The cell lines described in the article were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA) and cultured as recommended. Frozen unpurified prostate tissues were obtained during routine surgery, and classified pathologically by one of us. The total RNA was extracted with Trizol (Invitrogen, Carlsbad, CA, USA) following the manufacturer's instructions. The primary tumor samples were purified by Qiagen RNeasy mini kit (Qiagen, Valencia, CA, USA).