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Lumahan LEV, Arif M, Whitener AE, Yi P. Regulating Androgen Receptor Function in Prostate Cancer: Exploring the Diversity of Post-Translational Modifications. Cells 2024; 13:191. [PMID: 38275816 PMCID: PMC10814774 DOI: 10.3390/cells13020191] [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: 12/01/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/27/2024] Open
Abstract
Androgen receptor (AR) transcriptional activity significantly influences prostate cancer (PCa) progression. In addition to ligand stimulation, AR transcriptional activity is also influenced by a variety of post-translational modifications (PTMs). A number of oncogenes and tumor suppressors have been observed leveraging PTMs to influence AR activity. Subjectively targeting these post-translational modifiers based on their impact on PCa cell proliferation is a rapidly developing area of research. This review elucidates the modifiers, contextualizes the effects of these PTMs on AR activity, and connects these cellular interactions to the progression of PCa.
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Affiliation(s)
- Lance Edward V. Lumahan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77204, USA
| | - Mazia Arif
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77205, USA
| | - Amy E. Whitener
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77205, USA
| | - Ping Yi
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77205, USA
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2
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Yang C, Wierbiłowicz K, Dworak NM, Bae SY, Tengse SB, Abianeh N, Drake JM, Abbas T, Ratan A, Wotton D, Paschal BM. Induction of PARP7 Creates a Vulnerability for Growth Inhibition by RBN2397 in Prostate Cancer Cells. CANCER RESEARCH COMMUNICATIONS 2023; 3:592-606. [PMID: 37077937 PMCID: PMC10108886 DOI: 10.1158/2767-9764.crc-23-0086] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
The ADP-ribosyltransferase PARP7 modulates protein function by conjugating ADP-ribose to the side chains of acceptor amino acids. PARP7 has been shown to affect gene expression in prostate cancer cells and certain other cell types by mechanisms that include transcription factor ADP-ribosylation. Here, we use a recently developed catalytic inhibitor to PARP7, RBN2397, to study the effects of PARP7 inhibition in androgen receptor (AR)-positive and AR-negative prostate cancer cells. We find that RBN2397 has nanomolar potency for inhibiting androgen-induced ADP-ribosylation of the AR. RBN2397 inhibits the growth of prostate cancer cells in culture when cells are treated with ligands that activate the AR, or the aryl hydrocarbon receptor, and induce PARP7 expression. We show that the growth-inhibitory effects of RBN2397 are distinct from its enhancement of IFN signaling recently shown to promote tumor immunogenicity. RBN2397 treatment also induces trapping of PARP7 in a detergent-resistant fraction within the nucleus, which is reminiscent of how inhibitors such as talazoparib affect PARP1 compartmentalization. Because PARP7 is expressed in AR-negative metastatic tumors and RBN2397 can affect cancer cells through multiple mechanisms, PARP7 may be an actionable target in advanced prostate cancer. Significance RBN2397 is a potent and selective inhibitor of PARP7 that reduces the growth of prostate cancer cells, including a model for treatment-emergent neuroendocrine prostate cancer. RBN2397 induces PARP7 trapping on chromatin, suggesting its mechanism of action might be similar to clinically used PARP1 inhibitors.
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Affiliation(s)
- Chunsong Yang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Krzysztof Wierbiłowicz
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Natalia M. Dworak
- Advanced Microscopy Facility, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Song Yi Bae
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Sachi B. Tengse
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Nicki Abianeh
- Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Justin M. Drake
- Department of Pharmacology and Urology, Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Tarek Abbas
- Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Aakrosh Ratan
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - David Wotton
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Bryce M. Paschal
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia
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3
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Ji Y, Zhang R, Han X, Zhou J. Targeting the N-terminal domain of the androgen receptor: The effective approach in therapy of CRPC. Eur J Med Chem 2023; 247:115077. [PMID: 36587421 DOI: 10.1016/j.ejmech.2022.115077] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 12/31/2022]
Abstract
The androgen receptor (AR) is dominant in prostate cancer (PCa) pathology. Current therapeutic agents for advanced PCa include androgen synthesis inhibitors and AR antagonists that bind to the hormone binding pocket (HBP) at the ligand binding domain (LBD). However, AR amplification, AR splice variants (AR-Vs) expression, and intra-tumoral de novo synthesis of androgens result in the reactivation of AR signalling. The AR N-terminal domain (NTD) plays an essential role in AR transcriptional activity. The AR inhibitor targeting NTD could potentially block the activation of both full-length AR and AR-Vs, thus overcoming major resistance mechanisms to current treatments. This review discusses the progress of research in various NTD inhibitors and provides new insight into the development of AR-NTD inhibitors.
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Affiliation(s)
- Yang Ji
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China
| | - Rongyu Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China
| | - Xiaoli Han
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China
| | - Jinming Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China.
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4
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Mobisson SK, Ikpi DE, Wopara I, Obembe AO, Omotuyi O. Inhibition of human androgen receptor by delta 9-tetrahydro-cannabinol and cannabidiol related to reproductive dysfunction: A computational study. Andrologia 2022; 54:e14454. [PMID: 35524041 DOI: 10.1111/and.14454] [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: 03/11/2022] [Revised: 04/04/2022] [Accepted: 04/19/2022] [Indexed: 12/01/2022] Open
Abstract
There have been conflicting reports on the impact of Cannabis sativa impact on reproductive function. Hence this study was aimed to ascertain the impact of tetrahydrocannabinol (THC) and cannabidiol (CBD) binding affinity on human androgen receptor (AR) via computational molecular dynamic simulation. The human AR coordinate in this study is derived from human AR in complex with the ligand metribolone (R18) (PBD ID: 1E3G) template using (MODELER version. 9.15). CBD (PubChem CID: 644019), and THC (PubChem CID: 16078) 2D structures were retrieved from PubChem and docked (Autodock-Vina inbuilt in PyMol into the active site of human AR using the coordinates of the co-crystalized ligand (R18). All atomic representations in this study were created using visual molecular dynamics (VMD) tools. The result revealed that neither CBD nor THC bear significant 2D similarity with R18. Despite the diversity within the chemical space, both CBD and THC poses bond flexibility required to bind avidly to AR with the docking scores comparable to R18. In fully bound state, the three compounds engage the AR pocket hydrophobic residues such as L701, L704, and L707, and aromatic residues such as F764. Polar contacts with T877 observed in R18 bound state is avoided in the THC and CBD bound states. Moreso, the results revealed that CBD has lesser binding energy compared to THC and R18 compound which serves as standard. This study hypothesized that CBD and THC binds complimentarily to the pocket AR, indicating a likely inhibition of reproductive function and prostate cancer progression.
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Affiliation(s)
- Samuel Kelechi Mobisson
- Department of Human Physiology, Faculty of Basic Medical Sciences, Madonna University, Elele, Rivers State, Nigeria
| | - Daniel Ewa Ikpi
- Department of Human Physiology, Faculty of Basic Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Iheanyichukwu Wopara
- Department of Biochemistry, Faculty of Sciences, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria
| | - Agona Odey Obembe
- Department of Human Physiology, Faculty of Basic Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Olaposi Omotuyi
- Institute for Drug Research and Development, S.E. Bogoro Center, Afe Babalola University, Ado Ekiti, Nigeria
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5
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Miller KJ, Asim M. Unravelling the Role of Kinases That Underpin Androgen Signalling in Prostate Cancer. Cells 2022; 11:cells11060952. [PMID: 35326402 PMCID: PMC8946764 DOI: 10.3390/cells11060952] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 02/07/2023] Open
Abstract
The androgen receptor (AR) signalling pathway is the key driver in most prostate cancers (PCa), and is underpinned by several kinases both upstream and downstream of the AR. Many popular therapies for PCa that target the AR directly, however, have been circumvented by AR mutation, such as androgen receptor variants. Some upstream kinases promote AR signalling, including those which phosphorylate the AR and others that are AR-regulated, and androgen regulated kinase that can also form feed-forward activation circuits to promotes AR function. All of these kinases represent potentially druggable targets for PCa. There has generally been a divide in reviews reporting on pathways upstream of the AR and those reporting on AR-regulated genes despite the overlap that constitutes the promotion of AR signalling and PCa progression. In this review, we aim to elucidate which kinases—both upstream and AR-regulated—may be therapeutic targets and require future investigation and ongoing trials in developing kinase inhibitors for PCa.
