Nobiletin's effects on HIF-1α expression in PC-3 and DU-145 cells. Nobiletin's effect on HIF-1α expression. PC-3 and DU-145 cells (1.0 × 106) were seeded in 60-mm dishes, incubated overnight, and treated with nobiletin for 24 hours. Cells were harvested and analyzed by SDS-PAGE and Western Blotting. HIF-1α protein levels were normalized by GAPDH protein levels. Data represents means ± SE from 3 independent experiments. *P < 0.05 compared to control. **P < 0.01 compared to control.