scholarly journals Functional mapping of androgen receptor enhancer activity

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chia-Chi Flora Huang ◽  
Shreyas Lingadahalli ◽  
Tunc Morova ◽  
Dogancan Ozturan ◽  
Eugene Hu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Binding Sites ◽  
Gene Promoters ◽  
Strongly Correlated ◽  
Enhancer Activity ◽  
Drive Gene Expression ◽  
In Vitro Cell Lines ◽  
Drive Gene

Abstract Background Androgen receptor (AR) is critical to the initiation, growth, and progression of prostate cancer. Once activated, the AR binds to cis-regulatory enhancer elements on DNA that drive gene expression. Yet, there are 10–100× more binding sites than differentially expressed genes. It is unclear how or if these excess binding sites impact gene transcription. Results To characterize the regulatory logic of AR-mediated transcription, we generated a locus-specific map of enhancer activity by functionally testing all common clinical AR binding sites with Self-Transcribing Active Regulatory Regions sequencing (STARRseq). Only 7% of AR binding sites displayed androgen-dependent enhancer activity. Instead, the vast majority of AR binding sites were either inactive or constitutively active enhancers. These annotations strongly correlated with enhancer-associated features of both in vitro cell lines and clinical prostate cancer samples. Evaluating the effect of each enhancer class on transcription, we found that AR-regulated enhancers frequently interact with promoters and form central chromosomal loops that are required for transcription. Somatic mutations of these critical AR-regulated enhancers often impact enhancer activity. Conclusions Using a functional map of AR enhancer activity, we demonstrated that AR-regulated enhancers act as a regulatory hub that increases interactions with other AR binding sites and gene promoters.

scholarly journals Functional mapping of androgen receptor enhancer activity

2020 ◽  
Author(s):  
Chia-Chi Flora Huang ◽  
Shreyas Lingadahalli ◽  
Tunc Morova ◽  
Dogancan Ozturan ◽  
Eugene Hu ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Gene Transcription ◽  
Binding Sites ◽  
Regulatory Element ◽  
Gene Promoters ◽  
Hormonal Stimulation ◽  
Enhancer Activity ◽  
Prostate Cancers ◽  
Drive Gene ◽  
Almost All

AbstractAndrogen receptor (AR) is critical to the initiation, growth and progression of almost all prostate cancers. Once activated, the AR binds to cis-regulatory enhancer elements on DNA that drive gene expression. Yet, there are 10-100x more binding sites than differentially expressed genes. It still remains unclear how individual sites contribute to AR-mediated transcription. While descriptive functional genomic approaches broadly correlate with enhancer activity, they do not provide the locus-specific resolution needed to delineate the underlying regulatory logic of AR-mediated transcription. Therefore, we functionally tested all commonly occuring clinical AR binding sites with Self-Transcribing Active Regulatory Regions sequencing (STARRseq) to generate the first map of intrinsic AR enhancer activity. This approach is not significantly affected by endogenous chromatin modifications and measures the potential enhancer activity at each cis-regulatory element. Interestingly we found that only 7% of AR binding sites displayed increased enhancer activity upon hormonal stimulation. Instead, the vast majority of AR binding sites were either inactive (81%) or constitutively active enhancers (11%). These annotations strongly correlated with enhancer-associated features in both cell line and clinical prostate cancer. With these validated annotations we next investigated the effect of each enhancer class on transcription and found that AR-driven inducible enhancers frequently interacted with promoters, forming central chromosomal loops critical for gene transcription. We demonstrated that these inducible enhancers act as regulatory hubs that increase contacts with both other AR binding sites and gene promoters. This functional map was used to identify a somatic mutation that significantly reduces the expression of a commonly mutated AR-regulated tumour suppressor. Together, our data reveal a complex interplay between different AR binding sites that work in a highly coordinated manner to drive gene transcription.

Androgen receptor: acting in the three-dimensional chromatin landscape of prostate cancer cells

2011 ◽  
Vol 5 (1) ◽  
Author(s):  
Harri Makkonen ◽  
Jorma J. Palvimo
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Binding Sites ◽  
Target Genes ◽  
Three Dimensional ◽  
Regulatory Elements ◽  
Gene Promoters ◽  
Loop Formation ◽  
Prostate Cancer Cells

