Figure 3
The AR-associated PI3K activity is modulated by RES in androgen-sensitive LNCaP cells. (A) LNCaP cells were cultured for 5 days in steroid-depleted medium and then treated with DMSO (control), 10−9 M of the AR agonist DHT (30 min), 10−9 M DHT (30 min) plus 10−4 M of the AR antagonist Bic (30 min) or 150 μ M RES (30 min). Aliquots of 1 mg total cell extract were immunoprecipitated with an AR-specific antibody and PI3K activity determined in the immunoprecipitates using PI as substrate. (B) PI3K activity was determined in AR immunoprecipitates obtained from cultures grown in steroid-depleted medium and left untreated (DMSO) or treated with 1, 10, 50, 100 or 150 μ M RES for 36 h. Some cultures were treated with 20 μ M of the PI3K inhibitor LY294002 (LY). (C) PI3K activity was also determined in AR immunoprecipitates from cultures grown in complete medium and treated with 0 (DMSO), 1, 10, 50, 100 or 150 μ M RES. Androgen-insensitive PC-3 cells (PC3) were used as negative control. A representative experiment out of two is shown.
