(A) Top: Map of predicted AR and CSL binding sites (gray and red arrowheads, respectively) on the selected regions of the IL6 gene encompassing the promoter and a distant enhancer. Areas enriched for the H3K4Me3 (dark green) and H3K4Me1 (light green) histone marks (obtained from ENCODE tracks for HDFs) are also indicated. s1–s5 indicate the sites selected for analysis. Bottom: ChIP assay at the indicated sites of the IL6 gene, as shown in the previous panel, together with a region 11 kb upstream from the transcription start site devoid of AR recognition sequence as negative control (ct), using 3 different HDF strains cultured in charcoal-stripped medium (to remove serum-bound testosterone) with or without treatment with DHT (10 nM, 24 hours). Data are expressed as relative fold enrichment over IgGs, and values for each strain are indicated as dots with mean ± SD. Statistical significance of differences in AR enrichment with versus without DHT treatment at the indicated sites was calculated. n(HDF strains) = 3; *P < 0.05, ***P < 0.005, 2-tailed unpaired t test. (B) Map of predicted AR and CSL binding sites on the POSTN promoter regulatory region and determination of AR binding by ChIP in the absence or presence of the AR agonist DHT (10 nM, 24 hours) as in A. n(HDF strains) = 3; *P < 0.05, **P < 0.01, ***P < 0.005, 2-tailed unpaired t test. (C) Determination of CSL and CSL-AR binding on the indicated sites of the IL6 and POSTN genes, by ChIP and re-ChIP assays based on immunoprecipitation with anti-CSL antibodies alone or sequentially with anti-AR antibodies (white and gray bars, respectively). Data are expressed as relative fold enrichment over IgGs. Additional ChIP data are available in Supplemental Figures 7–9.