Effects of different HDAC inhibitors on androgen responsiveness of PCa cells. LNCaP C-81 cells were plated in 6-wells plate and then treated with a 1 mM NaB; b 2.5 µM SAHA; c 2.5 µM PxD101; d 1.0 µM MS-275; e 0.5 µM AR42 or solvent alone for 48 h. Cell were then maintained in a steroid-reduced medium with or without 1 and 10 nM DHT for 3 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 were analyzed for cPAcP, PSA and AR protein. β-Actin was analyzed and used as a loading control (right panel).