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6
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Alhawas L, Amin KS, Salla B, Banerjee PP. T-LAK cell-originated protein kinase (TOPK) enhances androgen receptor splice variant (ARv7) and drives androgen-independent growth in prostate cancer. Carcinogenesis 2021; 42:423-435. [PMID: 33185682 DOI: 10.1093/carcin/bgaa120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/07/2020] [Indexed: 12/19/2022] Open
Abstract
Despite impressive advances in the treatment of prostate cancer with various efficacious inhibitors along the androgen/androgen receptor axis, eventual development of incurable metastatic Castration-Resistant Prostate Cancer (mCRPC) is inevitable and remains a major clinical challenge. Constitutively active androgen receptor (AR) spliced variants have emerged as primary means of resistance to anti-androgens and androgen synthesis inhibitors. The alternatively spliced AR variant, ARv7, has attracted significant interest due to its constitutively active status in CRPC that drives androgen-independence. Factors that are involved in regulating ARv7 levels in CRPC are not clearly known. We recently demonstrated that a protein kinase, T-LAK cell-originated protein kinase (TOPK) level correlates with the aggressiveness of prostate cancer and its invasive behavior. In this study, we investigated whether TOPK plays a role in driving androgen-independence in prostate cancer cells. Our data demonstrate that TOPK overexpression in androgen-dependent LNCaP and VCaP induces ARv7 and drives androgen-independent growth. On the other hand, pharmacological inhibition of TOPK in androgen-independent LNCaP95 and 22Rv1 represses AR transactivation, and AR stability. In summary, this study illustrates a direct role of TOPK in regulating ARv7 and driving androgen-independence in prostate cancer cells.
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MESH Headings
- Alternative Splicing
- Androgen Antagonists/pharmacology
- Androgen Antagonists/therapeutic use
- Androgens/metabolism
- Antineoplastic Agents, Hormonal/pharmacology
- Antineoplastic Agents, Hormonal/therapeutic use
- Antineoplastic Combined Chemotherapy Protocols/pharmacology
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Biomarkers, Tumor/analysis
- Biomarkers, Tumor/antagonists & inhibitors
- Biomarkers, Tumor/metabolism
- Cell Line, Tumor
- Disease-Free Survival
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Humans
- Inhibitory Concentration 50
- Male
- Mitogen-Activated Protein Kinase Kinases/analysis
- Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors
- Mitogen-Activated Protein Kinase Kinases/metabolism
- Neoplasm Recurrence, Local/epidemiology
- Neoplasm Recurrence, Local/genetics
- Neoplasm Recurrence, Local/prevention & control
- Prognosis
- Prostate/pathology
- Prostatic Neoplasms, Castration-Resistant/drug therapy
- Prostatic Neoplasms, Castration-Resistant/genetics
- Prostatic Neoplasms, Castration-Resistant/mortality
- Prostatic Neoplasms, Castration-Resistant/pathology
- Protein Kinase Inhibitors/pharmacology
- Protein Kinase Inhibitors/therapeutic use
- Quinolones/pharmacology
- Quinolones/therapeutic use
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Thiophenes/pharmacology
- Thiophenes/therapeutic use
- Transcriptional Activation/drug effects
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Affiliation(s)
| | | | | | - Partha P Banerjee
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, DC, USA
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7
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Yang CS, Jividen K, Kamata T, Dworak N, Oostdyk L, Remlein B, Pourfarjam Y, Kim IK, Du KP, Abbas T, Sherman NE, Wotton D, Paschal BM. Androgen signaling uses a writer and a reader of ADP-ribosylation to regulate protein complex assembly. Nat Commun 2021; 12:2705. [PMID: 33976187 PMCID: PMC8113490 DOI: 10.1038/s41467-021-23055-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 04/14/2021] [Indexed: 02/03/2023] Open
Abstract
Androgen signaling through the androgen receptor (AR) directs gene expression in both normal and prostate cancer cells. Androgen regulates multiple aspects of the AR life cycle, including its localization and post-translational modification, but understanding how modifications are read and integrated with AR activity has been difficult. Here, we show that ADP-ribosylation regulates AR through a nuclear pathway mediated by Parp7. We show that Parp7 mono-ADP-ribosylates agonist-bound AR, and that ADP-ribosyl-cysteines within the N-terminal domain mediate recruitment of the E3 ligase Dtx3L/Parp9. Molecular recognition of ADP-ribosyl-cysteine is provided by tandem macrodomains in Parp9, and Dtx3L/Parp9 modulates expression of a subset of AR-regulated genes. Parp7, ADP-ribosylation of AR, and AR-Dtx3L/Parp9 complex assembly are inhibited by Olaparib, a compound used clinically to inhibit poly-ADP-ribosyltransferases Parp1/2. Our study reveals the components of an androgen signaling axis that uses a writer and reader of ADP-ribosylation to regulate protein-protein interactions and AR activity.
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Affiliation(s)
- Chun-Song Yang
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Kasey Jividen
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
| | - Teddy Kamata
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Natalia Dworak
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
| | - Luke Oostdyk
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Bartlomiej Remlein
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Yasin Pourfarjam
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, USA
| | - In-Kwon Kim
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, USA
| | - Kang-Ping Du
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA
| | - Tarek Abbas
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA
| | - Nicholas E Sherman
- W. M. Keck Biomedical Mass Spectrometry Laboratory, University of Virginia, Charlottesville, VA, USA
| | - David Wotton
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Bryce M Paschal
- Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA.
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.
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8
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Hao J, Ci X, Wang Y, Choi SYC, Sullivan SE, Xue H, Wu R, Dong X, Haegert AM, Collins CC, Lin D, Wang Y. GRB10 sustains AR activity by interacting with PP2A in prostate cancer cells. Int J Cancer 2020; 148:469-480. [PMID: 33038264 DOI: 10.1002/ijc.33335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/06/2020] [Accepted: 09/30/2020] [Indexed: 01/22/2023]
Abstract
Prostate cancer (PCa) progression is driven by androgen receptor (AR) signaling. Unfortunately, androgen-deprivation therapy and the use of even more potent AR pathway inhibitors (ARPIs) cannot bring about a cure. ARPI resistance (ie, castration-resistant PCa, CRPC) will inevitably develop. Previously, we demonstrated that GRB10 is an AR transcriptionally repressed gene that functionally contributes to CRPC development and ARPI resistance. GRB10 expression is elevated prior to CRPC development in our patient-derived xenograft models and is significantly upregulated in clinical CRPC samples. Here, we analyzed transcriptomic data from GRB10 knockdown in PCa cells and found that AR signaling is downregulated. While the mRNA expression of AR target genes decreased upon GRB10 knockdown, AR expression was not affected at the mRNA or protein level. We further found that phosphorylation of AR serine 81 (S81), which is critical for AR transcriptional activity, is decreased by GRB10 knockdown and increased by its overexpression. Luciferase assay using GRB10-knockdown cells also indicate reduced AR activity. Immunoprecipitation coupled with mass spectrometry revealed an interaction between GRB10 and the PP2A complex, which is a known phosphatase of AR. Further validations and analyses showed that GRB10 binds to the PP2Ac catalytic subunit with its PH domain. Mechanistically, GRB10 knockdown increased PP2Ac protein stability, which in turn decreased AR S81 phosphorylation and reduced AR activity. Our findings indicate a reciprocal feedback between GRB10 and AR signaling, implying the importance of GRB10 in PCa progression.
