1
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Riley CM, Elwood JML, Henry MC, Hunter I, Daniel Lopez-Fernandez J, McEwan IJ, Jamieson C. Current and emerging approaches to noncompetitive AR inhibition. Med Res Rev 2023; 43:1701-1747. [PMID: 37062876 DOI: 10.1002/med.21961] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/14/2023] [Accepted: 03/28/2023] [Indexed: 04/18/2023]
Abstract
The androgen receptor (AR) has been shown to be a key determinant in the pathogenesis of castration-resistant prostate cancer (CRPC). The current standard of care therapies targets the ligand-binding domain of the receptor and can afford improvements to life expectancy often only in the order of months before resistance occurs. Emerging preclinical and clinical compounds that inhibit receptor activity via differentiated mechanisms of action which are orthogonal to current antiandrogens show promise for overcoming treatment resistance. In this review, we present an authoritative summary of molecules that noncompetitively target the AR. Emerging small molecule strategies for targeting alternative domains of the AR represent a promising area of research that shows significant potential for future therapies. The overall quality of lead candidates in the area of noncompetitive AR inhibition is discussed, and it identifies the key chemotypes and associated properties which are likely to be, or are currently, positioned to be first in human applications.
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Affiliation(s)
- Christopher M Riley
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK
| | - Jessica M L Elwood
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK
| | - Martyn C Henry
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK
| | - Irene Hunter
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | | | - Iain J McEwan
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Craig Jamieson
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK
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2
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Kanno Y, Saito N, Saito R, Kosuge T, Shizu R, Yatsu T, Hosaka T, Nemoto K, Kato K, Yoshinari K. Differential DNA-binding and cofactor recruitment are possible determinants of the synthetic steroid YK11-dependent gene expression by androgen receptor in breast cancer MDA-MB 453 cells. Exp Cell Res 2022; 419:113333. [PMID: 36030969 DOI: 10.1016/j.yexcr.2022.113333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/13/2022] [Accepted: 08/21/2022] [Indexed: 11/04/2022]
Abstract
Recently, selective androgen receptor modulators (SARMs), which bind to AR and act in a tissue/effect-specific manner, have been developed, but the selective mechanism is not well understood. In this study, we investigated the selective mechanism using the synthetic steroid YK11, which showed AR-mediated gene-selective transactivation. In the AR-positive human breast cancer MDA-MB-453 cells, different patterns of AR-mediated target gene expression and AR recruitment to their enhancer regions were observed between DHT and YK11. A docking study suggested the helices 11 and 12 was moved by the sterically hindered C17-group of YK11. Furthermore, the mutational studies of AR Gln902 and mammalian two-hybrid assays suggested different cofactor recruitment between DHT and YK11. The results of this study suggest that gene selective regulation by SARMs results from differential DNA-binding and/or cofactor recruitment by ligands. These results provide novel insights into the mechanism of action of SARMs.
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Affiliation(s)
- Yuichiro Kanno
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, 422-8526, Japan; Department of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan.
| | - Nao Saito
- Department of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Ryota Saito
- Department of Chemistry, Toho University, 2-2-1, Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Tomohiro Kosuge
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Ryota Shizu
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Tomofumi Yatsu
- Department of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Takuomi Hosaka
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Kiyomitsu Nemoto
- Department of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Keisuke Kato
- Department of organic Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Kouichi Yoshinari
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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3
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Steroid receptor-coregulator transcriptional complexes: new insights from CryoEM. Essays Biochem 2021; 65:857-866. [PMID: 34061186 DOI: 10.1042/ebc20210019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/04/2021] [Accepted: 05/06/2021] [Indexed: 01/14/2023]
Abstract
Steroid receptors activate gene transcription through recruitment of a number of coregulators to facilitate histone modification, chromatin remodeling, and general transcription machinery stabilization. Understanding the structures of full-length steroid receptor and coregulatory complexes has been difficult due to their large molecular sizes and dynamic structural conformations. Recent developments in cryo-electron microscopy (cryoEM) technology and proteomics have advanced the structural studies of steroid receptor complexes. Here, we will review the insights we learned from cryoEM studies of the estrogen and androgen receptor transcriptional complexes. Despite similar domain organizations, the two receptors have different coregulator interaction modes. The cryoEM structures now have revealed the fundamental differences between the two receptors and their functional mechanisms.
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4
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Nogueira TR, de Oliveira VA, Pereira IC, de Carvalho CMRG, Péres-Rodrigues G, do Carmo de Carvalho e Martins M, de Macedo G. Frota K, de Azevedo Paiva A, de Jesus e Silva de Almendra Freitas B. Vitamin A: Modulating Effect on Breast Carcinogenesis. CURRENT NUTRITION & FOOD SCIENCE 2021. [DOI: 10.2174/1573401316999200706011813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Breast cancer has a multifactorial etiology and, among the main causal factors, the dietary
profile stands out, mainly the components of the pro-inflammatory diet and their interaction with genetic
characteristics. In this sense, deciphering the molecular networks involved in the proliferation
of cancer cells in breast tissue can determine ways of action of organic compounds that modulate the
pathogenesis of cancer, such as vitamin A and analogs, as well as their possible mechanisms of modulation
of breast tumorigenesis. This is a review study conducted according to the guidelines of the
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and by consulting
the PubMed and Web of Science databases including articles, published in Portuguese, English and
Spanish, in the last five years. 126 articles were obtained, of which 13 were selected for full analysis
and only 6 were included in the study for meeting the eligibility criteria. The results of the compiled
studies demonstrate the role of some retinol-binding proteins in metabolism, as well as in differentiation,
cell proliferation and inflammation. Although controversial, the results point to the use of these
proteins as possible prognostic markers. The need for further studies in humans is also emphasized in
order to assess the main effects of vitamin isoforms on tumor activity.
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Affiliation(s)
- Thaís R. Nogueira
- Department of Nutrition, Federal University of Piaui, UFPI, Piaui State, Teresina, Brazil
| | - Victor A. de Oliveira
- Department of Nutrition, Federal University of Piaui, UFPI, Piaui State, Teresina, Brazil
| | - Irislene C. Pereira
- Department of Nutrition, Federal University of Piaui, UFPI, Piaui State, Teresina, Brazil
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5
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Penning TM, Asangani IA, Sprenger C, Plymate S. Intracrine androgen biosynthesis and drug resistance. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2020; 3:912-929. [PMID: 35582223 PMCID: PMC8992556 DOI: 10.20517/cdr.2020.60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/30/2020] [Accepted: 10/10/2020] [Indexed: 06/15/2023]
Abstract
Castration-resistant prostate cancer is the lethal form of prostate cancer and most commonly remains dependent on androgen receptor (AR) signaling. Current therapies use AR signaling inhibitors (ARSI) exemplified by abiraterone acetate, a P450c17 inhibitor, and enzalutamide, a potent AR antagonist. However, drug resistance to these agents occurs within 12-18 months and they only prolong overall survival by 3-4 months. Multiple mechanisms can contribute to ARSI drug resistance. These mechanisms can include but are not limited to germline mutations in the AR, post-transcriptional alterations in AR structure, and adaptive expression of genes involved in the intracrine biosynthesis and metabolism of androgens within the tumor. This review focuses on intracrine androgen biosynthesis, how this can contribute to ARSI drug resistance, and therapeutic strategies that can be used to surmount these resistance mechanisms.
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Affiliation(s)
- Trevor M. Penning
- Department of Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Irfan A. Asangani
- Department Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cynthia Sprenger
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Stephen Plymate
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98109, USA
- Geriatric Research Education and Clinical Center (GRECC), VA Puget Sound Health Care System, Seattle, WA 98108, USA
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6
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Yu X, Yi P, Hamilton RA, Shen H, Chen M, Foulds CE, Mancini MA, Ludtke SJ, Wang Z, O'Malley BW. Structural Insights of Transcriptionally Active, Full-Length Androgen Receptor Coactivator Complexes. Mol Cell 2020; 79:812-823.e4. [PMID: 32668201 DOI: 10.1016/j.molcel.2020.06.031] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/01/2020] [Accepted: 06/18/2020] [Indexed: 01/15/2023]
Abstract
Steroid receptors activate gene transcription by recruiting coactivators to initiate transcription of their target genes. For most nuclear receptors, the ligand-dependent activation function domain-2 (AF-2) is a primary contributor to the nuclear receptor (NR) transcriptional activity. In contrast to other steroid receptors, such as ERα, the activation function of androgen receptor (AR) is largely dependent on its ligand-independent AF-1 located in its N-terminal domain (NTD). It remains unclear why AR utilizes a different AF domain from other receptors despite that NRs share similar domain organizations. Here, we present cryoelectron microscopy (cryo-EM) structures of DNA-bound full-length AR and its complex structure with key coactivators, SRC-3 and p300. AR dimerization follows a unique head-to-head and tail-to-tail manner. Unlike ERα, AR directly contacts a single SRC-3 and p300. The AR NTD is the primary site for coactivator recruitment. The structures provide a basis for understanding assembly of the AR:coactivator complex and its domain contributions for coactivator assembly and transcriptional regulation.
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Affiliation(s)
- Xinzhe Yu
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ping Yi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ross A Hamilton
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hong Shen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Muyuan Chen
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Charles E Foulds
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael A Mancini
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Steven J Ludtke
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhao Wang
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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7
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Wang Q, Shen JY, Zhang R, Hong JW, Li Z, Ding Z, Wang HX, Zhang JP, Zhang MR, Xu LC. Effects and mechanisms of pyrethroids on male reproductive system. Toxicology 2020; 438:152460. [PMID: 32278050 DOI: 10.1016/j.tox.2020.152460] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/21/2022]
Abstract
Synthetic pyrethroids are used as insecticides in agriculture and a variety of household applications worldwide. Pyrethroids are widely distributed in all environmental compartments and the general populations are exposed to pyrethroids through various routes. Pyrethroids have been identified as endocrine-disrupting chemicals (EDCs) which are responsible for the male reproductive impairments. The data confirm pyrethroids cause male reproductive damages. The insecticides exert the toxic effects on male reproductive system through various complex mechanisms including antagonizing androgen receptor (AR), inhibiting steroid synthesis, affecting the hypothalamic-pituitary-gonadal (HPG) axis, acting as estrogen receptor (ER) modulators and inducing oxidative stress. The mechanisms of male reproductive toxicity of pyrethroids involve multiple targets and pathways. The review will provide further insight into pyrethroid-induced male reproductive toxicity and mechanisms, which is crucial to preserve male reproductive health.
