Figure 6

KLF5 regulates HIF1α protein via AKT1 kinase. (A, B) Phospho-AKT (S473) is upregulated by the knockdown of KLF5 (A) and downregulated by ectopic expression of KLF5 (B) in PC-3 and DU 145 human prostate cancer cells, as detected by Western blotting. (C) Wortmannin, a PI3K inhibitor, rescued the elevation of HuVEC tube formation and the expression of p-AKT, HIF1α, PDGF-B and VEGF induced by KLF5 knockdown. Conditioned media, collected after 24 hours of 1 μM Wortmannin treatment or solvent control from PC-3 and DU 145 cells with KLF5 knockdown (shK2), were used for HuVEC tube formation assay and detection of PDGF-BB and VEGF expression by ELISA. Expression of HIF1α and p-AKT was detected by Western blotting. (D) Detection of HIF1α and phospho-AKT (S473) by Western blotting in PC-3 and DU 145 cells with transient knockdown of KLF5 and treatment of PI3K inhibitor LY294002 for 3 hours. Solvent control for Wortmannin and LY294002 was DMSO. shK1 and shK2 indicate 2 lentiviral shRNAs targeting KLF5 (sh36 and sh37), siK represents siRNA targeting KLF5 (siKLF5), and Ad-K represents adenovirus expressing KLF5. The concentration of siRNA was at 100 nM for panel D. *, P < 0.05; **, P < 0.01; N.S., not statistically significant.