Genome-wide maps of PRC2 complex components and chromatin states in prostate cancer cell lines

We report the high-throughput profiling of PRC2 core subunits chromatin states and histone modifications in two prostate cancer cell lines, androgen-dependent cells LNCaP and androgen-independent cells LNCaP-abl (abl). By obtaining over 1 billion bases of sequence from chromatin immunoprecipitated DNA, we generated the genome-wide localizations of EZH2, SUZ12 and H3K27 trimethylation in both cell lines, and found that EZH2 can be localized to a subsets of chromating sites that don't have H3K27me3 or SUZ12 signals nearby. Interestingly, these sites are enriched for the active histone marks H3K4 di/trimethylation as well as the RNA polymerase II, which suggest the potential function of these peaks in gene activation. Indeed, these sites are enriched near the transcription start sites of EZH2-activated genes. Further analysis of the transcription factor motifs enriched at these peaks revealed the enrichement of androgen receptor motif, suggesting a co-activator role for EZH2 in concert with AR. Our work demonstrated a novel funtion of EZH2 in transcriptional activation by directly binding to the chromatin sites that cooperate with AR.