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Affiliation(s)
- Qi Wang
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Jun-Yu Shen
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Rui Zhang
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Jia-Wei Hong
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Zheng Li
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Zhen Ding
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Heng-Xue Wang
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Jin-Peng Zhang
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Mei-Rong Zhang
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China
| | - Li-Chun Xu
- School of Public Health, Xuzhou Medical University, 209 Tong-Shan Road, Xuzhou, 221004, Jiangsu, China.
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8
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Chaturvedi AP, Dehm SM. Androgen Receptor Dependence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1210:333-350. [PMID: 31900916 DOI: 10.1007/978-3-030-32656-2_15] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Androgens and the androgen receptor (AR) play crucial roles in the biology of normal and diseased prostate tissue, including prostate cancer (PCa). This dependence is evidenced by the use of androgen depletion therapy (ADT) as the primary treatment for locally advanced, metastatic, or relapsed PCa. This dependence is further evidenced by the various mechanisms employed by PCa cells to re-activate the AR to circumvent the growth-inhibitory effects of ADT. Re-activation of the AR during ADT is central to the disease evolving into the lethal castration resistant PCa (CRPC) phenotype, which is responsible for nearly all PCa mortality. Thus, understanding the regulation of AR and AR signaling is important for understanding the development and progression of PCa. This understanding provides the foundation for development of newer approaches for targeting CRPC therapeutically.
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Affiliation(s)
| | - Scott M Dehm
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
- Department of Urology, University of Minnesota, Minneapolis, MN, USA.
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9
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Abstract
Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by a polyglutamine (polyQ) expansion in the androgen receptor (AR). Despite the fact that the monogenic cause of SBMA has been known for nearly 3 decades, there is no effective treatment for this disease, underscoring the complexity of the pathogenic mechanisms that lead to a loss of motor neurons and muscle in SBMA patients. In the current review, we provide an overview of the system-wide clinical features of SBMA, summarize the structure and function of the AR, discuss both gain-of-function and loss-of-function mechanisms of toxicity caused by polyQ-expanded AR, and describe the cell and animal models utilized in the study of SBMA. Additionally, we summarize previously conducted clinical trials which, despite being based on positive results from preclinical studies, proved to be largely ineffective in the treatment of SBMA; nonetheless, these studies provide important insights as researchers develop the next generation of therapies.
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Affiliation(s)
- Frederick J Arnold
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 411E Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, Pennsylvania, 19107, USA
| | - Diane E Merry
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 411E Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, Pennsylvania, 19107, USA.
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10
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Feng Q, He B. Androgen Receptor Signaling in the Development of Castration-Resistant Prostate Cancer. Front Oncol 2019; 9:858. [PMID: 31552182 PMCID: PMC6738163 DOI: 10.3389/fonc.2019.00858] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 08/20/2019] [Indexed: 12/19/2022] Open
Abstract
Most prostate cancers are androgen-sensitive malignancies whose growths depend on the transcriptional activity of the androgen receptor (AR). In the 1940s, Charles Huggins demonstrated that the surgical removal of testes in men can result in a dramatic improvement in symptoms and can induce prostate cancer regression. Since then, androgen deprivation therapies have been the standard first-line treatment for advanced prostate cancer, including: surgical castration, medical castration, antiandrogens, and androgen biosynthesis inhibitors. These therapies relieve symptoms, reduce tumor burden, and prolong patient survival, while having relatively modest side effects. Unfortunately, hormone deprivation therapy rarely cures the cancer itself. Prostate cancer almost always recurs, resulting in deadly castration-resistant prostate cancer. The underlying escape mechanisms include androgen receptor gene/enhancer amplification, androgen receptor mutations, androgen receptor variants, coactivator overexpression, intratumoral de novo androgen synthesis, etc. Whereas, the majority of the castration-resistant prostate cancers continuously rely on the androgen axis, a subset of recurrent cancers have completely lost androgen receptor expression, undergone divergent clonal evolution or de-differentiation, and become truly androgen receptor-independent small-cell prostate cancers. There is an urgent need for the development of novel targeted and immune therapies for this subtype of prostate cancer, when more deadly small-cell prostate cancers are induced by thorough androgen deprivation and androgen receptor ablation.
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Affiliation(s)
- Qin Feng
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, United States
| | - Bin He
- Departments of Surgery and Urology, Immunobiology & Transplant Science Center, Houston Methodist Cancer Center, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, United States
- Department of Medicine-Cancer Biology, Weill Cornell Medicine, Cornell University, New York, NY, United States
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11
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Review: Understanding the role of androgens and placental AR variants: Insight into steroid-dependent fetal-placental growth and development. Placenta 2019; 84:63-68. [DOI: 10.1016/j.placenta.2019.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 03/07/2019] [Accepted: 03/14/2019] [Indexed: 12/30/2022]
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12
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Cato L, de Tribolet-Hardy J, Lee I, Rottenberg JT, Coleman I, Melchers D, Houtman R, Xiao T, Li W, Uo T, Sun S, Kuznik NC, Göppert B, Ozgun F, van Royen ME, Houtsmuller AB, Vadhi R, Rao PK, Li L, Balk SP, Den RB, Trock BJ, Karnes RJ, Jenkins RB, Klein EA, Davicioni E, Gruhl FJ, Long HW, Liu XS, Cato ACB, Lack NA, Nelson PS, Plymate SR, Groner AC, Brown M. ARv7 Represses Tumor-Suppressor Genes in Castration-Resistant Prostate Cancer. Cancer Cell 2019; 35:401-413.e6. [PMID: 30773341 PMCID: PMC7246081 DOI: 10.1016/j.ccell.2019.01.008] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 08/23/2018] [Accepted: 01/14/2019] [Indexed: 12/19/2022]
Abstract
Androgen deprivation therapy for prostate cancer (PCa) benefits patients with early disease, but becomes ineffective as PCa progresses to a castration-resistant state (CRPC). Initially CRPC remains dependent on androgen receptor (AR) signaling, often through increased expression of full-length AR (ARfl) or expression of dominantly active splice variants such as ARv7. We show in ARv7-dependent CRPC models that ARv7 binds together with ARfl to repress transcription of a set of growth-suppressive genes. Expression of the ARv7-repressed targets and ARv7 protein expression are negatively correlated and predicts for outcome in PCa patients. Our results provide insights into the role of ARv7 in CRPC and define a set of potential biomarkers for tumors dependent on ARv7.
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Affiliation(s)
- Laura Cato
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Jonas de Tribolet-Hardy
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Irene Lee
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Jaice T Rottenberg
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Ilsa Coleman
- Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Diana Melchers
- PamGene International B.V., 5211 HH Den Bosch, the Netherlands
| | - René Houtman
- PamGene International B.V., 5211 HH Den Bosch, the Netherlands
| | - Tengfei Xiao
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard TH Chan School of Public Health, Boston, MA 02215, USA
| | - Wei Li
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard TH Chan School of Public Health, Boston, MA 02215, USA
| | - Takuma Uo
- Department of Medicine, University of Washington School of Medicine and GRECC-VAPSHCS, Seattle, WA 98104, USA
| | - Shihua Sun
- Department of Medicine, University of Washington School of Medicine and GRECC-VAPSHCS, Seattle, WA 98104, USA
| | - Nane C Kuznik
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Bettina Göppert
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Fatma Ozgun
- School of Medicine, Koç University, 34450 Istanbul, Turkey
| | - Martin E van Royen
- Department of Pathology, Erasmus Optical Imaging Centre, Erasmus MC, 3015 GE Rotterdam, the Netherlands
| | - Adriaan B Houtsmuller
- Department of Pathology, Erasmus Optical Imaging Centre, Erasmus MC, 3015 GE Rotterdam, the Netherlands
| | - Raga Vadhi
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Prakash K Rao
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Lewyn Li
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Steven P Balk
- Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Robert B Den
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Bruce J Trock
- Department of Urology, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Robert B Jenkins
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
| | - Eric A Klein
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | | | - Friederike J Gruhl
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Henry W Long
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - X Shirley Liu
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard TH Chan School of Public Health, Boston, MA 02215, USA
| | - Andrew C B Cato
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Nathan A Lack
- School of Medicine, Koç University, 34450 Istanbul, Turkey; Vancouver Prostate Center, University of British Columbia, Vancouver, BC V6H 3Z6, Canada
| | - Peter S Nelson
- Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Stephen R Plymate
- Department of Medicine, University of Washington School of Medicine and GRECC-VAPSHCS, Seattle, WA 98104, USA.
| | - Anna C Groner
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland.
| | - Myles Brown
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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13
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Ponnusamy S, Coss CC, Thiyagarajan T, Watts K, Hwang DJ, He Y, Selth LA, McEwan IJ, Duke CB, Pagadala J, Singh G, Wake RW, Ledbetter C, Tilley WD, Moldoveanu T, Dalton JT, Miller DD, Narayanan R. Novel Selective Agents for the Degradation of Androgen Receptor Variants to Treat Castration-Resistant Prostate Cancer. Cancer Res 2017; 77:6282-6298. [PMID: 28978635 DOI: 10.1158/0008-5472.can-17-0976] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/08/2017] [Accepted: 09/22/2017] [Indexed: 01/01/2023]
Abstract
Androgen receptor (AR) mediates the growth of prostate cancer throughout its course of development, including in abnormal splice variants (AR-SV)-driven advanced stage castration-resistant disease. AR stabilization by androgens makes it distinct from other steroid receptors, which are typically ubiquitinated and degraded by proteasomes after ligand binding. Thus, targeting AR in advanced prostate cancer requires the development of agents that can sustainably degrade variant isoforms for effective therapy. Here we report the discovery and characterization of potent selective AR degraders (SARD) that markedly reduce the activity of wild-type and splice variant isoforms of AR at submicromolar doses. Three SARDs (UT-69, UT-155, and (R)-UT-155) bind the amino-terminal transcriptional activation domain AF-1, which has not been targeted for degradation previously, with two of these SARD (UT-69 and UT-155) also binding the carboxy-terminal ligand binding domain. Despite different mechanisms of action, all three SARDs degraded wild-type AR and inhibited AR function, exhibiting greater inhibitory potency than the approved AR antagonists. Collectively, our results introduce a new candidate class of next-generation therapeutics to manage advanced prostate cancer. Cancer Res; 77(22); 6282-98. ©2017 AACR.