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Affiliation(s)
- Jun Hao
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Xinpei Ci
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Yong Wang
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Urology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Stephen Yiu Chuen Choi
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Sarah E Sullivan
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Kinesiology and Physical Education, McGill University, Quebec, Canada
| | - Hui Xue
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Rebecca Wu
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Xin Dong
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Anne M Haegert
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin C Collins
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dong Lin
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Yuzhuo Wang
- Vancouver Prostate Centre, Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
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9
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Wen S, Niu Y, Huang H. Posttranslational regulation of androgen dependent and independent androgen receptor activities in prostate cancer. Asian J Urol 2019; 7:203-218. [PMID: 33024699 PMCID: PMC7525085 DOI: 10.1016/j.ajur.2019.11.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 08/21/2019] [Accepted: 10/11/2019] [Indexed: 12/12/2022] Open
Abstract
Prostate cancer (PCa) is the most commonly diagnosed cancer among men in western countries. Androgen receptor (AR) signaling plays key roles in the development of PCa. Androgen deprivation therapy (ADT) remains the standard therapy for advanced PCa. In addition to its ligand androgen, accumulating evidence indicates that posttranscriptional modification is another important mechanism to regulate AR activities during the progression of PCa, especially in castration resistant prostate cancer (CRPC). To date, a number of posttranscriptional modifications of AR have been identified, including phosphorylation (e.g. by CDK1), acetylation (e.g. by p300 and recognized by BRD4), methylation (e.g. by EZH2), ubiquitination (e.g. by SPOP), and SUMOylation (e.g. by PIAS1). These modifications are essential for the maintenance of protein stability, nuclear localization and transcriptional activity of AR. This review summarizes posttranslational modifications that influence androgen-dependent and -independent activities of AR, PCa progression and therapy resistance. We further emphasize that in addition to androgen, posttranslational modification is another important way to regulate AR activity, suggesting that targeting AR posttranslational modifications, such as proteolysis targeting chimeras (PROTACs) of AR, represents a potential and promising alternate for effective treatment of CRPC. Potential areas to be investigated in the future in the field of AR posttranslational modifications are also discussed.
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Affiliation(s)
- Simeng Wen
- Department of Urology, The Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin Medical University, Tianjin, China.,Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine and Science, Rochester, USA
| | - Yuanjie Niu
- Department of Urology, The Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin Medical University, Tianjin, China
| | - Haojie Huang
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine and Science, Rochester, USA.,Department of Urology, Mayo Clinic College of Medicine and Science, Rochester, USA.,Mayo Clinic Cancer Center, Mayo Clinic College of Medicine and Science, Rochester, USA
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10
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Agbo L, Lambert JP. Proteomics contribution to the elucidation of the steroid hormone receptors functions. J Steroid Biochem Mol Biol 2019; 192:105387. [PMID: 31173874 DOI: 10.1016/j.jsbmb.2019.105387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 10/26/2022]
Abstract
Steroid hormones have far-ranging biological impacts and more are continuously being uncovered. Over the last decades, proteomics approaches have become key to better understand biological processes. Due to multiple technical breakthroughs allowing for the concurrent identification and/or quantification of thousands of analytes using mass spectrometers, researchers employing proteomics tools today can now obtain truly holistic views of multiple facets of the human proteome. Here, we review how the field of proteomics has contributed to discoveries about steroid hormones, their receptors and their impact on human pathologies. In particular, the involvement of steroid receptors in cancer initiation, development, metastasis and treatment will be highlighted. Techniques at the forefront of the proteomics field will also be discussed to present how they can contribute to a better understanding of steroid hormone receptors.
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Affiliation(s)
- Lynda Agbo
- Department of Molecular Medicine and Cancer Research Centre, Université Laval, Québec, QC, Canada; Research Center CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada
| | - Jean-Philippe Lambert
- Department of Molecular Medicine and Cancer Research Centre, Université Laval, Québec, QC, Canada; Research Center CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada.
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11
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McClinch K, Avelar RA, Callejas D, Izadmehr S, Wiredja D, Perl A, Sangodkar J, Kastrinsky DB, Schlatzer D, Cooper M, Kiselar J, Stachnik A, Yao S, Hoon D, McQuaid D, Zaware N, Gong Y, Brautigan DL, Plymate SR, Sprenger CCT, Oh WK, Levine AC, Kirschenbaum A, Sfakianos JP, Sears R, DiFeo A, Ioannou Y, Ohlmeyer M, Narla G, Galsky MD. Small-Molecule Activators of Protein Phosphatase 2A for the Treatment of Castration-Resistant Prostate Cancer. Cancer Res 2018; 78:2065-2080. [PMID: 29358171 DOI: 10.1158/0008-5472.can-17-0123] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/13/2017] [Accepted: 01/17/2018] [Indexed: 02/01/2023]
Abstract
Primary prostate cancer is generally treatable by androgen deprivation therapy, however, later recurrences of castrate-resistant prostate cancer (CRPC) that are more difficult to treat nearly always occur due to aberrant reactivation of the androgen receptor (AR). In this study, we report that CRPC cells are particularly sensitive to the growth-inhibitory effects of reengineered tricyclic sulfonamides, a class of molecules that activate the protein phosphatase PP2A, which inhibits multiple oncogenic signaling pathways. Treatment of CRPC cells with small-molecule activators of PP2A (SMAP) in vitro decreased cellular viability and clonogenicity and induced apoptosis. SMAP treatment also induced an array of significant changes in the phosphoproteome, including most notably dephosphorylation of full-length and truncated isoforms of the AR and downregulation of its regulatory kinases in a dose-dependent and time-dependent manner. In murine xenograft models of human CRPC, the potent compound SMAP-2 exhibited efficacy comparable with enzalutamide in inhibiting tumor formation. Overall, our results provide a preclinical proof of concept for the efficacy of SMAP in AR degradation and CRPC treatment.Significance: A novel class of small-molecule activators of the tumor suppressor PP2A, a serine/threonine phosphatase that inhibits many oncogenic signaling pathways, is shown to deregulate the phosphoproteome and to destabilize the androgen receptor in advanced prostate cancer. Cancer Res; 78(8); 2065-80. ©2018 AACR.
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Affiliation(s)
- Kimberly McClinch
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rita A Avelar
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio
| | - David Callejas
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Sudeh Izadmehr
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Danica Wiredja
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Abbey Perl
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Jaya Sangodkar
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - David B Kastrinsky
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio
| | - Daniela Schlatzer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Maxwell Cooper
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Janna Kiselar
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Agnes Stachnik
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Shen Yao
- Department of Medicine, Division of Endocrine, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Divya Hoon
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Daniel McQuaid
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Nilesh Zaware
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio
| | - Yixuan Gong
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - David L Brautigan
- Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Stephen R Plymate
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Cynthia C T Sprenger
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - William K Oh
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Alice C Levine
- Department of Medicine, Division of Endocrine, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, New York
| | | | - John P Sfakianos
- Department of Urology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rosalie Sears
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon
| | - Analisa DiFeo
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio
| | - Yiannis Ioannou
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Michael Ohlmeyer
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio
| | - Goutham Narla
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio.
