Figure 4.

ATO interferes with AR and TIF2 recruitment to chromatin. LNCaP cells were treated with vehicle, 5 nm R1881, or 5 nm R1881 and 5 μm ATO after which chromatin immunoprecipitation was performed. A, After immunoprecipitation with AR (PG21) antibody, a fraction of each sample was immunoblotted for AR (N-20). After either 24 h (B) or 2.5 h (C) treatment, AR recruitment to the PSA proximal promoter was determined by real-time PCR. AR (D) and TIF2 (E) recruitment to the PSA distal enhancer after 24 h treatment was examined using real-time PCR. These are the averages of at least three independent experiments plotted as means ± sem. P values were determined by a comparison of androgen treatment alone vs. a combination of androgen and ATO. *, P < 0.05; **, P < 0.01.