Activation of P-TEFb by enhancer RNAs associated with lethal prostate cancer [ChIP-seq]

Castration resistant prostate cancer (CRPC) is a lethal disease. Sustained aberrant activation of androgen receptor (AR) becomes a central mechanism that contributes to endocrine therapy resistance. Here, we demonstrate that AR-bound enhancer RNAs (AR-eRNAs), including eRNA of the KLK3 (or PSA) gene, are upregulated in human CRPC cells and patient tissues. By enhancing C-termine domain (CTD) serine-2 phosphorylation of RNA polymerase II (Pol II-Ser2p), PSA eRNA acts in cis to promote PSA mRNA transcription and in trans to induce mRNA expression of a large set of genes involved in androgen action, cell cycle progression and tumorgenesis. Accordingly, we demonstrate that PSA eRNA binds in vitro and in vivo to CYCLIN T1, a regulatory subunit of the positive transcription elongation factor b (P-TEFb) complex that mediates Pol II-Ser2p. To identify the PSA eRNA's functions on the Pol II-Ser2p and CYCLINT1 in the CRPC C4-2 cells, we detected the Pol II-Ser2p and CYCLINT1 ChIP-seq with or without PSA eRNA knockdown in the C4-2 cells. Moreover, to rule out the AR binding changes and identify the AR binding sites around the new genes, we detected the AR ChIP-seq in LNCaP and C4-2 cells with or without the androgen. Overall design: Androgen receptor (AR) binding sites in human prostate cancer cell lines, LNCaP and C4-2, were studied using ChIP-seq. Pol II Ser-2p and CYCLINT1 binding sites in human prostate cancer cell lines C4-2 with or without PSA eRNA knockdown, were studied using ChIP-seq. ChIP enriched and input DNA were sequenced using Illumina HiSeq 2000.