Effects of Icaritin on major oncogenic signaling pathways in 786-O and Renca cells.

<p>Icaritin reduced STAT3 and JAK activity, with no dramatic reduction of AKT, MAPK signaling in 786-O (A) and Renca (B, C) tumor cells. Tumor cells were treated with Icaritin at indicated concentrations for 2 or 24 hours. Total cell lysates were prepared and Western blots were performed using relevant antibodies to detect total protein levels, with β-actin used as the loading control. C. Pre-incubation of Icaritin inhibited the phosphorylation of STAT3 (Tyr705) induced by IL-6. To assess whether icaritin inhibits the phosphorylation of STAT3 at Tyr705 induced by IL-6, Renca cells were serum-free starved for 24 hours, and treated with Icaritin for 2 hours followed by the addition of IL-6 (10 ng/mL) for 20 minutes. Anti–β-actin monoclonal antibody was used as a loading control. Bottom. The optical density of each protein was quantified by β-actin optical density.