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio
| | - Matthew D Galsky
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York.
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12
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Grey J, Jones D, Wilson L, Nakjang S, Clayton J, Temperley R, Clark E, Gaughan L, Robson C. Differential regulation of the androgen receptor by protein phosphatase regulatory subunits. Oncotarget 2018; 9:3922-3935. [PMID: 29423094 PMCID: PMC5790511 DOI: 10.18632/oncotarget.22883] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 11/09/2017] [Indexed: 11/25/2022] Open
Abstract
The Androgen Receptor (AR) is a key molecule in the development, maintenance and progression of prostate cancer (PC). However, the relationship between the AR and co-regulatory proteins that facilitate AR activity in castrate resistant settings remain understudied. Here we show that protein phosphatase 1 regulatory subunits, identified from a phosphatase RNAi screen, direct PP1 catalytic subunits to a varied yet significant response in AR function. As such, we have characterised the PP1β holoenzyme, myosin phosphatase (MLCP), as a novel ligand independent regulator of the AR. Sustained MLCP activity through down-regulation of the MLCP inhibitory subunit, PPP1R14C, results in impaired AR nuclear translocation, protein stability and transcriptional activity in distinct models of PC progression, culminating in restoration of a non-malignant prostate genotype. Phenotypically, a marked reduction in cell proliferation and migration, characterised by G1 cell cycle arrest is observed, confirming PP1 holoenzyme disruption as a novel treatment approach in PC.
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Affiliation(s)
- James Grey
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Dominic Jones
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Laura Wilson
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Sirintra Nakjang
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Jake Clayton
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Richard Temperley
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Emma Clark
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Luke Gaughan
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Craig Robson
- Northern Institute for Cancer Research, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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13
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Goicochea NL, Garnovskaya M, Blanton MG, Chan G, Weisbart R, Lilly MB. Development of cell-penetrating bispecific antibodies targeting the N-terminal domain of androgen receptor for prostate cancer therapy†. Protein Eng Des Sel 2017; 30:785-793. [DOI: 10.1093/protein/gzx058] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Nancy L Goicochea
- Department of Medicine, Division of Hematology/Oncology, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas St., Charleston, SC 29425, USA
| | - Maria Garnovskaya
- Department of Medicine, Division of Hematology/Oncology, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas St., Charleston, SC 29425, USA
| | - Mary G Blanton
- Department of Medicine, Division of Hematology/Oncology, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas St., Charleston, SC 29425, USA
| | - Grace Chan
- Veterans Affairs Greater Los Angeles Health Care System, 16111 Plummer St., Sepulveda, CA 91343, USA
| | - Richard Weisbart
- Veterans Affairs Greater Los Angeles Health Care System, 16111 Plummer St., Sepulveda, CA 91343, USA
| | - Michael B Lilly
- Department of Medicine, Division of Hematology/Oncology, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas St., Charleston, SC 29425, USA
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14
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Liu X, Gao Y, Ye H, Gerrin S, Ma F, Wu Y, Zhang T, Russo J, Cai C, Yuan X, Liu J, Chen S, Balk SP. Positive feedback loop mediated by protein phosphatase 1α mobilization of P-TEFb and basal CDK1 drives androgen receptor in prostate cancer. Nucleic Acids Res 2017; 45:3738-3751. [PMID: 28062857 PMCID: PMC5397168 DOI: 10.1093/nar/gkw1291] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/25/2016] [Indexed: 01/05/2023] Open
Abstract
P-TEFb (CDK9/cyclin T) plays a central role in androgen receptor (AR)-mediated transactivation by phosphorylating both RNA polymerase 2 complex proteins and AR at S81. CDK9 dephosphorylation mobilizes P-TEFb from an inhibitory 7SK ribonucleoprotein complex, but mechanisms targeting phosphatases to P-TEFb are unclear. We show that AR recruits protein phosphatase 1α (PP1α), resulting in P-TEFb mobilization and CDK9-mediated AR S81 phosphorylation. This increased pS81 enhances p300 recruitment, histone acetylation, BRD4 binding and subsequent further recruitment of P-TEFb, generating a positive feedback loop that sustains transcription. AR S81 is also phosphorylated by CDK1, and blocking basal CDK1-mediated S81 phosphorylation markedly suppresses AR activity and initiation of this positive feedback loop. Finally, androgen-independent AR activity in castration-resistant prostate cancer (CRPC) cells is driven by increased CDK1-mediated S81 phosphorylation. Collectively these findings reveal a mechanism involving PP1α, CDK9 and CDK1 that is used by AR to initiate and sustain P-TEFb activity, which may be exploited to drive AR in CRPC.
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Affiliation(s)
- Xiaming Liu
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Yanfei Gao
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - HuiHui Ye
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Sean Gerrin
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Fen Ma
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Yiming Wu
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Tengfei Zhang
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Joshua Russo
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Changmeng Cai
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Xin Yuan
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Jihong Liu
- Department of Urology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shaoyong Chen
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Steven P Balk
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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15
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Abstract
Protein phosphatase 2A (PP2A) plays a critical multi-faceted role in the regulation of the cell cycle. It is known to dephosphorylate over 300 substrates involved in the cell cycle, regulating almost all major pathways and cell cycle checkpoints. PP2A is involved in such diverse processes by the formation of structurally distinct families of holoenzymes, which are regulated spatially and temporally by specific regulators. Here, we review the involvement of PP2A in the regulation of three cell signaling pathways: wnt, mTOR and MAP kinase, as well as the G1→S transition, DNA synthesis and mitotic initiation. These processes are all crucial for proper cell survival and proliferation and are often deregulated in cancer and other diseases.
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Affiliation(s)
- Nathan Wlodarchak
- a McArdle Laboratory for Cancer Research, University of Wisconsin-Madison , Madison , WI , USA
| | - Yongna Xing
- a McArdle Laboratory for Cancer Research, University of Wisconsin-Madison , Madison , WI , USA
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16
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Liu X, Han W, Gulla S, Simon NI, Gao Y, Cai C, Yang H, Zhang X, Liu J, Balk SP, Chen S. Protein phosphatase 1 suppresses androgen receptor ubiquitylation and degradation. Oncotarget 2016; 7:1754-64. [PMID: 26636645 PMCID: PMC4811495 DOI: 10.18632/oncotarget.6434] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/18/2015] [Indexed: 12/20/2022] Open
Abstract
The phosphoprotein phosphatases are emerging as important androgen receptor (AR) regulators in prostate cancer (PCa). We reported previously that the protein phosphatase 1 catalytic subunit (PP1α) can enhance AR activity by dephosphorylating a site in the AR hinge region (Ser650) and thereby decrease AR nuclear export. In this study we show that PP1α increases the expression of wildtype as well as an S650A mutant AR, indicating that it is acting through one or more additional mechanisms. We next show that PP1α binds primarily to the AR ligand binding domain and decreases its ubiquitylation and degradation. Moreover, we find that the PP1α inhibitor tautomycin increases phosphorylation of AR ubiquitin ligases including SKP2 and MDM2 at sites that enhance their activity, providing a mechanism by which PP1α may suppress AR degradation. Significantly, the tautomycin mediated decrease in AR expression was most pronounced at low androgen levels or in the presence of the AR antagonist enzalutamide. Consistent with this finding, the sensitivity of LNCaP and C4-2 PCa cells to tautomycin, as assessed by PSA synthesis and proliferation, was enhanced at low androgen levels or by treatment with enzalutamide. Together these results indicate that PP1α may contribute to stabilizing AR protein after androgen deprivation therapies, and that targeting PP1α or the AR-PP1α interaction may be effective in castration-resistant prostate cancer (CRPC).