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MESH Headings
- Alternative Splicing
- Androgen Receptor Antagonists/chemistry
- Androgen Receptor Antagonists/pharmacology
- Anilides/chemistry
- Anilides/pharmacology
- Animals
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Proliferation/genetics
- Gene Expression Profiling/methods
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Indoles/chemistry
- Indoles/pharmacology
- Male
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Molecular Structure
- Prostatic Neoplasms, Castration-Resistant/drug therapy
- Prostatic Neoplasms, Castration-Resistant/genetics
- Prostatic Neoplasms, Castration-Resistant/metabolism
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Suriyan Ponnusamy
- Department of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | | | - Thirumagal Thiyagarajan
- Department of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Kate Watts
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Dong-Jin Hwang
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Yali He
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Luke A Selth
- Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, The University of Adelaide, South Australia
- Freemasons Foundation Centre for Men's Health, School of Medicine, The University of Adelaide, South Australia
| | - Iain J McEwan
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Charles B Duke
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jayaprakash Pagadala
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Geetika Singh
- St. Jude Children's Hospital and Research Center, Memphis, Tennessee
| | - Robert W Wake
- Department of Urology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Christopher Ledbetter
- Department of Urology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Wayne D Tilley
- Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, The University of Adelaide, South Australia
- Freemasons Foundation Centre for Men's Health, School of Medicine, The University of Adelaide, South Australia
| | - Tudor Moldoveanu
- St. Jude Children's Hospital and Research Center, Memphis, Tennessee
| | | | - Duane D Miller
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ramesh Narayanan
- Department of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee.
- West Cancer Center, Memphis, Tennessee
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14
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Askew EB, Bai S, Parris AB, Minges JT, Wilson EM. Androgen receptor regulation by histone methyltransferase Suppressor of variegation 3-9 homolog 2 and Melanoma antigen-A11. Mol Cell Endocrinol 2017; 443:42-51. [PMID: 28042025 PMCID: PMC5303141 DOI: 10.1016/j.mce.2016.12.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/13/2016] [Accepted: 12/28/2016] [Indexed: 11/22/2022]
Abstract
Androgen receptor (AR) transcriptional activity depends on interactions between the AR NH2-terminal region and transcriptional coregulators. A yeast two-hybrid screen of a human testis library using predicted α-helical NH2-terminal fragment AR-(370-420) as bait identified suppressor of variegation 3-9 homolog 2 (SUV39H2) histone methyltransferase as an AR interacting protein. SUV39H2 interaction with AR and the AR coregulator, melanoma antigen-A11 (MAGE-A11), was verified in two-hybrid, in vitro glutathione S-transferase affinity matrix and coimmunoprecipitation assays. Fluorescent immunocytochemistry colocalized SUV39H2 and AR in the cytoplasm without androgen, in the nucleus with androgen, and with MAGE-A11 in the nucleus independent of androgen. Chromatin immunoprecipitation using antibodies raised against SUV39H2 demonstrated androgen-dependent recruitment of AR and SUV39H2 to the androgen-responsive upstream enhancer of the prostate-specific antigen gene. SUV39H2 functioned cooperatively with MAGE-A11 to increase androgen-dependent AR transcriptional activity. SUV39H2 histone methyltransferase is an AR coactivator that increases androgen-dependent transcriptional activity through interactions with AR and MAGE-A11.
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Affiliation(s)
- Emily B Askew
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Suxia Bai
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Amanda B Parris
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, United States
| | - John T Minges
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Elizabeth M Wilson
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, United States.
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15
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Pakula H, Xiang D, Li Z. A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland. Cancers (Basel) 2017; 9:E14. [PMID: 28134791 PMCID: PMC5332937 DOI: 10.3390/cancers9020014] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/19/2017] [Accepted: 01/24/2017] [Indexed: 12/13/2022] Open
Abstract
Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent.
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Affiliation(s)
- Hubert Pakula
- Division of Genetics, Brigham and Women's Hospital, 77 Avenue Louis Pasteur, Room 466, Boston, MA 02115, USA.
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
| | - Dongxi Xiang
- Division of Genetics, Brigham and Women's Hospital, 77 Avenue Louis Pasteur, Room 466, Boston, MA 02115, USA.
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
| | - Zhe Li
- Division of Genetics, Brigham and Women's Hospital, 77 Avenue Louis Pasteur, Room 466, Boston, MA 02115, USA.
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
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16
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Rahaman MH, Kumarasiri M, Mekonnen LB, Yu M, Diab S, Albrecht H, Milne RW, Wang S. Targeting CDK9: a promising therapeutic opportunity in prostate cancer. Endocr Relat Cancer 2016; 23:T211-T226. [PMID: 27582311 DOI: 10.1530/erc-16-0299] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 08/31/2016] [Indexed: 12/18/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9) is a key transcriptional regulator and a lucrative target for cancer treatment. Targeting CDK9 can effectively confine the hyperactivity of androgen receptor and the constitutive expression of anti-apoptotic proteins; both being main causes of prostate cancer (PCa) development and progression. In castrate-resistant PCa, traditional therapies that only target androgen receptor (AR) have become obsolete due to reprograming in AR activity to make the cells independent of androgen. CDK9 inhibitors may provide a new and better therapeutic opportunity over traditional treatment options by targeting both androgen receptor activity and anti-apoptotic proteins, improving the chances of positive outcomes, especially in patients with the advanced disease. This review focuses on biological functions of CDK9, its involvement with AR and the potential for therapeutic opportunities in PCa treatment.
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Affiliation(s)
| | | | - Laychiluh B Mekonnen
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mingfeng Yu
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sarah Diab
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Hugo Albrecht
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Robert W Milne
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Shudong Wang
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
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17
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Prekovic S, van Royen ME, Voet ARD, Geverts B, Houtman R, Melchers D, Zhang KYJ, Van den Broeck T, Smeets E, Spans L, Houtsmuller AB, Joniau S, Claessens F, Helsen C. The Effect of F877L and T878A Mutations on Androgen Receptor Response to Enzalutamide. Mol Cancer Ther 2016; 15:1702-12. [PMID: 27196756 DOI: 10.1158/1535-7163.mct-15-0892] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/26/2016] [Indexed: 11/16/2022]
Abstract
Treatment-induced mutations in the ligand-binding domain of the androgen receptor (AR) are known to change antagonists into agonists. Recently, the F877L mutation has been described to convert enzalutamide into an agonist. This mutation was seen to co-occur in the endogenous AR allele of LNCaP cells, next to the T878A mutation. Here, we studied the effects of enzalutamide on the F877L and T878A mutants, as well as the double-mutant AR (F877L/T878A). Molecular modeling revealed favorable structural changes in the double-mutant AR that lead to a decrease in steric clashes for enzalutamide. Ligand-binding assays confirmed that the F877L mutation leads to an increase in relative binding affinity for enzalutamide, but only the combination with the T878A mutation resulted in a strong agonistic activity. This correlated with changes in coregulator recruitment and chromatin interactions. Our data show that enzalutamide is only a very weak partial agonist of the AR F877L, and a strong partial agonist of the double-mutant AR. Mol Cancer Ther; 15(7); 1702-12. ©2016 AACR.
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Affiliation(s)
- Stefan Prekovic
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | | | - Arnout R D Voet
- Structural Bioinformatics Team, Division of Structural and Synthetic Biology, Center for Life Science Technologies, RIKEN, Yokohama, Japan. Laboratory for Biomolecular Modeling and Design, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Bart Geverts
- Department of Pathology, Erasmus MC, Rotterdam, the Netherlands
| | | | | | - Kam Y J Zhang
- Structural Bioinformatics Team, Division of Structural and Synthetic Biology, Center for Life Science Technologies, RIKEN, Yokohama, Japan
| | - Thomas Van den Broeck
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium. Department of Urology, University Hospitals Leuven, Leuven, Belgium
| | - Elien Smeets
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Lien Spans
- Laboratory for Genetics of Malignant Disorders, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Adriaan B Houtsmuller
- Department of Pathology, Erasmus MC, Rotterdam, the Netherlands. Erasmus Optical Imaging Center, Erasmus MC, Rotterdam, the Netherlands
| | - Steven Joniau
- Department of Urology, University Hospitals Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Christine Helsen
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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18
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19
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Zboray L, Pluciennik A, Curtis D, Liu Y, Berman-Booty LD, Orr C, Kesler CT, Berger T, Gioeli D, Paschal BM, Merry DE. Preventing the Androgen Receptor N/C Interaction Delays Disease Onset in a Mouse Model of SBMA. Cell Rep 2015; 13:2312-23. [PMID: 26673324 DOI: 10.1016/j.celrep.2015.11.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 09/17/2015] [Accepted: 11/03/2015] [Indexed: 11/30/2022] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by a polyglutamine expansion in the androgen receptor (AR) and is associated with misfolding and aggregation of the mutant AR. We investigated the role of an interdomain interaction between the amino (N)-terminal FxxLF motif and carboxyl (C)-terminal AF-2 domain in a mouse model of SBMA. Male transgenic mice expressing polyQ-expanded AR with a mutation in the FxxLF motif (F23A) to prevent the N/C interaction displayed substantially improved motor function compared with N/C-intact AR-expressing mice and showed reduced pathological features of SBMA. Serine 16 phosphorylation was substantially enhanced by the F23A mutation; moreover, the protective effect of AR F23A was dependent on this phosphorylation. These results reveal an important role for the N/C interaction on disease onset in mice and suggest that targeting AR conformation could be a therapeutic strategy for patients with SBMA.
