For ChIP-seq, cells were fixed on plate with 1% formaldehyde, nuclei were isolated and then sonicated by a Bioruptor bath sonicator (Diagenode). Lysates were clarified and DNA-histone complexes were isolated by either H3K18Ac (ab1191) or H3K18Cr (PTM-517) immobilized by protein A dynabeads (Life). For ChIP-seq, purified DNA was prepared for sequencing with the TruSeq ChIP sample Prep Kit (Illumina) as per manufacturer's instructions. Libraries were sequenced on HiSeq2000 (Illumina) with 50bp reads.