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Affiliation(s)
- Xiaming Liu
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Weiwei Han
- Department of Urology, Union Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Sarah Gulla
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Nicholas I. Simon
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Yanfei Gao
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Changmeng Cai
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Hongmei Yang
- Department of Pathogen Biology, Tongji Medical School, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoping Zhang
- Department of Urology, Union Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jihong Liu
- Department of Urology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Steven P. Balk
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Shaoyong Chen
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
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17
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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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18
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Robitaille CN, Rivest P, Sanderson JT. Antiandrogenic mechanisms of pesticides in human LNCaP prostate and H295R adrenocortical carcinoma cells. Toxicol Sci 2014; 143:126-35. [PMID: 25324206 DOI: 10.1093/toxsci/kfu212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Several pesticides suspected or known to have endocrine disrupting effects were screened for pro- or antiandrogenic properties by determining their effects on proliferation, prostatic-specific antigen (PSA) secretion and androgen receptor (AR) expression, and AR phosphorylation in androgen-dependent LNCaP human prostate cancer cells, as well as on the expression and catalytic activity of the enzyme CYP17 in H295R human adrenocortical carcinoma cells, an in vitro model of steroidogenesis. Effects on SRD5A gene expression were determined in both cell lines. Benomyl, vinclozolin, and prochloraz, but not atrazine, concentration dependently (1-30 μM) decreased dihydrotestosterone (DHT)-stimulated proliferation of LNCaP cells. All pesticides except atrazine decreased DHT-stimulated PSA secretion, AR nuclear accumulation, and AR phosphorylation on serines 81 and 213 in LNCaP cells. Benomyl and prochloraz, but not vinclozolin or atrazine, decreased levels of CYP17 gene and protein expression, as well as catalytic activity in H295R cells. In the case of prochloraz, some of these effects corresponded with cytotoxicity. H295R cells expressed AR protein and SRD5A1, but not SRD5A2 transcripts. SRD5A1 gene expression in H295R cells was increased by 10 nM DHT, whereas in LNCaP cells significant induction was observed by 0.1 nM DHT. AR protein expression in H295R cells was not increased by DHT. Vinclozolin decreased DHT-induced SRD5A1 gene expression in LNCaP, but not H295R cells, indicating a functional difference of AR between the cell lines. In conclusion, pesticides may exert antiandrogenic effects through several mechanisms that are cell type-specific, including AR antagonism and down-regulation or catalytic inhibition of androgen biosynthetic enzymes, such as CYP17 and SRD5A1.
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Affiliation(s)
- Christina N Robitaille
- INRS-Institut Armand-Frappier, Université du Québec, 531 boulevard des Prairies, Laval, Quebec, Canada H7V 1B7
| | - Patricia Rivest
- INRS-Institut Armand-Frappier, Université du Québec, 531 boulevard des Prairies, Laval, Quebec, Canada H7V 1B7
| | - J Thomas Sanderson
- INRS-Institut Armand-Frappier, Université du Québec, 531 boulevard des Prairies, Laval, Quebec, Canada H7V 1B7
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19
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Koryakina Y, Ta HQ, Gioeli D. Androgen receptor phosphorylation: biological context and functional consequences. Endocr Relat Cancer 2014; 21:T131-45. [PMID: 24424504 PMCID: PMC4437516 DOI: 10.1530/erc-13-0472] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The androgen receptor (AR) is a ligand-regulated transcription factor that belongs to the family of nuclear receptors. In addition to regulation by steroid, the AR is also regulated by post-translational modifications generated by signal transduction pathways. Thus, the AR functions not only as a transcription factor but also as a node that integrates multiple extracellular signals. The AR plays an important role in many diseases, including complete androgen insensitivity syndrome, spinal bulbar muscular atrophy, prostate and breast cancer, etc. In the case of prostate cancer, dependence on AR signaling has been exploited for therapeutic intervention for decades. However, the effectiveness of these therapies is limited in advanced disease due to restoration of AR signaling. Greater understanding of the molecular mechanisms involved in AR action will enable the development of improved therapeutics to treat the wide range of AR-dependent diseases. The AR is subject to regulation by a number of kinases through post-translational modifications on serine, threonine, and tyrosine residues. In this paper, we review the AR phosphorylation sites, the kinases responsible for these phosphorylations, as well as the biological context and the functional consequences of these phosphorylations. Finally, what is known about the state of AR phosphorylation in clinical samples is discussed.
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Affiliation(s)
- Yulia Koryakina
- Department of MicrobiologyImmunology, and Cancer BiologyUVA Cancer CenterUniversity of Virginia, PO Box 800734, Charlottesville, Virginia 22908, USA
| | - Huy Q Ta
- Department of MicrobiologyImmunology, and Cancer BiologyUVA Cancer CenterUniversity of Virginia, PO Box 800734, Charlottesville, Virginia 22908, USA
| | - Daniel Gioeli
- Department of MicrobiologyImmunology, and Cancer BiologyUVA Cancer CenterUniversity of Virginia, PO Box 800734, Charlottesville, Virginia 22908, USADepartment of MicrobiologyImmunology, and Cancer BiologyUVA Cancer CenterUniversity of Virginia, PO Box 800734, Charlottesville, Virginia 22908, USA
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20
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Androgen induces a switch from cytoplasmic retention to nuclear import of the androgen receptor. Mol Cell Biol 2013; 33:4766-78. [PMID: 24100013 DOI: 10.1128/mcb.00647-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The androgen receptor (AR) has critical functions as a transcription factor in both normal and cancer cells, but the specific mechanisms that regulate its nuclear localization are not well defined. We found that an AR mutation commonly reported in prostate cancer generates an androgen-independent gain of function for nuclear import. The substitution, Thr877Ala, is within the ligand-binding domain, but the nuclear import gain of function is mediated by the bipartite nuclear localization signal (NLS) spanning the DNA-binding domain (DBD) and hinge region. Bipartite NLS activity depends on the structure provided by the DBD, and protein interactions with the bipartite NLS are repressed by the hinge region. The bipartite NLS is recognized by importin 7, a nuclear import receptor for several proteins. Importin 7 binding to AR, however, inhibits import by shielding the bipartite NLS. Androgen binding relieves the inhibition by inducing a switch that promotes exchange of importin 7 for karyopherin alpha import receptors. Importin 7 contributes to the regulation of AR import by restraining import until androgen is detected in the cytoplasm.
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21
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van der Steen T, Tindall DJ, Huang H. Posttranslational modification of the androgen receptor in prostate cancer. Int J Mol Sci 2013; 14:14833-59. [PMID: 23863692 PMCID: PMC3742275 DOI: 10.3390/ijms140714833] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/01/2013] [Accepted: 07/03/2013] [Indexed: 01/03/2023] Open
Abstract
The androgen receptor (AR) is important in the development of the prostate by regulating transcription, cellular proliferation, and apoptosis. AR undergoes posttranslational modifications that alter its transcription activity, translocation to the nucleus and stability. The posttranslational modifications that regulate these events are of utmost importance to understand the functional role of AR and its activity. The majority of these modifications occur in the activation function-1 (AF1) region of the AR, which contains the transcriptional activation unit 1 (TAU1) and 5 (TAU5). Identification of the modifications that occur to these regions may increase our understanding of AR activation in prostate cancer and the role of AR in the progression from androgen-dependent to castration-resistant prostate cancer (CRPC). Most of the posttranslational modifications identified to date have been determined using the full-length AR in androgen dependent cells. Further investigations into the role of posttranslational modifications in androgen-independent activation of full-length AR and constitutively active splicing variants are warranted, findings from which may provide new therapeutic options for CRPC.