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Affiliation(s)
- Lori Zboray
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Anna Pluciennik
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Dana Curtis
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Yuhong Liu
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Lisa D Berman-Booty
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Christopher Orr
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Cristina T Kesler
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Center for Cell Signaling, Charlottesville, VA 22908, USA
| | - Tamar Berger
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Daniel Gioeli
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Bryce M Paschal
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Center for Cell Signaling, Charlottesville, VA 22908, USA
| | - Diane E Merry
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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20
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Todd TW, Kokubu H, Miranda HC, Cortes CJ, La Spada AR, Lim J. Nemo-like kinase is a novel regulator of spinal and bulbar muscular atrophy. eLife 2015; 4:e08493. [PMID: 26308581 PMCID: PMC4577982 DOI: 10.7554/elife.08493] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 08/24/2015] [Indexed: 01/03/2023] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA) is a progressive neuromuscular disease caused by polyglutamine expansion in the androgen receptor (AR) protein. Despite extensive research, the exact pathogenic mechanisms underlying SBMA remain elusive. In this study, we present evidence that Nemo-like kinase (NLK) promotes disease pathogenesis across multiple SBMA model systems. Most remarkably, loss of one copy of Nlk rescues SBMA phenotypes in mice, including extending lifespan. We also investigated the molecular mechanisms by which NLK exerts its effects in SBMA. Specifically, we have found that NLK can phosphorylate the mutant polyglutamine-expanded AR, enhance its aggregation, and promote AR-dependent gene transcription by regulating AR-cofactor interactions. Furthermore, NLK modulates the toxicity of a mutant AR fragment via a mechanism that is independent of AR-mediated gene transcription. Our findings uncover a crucial role for NLK in controlling SBMA toxicity and reveal a novel avenue for therapy development in SBMA. DOI:http://dx.doi.org/10.7554/eLife.08493.001 Spinal and bulbar muscular atrophy (SBMA) is an inherited disease that eventually leads to degeneration in motor neurons and weakness in muscles. It is caused by a specific genetic mutation in the gene that encodes the androgen receptor protein, which leads to the production of a mutant protein that is larger than normal. Similar mutations in other genes can lead to the development of other so-called ‘polyglutamine’ diseases such as Huntington's disease and spinocerebellar ataxia. However, the precise details of how these mutations lead to disease symptoms are not known, and there are currently no effective ways of treating these conditions. Previous research has shown that an enzyme called Nemo-like kinase (or NLK for short) regulates the normal androgen receptor in cancer cells. NLK has kinase activity, that is, it adds phosphate molecules to other proteins to regulate their activity. Todd et al. used human cells, fruit flies, and mice as model systems to investigate whether NLK is involved in the development of SBMA. The experiments show that NLK promotes the development of features associated with SBMA in all three models. The kinase activity of NLK is required for these features to develop. Todd et al. also found that NLK can bind to and add phosphate molecules to the mutant version of the androgen receptor protein. This causes the mutant androgen receptor proteins to accumulate and increases the ability of the mutant proteins to activate particular genes. Todd et al.'s findings suggest that NLK promotes the development of SBMA by interacting with the mutant androgen receptor. Previous studies have shown that NLK is able to modulate the development of spinocerebellar ataxia type 1, which suggests that NLK may also play an important role in other polyglutamine diseases. The next challenge will be to fully understand the role of NLK in these diseases, which may aid future efforts to develop new treatments. DOI:http://dx.doi.org/10.7554/eLife.08493.002
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Affiliation(s)
- Tiffany W Todd
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Genetics, Yale School of Medicine, New Haven, United States
| | - Hiroshi Kokubu
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Genetics, Yale School of Medicine, New Haven, United States
| | - Helen C Miranda
- Departments of Cellular and Molecular Medicine, Neurosciences, and Pediatrics, Division of Biological Sciences, Institute for Genomic Medicine, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, United States
| | - Constanza J Cortes
- Departments of Cellular and Molecular Medicine, Neurosciences, and Pediatrics, Division of Biological Sciences, Institute for Genomic Medicine, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, United States
| | - Albert R La Spada
- Departments of Cellular and Molecular Medicine, Neurosciences, and Pediatrics, Division of Biological Sciences, Institute for Genomic Medicine, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, United States
| | - Janghoo Lim
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Genetics, Yale School of Medicine, New Haven, United States
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21
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Spillane M, Schwarz N, Willoughby DS. Upper-body resistance exercise augments vastus lateralis androgen receptor-DNA binding and canonical Wnt/β-catenin signaling compared to lower-body resistance exercise in resistance-trained men without an acute increase in serum testosterone. Steroids 2015; 98:63-71. [PMID: 25742735 DOI: 10.1016/j.steroids.2015.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/12/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
The purpose of the study was to determine the effect of single bouts of lower-body (LB) and upper- and lower-body (ULB) resistance exercise on serum testosterone concentrations and the effects on muscle testosterone, dihydrotestosterone (DHT), androgen receptor (AR) protein content, and AR-DNA binding. A secondary purpose was to determine the effects on serum wingless-type MMTV integration site (Wnt4) levels and skeletal muscle β-catenin content. In a randomized cross-over design, exercise bouts consisted of a LB and ULB protocol, and each bout was separated by 1 week. Blood and muscle samples were obtained before exercise and 3 and 24h post-exercise; blood samples were also obtained at 0.5, 1, and 2 h post-exercise. Statistical analyses were performed by separate two-way factorial analyses of variance (ANOVA) with repeated measures. No significant differences from baseline were observed in serum total and free testosterone and skeletal muscle testosterone and DHT with either protocol (p>0.05). AR protein was significantly increased at 3 h post-exercise and decreased at 24 h post-exercise for ULB, whereas AR-DNA binding was significantly increased at 3 and 24h post-exercise (p<0.05). In response to ULB, serum Wnt4 was significantly increased at 0.5, 1, and 2 h post-exercise (p<0.05) and β-catenin was significantly increased at 3 and 24 h post-exercise (p<0.05). It was concluded that, despite a lack of increase in serum testosterone and muscle androgen concentrations from either mode of resistance exercise, ULB resistance exercise increased Wnt4/β-catenin signaling and AR-DNA binding.
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Affiliation(s)
- Mike Spillane
- Department of Health, Physical Education, and Leisure Studies, University of South Alabama, Mobile, AL 36688, USA
| | - Neil Schwarz
- Department of Health, Physical Education, and Leisure Studies, University of South Alabama, Mobile, AL 36688, USA
| | - Darryn S Willoughby
- Exercise and Biochemical Nutrition Lab, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX 76798, USA.
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22
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Brooke GN, Powell SM, Lavery DN, Waxman J, Buluwela L, Ali S, Bevan CL. Engineered repressors are potent inhibitors of androgen receptor activity. Oncotarget 2015; 5:959-69. [PMID: 24659630 PMCID: PMC4011597 DOI: 10.18632/oncotarget.1360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Prostate cancer growth is dependent upon the Androgen Receptor (AR) pathway, hence therapies for this disease often target this signalling axis. Such therapies are successful in the majority of patients but invariably fail after a median of 2 years and tumours progress to a castrate resistant stage (CRPC). Much evidence exists to suggest that the AR remains key to CRPC growth and hence remains a valid therapeutic target. Here we describe a novel method to inhibit AR activity, consisting of an interaction motif, that binds to the AR ligand-binding domain, fused to repression domains. These ‘engineered repressors’ are potent inhibitors of AR activity and prostate cancer cell growth and importantly inhibit the AR under circumstances in which conventional therapies would be predicted to fail, such as AR mutation and altered cofactor levels.
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Affiliation(s)
- Greg N Brooke
- Department of Surgery and Cancer, Imperial Centre for Translational and Experimental Medicine, Imperial College London, W12 0NN, UK
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23
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Androgen receptor and its splice variant, AR-V7, differentially regulate FOXA1 sensitive genes in LNCaP prostate cancer cells. Int J Biochem Cell Biol 2014; 54:49-59. [PMID: 25008967 DOI: 10.1016/j.biocel.2014.06.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 05/25/2014] [Accepted: 06/18/2014] [Indexed: 11/23/2022]
Abstract
Prostate cancer (PCa) is an androgen-dependent disease, and tumors that are resistant to androgen ablation therapy often remain androgen receptor (AR) dependent. Among the contributors to castration-resistant PCa are AR splice variants that lack the ligand-binding domain (LBD). Instead, they have small amounts of unique sequence derived from cryptic exons or from out of frame translation. The AR-V7 (or AR3) variant is constitutively active and is expressed under conditions consistent with CRPC. AR-V7 is reported to regulate a transcriptional program that is similar but not identical to that of AR. However, it is unknown whether these differences are due to the unique sequence in AR-V7, or simply to loss of the LBD. To examine transcriptional regulation by AR-V7, we have used lentiviruses encoding AR-V7 (amino acids 1-627 of AR with the 16 amino acids unique to the variant) to prepare a derivative of the androgen-dependent LNCaP cells with inducible expression of AR-V7. An additional cell line was generated with regulated expression of AR-NTD (amino acids 1-660 of AR); this mutant lacks the LBD but does not have the AR-V7 specific sequence. We find that AR and AR-V7 have distinct activities on target genes that are co-regulated by FOXA1. Transcripts regulated by AR-V7 were similarly regulated by AR-NTD, indicating that loss of the LBD is sufficient for the observed differences. Differential regulation of target genes correlates with preferential recruitment of AR or AR-V7 to specific cis-regulatory DNA sequences providing an explanation for some of the observed differences in target gene regulation.
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Tan JA, Bai S, Grossman G, Titus MA, Harris Ford O, Pop EA, Smith GJ, Mohler JL, Wilson EM, French FS. Mechanism of androgen receptor corepression by CKβBP2/CRIF1, a multifunctional transcription factor coregulator expressed in prostate cancer. Mol Cell Endocrinol 2014; 382:302-313. [PMID: 24103312 PMCID: PMC3880566 DOI: 10.1016/j.mce.2013.09.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/27/2013] [Indexed: 01/12/2023]
Abstract
The transcription factor coregulator Casein kinase IIβ-binding protein 2 or CR6-interacting factor 1 (CKβBP2/CRIF1) binds the androgen receptor (AR) in prostate cancer cells and in response to dihydrotestosterone localizes with AR on the prostate-specific antigen gene enhancer, but does not bind DNA suggesting CKβBP2/CRIF1 localization in chromatin is determined by AR. In this study we show also that CKβBP2/CRIF1 inhibits wild-type AR and AR N-terminal transcriptional activity, binds to the AR C-terminal region, inhibits interaction of the AR N- and C-terminal domains (N/C interaction) and competes with p160 coactivator binding to the AR C-terminal domain, suggesting CKβBP2/CRIF1 interferes with AR activation functions 1 and 2. CKβBP2/CRIF1 is expressed mainly in stromal cells of benign prostatic hyperplasia and in stroma and epithelium of prostate cancer. CKβBP2/CRIF1 protein is increased in epithelium of androgen-dependent prostate cancer compared to benign prostatic hyperplasia and decreased slightly in castration recurrent epithelium compared to androgen-dependent prostate cancer. The multifunctional CKβBP2/CRIF1 is a STAT3 interacting protein and reported to be a coactivator of STAT3. CKβBP2/CRIF1 is expressed with STAT3 in prostate cancer where STAT3 may help to offset the AR repressor effect of CKβBP2/CRIF1 and allow AR regulation of prostate cancer growth.