AbstractAndrogen receptor (AR) acts as a hormone-controlled transcription factor that conveys the messages of both natural and synthetic androgens to the level of genes and gene programs. Defective AR signaling leads to a wide array of androgen insensitivity disorders, and deregulated AR function, in particular overexpression of AR, is involved in the growth and progression of prostate cancer. Classic models of AR action view AR-binding sites as upstream regulatory elements in gene promoters or their proximity. However, recent wider genomic screens indicate that AR target genes are commonly activated through very distal chromatin-binding sites. This highlights the importance of long-range chromatin regulation of transcription by the AR, shifting the focus from the linear gene models to three-dimensional models of AR target genes and gene programs. The capability of AR to regulate promoters from long distances in the chromatin is particularly important when evaluating the role of AR in the regulation of genes in malignant prostate cells that frequently show striking genomic aberrations, especially gene fusions. Therefore, in addition to the mechanisms of DNA loop formation between the enhancer bound ARs and the transcription apparatus at the target core promoter, the mechanisms insulating distally bound ARs from promiscuously making contacts and activating other than their normal target gene promoters are critical for proper physiological regulation and thus currently under intense investigation. This review discusses the current knowledge about the AR action in the context of gene aberrations and the three-dimensional chromatin landscape of prostate cancer cells.

scholarly journals TRIM59 is Suppressed by Androgen Receptor and Acts to Promote Lineage Plasticity and Neuroendocrine Differentiation in Prostate Cancer

2021 ◽  
Author(s):  
Liancheng Fan ◽  
Yiming Gong ◽  
Yuman He ◽  
Wei-Qiang Gao ◽  
Baijun Dong ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Molecular Mechanisms ◽  
Neuroendocrine Differentiation ◽  
Tumor Model ◽  
Strongly Correlated ◽  
Neuroendocrine Prostate Cancer ◽  
In Vitro Effects

Abstract Background: The incidence of treatment-induced neuroendocrine prostate cancer (t-NEPC) has been greatly increasing after the usage of second-generation androgen receptor (AR) pathway inhibitors (ARPIs). Neuroendocrine differentiation (NED) is closely associated with ARPI treatment failure and poor prognosis in prostate cancer (PCa) patients. However, the molecular mechanisms of NED are not fully understood. Methods: TRIM59 expression was evaluated in PCa samples from patients at first diagnosis or at relapse stage post ARPI treatment by immunohistochemistry; in vitro effects of TRIM59 were determined by cell proliferation, sphere formation and cell migration assays; while in vivo analysis was performed using subcutaneous tumor model. Western blot, qPCR assay, dual luciferase assessment, chromatin immunoprecipitation and RNA sequencing were applied for mechanistic exploration.Results: Here we report that upregulation of TRIM59, a TRIM family protein, is strongly correlated with ARPI treatment mediated NED and shorter patient survival in PCas. AR binds to TRIM59 promoter and represses its transcription. ARPI treatment leads to a reversal of repressive epigenetic modifications on TRIM59 gene and the transcriptional restraint on TRIM59 by AR. Upregulated TRIM59 then drives the NED of PCa by enhancing the degradation of RB1 and P53 and upregulating downstream lineage plasticity-promoting transcription factor SOX2. Conclusion: Altogether, TRIM59 is negatively regulated by AR and acts as a key driver for NED in PCas. Our study provides a novel prognostic marker for PCas and shed new light on the molecular pathogenesis of t-NEPC, a deadly variant of PCa.

scholarly journals Acetylation of Androgen Receptor Enhances Coactivator Binding and Promotes Prostate Cancer Cell Growth

2003 ◽  
Vol 23 (23) ◽  
pp. 8563-8575 ◽  
Author(s):  
Maofu Fu ◽  
Mahadev Rao ◽  
Chenguang Wang ◽  
Toshiyuki Sakamaki ◽  
Jian Wang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Transcription Factor ◽  
Androgen Receptor ◽  
Hdac Inhibitors ◽  
Growth Control ◽  
Cellular Growth ◽  
Gene Promoters ◽  
P300 Binding

ABSTRACT Modification by acetylation occurs at ε-amino lysine residues of histones and transcription factors. Unlike phosphorylation, a direct link between transcription factor acetylation and cellular growth or apoptosis has not been established. We show that the nuclear androgen receptor (AR), a DNA-binding transcriptional regulator, is acetylated in vivo. The acetylation of the AR is induced by ligand dihydrotestosterone and by histone deacetylase (HDAC) inhibitors in living cells. Direct AR acetylation augmented p300 binding in vitro. Constructs mimicking neutral polar substitution acetylation (ARK630Q, ARK630T) enhanced p300 binding and reduced N-CoR/HDAC/Smad3 corepressor binding, whereas charged residue substitution (ARK630R) reduced p300 binding and enhanced corepressor binding. The AR acetylation mimics promoted cell survival and growth of prostate cancer cells in soft agar and in nude mice and augmented transcription of a subset of growth control target gene promoters. Thus, transcription factor acetylation regulates coactivator/corepressor complex binding, altering expression of specific growth control genes to promote aberrant cellular growth in vivo.

