Figure 3

XN inhibits FAK, AKT and NF-κB activation and controls VEGF release and the migratory potential of PCa cells. Western blot analyses show a remarkable decrease of constitutive FAK phosphorylation after 5 h of treatment with XN (A), which correlates with reduced VEGF secretion by DU145 and PC3 cells exposed for 16 h to the drug and analyzed by ELISA (B). Means ± SD are shown (*P < 0.05, **P < 0.01). (C) Western blot analyses of lysates from DU145 and PC3 cells pulsed for 30 min with IGF-I at 100 ng/mL show a strong induction of AKT phosphorylation, almost completely abolished by 5-h pretreatment with 10 µmol/L XN. Representative results from three independent Western blot experiments are shown. (D) DU145 and PC3 cell migration is significantly enhanced by IGF-I (100 ng/mL), compared with control cells. IGF-I effect is completely abrogated when cell migration is carried out in the presence of XN (5–10 µmol/L). Experiments were done in triplicate and repeated thrice. Means ± SD are shown (***p < 0.001). (E) ELISA analyses show that 5 h treatment with XN (5–10 µmol/L) reduces the amount of active NF-κB in TNF-α (10 ng/mL) DU145- and PC3-stimulated cells. Means ± SD are shown (**P < 0.01, ***P < 0.001). C (within panels A and B), control.