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Guzman J, Weigelt K, Neumann A, Tripal P, Schmid B, Winter Z, Palmisano R, Culig Z, Cronauer MV, Muschler P, Wullich B, Taubert H, Wach S. NanoLuc Binary Technology as a methodological approach: an important new tool for studying the localization of androgen receptor and androgen receptor splice variant V7 homo and heterodimers. BMC Cancer 2024; 24:346. [PMID: 38500100 PMCID: PMC10949640 DOI: 10.1186/s12885-024-12110-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 03/12/2024] [Indexed: 03/20/2024] Open
Abstract
BACKGROUND The androgen/androgen receptor (AR)-signaling axis plays a central role in prostate cancer (PCa). Upon androgen-binding the AR dimerizes with another AR, and translocates into the nucleus where the AR-dimer activates/inactivates androgen-dependent genes. Consequently, treatments for PCa are commonly based on androgen deprivation therapy (ADT). The clinical benefits of ADT are only transitory and most tumors develop mechanisms allowing the AR to bypass its need for physiological levels of circulating androgens. Clinical failure of ADT is often characterized by the synthesis of a constitutively active AR splice variant, termed AR-V7. AR-V7 mRNA expression is considered as a resistance mechanism following ADT. AR-V7 no longer needs androgenic stimuli for nuclear entry and/or dimerization. METHODS Our goal was to mechanistically decipher the interaction between full-length AR (AR-FL) and AR-V7 in AR-null HEK-293 cells using the NanoLuc Binary Technology under androgen stimulation and deprivation conditions. RESULTS Our data point toward a hypothesis that AR-FL/AR-FL homodimers form in the cytoplasm, whereas AR-V7/AR-V7 homodimers localize in the nucleus. However, after androgen stimulation, all the AR-FL/AR-FL, AR-FL/AR-V7 and AR-V7/AR-V7 dimers were localized in the nucleus. CONCLUSIONS We showed that AR-FL and AR-V7 form heterodimers that localize to the nucleus, whereas AR-V7/AR-V7 dimers were found to localize in the absence of androgens in the nucleus.
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Affiliation(s)
- Juan Guzman
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany
| | - Katrin Weigelt
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany
| | - Angela Neumann
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany
| | - Philipp Tripal
- Optical Imaging Centre Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Benjamin Schmid
- Optical Imaging Centre Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Zoltán Winter
- Optical Imaging Centre Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Ralph Palmisano
- Optical Imaging Centre Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Zoran Culig
- Department of Urology, Division of Experimental Urology, Medical University of Innsbruck, Innsbruck, 6020, Austria
| | - Marcus V Cronauer
- Institute of Pathology, Universitätsklinikum Bonn, Universität Bonn, Bonn, 53127, Germany
| | | | - Bernd Wullich
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany
| | - Helge Taubert
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany.
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany.
| | - Sven Wach
- Department of Urology and Pediatric Urology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, 91054, Germany
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The Crucial Role of AR-V7 in Enzalutamide-Resistance of Castration-Resistant Prostate Cancer. Cancers (Basel) 2022; 14:cancers14194877. [PMID: 36230800 PMCID: PMC9563243 DOI: 10.3390/cancers14194877] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/29/2022] Open
Abstract
Simple Summary Androgen receptor splice variant 7 (AR-V7) has always been considered a key driver for triggering enzalutamide resistance of castration-resistant prostate cancer (CRPC). In recent years, both the homeostasis of AR-V7 protein and AR-V7’s relationship with LncRNAs have gained great attention with in-depth studies. Starting from protein stability and LncRNA, the paper discusses and summarizes the mechanisms and drugs that affect the CRPC patients’ sensitivity to enzalutamide by regulating the protein or transcriptional stability of AR-V7, hoping to provide therapeutic ideas for subsequent research to break through the CRPC therapeutic bottleneck. Abstract Prostate cancer (PCa) has the second highest incidence of malignancies occurring in men worldwide. The first-line therapy of PCa is androgen deprivation therapy (ADT). Nonetheless, most patients progress to castration-resistant prostate cancer (CRPC) after being treated by ADT. As a second-generation androgen receptor (AR) antagonist, enzalutamide (ENZ) is the current mainstay of new endocrine therapies for CRPC in clinical use. However, almost all patients develop resistance during AR antagonist therapy due to various mechanisms. At present, ENZ resistance (ENZR) has become challenging in the clinical treatment of CRPC. AR splice variant 7 (AR-V7) refers to a ligand-independent and constitutively active variant of the AR and is considered a key driver of ENZR in CRPC. In this review, we summarize the mechanisms and biological behaviors of AR-V7 in ENZR of CRPC to contribute novel insights for CRPC therapy.
