Effect of VPA on androgen responsiveness of PCa cell lines. a LNCaP C-33; b LNCaP C4-2B; c MDA PCa2B AS cells were seeded in 6-wells plate and then treated with 1 mM VPA or solvent for 48 h. Cell were then maintained in a steroid-reduced medium with or without 10 nM DHT for 2 days. Total cell number was counted. The ratio of cell growth was calculated by normalizing the cell number to that of control cells (column #1, left panel, n = 3×2). Total cell lysate proteins from 3-day DHT treatment were analyzed for cPAcP, PSA, AR protein. β-Actin was analyzed and used as a loading control (right panel).