Figure 6

The effect of LS081 on the expression of HIF1α and HIF2α. MDA-MB231 and DU145 cells were treated with 10 μM LS081 in 10% FCS-RPMI1640 ± 2 μM ferric ammonium citrate for 16 hr before harvesting for Western blot detection of HIF-1α and 2α as described in the Methods. The Western blots were quantitated by densitometry and the amounts of HIF as the ratio of HIF-1α or HIF-2α to the actin loading control were expressed relative to the DMSO control. The left panels are representative Western blots. A, HIF-1α was detected in DU145 cells cultured at 1% oxygen concentration (hypoxic). In B, HIF-2α was detected in MDA-MB231 cells grown in normal oxygen tension (21%). The right panels show the reduction of HIF-1α or -2α in the treated cells compared to control (means ± SEM of 3-4 experiments). *: p < 0.05; **: P < 0.01 compared to DMSO by 1-way ANOVA with Tukey's posttests.