Figure 5. GRHL2 enhances AR's transcriptional activity and associates with AR on chromatin.

(A) PC3 cells were transfected with plasmids expressing AR, GRHL2 and a probasin-derived AR-responsive reporter and subsequently treated with 1 nM DHT or vehicle (Veh) control. Transcriptional activity values as assessed by luciferase assays represent the mean (±SEM) of 6 biological replicates; results are a representative of three independent experiments. An unpaired t test was used to assess the affect of GRHL2 on AR activity. (B) Examples of AR-specific, GRHL2-specific and shared binding sites (left). (C) Select motifs enriched in AR-specific, GRHL2-specific and shared peaksets. Motifs were identified using a de novo Gibbs motif sampling approach. P values for enrichment over genomic background are shown. (D) Genomic location summary of AR-specific, GRHL2-specific and shared binding events. (E) Distribution of normalized sequence tag density for H3K27ac, H3K4me2, RNAPII, FoxA1, P300 and Med12 in AR-specific, GRHL2-specific and shared binding events. (F) A gene signature based on shared GRHL2/AR binding events is upregulated in metastatic CRPC (two left panels) and associated with recurrence following radical prostatectomy (right panel).