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Affiliation(s)
- Travis van der Steen
- Department of Urology Research, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; E-Mails: (T.V.S.); (D.J.T.)
| | - Donald J. Tindall
- Department of Urology Research, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; E-Mails: (T.V.S.); (D.J.T.)
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Haojie Huang
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-507-284-0020; Fax: +1-507-293-3071
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22
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Abstract
The androgen receptor (AR) is a key molecule in prostate cancer and Kennedy's disease. Understanding the regulatory mechanisms of this steroid receptor is important in the development of potential therapies for these diseases. One layer of AR regulation is provided by post-translational modifications including phosphorylation, acetylation, sumoylation, ubiquitination and methylation. While these modifications have mostly been studied as individual events, it is becoming clear that these modifications can functionally interact with each other in a signalling pathway. In this review, the effects of all modifications are described with a focus on interplay between them and the functional consequences for the AR.
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Affiliation(s)
- Kelly Coffey
- Solid Tumour Target Discovery Group, The Medical School, Newcastle Cancer Centre at the Northern Institute for Cancer Research, Newcastle University, Framlington Place, Newcastle upon Tyne, Tyne and Wear, UK
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23
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Karacosta LG, Foster BA, Azabdaftari G, Feliciano DM, Edelman AM. A regulatory feedback loop between Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) and the androgen receptor in prostate cancer progression. J Biol Chem 2012; 287:24832-43. [PMID: 22654108 DOI: 10.1074/jbc.m112.370783] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The androgen receptor (AR) plays a critical role in prostate cancer (PCa) progression, however, the molecular mechanisms by which the AR regulates cell proliferation in androgen-dependent and castration-resistant PCa are incompletely understood. We report that Ca(2+)/calmodulin-dependent kinase kinase 2 (CaMKK2) expression increases and becomes nuclear or perinuclear in advanced PCa. In the TRAMP (transgenic adenocarcinoma of mouse prostate) model of PCa, CaMKK2 expression increases with PCa progression with many cells exhibiting nuclear staining. CaMKK2 expression is higher in human castration-resistant tumor xenografts compared with androgen-responsive xenografts and is markedly higher in the AR-expressing, tumorigenic cell line LNCaP compared with cell lines that are AR-nonexpressing and/or nontumorigenic. In LNCaP cells, dihydrotestosterone induced CaMKK2 mRNA and protein expression and translocation of CaMKK2 to the nucleus. Conversely, androgen withdrawal suppressed CaMKK2 expression. Knockdown of CaMKK2 expression by RNAi reduced LNCaP cell proliferation and increased percentages of cells in G(1) phase, whereas correspondingly reducing percentages in S phase, of the cell cycle. CaMKK2 knockdown reduced expression of the AR target gene prostate-specific antigen at both mRNA and protein levels, AR transcriptional activity driven by androgen responsive elements from the prostate-specific probasin gene promoter and levels of the AR-regulated cell cycle proteins, cyclin D1 and hyperphosphorylated Rb. Our results suggest that in PCa progression, CaMKK2 and the AR are in a feedback loop in which CaMKK2 is induced by the AR to maintain AR activity, AR-dependent cell cycle control, and continued cell proliferation.
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Affiliation(s)
- Loukia G Karacosta
- Department of Pharmacology and Toxicology, State University of New York, Buffalo, New York 14214, USA
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24
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Gioeli D, Paschal BM. Post-translational modification of the androgen receptor. Mol Cell Endocrinol 2012; 352:70-8. [PMID: 21820033 DOI: 10.1016/j.mce.2011.07.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/30/2011] [Accepted: 07/01/2011] [Indexed: 01/01/2023]
Abstract
Regulation of the androgen receptor (AR) by its cognate ligand is well established, but how post-translational modification modulates AR activity is only emerging. The AR is subject to modification by phosphorylation, acetylation, methylation, SUMOylation, and ubiquitination. As several of the enzymes that modify the AR are altered in prostate cancer, defining the context and physiological effects of these modifications could provide insight into mechanisms that underpin human disease. Here, we review how post-translational modification contributes to AR function as a transcription factor with particular emphasis on phosphorylation and dephosphorylation mechanisms.
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Affiliation(s)
- Daniel Gioeli
- Department of Microbiology, University of Virginia, Charlottesville, Virginia, USA
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25
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Retention and transmission of active transcription memory from progenitor to progeny cells via ligand-modulated transcription factors: elucidation of a concept by BIOPIT model. Cell Biol Int 2012; 36:177-82. [DOI: 10.1042/cbi20090329] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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26
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Sukhwal A, Bhattacharyya M, Vishveshwara S. Network approach for capturing ligand-induced subtle global changes in protein structures. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2011; 67:429-39. [PMID: 21543845 DOI: 10.1107/s0907444911007062] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 02/24/2011] [Indexed: 01/12/2023]
Abstract
Ligand-induced conformational changes in proteins are of immense functional relevance. It is a major challenge to elucidate the network of amino acids that are responsible for the percolation of ligand-induced conformational changes to distal regions in the protein from a global perspective. Functionally important subtle conformational changes (at the level of side-chain noncovalent interactions) upon ligand binding or as a result of environmental variations are also elusive in conventional studies such as those using root-mean-square deviations (r.m.s.d.s). In this article, the network representation of protein structures and their analyses provides an efficient tool to capture these variations (both drastic and subtle) in atomistic detail in a global milieu. A generalized graph theoretical metric, using network parameters such as cliques and/or communities, is used to determine similarities or differences between structures in a rigorous manner. The ligand-induced global rewiring in the protein structures is also quantified in terms of network parameters. Thus, a judicious use of graph theory in the context of protein structures can provide meaningful insights into global structural reorganizations upon perturbation and can also be helpful for rigorous structural comparison. Data sets for the present study include high-resolution crystal structures of serine proteases from the S1A family and are probed to quantify the ligand-induced subtle structural variations.
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Affiliation(s)
- Anshul Sukhwal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
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27
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Abstract
Over 50 years of polyomavirus research has produced a wealth of insights into not only general biologic processes in mammalian cells, but also, how conditions can be altered and signaling systems tweaked to produce transformation phenotypes. In the past few years three new members (KIV, WUV, and MCV) have joined two previously known (JCV and BKV) human polyomaviruses. In this review, we present updated information on general virologic features of these polyomaviruses in their natural host, concentrating on the association of MCV with human Merkel cell carcinoma. We further present a discussion on advances made in SV40 as the prototypic model, which has and will continue to inform our understanding about viruses and cancer.
