Inhibition of Hypoxia Inducible Factor Alpha and Astrocyte-Elevated Gene-1 Mediates Cryptotanshinone Exerted Antitumor Activity in Hypoxic PC-3 Cells
Figure 4
CT exerts antiangiogenic activity via inhibition of HIF-1α under hypoxia. (a) Effect of CT on the protein expression of VEGF in hypoxic PC-3 cells. Cell lysates were prepared and subjected to Western blotting to determine VEGF expression. (b) Effect of CT on the secreted production of VEGF in hypoxic PC-3 cells. VEGF levels in the culture supernatants were measured by using a Quantikine VEGF ELISA kit. Data represent means ± S.D. ### versus normoxia control. ** versus hypoxia control. (c) Effect of CT on tube formation in HUVECs treated with supernatant of PC-3 culture media. HUVECs were treated with VEGF (20 ng/mL) or the supernatant from PC-3 culture media with or without CT under hypoxia for 24 h. Tube formation assay was performed using growth factor-reduced matrigel. Cells were fixed with Diff-Quick solution, photographed randomly under an Axiovert S 100 light microscope at ×100 magnification. (d) Effect of CT on the binding of HIF-1α to VEGF promoter. Cells were treated with or without CT (5 or 10 μM) under hypoxia for 6 h. The immunoprecipitated DNA with HIF-1α antibody was amplified by PCR analysis for VEGF promoter using ChIP primers.