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Özgün F, Kaya Z, Morova T, Geverts B, Abraham TE, Houtsmuller AB, van Royen ME, Lack NA. DNA binding alters ARv7 dimer interactions. J Cell Sci 2021; 134:jcs258332. [PMID: 34318896 DOI: 10.1242/jcs.258332] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 06/02/2021] [Indexed: 11/20/2022] Open
Abstract
Androgen receptor (AR) splice variants are proposed to be a potential driver of lethal castration-resistant prostate cancer. AR splice variant 7 (ARv7) is the most commonly observed isoform and strongly correlates with resistance to second-generation anti-androgens. Despite this clinical evidence, the interplay between ARv7 and the highly expressed full-length AR (ARfl) remains unclear. In this work, we show that ARfl/ARv7 heterodimers readily form in the nucleus via an intermolecular N/C interaction that brings the four termini of the proteins in close proximity. Combining fluorescence resonance energy transfer and fluorescence recovery after photobleaching, we demonstrate that these heterodimers undergo conformational changes following DNA binding, indicating dynamic nuclear receptor interaction. Although transcriptionally active, ARv7 can only form short-term interactions with DNA at highly accessible high-occupancy ARfl binding sites. Dimerization with ARfl does not affect ARv7 binding dynamics, suggesting that DNA binding occupancy is determined by the individual protein monomers and not the homodimer or heterodimer complex. Overall, these biophysical studies reveal detailed properties of ARv7 dynamics as both a homodimer or heterodimer with ARfl.
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Affiliation(s)
- Fatma Özgün
- School of Medicine, Koç University, Istanbul 34450, Turkey
| | - Zeynep Kaya
- School of Medicine, Koç University, Istanbul 34450, Turkey
| | - Tunç Morova
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, BC V6H 3Z6, Canada
| | - Bart Geverts
- Erasmus Optical Imaging Centre, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
| | - Tsion E Abraham
- Erasmus Optical Imaging Centre, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
| | - Adriaan B Houtsmuller
- Erasmus Optical Imaging Centre, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
- Department of Pathology, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
| | - Martin E van Royen
- Erasmus Optical Imaging Centre, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
- Department of Pathology, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
| | - Nathan A Lack
- School of Medicine, Koç University, Istanbul 34450, Turkey
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, BC V6H 3Z6, Canada
- Koç University Research Centre for Translational Medicine (KUTTAM), Koç University, Istanbul 34450, Turkey
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A detailed characterization of stepwise activation of the androgen receptor variant 7 in prostate cancer cells. Oncogene 2020; 40:1106-1117. [PMID: 33323969 PMCID: PMC7880901 DOI: 10.1038/s41388-020-01585-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 11/11/2020] [Accepted: 11/24/2020] [Indexed: 01/28/2023]
Abstract
Expression of the andrgogen receptor splice variant 7 (AR-V7) is frequently detected in castrate resistant prostate cancer and associated with resistance to AR-targeted therapies. While we have previously noted that homodimerization is required for the transcriptional activity of AR-V7 and that AR-V7 can also form heterodimers with the full-length AR (AR-FL), there are still many gaps of knowledge in AR-V7 stepwise activation. In the present study, we show that neither AR-V7 homodimerization nor AR-V7/AR-FL heterodimerization requires cofactors or DNA binding. AR-V7 can enter the nucleus as a monomer and drive a transcriptional program and DNA-damage repair as a homodimer. While forming a heterodimer with AR-FL to induce nuclear localization of unliganded AR-FL, AR-V7 does not need to interact with AR-FL to drive gene transcription or DNA-damage repair in prostate cancer cells that co-express AR-V7 and AR-FL. These data indicate that AR-V7 can function independently of its interaction with AR-FL in the true castrate state or “absence of ligand”, providing support for the utility of targeting AR-V7 in improving outcomes of patients with castrate resistant prostate cancer.
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Uo T, Plymate SR, Sprenger CC. Allosteric alterations in the androgen receptor and activity in prostate cancer. Endocr Relat Cancer 2017; 24:R335-R348. [PMID: 28808043 PMCID: PMC6812555 DOI: 10.1530/erc-17-0108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/13/2017] [Indexed: 12/19/2022]
Abstract
Organisms have evolved to generate biological complexity in their proteome and transcriptome from a limited number of genes. This concept holds true for the androgen receptor, which displays a diversity of inclusion/exclusion events in its structural motifs as a mechanism of resistance to the most forefront anti-androgen therapies. More than 20 androgen receptor variants that lack various portions of ligand-binding domain have been identified in human prostate cancer (PCa) samples. Most of the variants are inactive on their own, with a few exceptions displaying constitutive activity. The full-length receptor and one or more variants can be co-expressed in the same cell under many circumstances, which raises the question of how these variants physically and functionally interact with the full-length receptor or one another in the course of PCa progression. To address this issue, in this review, we will characterize and discuss androgen receptor variants, including the novel variants discovered in the last couple of years (i) individually, (ii) with respect to their physical and functional interaction with one another and (iii) in clinical relevance. Here, we also introduce the very recent understanding of AR-Vs obtained through successful development of some AR-V-specific antibodies as well as identification of novel AR-Vs by data mining approaches.
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Affiliation(s)
- Takuma Uo
- Department of MedicineUniversity of Washington, Seattle, Washington, USA
| | - Stephen R Plymate
- Department of MedicineUniversity of Washington, Seattle, Washington, USA
- Geriatrics Research Education and Clinical CenterVA Puget Sound Health Care System, Seattle, Washington, USA
| | - Cynthia C Sprenger
- Department of MedicineUniversity of Washington, Seattle, Washington, USA
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