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Targeting chromatin binding regulation of constitutively active AR variants to overcome prostate cancer resistance to endocrine-based therapies.

Chan SC, Selth LA, Li Y, Nyquist MD, Miao L, Bradner JE, Raj GV, Tilley WD, Dehm SM - Nucleic Acids Res. (2015)

Bottom Line: Dimerization was an absolute requirement for constitutive AR-V DNA binding and transcriptional activation.Treatment with the bromodomain and extraterminal (BET) inhibitor JQ1 resulted in inhibition of AR-V chromatin binding and impaired AR-V driven PCa cell growth in vitro and in vivo.Importantly, this was associated with a novel JQ1 action of down-regulating AR-V transcript and protein expression.

View Article: PubMed Central - PubMed

Affiliation: Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55905, USA.

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Related in: MedlinePlus

Genome-wide binding of ARv567es to canonical AREs. (A) Heatmap of ChIP-seq signals ± 3 kb around R1-AD1 AR peak midpoints from three biological replicate experiments for a set of binding sites identified by peak calling with biological replicate 1 data as being common to dihydrotestosterone (DHT)-treated R1-AD1 and vehicle (ethanol, ETH)-treated R1-D567 cells (upper panel), or ‘unique’ to R1-AD1 cells (lower panel). (B) Western blot of chromatin processed for ChIP as in (A) probed with a monoclonal antibody specific for the AR NTD (AR441). (C) Sequence motifs enriched at AR (R1-AD1) and ARv567es (R1-D567) binding sites identified de novo using the Gibbs Motif Sampling approach. (D) Average ChIP-seq tag intensities expressed in mapped reads per base pair per peak normalized per 106 reads from three datasets at binding sites identified as common to R1-AD1 and R1-D567 cells, or ‘unique’ to R1-AD1 cells.
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Figure 2: Genome-wide binding of ARv567es to canonical AREs. (A) Heatmap of ChIP-seq signals ± 3 kb around R1-AD1 AR peak midpoints from three biological replicate experiments for a set of binding sites identified by peak calling with biological replicate 1 data as being common to dihydrotestosterone (DHT)-treated R1-AD1 and vehicle (ethanol, ETH)-treated R1-D567 cells (upper panel), or ‘unique’ to R1-AD1 cells (lower panel). (B) Western blot of chromatin processed for ChIP as in (A) probed with a monoclonal antibody specific for the AR NTD (AR441). (C) Sequence motifs enriched at AR (R1-AD1) and ARv567es (R1-D567) binding sites identified de novo using the Gibbs Motif Sampling approach. (D) Average ChIP-seq tag intensities expressed in mapped reads per base pair per peak normalized per 106 reads from three datasets at binding sites identified as common to R1-AD1 and R1-D567 cells, or ‘unique’ to R1-AD1 cells.

Mentions: We used the R1-AD1/R1-D567 model to study genome-wide AR and ARv567es binding via ChIP-seq using an antibody targeted to the AR NH2-terminal domain (NTD). Peak calling with data from a single ChIP-seq experiment resulted in the identification of 12 030 AR binding sites in R1-AD1 cells and 3554 ARv567es binding sites in R1-D567 cells (Figure 2A and B, Supplemental Table S4). Motif analysis revealed enrichment of canonical androgen response elements (AREs) in both R1-AD1 and R1-D567 cells (Figure 2C, Supplemental Table S5). Further motif analysis revealed that occurrences of stringent and relaxed specificity AREs (33) were similar in both datasets (Supplemental Table S6). These data indicate that regulation of AR and ARv567es DNA binding may proceed through similar mechanisms.


Targeting chromatin binding regulation of constitutively active AR variants to overcome prostate cancer resistance to endocrine-based therapies.

Chan SC, Selth LA, Li Y, Nyquist MD, Miao L, Bradner JE, Raj GV, Tilley WD, Dehm SM - Nucleic Acids Res. (2015)

Genome-wide binding of ARv567es to canonical AREs. (A) Heatmap of ChIP-seq signals ± 3 kb around R1-AD1 AR peak midpoints from three biological replicate experiments for a set of binding sites identified by peak calling with biological replicate 1 data as being common to dihydrotestosterone (DHT)-treated R1-AD1 and vehicle (ethanol, ETH)-treated R1-D567 cells (upper panel), or ‘unique’ to R1-AD1 cells (lower panel). (B) Western blot of chromatin processed for ChIP as in (A) probed with a monoclonal antibody specific for the AR NTD (AR441). (C) Sequence motifs enriched at AR (R1-AD1) and ARv567es (R1-D567) binding sites identified de novo using the Gibbs Motif Sampling approach. (D) Average ChIP-seq tag intensities expressed in mapped reads per base pair per peak normalized per 106 reads from three datasets at binding sites identified as common to R1-AD1 and R1-D567 cells, or ‘unique’ to R1-AD1 cells.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4499120&req=5

Figure 2: Genome-wide binding of ARv567es to canonical AREs. (A) Heatmap of ChIP-seq signals ± 3 kb around R1-AD1 AR peak midpoints from three biological replicate experiments for a set of binding sites identified by peak calling with biological replicate 1 data as being common to dihydrotestosterone (DHT)-treated R1-AD1 and vehicle (ethanol, ETH)-treated R1-D567 cells (upper panel), or ‘unique’ to R1-AD1 cells (lower panel). (B) Western blot of chromatin processed for ChIP as in (A) probed with a monoclonal antibody specific for the AR NTD (AR441). (C) Sequence motifs enriched at AR (R1-AD1) and ARv567es (R1-D567) binding sites identified de novo using the Gibbs Motif Sampling approach. (D) Average ChIP-seq tag intensities expressed in mapped reads per base pair per peak normalized per 106 reads from three datasets at binding sites identified as common to R1-AD1 and R1-D567 cells, or ‘unique’ to R1-AD1 cells.
Mentions: We used the R1-AD1/R1-D567 model to study genome-wide AR and ARv567es binding via ChIP-seq using an antibody targeted to the AR NH2-terminal domain (NTD). Peak calling with data from a single ChIP-seq experiment resulted in the identification of 12 030 AR binding sites in R1-AD1 cells and 3554 ARv567es binding sites in R1-D567 cells (Figure 2A and B, Supplemental Table S4). Motif analysis revealed enrichment of canonical androgen response elements (AREs) in both R1-AD1 and R1-D567 cells (Figure 2C, Supplemental Table S5). Further motif analysis revealed that occurrences of stringent and relaxed specificity AREs (33) were similar in both datasets (Supplemental Table S6). These data indicate that regulation of AR and ARv567es DNA binding may proceed through similar mechanisms.

Bottom Line: Dimerization was an absolute requirement for constitutive AR-V DNA binding and transcriptional activation.Treatment with the bromodomain and extraterminal (BET) inhibitor JQ1 resulted in inhibition of AR-V chromatin binding and impaired AR-V driven PCa cell growth in vitro and in vivo.Importantly, this was associated with a novel JQ1 action of down-regulating AR-V transcript and protein expression.

View Article: PubMed Central - PubMed

Affiliation: Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55905, USA.

Show MeSH
Related in: MedlinePlus