Figure 3.

HIF-1α knockdown prevents hypoxic induction of IGFBP3. TE12 cells were transfected with two independent siRNA sequences directed against either HIF-1α or HIF-2α [HIF-1α (1), HIF-1α (2), HIF-2α (1), and HIF-2α (2)] or a scrambled nonsilencing control sequence (scramble). Cells were further transfected with (eHRE)₃-luc (A; ref. 24). Following transfection, cells were exposed to hypoxia or normoxia for 48 h and subjected to luciferase assays (A), Western blotting (B), and real-time PCR (C). Arrow indicates specific signal for HIF-2α (B). *P < 0.05 vs. scramble under hypoxia (n=3).