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Affiliation(s)
- Jiann-An Tan
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States
| | - Suxia Bai
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States
| | - Gail Grossman
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States
| | - Mark A Titus
- Department of Urology, Roswell Park Cancer Institute, Buffalo, NY, United States
| | - O Harris Ford
- Lineberger Comprehensive Cancer Center, University of North Carolina, School of Medicine, Chapel Hill, NC, United States
| | - Elena A Pop
- Department of Urology, Roswell Park Cancer Institute, Buffalo, NY, United States
| | - Gary J Smith
- Department of Urology, Roswell Park Cancer Institute, Buffalo, NY, United States
| | - James L Mohler
- Department of Urology, Roswell Park Cancer Institute, Buffalo, NY, United States; Lineberger Comprehensive Cancer Center, University of North Carolina, School of Medicine, Chapel Hill, NC, United States; Department of Urology, University of Buffalo, School of Medicine and Biotechnology, Buffalo, NY, United States
| | - Elizabeth M Wilson
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States; Lineberger Comprehensive Cancer Center, University of North Carolina, School of Medicine, Chapel Hill, NC, United States; Department of Biochemistry and Biophysics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States
| | - Frank S French
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, School of Medicine, Chapel Hill, NC, United States; Lineberger Comprehensive Cancer Center, University of North Carolina, School of Medicine, Chapel Hill, NC, United States.
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Tadokoro-Cuccaro R, Davies J, Mongan NP, Bunch T, Brown RS, Audi L, Watt K, McEwan IJ, Hughes IA. Promoter-Dependent Activity on Androgen Receptor N-Terminal Domain Mutations in Androgen Insensitivity Syndrome. Sex Dev 2014; 8:339-49. [DOI: 10.1159/000369266] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
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Su S, Minges JT, Grossman G, Blackwelder AJ, Mohler JL, Wilson EM. Proto-oncogene activity of melanoma antigen-A11 (MAGE-A11) regulates retinoblastoma-related p107 and E2F1 proteins. J Biol Chem 2013; 288:24809-24. [PMID: 23853093 DOI: 10.1074/jbc.m113.468579] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Melanoma antigen-A11 (MAGE-A11) is a low-abundance, primate-specific steroid receptor coregulator in normal tissues of the human reproductive tract that is expressed at higher levels in prostate cancer. Increased expression of MAGE-A11 enhances androgen receptor transcriptional activity and promotes prostate cancer cell growth. Further investigation into the mechanisms of MAGE-A11 function in prostate cancer demonstrated interactions with the retinoblastoma-related protein p107 and Rb tumor suppressor but no interaction with p130 of the Rb family. MAGE-A11 interaction with p107 was associated with transcriptional repression in cells with low MAGE-A11 and transcriptional activation in cells with higher MAGE-A11. Selective interaction of MAGE-A11 with retinoblastoma family members suggested the regulation of E2F transcription factors. MAGE-A11 stabilized p107 by inhibition of ubiquitination and linked p107 to hypophosphorylated E2F1 in association with the stabilization and activation of E2F1. The androgen receptor and MAGE-A11 modulated endogenous expression of the E2F1-regulated cyclin-dependent kinase inhibitor p27(Kip1). The ability of MAGE-A11 to increase E2F1 transcriptional activity was similar to the activity of adenovirus early oncoprotein E1A and depended on MAGE-A11 interactions with p107 and p300. The immunoreactivity of p107 and MAGE-A11 was greater in advanced prostate cancer than in benign prostate, and knockdown with small inhibitory RNA showed that p107 is a transcriptional activator in prostate cancer cells. These results suggest that MAGE-A11 is a proto-oncogene whose increased expression in prostate cancer reverses retinoblastoma-related protein p107 from a transcriptional repressor to a transcriptional activator of the androgen receptor and E2F1.
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Affiliation(s)
- Shifeng Su
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Abstract
Androgenic steroids are important for male development in utero and secondary sexual characteristics at puberty. In addition, androgens play a role in non-reproductive tissues, such as bone and muscle in both sexes. The actions of the androgens testosterone and dihydrotestosterone are mediated by a single receptor protein, the androgen receptor. Over the last 60–70 years there has been considerable research interest in the development of inhibitors of androgen receptor for the management of diseases such as prostate cancer. However, more recently, there is also a growing appreciation of the need for selective androgen modulators that would demonstrate tissue-selective agonist or antagonist activity. The chemistry and biology of selective agonists, antagonists and selective androgen receptor modulators will be discussed in this review.
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Beitel LK, Alvarado C, Mokhtar S, Paliouras M, Trifiro M. Mechanisms mediating spinal and bulbar muscular atrophy: investigations into polyglutamine-expanded androgen receptor function and dysfunction. Front Neurol 2013; 4:53. [PMID: 23720649 PMCID: PMC3654311 DOI: 10.3389/fneur.2013.00053] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 04/26/2013] [Indexed: 11/13/2022] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA, Kennedy’s disease), a late-onset neuromuscular disorder, is caused by expansion of the polymorphic polyglutamine tract in the androgen receptor (AR). The AR is a ligand-activated transcription factor, but plays roles in other cellular pathways. In SBMA, selective motor neuron degeneration occurs in the brainstem and spinal cord, thus the causes of neuronal dysfunction have been studied. However, pathogenic pathways in muscles may also be involved. Cultured cells, fly and mouse models are used to study the molecular mechanisms leading to SBMA. Both the structure of the polyglutamine-expanded AR (polyQ AR) and its interactions with other proteins are altered relative to the normal AR. The ligand-dependent translocation of the polyQ AR to the nucleus appears to be critical, as are interdomain interactions. The polyQ AR, or fragments thereof, can form nuclear inclusions, but their pathogenic or protective nature is unclear. Other data suggests soluble polyQ AR oligomers can be harmful. Post-translational modifications such as phosphorylation, acetylation, and ubiquitination influence AR function and modulate the deleterious effects of the polyQ AR. Transcriptional dysregulation is highly likely to be a factor in SBMA; deregulation of non-genomic AR signaling may also be involved. Studies on polyQ AR-protein degradation suggest inhibition of the ubiquitin proteasome system and changes to autophagic pathways may be relevant. Mitochondrial function and axonal transport may also be affected by the polyQ AR. Androgens, acting through the AR, can be neurotrophic and are important in muscle development; hence both loss of normal AR functions and gain of novel harmful functions by the polyQ AR can contribute to neurodegeneration and muscular atrophy. Thus investigations into polyQ AR function have shown that multiple complex mechanisms lead to the initiation and progression of SBMA.
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Affiliation(s)
- Lenore K Beitel
- Lady Davis Institute for Medical Research, Jewish General Hospital Montreal, QC, Canada ; Department of Medicine, McGill University Montreal, QC, Canada ; Department of Human Genetics, McGill University Montreal, QC, Canada
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van Royen ME, van de Wijngaart DJ, Cunha SM, Trapman J, Houtsmuller AB. A multi-parameter imaging assay identifies different stages of ligand-induced androgen receptor activation. Cytometry A 2013; 83:806-17. [DOI: 10.1002/cyto.a.22284] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/09/2013] [Accepted: 02/26/2013] [Indexed: 12/29/2022]
Affiliation(s)
- Martin E. van Royen
- Department of Pathology; Josephine Nefkens Institute; Erasmus MC; 3000 CA Rotterdam; The Netherlands
| | | | - Sónia M. Cunha
- Department of Pathology; Josephine Nefkens Institute; Erasmus MC; 3000 CA Rotterdam; The Netherlands
| | - Jan Trapman
- Department of Pathology; Josephine Nefkens Institute; Erasmus MC; 3000 CA Rotterdam; The Netherlands
| | - Adriaan B. Houtsmuller
- Department of Pathology; Josephine Nefkens Institute; Erasmus MC; 3000 CA Rotterdam; The Netherlands
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Yang YC, Meimetis LG, Tien AH, Mawji NR, Carr G, Wang J, Andersen RJ, Sadar MD. Spongian diterpenoids inhibit androgen receptor activity. Mol Cancer Ther 2013; 12:621-31. [PMID: 23443807 DOI: 10.1158/1535-7163.mct-12-0978] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Androgen receptor is a ligand-activated transcription factor and a validated drug target for all stages of prostate cancer. Antiandrogens compete with physiologic ligands for androgen receptor ligand-binding domain (LBD). High-throughput screening of a marine natural product library for small molecules that inhibit androgen receptor transcriptional activity yielded the furanoditerpenoid spongia-13(16),-14-dien-19-oic acid, designated terpene 1 (T1). Characterization of T1 and the structurally related semisynthetic analogues (T2 and T3) revealed that these diterpenoids have antiandrogen properties that include inhibition of both androgen-dependent proliferation and androgen receptor transcriptional activity by a mechanism that involved competing with androgen for androgen receptor LBD and blocking essential N/C interactions required for androgen-induced androgen receptor transcriptional activity. Structure-activity relationship analyses revealed some chemical features of T1 that are associated with activity and yielded T3 as the most potent analogue. In vivo, T3 significantly reduced the weight of seminal vesicles, which are an androgen-dependent tissue, thereby confirming the on-target activity of T3. The ability to create analogues of diterpenoids that have varying antiandrogen activity represents a novel class of chemical compounds for the analysis of androgen receptor ligand-binding properties and therapeutic development.
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Affiliation(s)
- Yu Chi Yang
- Department of Genome Sciences Centre, BC Cancer Agency, Vancouver, BC, Canada
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31
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Minges JT, Su S, Grossman G, Blackwelder AJ, Pop EA, Mohler JL, Wilson EM. Melanoma antigen-A11 (MAGE-A11) enhances transcriptional activity by linking androgen receptor dimers. J Biol Chem 2012; 288:1939-52. [PMID: 23172223 DOI: 10.1074/jbc.m112.428409] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Prostate cancer growth and progression depend on androgen receptor (AR) signaling through transcriptional mechanisms that require interactions with coregulatory proteins, one of which is the primate-specific steroid receptor coregulator melanoma antigen-A11 (MAGE-A11). In this report, we provide evidence how increased expression of MAGE-A11 during prostate cancer progression enhances AR signaling and prostate cancer growth. MAGE-A11 protein levels were highest in castration-recurrent prostate cancer. The cyclic AMP-induced increase in androgen-dependent and androgen-independent AR transcriptional activity correlated with an increase in MAGE-A11 and was inhibited by silencing MAGE-A11 expression. MAGE-A11 mediated synergistic AR transcriptional activity in LAPC-4 prostate cancer cells. The ability of MAGE-A11 to rescue transcriptional activity of complementary inactive AR mutants and promote coimmunoprecipitation between unlike forms of AR suggests that MAGE-A11 links transcriptionally active AR dimers. A model for the AR·MAGE-A11 multidimeric complex is proposed in which one AR FXXLF motif of the AR dimer engages in the androgen-dependent AR NH(2)- and carboxyl-terminal interaction, whereas the second FXXLF motif region of the AR dimer interacts with dimeric MAGE-A11. The AR·MAGE-A11 multidimeric complex accounts for the dual functions of the AR FXXLF motif in the androgen-dependent AR NH(2)- and carboxyl-terminal interaction and binding MAGE-A11 and for synergy between reported AR splice variants and full-length AR. We conclude that the increased expression of MAGE-A11 in castration-recurrent prostate cancer, which is enhanced by cyclic AMP signaling, increases AR-dependent growth of prostate cancer by MAGE-A11 forming a molecular bridge between transcriptionally active AR dimers.
