Figure 2.

CPT inhibits HIF-1α and HIF-2α protein synthesis. (a) RCC4/VHL cells were incubated with 500 μM desferrioxamine (DFX) in the absence or presence of 2 μM CPT for 24 h as indicated. Whole-cell lysates were assayed by western blot for HIF-2α. Actin was used as a loading control. (b) The 786-O cells were incubated with 2 μM CPT or vehicle control (DMSO) for 24 h and analyzed for mRNA expression of HIF-2α by real-time quantitative PCR relative to GAPDH. (c and d) RCC4 cells were incubated with or without 2 μM CPT for 6 h in the absence or presence of 10 μM MG-132 or 10 μM cycloheximide (CHX) for the final 3 h as indicated. Whole-cell lysates were assayed by western blot for HIF-1α and HIF-2α. Actin was used as a loading control