Cell culture

Human prostate cancer cells LNCaP and C4-2 were purchased from ATCC and provided by Dr. Leland W.K. Chung, respectively. These cells were maintained in RPMI 1640 with 10% fetal bovine serum (FBS), 1% Glutamine, 1% penicillin/streptomycin (Invitrogen, Carlsbad, CA) at 37°C in a humidified atmosphere containing 5% CO₂. HEK 293 cells were obtained from ATCC and were maintained in DMEM supplemented with 10% fetal bovine serum (FBS). MG132 was added at 10–20 μM, 3 h before cell lysis. Transient transfections were carried out using Polyjet DNA Reagent (Signa Gen Laboratories, Rockville, MD, USA). Appropriate empty vectors were included as controls in all the transfections.