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Affiliation(s)
- Ole Gjoerup
- Cancer Virology Program, Hillman Cancer Research Pavilion, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
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28
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McEwan IJ, McGuinness D, Hay CW, Millar RP, Saunders PTK, Fraser HM. Identification of androgen receptor phosphorylation in the primate ovary in vivo. Reproduction 2010; 140:93-104. [PMID: 20406952 PMCID: PMC2892820 DOI: 10.1530/rep-10-0140] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The androgen receptor (AR) is a member of the nuclear receptor superfamily, and is important for both male and female reproductive health. The receptor is a target for a number of post-translational modifications including phosphorylation, which has been intensively studied in vitro. However, little is known about the phosphorylation status of the receptor in target tissues in vivo. The common marmoset is a useful model for studying human reproductive functions, and comparison of the AR primary sequence from this primate shows high conservation of serines known to be phosphorylated in the human receptor and corresponding flanking amino acids. We have used a panel of phosphospecific antibodies to study AR phosphorylation in the marmoset ovary throughout the follicular phase and after treatment with GNRH antagonist or testosterone propionate. In normal follicular phase ovaries, total AR (both phosphorylated and non-phosphorylated forms) immunopositive staining was observed in several cell types including granulosa cells of developing follicles, theca cells and endothelial cells lining blood vessels. Receptor phosphorylation at serines 81, 308, and 650 was detected primarily in the granulosa cells of developing follicles, surface epithelium, and vessel endothelial cells. Testosterone treatment lead to a modest increase in AR staining in all stages of follicle studied, while GNRH antagonist had no effect. Neither treatment significantly altered the pattern of phosphorylation compared to the control group. These results demonstrate that phosphorylation of the AR occurs, at a subset of serine residues, in a reproductive target tissue in vivo, which appears refractory to hormonal manipulations.
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Affiliation(s)
- Iain J McEwan
- MRC Human Reproductive Sciences Unit, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, Scotland, UK.
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29
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FKBP51 promotes assembly of the Hsp90 chaperone complex and regulates androgen receptor signaling in prostate cancer cells. Mol Cell Biol 2010; 30:1243-53. [PMID: 20048054 DOI: 10.1128/mcb.01891-08] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prostate cancer progression to the androgen-independent (AI) state involves acquisition of pathways that allow tumor growth under low-androgen conditions. We hypothesized that expression of molecular chaperones that modulate androgen binding to AR might be altered in prostate cancer and contribute to progression to the AI state. Here, we report that the Hsp90 cochaperone FKBP51 is upregulated in LAPC-4 AI tumors grown in castrated mice and describe a molecular mechanism by which FKBP51 regulates AR activity. Using recombinant proteins, we show that FKBP51 stimulates recruitment of the cochaperone p23 to the ATP-bound form of Hsp90, forming an FKBP51-Hsp90-p23 superchaperone complex. In cells, FKBP51 expression promotes superchaperone complex association with AR and increases the number of AR molecules that undergo androgen binding. FKBP51 stimulates androgen-dependent transcription and cell growth, and FKBP51 is part of a positive feedback loop that is regulated by AR and androgen. Finally, depleting FKBP51 levels by short hairpin RNA reduces the transcript levels of genes regulated by AR and androgen. Because the superchaperone complex plays a critical role in determining the ligand-binding competence and transcription function of AR, it provides an attractive target for inhibiting AR activity in prostate cancer cells.
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30
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Chen S, Kesler CT, Paschal BM, Balk SP. Androgen receptor phosphorylation and activity are regulated by an association with protein phosphatase 1. J Biol Chem 2009; 284:25576-84. [PMID: 19622840 DOI: 10.1074/jbc.m109.043133] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Androgen receptor (AR) is phosphorylated at multiple sites in response to ligand binding, but the functional consequences and mechanisms regulating AR phosphorylation remain to be established. We observed initially that okadaic acid, an inhibitor of the major PPP family serine/threonine phosphatases PP2A and protein phosphatase 1 (PP1), had cell type-dependent effects on AR expression. More specific inhibitors of PP2A (fostriecin) and PP1 (tautomycin and siRNA against the PP1alpha catalytic subunit) demonstrated that PP1 and protein phosphatase 2A had opposite effects on AR protein and transcriptional activity. PP1 inhibition enhanced proteasome-mediated AR degradation, while PP1alpha overexpression increased AR expression and markedly enhanced AR transcriptional activity. Coprecipitation experiments demonstrated an AR-PP1 interaction, while immunofluorescence and nuclear-cytoplasmic fractionation showed androgen-stimulated nuclear translocation of both AR and PP1 in prostate cancer cells. Studies with phosphospecific AR antibodies showed that PP1 inhibition dramatically increased phosphorylation of Ser-650, a site in the AR hinge region shown to mediate nuclear export. Significantly, PP1 inhibition caused a marked decrease in nuclear localization of the wild-type AR, but did not alter total or nuclear levels of a S650A mutant AR. These findings reveal a critical role of PP1 in regulating AR protein stability and nuclear localization through dephosphorylation of Ser-650. Moreover, AR may function as a PP1 regulatory subunit and mediate PP1 recruitment to chromatin, where it can modulate transcription and splicing.
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Affiliation(s)
- Shaoyong Chen
- Cancer Biology Program, Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
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31
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Zheng B, Han M, Bernier M, Wen JK. Nuclear actin and actin-binding proteins in the regulation of transcription and gene expression. FEBS J 2009; 276:2669-85. [PMID: 19459931 PMCID: PMC2978034 DOI: 10.1111/j.1742-4658.2009.06986.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nuclear actin is involved in the transcription of all three RNA polymerases, in chromatin remodeling and in the formation of heterogeneous nuclear ribonucleoprotein complexes, as well as in recruitment of the histone modifier to the active gene. In addition, actin-binding proteins (ABPs) control actin nucleation, bundling, filament capping, fragmentation and monomer availability in the cytoplasm. In recent years, more and more attention has focused on the role of actin and ABPs in the modulation of the subcellular localization of transcriptional regulators. This review focuses on recent developments in the study of transcription and transcriptional regulation by nuclear actin, and the regulation of muscle-specific gene expression, nuclear receptor and transcription complexes by ABPs. Among the ABPs, striated muscle activator of Rho signaling and actin-binding LIM protein regulate actin dynamics and serum response factor-dependent muscle-specific gene expression. Functionally and structurally unrelated cytoplasmic ABPs interact cooperatively with nuclear receptor and regulate its transactivation. Furthermore, ABPs also participate in the formation of transcription complexes.
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Affiliation(s)
- Bin Zheng
- Department of Biochemistry and Molecular Biology, Hebei Medical University, Shijiazhuang, China
| | - Mei Han
- Department of Biochemistry and Molecular Biology, Hebei Medical University, Shijiazhuang, China
| | - Michel Bernier
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Jin-kun Wen
- Department of Biochemistry and Molecular Biology, Hebei Medical University, Shijiazhuang, China
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32
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Murphy LC, Skliris GP, Rowan BG, Al-Dhaheri M, Williams C, Penner C, Troup S, Begic S, Parisien M, Watson PH. The relevance of phosphorylated forms of estrogen receptor in human breast cancer in vivo. J Steroid Biochem Mol Biol 2009; 114:90-5. [PMID: 19429437 DOI: 10.1016/j.jsbmb.2009.01.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 01/21/2009] [Indexed: 10/21/2022]
Abstract
Estrogen receptor (ER)alpha activity is regulated by phosphorylation at several sites. Recently several antibodies specific for individual phosphorylated sites within ERalpha have became available. Validation and use of these antibodies suggests that several forms of phosphorylated ERalpha can be detected in multiple ER+ human breast tumor samples, thus providing relevance for investigating the regulation and function of phosphorylated ERalpha in human breast cancer. Generally, the phosphorylated ERalpha isoforms are associated with parameters that suggest that they are markers of an intact estrogen dependent signaling pathway and better clinical outcome with respect to tamoxifen therapy. Profiling of phosphorylated ERalpha may provide better biomarkers of endocrine therapy response over and above those currently available.
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Affiliation(s)
- Leigh C Murphy
- Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba, Canada.