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Affiliation(s)
- John T Minges
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599-7500, USA
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Nyrönen TH, Söderholm AA. Structural basis for computational screening of non-steroidal androgen receptor ligands. Expert Opin Drug Discov 2012; 5:5-20. [PMID: 22823968 DOI: 10.1517/17460440903468680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Deep structural and chemical understanding of the protein target and computational methods for detection of receptor-selective ligands are important for the early drug discovery in the steroid receptor field. AREAS COVERED IN THIS REVIEW This review focuses on the use of currently available structural information of the androgen receptor (AR) and known AR ligands to make computational strategies for the discovery of AR ligands in order to offer new chemical platforms for drug development. WHAT THE READER WILL GAIN AR is a challenging target for drug discovery and modeling even if there is a wealth of experimental data available. First, only the active structure of AR is currently known, which hampers the design of AR antagonists. Second, the structural similarity between the ligand-binding sites of AR and its mutated forms and closely related steroid receptors (SRs) such as progesterone receptors presents challenges for the development of drugs with receptor-selective function. TAKE HOME MESSAGE Research indicates that a very small chemical change in the structure of a non-steroidal ligand can cause a complete change in its activity. One source of this effect arises from binding to similar binding sites in related SRs and other proteins in the signaling pathway. Currently, computational methods are not able to predict the subtle differences between AR ligand activities but modeling does offer the possibility of generating new lead structures that might have the desired properties.
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Affiliation(s)
- Tommi H Nyrönen
- CSC - IT Center for Science Ltd., P.O. Box 405, Espoo, FI-02101, Finland +358 9 4572235 ; +358 9 4572302 ;
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Mohler ML, Coss CC, Duke CB, Patil SA, Miller DD, Dalton JT. Androgen receptor antagonists: a patent review (2008-2011). Expert Opin Ther Pat 2012; 22:541-65. [PMID: 22583332 DOI: 10.1517/13543776.2012.682571] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Androgen receptor (AR) antagonists are predominantly used as chemical castration to treat prostate cancer (i.e., in conjunction with androgen deprivation therapy (ADT)). Unfortunately, castration-resistant prostate cancer (CRPC) typically develops that is refractory to targeted therapy. Insights into CRPC biology have led to the emergence of a promising clinical candidate MDV3100 (1) and a resurgence in this field. A pipeline of preclinical competitive (C-terminally directed) antagonists was discovered using a variety of innovative screening paradigms. Some inhibit nuclear translocation, selectively downregulate or degrade AR (SARD), antagonize wild-type and escape mutant AR (pan-antagonists) and/or antagonize AR target organs in vivo. Separately, the N-terminal domain has emerged as a promising novel target for noncompetitive antagonists. AREAS COVERED AR antagonists whose patents published between 2008 and 2011 are reviewed. Antagonists are organized based on the screening paradigm reported as discussed above. EXPERT OPINION Novel mechanisms provide a more informed basis for selecting a competitive antagonist; however, high potency and favorable in vivo properties remain paramount. Noncompetitive antagonists have theoretical advantages suggestive of improved clinical efficacy, but no clinical proof of concept as of yet.
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Affiliation(s)
- Michael L Mohler
- Preclinical Research and Development, GTx, Inc., 3 North Dunlap Street, Memphis, TN 38163, USA
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Moore NL, Buchanan G, Harris JM, Selth LA, Bianco-Miotto T, Hanson AR, Birrell SN, Butler LM, Hickey TE, Tilley WD. An androgen receptor mutation in the MDA-MB-453 cell line model of molecular apocrine breast cancer compromises receptor activity. Endocr Relat Cancer 2012; 19:599-613. [PMID: 22719059 DOI: 10.1530/erc-12-0065] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent evidence indicates that the estrogen receptor-α-negative, androgen receptor (AR)-positive molecular apocrine subtype of breast cancer is driven by AR signaling. The MDA-MB-453 cell line is the prototypical model of this breast cancer subtype; its proliferation is stimulated by androgens such as 5α-dihydrotestosterone (DHT) but inhibited by the progestin medroxyprogesterone acetate (MPA) via AR-mediated mechanisms. We report here that the AR gene in MDA-MB-453 cells contains a G-T transversion in exon 7, resulting in a receptor variant with a glutamine to histidine substitution at amino acid 865 (Q865H) in the ligand binding domain. Compared with wild-type AR, the Q865H variant exhibited reduced sensitivity to DHT and MPA in transactivation assays in MDA-MB-453 and PC-3 cells but did not respond to non-androgenic ligands or receptor antagonists. Ligand binding, molecular modeling, mammalian two-hybrid and immunoblot assays revealed effects of the Q865H mutation on ligand dissociation, AR intramolecular interactions, and receptor stability. Microarray expression profiling demonstrated that DHT and MPA regulate distinct transcriptional programs in MDA-MB-453 cells. Gene Set Enrichment Analysis revealed that DHT- but not MPA-regulated genes were associated with estrogen-responsive transcriptomes from MCF-7 cells and the Wnt signaling pathway. These findings suggest that the divergent proliferative responses of MDA-MB-453 cells to DHT and MPA result from the different genetic programs elicited by these two ligands through the AR-Q865H variant. This work highlights the necessity to characterize additional models of molecular apocrine breast cancer to determine the precise role of AR signaling in this breast cancer subtype.
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Affiliation(s)
- Nicole L Moore
- Dame Roma Mitchell Cancer Research Laboratories, Discipline of Medicine, The University of Adelaide and Hanson Institute, PO Box 14, Rundle Mall, Adelaide, South Australia 5000, Australia
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The stress response mediator ATF3 represses androgen signaling by binding the androgen receptor. Mol Cell Biol 2012; 32:3190-202. [PMID: 22665497 DOI: 10.1128/mcb.00159-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activating transcription factor 3 (ATF3) is a common mediator of cellular stress response signaling and is often aberrantly expressed in prostate cancer. We report here that ATF3 can directly bind the androgen receptor (AR) and consequently repress AR-mediated gene expression. The ATF3-AR interaction requires the leucine zipper domain of ATF3 that independently binds the DNA-binding and ligand-binding domains of AR, and the interaction prevents AR from binding to cis-acting elements required for expression of androgen-dependent genes while inhibiting the AR N- and C-terminal interaction. The functional consequences of the loss of ATF3 expression include increased transcription of androgen-dependent genes in prostate cancer cells that correlates with increased ability to grow in low-androgen-containing medium and increased proliferative activity of the prostate epithelium in ATF3 knockout mice that is associated with prostatic hyperplasia. Our results thus demonstrate that ATF3 is a novel repressor of androgen signaling that can inhibit AR functions, allowing prostate cells to restore homeostasis and maintain integrity in the face of a broad spectrum of intrinsic and environmental insults.
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Kumar R, McEwan IJ. Allosteric modulators of steroid hormone receptors: structural dynamics and gene regulation. Endocr Rev 2012; 33:271-99. [PMID: 22433123 PMCID: PMC3596562 DOI: 10.1210/er.2011-1033] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Steroid hormones are synthesized from cholesterol primarily in the adrenal gland and the gonads and play vital roles in normal physiology, the control of development, differentiation, metabolic homeostasis, and reproduction. The actions of these small lipophilic molecules are mediated by intracellular receptor proteins. It is just over 25 yr since the first cDNA for steroid receptors were cloned, a development that led to the birth of a superfamily of ligand-activated transcription factors: the nuclear receptors. The receptor proteins share structurally and functionally related ligand binding and DNA-binding domains but possess distinct N-terminal domains and hinge regions that are intrinsically disordered. Since the original cloning experiments, considerable progress has been made in our understanding of the structure, mechanisms of action, and biology of this important class of ligand-activated transcription factors. In recent years, there has been interest in the structural plasticity and function of the N-terminal domain of steroid hormone receptors and in the allosteric regulation of protein folding and function in response to hormone, DNA response element architecture, and coregulatory protein binding partners. The N-terminal domain can exist as an ensemble of conformers, having more or less structure, which prime this region of the receptor to rapidly respond to changes in the intracellular environment through hormone binding and posttranslation modifications. In this review, we address the question of receptor structure and function dynamics with particular emphasis on the structurally flexible N-terminal domain, intra- and interdomain communications, and the allosteric regulation of receptor action.
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Affiliation(s)
- Raj Kumar
- Department of Basic Sciences, The Commonwealth Medical College, Scranton, Pennsylvania 18510, USA
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Hay CW, McEwan IJ. The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity. PLoS One 2012; 7:e32514. [PMID: 22403669 PMCID: PMC3293822 DOI: 10.1371/journal.pone.0032514] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 01/27/2012] [Indexed: 11/30/2022] Open
Abstract
Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.
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Affiliation(s)
- Colin W. Hay
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Iain J. McEwan
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- * E-mail:
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38
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Lagarde WH, Blackwelder AJ, Minges JT, Hnat AT, French FS, Wilson EM. Androgen receptor exon 1 mutation causes androgen insensitivity by creating phosphorylation site and inhibiting melanoma antigen-A11 activation of NH2- and carboxyl-terminal interaction-dependent transactivation. J Biol Chem 2012; 287:10905-15. [PMID: 22334658 DOI: 10.1074/jbc.m111.336081] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Naturally occurring germ line mutations in the X-linked human androgen receptor (AR) gene cause incomplete masculinization of the external genitalia by disrupting AR function in males with androgen insensitivity syndrome. Almost all AR missense mutations that cause androgen insensitivity syndrome are located in the highly structured DNA and ligand binding domains. In this report we investigate the functional defect associated with an AR exon 1 missense mutation, R405S, that caused partial androgen insensitivity. The 46,XX heterozygous maternal carrier had a wild-type Arg-405 CGC allele but transmitted an AGC mutant allele coding for Ser-405. At birth, the 46,XY proband had a bifid scrotum, hypospadias, and micropenis consistent with clinical stage 3 partial androgen insensitivity. Androgen-dependent transcriptional activity of AR-R405S expressed in CV1 cells was less than wild-type AR and refractory in androgen-dependent AR NH(2)- and carboxyl interaction transcription assays that depend on the coregulator effects of melanoma antigen-A11. This mutation created a Ser-405 phosphorylation site evident by the gel migration of an AR-R405S NH(2)-terminal fragment as a double band that converted to the wild-type single band after treatment with λ-phosphatase. Detrimental effects of the R405S mutation were related to the proximity of the AR WXXLF motif (433)WHTLF(437) required for melanoma antigen-A11 and p300 to stimulate transcriptional activity associated with the AR NH(2)- and carboxyl-terminal interaction. We conclude that the coregulator effects of melanoma antigen-A11 on the AR NH(2)- and carboxyl-terminal interaction amplify the androgen-dependent transcriptional response to p300 required for normal human male sex development in utero.
