Validation of androgen-dependent AR enrichment by quantitative ChIP analysis on the identified ChIP-chip ARBSs in LNCaP cells. Hormone-deprivated cells were stimulated with R1881 (10 nM) or vehicle (0.1% ethanol) for 24 h. Cross-linked samples were immunoprecipitated with anti-AR antibody. The precipitated DNA fragments were subjected to qPCR. PCR primer sets were designed to include ARE sequences on individual ARBSs no. 1–no. 10. PCR products including ARBSs no. 8 and no. 9 were not distinguishable, as ARBSs no. 8 and no. 9 are located in genome duplication regions from the same origin. PSA promoter (PSA Pro) and enhancer (PSA Enh) regions including ARE sequences were used as positive controls. Data are fold enrichment compared with individual input non-enriched DNA (mean±s.d., n=2).