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33
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Immunohistochemical validation of multiple phospho-specific epitopes for estrogen receptor alpha (ERalpha) in tissue microarrays of ERalpha positive human breast carcinomas. Breast Cancer Res Treat 2008; 118:443-53. [PMID: 19104930 DOI: 10.1007/s10549-008-0267-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 12/04/2008] [Indexed: 10/21/2022]
Abstract
Estrogen receptor alpha (ERalpha) activity is regulated by phosphorylation at several sites. Recently several antibodies specific for individual phosphorylated sites within ERalpha have became available. Such antibodies potentially provide invaluable tools to gain insight into the relevance in vivo of phosphorylated ERalpha in human breast tumors. However, validation of these antibodies for immunohistochemistry in particular is necessary in the first instance. In this study we have investigated the usefulness of several antibodies generated to specific phosphorylated sites within ERalpha for immunohistochemistry of formalin-fixed, paraffin-embedded human breast cancer biopsy samples. As well, these data demonstrate for the first time, the detection of multiple phosphorylated ERalpha forms in breast cancer (P-S104/106-ERalpha, P-S118-ERalpha, P-S167-ERalpha, P-S282-ERalpha, P-S294-ERalpha, P-T311-ERalpha, and P-S559-ERalpha) suggesting the possibility that profiling of phosphorylated ERalpha isoforms might be useful in selecting subgroups of breast cancer patients that would benefit from endocrine therapy.
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34
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Campbell LA, Faivre EJ, Show MD, Ingraham JG, Flinders J, Gross JD, Ingraham HA. Decreased recognition of SUMO-sensitive target genes following modification of SF-1 (NR5A1). Mol Cell Biol 2008; 23:292-307. [PMID: 19116244 DOI: 10.1210/me.2008-0219] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
SUMO modification of nuclear receptors, including the constitutively active receptor steroidogenic factor 1 (SF-1; NR5A1), is proposed to repress their transcriptional activity. We examined the functional and structural consequences of SF-1 sumoylation at two conserved lysines (Lys119 and Lys194) that reside adjacent to the DNA-binding domain (DBD) and ligand-binding domain (LBD), respectively. Surprisingly, while previous loss-of-function studies predicted that sumoylation at Lys194 would greatly impact SF-1 function, the conformation and coregulator recruitment of fully sumoylated SF-1 LBD protein was either unchanged or modestly impaired. Sumoylation at Lys194 also modestly reduced Ser203 phosphorylation. In contrast to these findings, sumoylation of the DBD at Lys119 resulted in a marked and selective loss of DNA binding to noncanonical SF-1 targets, such as inhibinalpha; this binding deficit was extended to all sites when the sumoylated human mutant (R92Q) protein, which exhibits lower activity, was used. Consistent with this result, the K119R mutant, compared to wild-type SF-1, was selectively recruited to a "SUMO-sensitive" site in the endogenous inhibinalpha promoter, leading to increased transcription. DNA binding and sumoylation of Lys119 appeared to be mutually exclusive, suggesting that once SF-1 is bound to DNA, sumoylation may be less important in regulating SF-1 activity. We propose that sumoylation of nuclear receptors imposes an active posttranslational mark that dampens recognition of SUMO-sensitive target genes to restrain their expression.
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Affiliation(s)
- Lioudmila A Campbell
- Department of Cellular and Molecular Pharmacology and Physiology, University of California, San Francisco, Box 0444, San Francisco, CA 94143-2611, USA
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35
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Narayanan R, Coss CC, Yepuru M, Kearbey JD, Miller DD, Dalton JT. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways. Mol Endocrinol 2008; 22:2448-65. [PMID: 18801930 DOI: 10.1210/me.2008-0160] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.
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Affiliation(s)
- Ramesh Narayanan
- Preclinical Research and Development, GTx, Inc., 3 North Dunlap Street, Memphis, Tennessee 38163, USA
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36
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Eichhorn PJA, Creyghton MP, Bernards R. Protein phosphatase 2A regulatory subunits and cancer. Biochim Biophys Acta Rev Cancer 2008; 1795:1-15. [PMID: 18588945 DOI: 10.1016/j.bbcan.2008.05.005] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 05/20/2008] [Accepted: 05/21/2008] [Indexed: 01/06/2023]
Abstract
The serine/threonine protein phosphatase (PP2A) is a trimeric holoenzyme that plays an integral role in the regulation of a number of major signaling pathways whose deregulation can contribute to cancer. The specificity and activity of PP2A are highly regulated through the interaction of a family of regulatory B subunits with the substrates. Accumulating evidence indicates that PP2A acts as a tumor suppressor. In this review we summarize the known effects of specific PP2A holoenzymes and their roles in cancer relevant pathways. In particular we highlight PP2A function in the regulation of MAPK and Wnt signaling.
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Affiliation(s)
- Pieter J A Eichhorn
- Division of Molecular Carcinogenesis, Center for Cancer Genomics and Center for Biomedical Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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37
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Shank LC, Kelley JB, Gioeli D, Yang CS, Spencer A, Allison LA, Paschal BM. Activation of the DNA-dependent protein kinase stimulates nuclear export of the androgen receptor in vitro. J Biol Chem 2008; 283:10568-80. [PMID: 18270197 DOI: 10.1074/jbc.m800810200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The androgen receptor undergoes nuclear import in response to ligand, but the mechanism by which it undergoes nuclear export is poorly understood. We developed a permeabilized cell assay to characterize nuclear export of the androgen receptor in LNCaP prostate cancer cells. We found that nuclear export of endogenous androgen receptor can be stimulated by short double-stranded DNA oligonucleotides. This androgen receptor export pathway is dependent on ATP hydrolysis and is enhanced by phosphatase inhibition with okadaic acid. Fluorescence recovery after photobleaching in permeabilized cells, under the conditions that stimulate androgen receptor export, suggested that double-stranded DNA-dependent export does not simply reflect the relief of a nuclear retention mechanism. A radiolabeled androgen was used to show that the androgen receptor remains ligand-bound during translocation through the nuclear pore complex. A specific inhibitor to the DNA-dependent protein kinase, NU7026, inhibits androgen receptor export and phosphorylation. In living cells, NU7026 treatment increases androgen-dependent transcription from endogenous genes that are regulated by androgen receptor. We suggest that DNA-dependent protein kinase phosphorylation of the androgen receptor, or an interacting component, helps target the androgen receptor for export from the nucleus.
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Affiliation(s)
- Leonard C Shank
- Center for Cell Signaling, Department of Biochemistry and Molecular Genetics, and Cancer Center, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
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38
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Weigel NL, Moore NL. Steroid receptor phosphorylation: a key modulator of multiple receptor functions. Mol Endocrinol 2007; 21:2311-9. [PMID: 17536004 DOI: 10.1210/me.2007-0101] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Steroid receptors are hormone-activated transcription factors, the expression and activities of which are also highly dependent upon posttranslational modifications including phosphorylation. The remarkable number of phosphorylation sites in these receptors and the wide variety of kinases participating in their phosphorylation facilitate integration between cell-signaling pathways and steroid receptor action. Sites have been identified in all of the functional domains although the sites are predominantly in the amino-terminal portions of the receptors. Regulation of function is receptor specific, site specific, and often dependent upon activation of a specific cell-signaling pathway. This complexity explains, in part, the early difficulties in identifying roles for phosphorylation in receptor function. With increased availability of phosphorylation site-specific antibodies and better means to measure receptor activities, numerous roles for site-specific phosphorylation have been identified including sensitivity of response to hormone, DNA binding, expression, stability, subcellular localization, and protein-protein interactions that determine the level of regulation of specific target genes. This review summarizes current knowledge regarding receptor phosphorylation and regulation of function. As functional assays become more sophisticated, it is likely that additional roles for phosphorylation in receptor function will be identified.
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Affiliation(s)
- Nancy L Weigel
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
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