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Affiliation(s)
- William H Lagarde
- Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina 27599-7500, USA
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Anti-androgen effects of cypermethrin on the amino- and carboxyl-terminal interaction of the androgen receptor. Toxicology 2012; 292:99-104. [DOI: 10.1016/j.tox.2011.11.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 11/27/2011] [Accepted: 11/28/2011] [Indexed: 11/18/2022]
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Askew EB, Minges JT, Hnat AT, Wilson EM. Structural features discriminate androgen receptor N/C terminal and coactivator interactions. Mol Cell Endocrinol 2012; 348:403-10. [PMID: 21664945 PMCID: PMC3199032 DOI: 10.1016/j.mce.2011.03.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 03/25/2011] [Accepted: 03/31/2011] [Indexed: 11/20/2022]
Abstract
Human androgen receptor (AR) transcriptional activity involves interdomain and coactivator interactions with the agonist-bound AR ligand binding domain (LBD). Structural determinants of the AR NH(2)- and carboxyl-terminal interaction between the AR NH(2)-terminal FXXLF motif and activation function 2 (AF2) in the LBD were shown previously by crystallography. In this report, we provide evidence for a region in AR LBD helix 12 outside the AF2 binding cleft that facilitates interactions with the FXXLF and LXXLL motifs. Mutagenesis of glutamine 902 to alanine in AR LBD helix 12 (Q902A) disrupted AR FXXLF motif binding to AF2, but enhanced coactivator LXXLL motif binding. Functional compensation for defective FXXLF motif binding by AR-Q902A was suggested by the slower dissociation rate of bound androgen. Functional importance of glutamine 902 was indicated by the charged residue germline mutation Q902R that caused partial androgen insensitivity, and a similar somatic mutation Q902K reported in prostate cancer, both of which increased the androgen dissociation rate and decreased AR transcriptional activity. High affinity equilibrium androgen binding was retained by alanine substitution mutations at Tyr-739 in AR LBD helix 5 or Lys-905 in helix 12 structurally adjacent to AF2, whereas transcriptional activity decreased and the androgen dissociation increased. Deleterious effects of these loss of function mutations were rescued by the helix stabilizing AR prostate cancer somatic mutation H874Y. Sequence NH(2)-terminal to the AR FXXLF motif contributed to the AR NH(2)- and carboxyl-terminal interaction based on greater AR-2-30 FXXLF motif peptide binding to the agonist-bound AR LBD than a shorter AR-20-30 FXXLF motif peptide. We conclude that helix 12 residues outside the AF2 binding cleft modulate AR transcriptional activity by providing flexibility to accommodate FXXLF or LXXLL motif binding.
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Affiliation(s)
| | | | | | - Elizabeth M. Wilson
- Corresponding author: EM Wilson, Laboratories for Reproductive Biology, University of North Carolina at Chapel Hill, NC 27599-7500 USA, TEL 919-966-5168, FAX 919-966-2203
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41
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Helsen C, Kerkhofs S, Clinckemalie L, Spans L, Laurent M, Boonen S, Vanderschueren D, Claessens F. Structural basis for nuclear hormone receptor DNA binding. Mol Cell Endocrinol 2012; 348:411-7. [PMID: 21801809 DOI: 10.1016/j.mce.2011.07.025] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 07/07/2011] [Accepted: 07/12/2011] [Indexed: 11/16/2022]
Abstract
The gene family of nuclear receptors is characterized by the presence of a typical, well conserved DNA-binding domain. In general, two zinc coordinating modules are folded such that an α-helix is inserted in the major groove of the DNA-helix displaying a sequence similar to one of two hexameric consensus motifs. Both zinc molecules coordinate four cysteines. Although the DNA-binding domains as well as the hormone response elements are very similar, each nuclear receptor will affect transcription of a specific set of target genes. This is in part due to some important receptor-specific variations on the general theme of DNA interaction. For most nuclear receptors, the DNA-binding domain dimerizes on DNA, which explains why most hormone response elements consist of a repeat of two hexamers. The hexamer dimers can be organized either as direct, inverted or everted repeats with spacers of varying lengths. The DNA can be bound by homodimers, heterodimers and for some orphan receptors, as monomer. Another key element for DNA binding by nuclear receptors is the carboxy-terminal extension of the DNA-binding domain extending into the hinge region. This part not only co-determines sequence specificity, but also affects other functions of the receptors like nuclear translocation, intranuclear mobility and transactivation potential. Moreover, allosteric signals passing through towards other receptor domains, explain why to some extent, the DNA elements can also be considered as controlling ligands.
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Affiliation(s)
- Christine Helsen
- Molecular Endocrinology Laboratory, Department Molecular Cell Biology, Campus GHB, ON1, Herestraat 49, 3000 Leuven, Belgium
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42
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Abstract
The androgen receptor (AR) is a key transcriptional regulator and therapeutic target in prostate cancer. During androgen deprivation therapy to treat metastatic prostate cancer, surviving cells acquire increased AR signaling through a variety of mechanisms, one of which is enhanced interactions with AR coactivators. One recently identified AR-specific coregulator expressed only in human and nonhuman primates is the melanoma antigen gene protein-A11 (MAGE-11). MAGE-11 increases AR transcriptional activity through direct interactions with AR and other coactivators, and its levels increase during prostate cancer progression to castration-recurrent growth. The MAGE-11 gene is located at Xq28 on the human X chromosome as part of an X-linked MAGE gene family of cancer-testis antigens. MAGE-11 stabilizes AR when androgen levels are low, and functions in a transcriptional hub to promote AR-mediated gene activation. The evolutionary development and organization of the MAGE-11 gene within the cancer-testis antigen family suggests that MAGE-11 provides a gain-of-function to AR among primates in both normal physiology and cancer, and may serve as a therapeutic target in the treatment of advanced prostate cancer.
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Affiliation(s)
- Elizabeth M Wilson
- Laboratories for Reproductive Biology, Lineberger Comprehensive Cancer Center, and the Departments of Pediatrics, and Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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Buchanan G, Need EF, Barrett JM, Bianco-Miotto T, Thompson VC, Butler LM, Marshall VR, Tilley WD, Coetzee GA. Corepressor effect on androgen receptor activity varies with the length of the CAG encoded polyglutamine repeat and is dependent on receptor/corepressor ratio in prostate cancer cells. Mol Cell Endocrinol 2011; 342:20-31. [PMID: 21664238 PMCID: PMC3314496 DOI: 10.1016/j.mce.2011.05.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/12/2011] [Accepted: 05/09/2011] [Indexed: 01/01/2023]
Abstract
The response of prostate cells to androgens reflects a combination of androgen receptor (AR) transactivation and transrepression, but how these two processes differ mechanistically and influence prostate cancer risk and disease outcome remain elusive. Given recent interest in targeting AR transrepressive processes, a better understanding of AR/corepressor interaction and responses is warranted. Here, we used transactivation and interaction assays with wild-type and mutant ARs, and deletion AR fragments, to dissect the relationship between AR and the corepressor, silencing mediator for retinoic acid and thyroid hormone receptors (SMRT). We additionally tested how these processes are influenced by AR agonist and antagonist ligands, as well as by variation in the polyglutamine tract in the AR amino terminal domain (NTD), which is encoded by a polymorphic CAG repeat in the gene. SMRT was recruited to the AR ligand binding domain by agonist ligand, and as determined by the effect of strategic mutations in activation function 2 (AF-2), requires a precise conformation of that domain. A distinct region of SMRT also mediated interaction with the AR-NTD via the transactivation unit 5 (TAU5; residues 315-538) region. The degree to which SMRT was able to repress AR increased from 17% to 56% as the AR polyglutamine repeat length was increased from 9 to 42 residues, but critically this effect could be abolished by increasing the SMRT:AR molar ratio. These data suggest that the extent to which the CAG encoded polyglutamine repeat influences AR activity represents a balance between corepressor and coactivator occupancy of the same ligand-dependent and independent AR interaction surfaces. Changes in the homeostatic relationship of AR to these molecules, including SMRT, may explain the variable penetrance of the CAG repeat and the loss of AR signaling flexibility in prostate cancer progression.
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Affiliation(s)
- Grant Buchanan
- Department of Preventive Medicine, Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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A novel nuclear role for the Vav3 nucleotide exchange factor in androgen receptor coactivation in prostate cancer. Oncogene 2011; 31:716-27. [PMID: 21765461 PMCID: PMC3203328 DOI: 10.1038/onc.2011.273] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Increased androgen receptor (AR) transcriptional activity mediated by coactivator proteins may drive castration-resistant prostate cancer (CRPC) growth. Vav3, a Rho GTPase guanine nucleotide exchange factor (GEF), is overexpressed in human prostate cancers, particularly in models of CRPC progression. Vav3 coactivates AR in a Vav3 pleckstrin homology (PH) domain-dependent but GEF-independent manner. Ectopic expression of Vav3 in androgen-dependent human prostate cancer cells conferred robust castration-resistant xenograft tumor growth. Vav3 but not a Vav3 PH mutant greatly stimulated interaction between the AR amino and carboxyl termini (N-C interaction), which is required for maximal receptor transcriptional activity. Vav3 was distributed between the cytoplasm and nucleus with nuclear localization-dependent on the Vav3 PH domain. Membrane targeting of Vav3 abolished Vav3 potentiation of AR activity, whereas nuclear targeting of a Vav3 PH mutant rescued AR coactivation, suggesting that nuclear localization is an important function of the Vav3 PH domain. A nuclear role for Vav3 was further demonstrated by sequential chromatin immunoprecipitation assays, which revealed that Vav3 and AR were recruited to the same transcriptional complexes of an AR target gene enhancer. These data demonstrate the importance of Vav3 in CRPC and define a novel nuclear function of Vav3 in regulating AR activity.
