Activation of the P-TEFb Complex by Lethal Prostate Cancer-Associated Enhancer RNAs [ChIP-Seq]

Castration resistant prostate cancer (CRPC) is a lethal disease1-4. Aberrant activation of the androgen receptor (AR) becomes a central mechanism contributing to the resistance of endocrine therapies2,3. Here we demonstrate that non-coding RNAs transcribed from the AR bound-enhancers RNAs (AR-eRNAs) are upregulated in human CRPC cells in vitro, xenografts in vivo and patient tissues. Expression of a subset of genes with elevated AR-eRNAs, including TLE1 and HTR3A, is inversely correlated with biochemical recurrence-free survival of CRPC patients. We identify aan HIV-1 TAR-like (TAR-L) motif in AR-eRNAs of AR target genes including KLK3 (or PSA) and TMPRSS2. The TAR-L motif is important for these eRNAs to bind to CYCLIN T1 of the positive transcription elongation factor b (P-TEFb) complex. Knockdown of PSA eRNA diminishes RNA polymerase II (Pol II) serine-2 (Ser-2) phosphorylation at the PSA promoter. The TAR-L motif in KLK3 eRNA is crucial for effective transcription of PSA mRNA. Together, wWe demonstrate a P-TEFb activation function of eRNA and reveal aberrant eRNA expression as a functional indicator of AR abnormality in CRPC. Our results also suggest that eRNAs as amay be a potential target for CRPC therapy. Overall design: Androgen receptor (AR) binding sites in human prostate cancer cell lines, LNCaP and C4-2, were studied using ChIP-seq. ChIP enriched and input DNA were sequenced using Illumina HiSeq 2000.