scholarly journals CK2 Pro-Survival Role in Prostate Cancer Is Mediated via Maintenance and Promotion of Androgen Receptor and NFκB p65 Expression

2019 ◽  
Vol 12 (2) ◽  
pp. 89
Author(s):  
Janeen H. Trembley ◽  
Betsy T. Kren ◽  
Md. J. Abedin ◽  
Daniel P. Shaughnessy ◽  
Yingming Li ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Inhibitory Effect ◽  
Strongly Correlated ◽  
Protein Levels ◽  
Small Molecule Inhibition ◽  
Prostate Cells ◽  
Cell Death Response ◽  
Stress Signals ◽  
Castrate Resistant

The prosurvival protein kinase CK2, androgen receptor (AR), and nuclear factor kappa B (NFκB) interact in the function of prostate cells, and there is evidence of crosstalk between these signals in the pathobiology of prostate cancer (PCa). As CK2 is elevated in PCa, and AR and NFκB are involved in the development and progression of prostate cancer, we investigated their interaction in benign and malignant prostate cells in the presence of altered CK2 expression. Our results show that elevation of CK2 levels caused increased levels of AR and NFκB p65 in prostate cells of different phenotypes. Analysis of TCGA PCa data indicated that AR and CK2α RNA expression are strongly correlated. Small molecule inhibition or molecular down-regulation of CK2 caused reduction in AR mRNA expression and protein levels in PCa cells and in orthotopic xenograft tumors by various pathways. Among these, regulation of AR protein stability plays a unifying role in CK2 maintenance of AR protein levels. Our results show induction of various endoplasmic reticulum stress signals after CK2 inhibition, which may play a role in the PCa cell death response. Of note, CK2 inhibition caused loss of cell viability in both parental and enzalutamide-resistant castrate-resistant PCa cells. The present work elucidates the specific link of CK2 to the pathogenesis of PCa in association with AR and NFκB expression; further, the observation that inhibition of CK2 can exert a growth inhibitory effect on therapy-resistant PCa cells emphasizes the potential utility of CK2 inhibition in patients who are on enzalutamide treatment for advanced cancer.

scholarly journals Genome-wide analysis of androgen receptor binding sites in prostate cancer cells

2015 ◽  
Vol 9 (6) ◽  
pp. 2319-2324 ◽  
Author(s):  
YUE CHENG ◽  
PAN YU ◽  
XIUZHI DUAN ◽  
CHUNHUA LIU ◽  
SIQI XU ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Receptor Binding ◽  
Binding Sites ◽  
Prostate Cancer Cells ◽  
Genome Wide Analysis ◽  
Genome Wide

scholarly journals In vitro model systems to study androgen receptor signaling in prostate cancer

2013 ◽  
Vol 20 (2) ◽  
pp. R49-R64 ◽  
Author(s):  
Natalie Sampson ◽  
Hannes Neuwirt ◽  
Martin Puhr ◽  
Helmut Klocker ◽  
Iris E Eder
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cellular Response ◽  
Three Dimensional ◽  
Model Systems ◽  
Transfer Of Knowledge ◽  
Prostate Epithelial Cells ◽  
Technological Advances ◽  
Culture Models

Prostate cancer (PCa) is one of the most common causes of male cancer-related death in Western nations. The cellular response to androgens is mediated via the androgen receptor (AR), a ligand-inducible transcription factor whose dysregulation plays a key role during PCa development and progression following androgen deprivation therapy, the current mainstay systemic treatment for advanced PCa. Thus, a better understanding of AR signaling and new strategies to abrogate AR activity are essential for improved therapeutic intervention. Consequently, a large number of experimental cell culture models have been established to facilitate in vitro investigations into the role of AR signaling in PCa development and progression. These different model systems mimic distinct stages of this heterogeneous disease and exhibit differences with respect to AR expression/status and androgen responsiveness. Technological advances have facilitated the development of in vitro systems that more closely reflect the physiological setting, for example via the use of three-dimensional coculture to study the interaction of prostate epithelial cells with the stroma, endothelium, immune system and tissue matrix environment. This review provides an overview of the most commonly used in vitro cell models currently available to study AR signaling with particular focus on their use in addressing key questions relating to the development and progression of PCa. It is hoped that the continued development of in vitro models will provide more biologically relevant platforms for mechanistic studies, drug discovery and design ensuring a more rapid transfer of knowledge from the laboratory to the clinic.

Abstract 3412: Androgen receptor binding sites are highly mutated in prostate cancer

2018 ◽  
Author(s):  
Tunc Morova ◽  
Mehmet Gonen ◽  
Attila Gursoy ◽  
Ozlem Keskin ◽  
Nathan A. Lack
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Receptor Binding ◽  
Binding Sites
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