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Brooke GN, Bevan CL. The role of androgen receptor mutations in prostate cancer progression. Curr Genomics 2011; 10:18-25. [PMID: 19721807 PMCID: PMC2699836 DOI: 10.2174/138920209787581307] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 10/11/2008] [Accepted: 10/20/2008] [Indexed: 12/03/2022] Open
Abstract
Prostate tumour growth is almost always dependent upon the androgen receptor pathway and hence therapies aimed at blocking this signalling axis are useful tools in the management of this disease. Unfortunately such therapies invariably fail; and the tumour progresses to an “androgen-independent” stage. In such cases androgen receptor expression is almost always maintained and much evidence exists to suggest that it may still be driving growth. One mechanism by which the receptor is thought to remain active is mutation. This review summarises the present data on androgen receptor mutations in prostate cancer, and how such substitutions offer a growth advantage by affecting cofactor interactions or by reducing ligand specificity. Such alterations appear to have a subsequent effect upon gene expression suggesting that tumours may “behave” differently dependent upon the ligand promoting growth and if a mutation is present.
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Affiliation(s)
- G N Brooke
- Androgen Signalling Laboratory, Department of Oncology, Imperial College London, London, W12 0NN, UK
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Liu Q, Su S, Blackwelder AJ, Minges JT, Wilson EM. Gain in transcriptional activity by primate-specific coevolution of melanoma antigen-A11 and its interaction site in androgen receptor. J Biol Chem 2011; 286:29951-63. [PMID: 21730049 DOI: 10.1074/jbc.m111.244715] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Male sex development and growth occur in response to high affinity androgen binding to the androgen receptor (AR). In contrast to complete amino acid sequence conservation in the AR DNA and ligand binding domains among mammals, a primate-specific difference in the AR NH(2)-terminal region that regulates the NH(2)- and carboxyl-terminal (N/C) interaction enables direct binding to melanoma antigen-A11 (MAGE-11), an AR coregulator that is also primate-specific. Human, mouse, and rat AR share the same NH(2)-terminal (23)FQNLF(27) sequence that mediates the androgen-dependent N/C interaction. However, the mouse and rat AR FXXLF motif is flanked by Ala(33) that evolved to Val(33) in primates. Human AR Val(33) was required to interact directly with MAGE-11 and for the inhibitory effect of the AR N/C interaction on activation function 2 that was relieved by MAGE-11. The functional importance of MAGE-11 was indicated by decreased human AR regulation of an androgen-dependent endogenous gene using lentivirus short hairpin RNAs and by the greater transcriptional strength of human compared with mouse AR. MAGE-11 increased progesterone and glucocorticoid receptor activity independently of binding an FXXLF motif by interacting with p300 and p160 coactivators. We conclude that the coevolution of the AR NH(2)-terminal sequence and MAGE-11 expression among primates provides increased regulatory control over activation domain dominance. Primate-specific expression of MAGE-11 results in greater steroid receptor transcriptional activity through direct interactions with the human AR FXXLF motif region and indirectly through steroid receptor-associated p300 and p160 coactivators.
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Affiliation(s)
- Qiang Liu
- Laboratories for Reproductive Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7500, USA
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Kino T, Chrousos GP. Acetylation-mediated epigenetic regulation of glucocorticoid receptor activity: circadian rhythm-associated alterations of glucocorticoid actions in target tissues. Mol Cell Endocrinol 2011; 336:23-30. [PMID: 21146585 PMCID: PMC3057275 DOI: 10.1016/j.mce.2010.12.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 11/30/2010] [Accepted: 12/02/2010] [Indexed: 11/25/2022]
Abstract
Glucocorticoids influence organ functions through the glucocorticoid receptor, a protein acetylated and deacetylated by several histone acetyltransferases and deacetylases. We reported that the circadian rhythm-related transcription factor "Clock", a key component of the biological CLOCK with inherent histone acetyltransferase activity, acetylates glucocorticoid receptor lysines within its hinge region--a "lysine cluster" containing a KXKK motif--and represses its transcriptional activity. This Clock-induced repression of the glucocorticoid receptor activity is inversely phased to the diurnally circulating glucocorticoids and may act as a local counter regulatory mechanism to the actions of these hormones. Importantly, uncoupling of the central CLOCK-regulated hypothalamic-pituitary-adrenal axis and peripheral CLOCK-mediated alterations of glucocorticoid action, such as chronic stress and frequent trans-time zone travel or night-shift work, may cause functional hypercortisolism and contribute to various pathologies. Thus, acetylation-mediated epigenetic regulation of the glucocorticoid receptor may be essential for the maintenance of proper time-integrated glucocorticoid action, significantly influencing human well-being and longevity.
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Affiliation(s)
- Tomoshige Kino
- Unit on Molecular Hormone Action, Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bldg. 10, CRC, Rm. 1-3140, 10 Center Drive MSC 1109, Bethesda, MD 20892-1109, USA.
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van de Wijngaart DJ, Dubbink HJ, Molier M, de Vos C, Jenster G, Trapman J. Inhibition of androgen receptor functions by gelsolin FxxFF peptide delivered by transfection, cell-penetrating peptides, and lentiviral infection. Prostate 2011; 71:241-53. [PMID: 20690138 DOI: 10.1002/pros.21238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Prostate cancer (PC) growth is dependent on the androgen-androgen receptor (AR) axis. Because current androgen ablation therapies of PC lead to resistance, novel approaches to block AR activity are urgently needed. METHODS We inhibited AR function beyond the level of hormone binding by blockade of the coactivator groove in the ligand-binding domain (LBD) using a high-affinity gelsolin FxxFF peptide. Following peptide selection, the effect of the gelsolin FxxFF peptide on AR functions was determined in Hep3B cells that were transiently transfected with pM-peptide expression vectors or were incubated with synthetic gelsolin FxxFF peptide coupled to the TAT cell-penetrating peptide. Lentiviruses expressing the gelsolin FxxFF peptide were used to study endogenous AR target gene expression in LNCaP cells. RESULTS pM-Gelsolin FxxFF efficiently interfered with AR N/C interaction and specifically inhibited AR-regulated reporter gene activity. The peptide did not inhibit progesterone receptor (PR) and glucocorticoid receptor (GR) activity, nor constitutively active gene promoters. The peptide also specifically blocked in vitro interactions of AR LBD with peptides. Like the gelsolin FxxFF peptide expressed by an expression vector, synthetic TAT-gelsolin FxxFF peptide efficiently blocked AR N/C interaction and inhibited full-length AR-regulated reporter gene activity. It hardly affected PR and GR activity, but the effect on constitutively active promoters was variable. Lentiviral gelsolin FxxFF peptide inhibited expression of KLK2 and NDRG1, but hardly affected PSA and TMPRSS2. CONCLUSIONS Our results show that the AR coactivator groove may function as a target to overcome therapeutic failure that arises during current androgen ablation therapies.
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Ko S, Ahn J, Song CS, Kim S, Knapczyk-Stwora K, Chatterjee B. Lysine methylation and functional modulation of androgen receptor by Set9 methyltransferase. Mol Endocrinol 2011; 25:433-44. [PMID: 21273441 DOI: 10.1210/me.2010-0482] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Lysine methyltransferases modulate activities of transcription factors and transcription coregulators by methylating specific lysine residue(s). We report that the androgen receptor (AR) is methylated at lysine-630 by Set9, which was originally identified as a histone H3K4 monomethyltransferase. Alanine substitution of lysine-630 prevented AR methylation in vitro and in vivo. Set9 methylated the nuclear and cytoplasmic AR utilizing the cofactor S-adenosyl-methionine. A pan-methyllysine antibody recognized endogenous AR, and Set9 coimmunoprecipitated with nuclear and cytoplasmic AR. Set9 overexpression potentiated AR-mediated transactivation of the probasin promoter, whereas Set9 depletion inhibited AR activity and target gene expression. Similar to AR, chromatin occupancy of Set9 at androgen response elements (AREs) was androgen dependent, and associated with methylated histone H3K4 chromatin activation marks and p300/CBP associated factor acetyltransferase recruitment. Set9 depletion increased the histone H3K9-dimethyl repressive mark at AREs and reduced histone activation marks and occupancy of p300/CBP associated factor. K630A mutation reduced amino- and carboxy-terminal (N-C) interaction in Set9-intact cells, whereas N-C interaction for wild-type AR was reduced upon Set9 depletion. The K630A mutant was resistant to loss of activity from Set9 silencing and to increase of activity from Set9 overexpression. The K630 dependence of Set9-regulated N-C interaction and AR activity suggests that Set9 directly acts on AR at the amino acid level. Chromatin recruitment of Set9 to AREs is suggestive of its additional role as a transcriptional coactivator. Because the cellular metabolic state determines the level of S-adenosylmethionine and consequently the activity of Set9, the enhanced activity of methylated AR may have special significance in certain metabolic contexts.
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Affiliation(s)
- Soyoung Ko
- Department of Molecular Medicine/Institute Biotechnology, The University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, Texas 78245, USA
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50
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Abstract
High-affinity binding of testosterone or dihydrotestosterone to the androgen receptor (AR) triggers the androgen-dependent AR NH2- and carboxyl-terminal (N/C) interaction between the AR NH2-terminal FXXLF motif and the activation function 2 (AF2) hydrophobic binding surface in the ligand-binding domain. The functional importance of the AR N/C interaction is supported by naturally occurring loss-of-function AR AF2 mutations where AR retains high-affinity androgen binding but is defective in AR FXXLF motif binding. Ligands with agonist activity in vivo such as testosterone, dihydrotestosterone, and the synthetic anabolic steroids induce the AR N/C interaction and increase AR transcriptional activity in part by slowing the dissociation rate of bound ligand and stabilizing AR against degradation. AR ligand-binding domain competitive antagonists inhibit the agonist-dependent AR N/C interaction. Although the human AR N/C interaction is important for transcriptional activity, it has an inhibitory effect on transcriptional activity from AF2 by competing for p160 coactivator LXXLL motif binding. The primate-specific AR coregulatory protein, melanoma antigen gene protein-A11 (MAGE-A11), modulates the AR N/C interaction through a direct interaction with the AR FXXLF motif. Inhibition of AF2 transcriptional activity by the AR N/C interaction is relieved by AR FXXLF motif binding to the F-box region of MAGE-11. Described here are methods to measure the androgen-dependent AR N/C interdomain interaction and the influence of transcriptional coregulators.
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Affiliation(s)
- Elizabeth M Wilson
- Laboratories for Reproductive Biology, Lineberger Comprehensive Cancer Center, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599, USA.
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