Figure 1.

Effect of CPT and apigenin on HIF-1α, HIF-2α and HIF-α target genes in RCC4 and 786-O cells. (a and b) 786-O or RCC4 cells were treated with CPT or apigenin at the concentrations indicated or vehicle control (DMSO). Panels, whole-cell lysates were assayed by western blot for HIF-1α, HIF-2α and cyclin D1 proteins. Actin and/or tubulin were used as loading controls. Graphs, conditioned media were harvested after 24 h and secreted protein levels of VEGF were determined by ELISA and normalized to cell number. (c) RCC4 cells were treated with 2 μM CPT or DMSO vehicle control for the times indicated. Conditioned media were harvested and secreted protein levels of VEGF, PAI-1 and ET-1 were determined by ELISA and normalized to cell number. Mean±S.E. of duplicate values of one representative experiment is shown. *P<0.05, **P<0.01, t-test compared with control