Prostate cancer cells were crosslinked with 1% formaldehyde and lysed in RIPA buffer with 0.3 M NaCl. ChIP DNA was purified using PCR Purification Kit (Qiagen) and then quantified by Quant-iTTM dsDNA HS Assay Kit (Invitrogen). ChIP-Seq libraries were prepared using ThruPLEX-FD Prep Kit (Rubicon Genomics) according to the manufacturer's protocol.