Pharmacodynamic effects of sorafenib administration. Sorafenib was administered at the indicated doses for 24 h to castration-naïve PTEN-deficient mice at 20 weeks of age. Prostate tumor lysates were prepared and protein levels were analyzed by western blot. (A) Protein levels of phosphorylated and total proteins of ERK, S6 and STAT3, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). (B) Densitometric analysis of p-ERK/ERK, p-S6/S6 and p-STAT3-pY705/STAT3. (C) Densitometric analysis of Cyclin D1, Cyclin B1, BIM, Bcl-2 and Cleaved Caspase-3 normalized to GAPDH. Plots are expressed as the mean ± s.e.