cells in 24-well plates were transfected with hERβ (0.2 μg). At 24 h post-transfection, cells were incubated for 48 h under hypoxic conditions. Culture medium from untransfected HEK293 cells and cells transfected with hERβ plasmids were analyzed using VEGF ELISA kit. Values represent the mean ± S.D. (N = 3). ** P <0.01. (b) At 24 h post-transfection of hERβ and HRE-Luc (0.5 μg), cells were incubated for 24 h under normoxic or hypoxic conditions. After incubation, luciferase expression was determined. Values represent the mean ± S.D. (N = 3). * P <0.05. (c) Cells were transfected with HRE-Luc reporter with or without the expression vector for 0.1 to 0.4 μg hERβ. At 24 h post-transfection, cells were incubated for 24 h under normoxic or hypoxic conditions. After incubation, luciferase expression was determined. Values represent the mean ± S.D. (N = 3). * P <0.05. (d) Cells were transfected with HRE-Luc reporter and hHIF-1α (0.2 μg) with or without the expression vector for hERβ (0.2 μg). At 24 h post-transfection, cells were left untreated or treated with 10 nM E2 or 1 μM ICI and incubated for 24 h under normoxic conditions. After incubation, luciferase expression was determined. Values represent the mean ± S.D. (N = 3). * P <0.05. All experiments were repeated at least three times.