1
|
Lv S, Song Q, Chen G, Cheng E, Chen W, Cole R, Wu Z, Pascal LE, Wang K, Wipf P, Nelson JB, Wei Q, Huang W, Wang Z. Regulation and targeting of androgen receptor nuclear localization in castration-resistant prostate cancer. J Clin Invest 2021; 131:141335. [PMID: 33332287 DOI: 10.1172/jci141335] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
Nuclear localization of the androgen receptor (AR) is necessary for its activation as a transcription factor. Defining the mechanisms regulating AR nuclear localization in androgen-sensitive cells and how these mechanisms are dysregulated in castration-resistant prostate cancer (CRPC) cells is fundamentally important and clinically relevant. According to the classical model of AR intracellular trafficking, androgens induce AR nuclear import and androgen withdrawal causes AR nuclear export. The present study has led to an updated model that AR could be imported in the absence of androgens, ubiquitinated, and degraded in the nucleus. Androgen withdrawal caused nuclear AR degradation, but not export. In comparison with their parental androgen-sensitive LNCaP prostate cancer cells, castration-resistant C4-2 cells exhibited reduced nuclear AR polyubiquitination and increased nuclear AR level. We previously identified 3-(4-chlorophenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (CPPI) in a high-throughput screen for its inhibition of androgen-independent AR nuclear localization in CRPC cells. The current study shows that CPPI is a competitive AR antagonist capable of enhancing AR interaction with its E3 ligase MDM2 and degradation of AR in the nuclei of CRPC cells. Also, CPPI blocked androgen-independent AR nuclear import. Overall, these findings suggest the feasibility of targeting androgen-independent AR nuclear import and stabilization, two necessary steps leading to AR nuclear localization and activation in CRPC cells, with small molecule inhibitors.
Collapse
Affiliation(s)
- Shidong Lv
- Department of Urology, Nanfang Hospital, Southern Medical University, and.,National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China.,Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Qiong Song
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Key Laboratory of Longevity and Ageing Related Disease of Chinese Ministry of Education, Center for Translational Medicine and School of Preclinical Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Guang Chen
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Urology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Erdong Cheng
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Wei Chen
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ryan Cole
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Zeyu Wu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Laura E Pascal
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ke Wang
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shanxi, China
| | - Peter Wipf
- UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joel B Nelson
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Qiang Wei
- Department of Urology, Nanfang Hospital, Southern Medical University, and
| | - Wenhua Huang
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhou Wang
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
2
|
de Santi F, Beltrame FL, Hinton BT, Cerri PS, Sasso-Cerri E. Reduced levels of stromal sex hormone-binding globulin and androgen receptor dysfunction in the sperm storage region of the rat epididymis. Reproduction 2018; 155:467-479. [DOI: 10.1530/rep-18-0014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 04/29/2018] [Indexed: 01/06/2023]
Abstract
The cauda epididymidis is the major sperm storage region whose androgenic supply, essential for the sperm viability, is provided by the vasculature and is dependent upon testosterone diffusion through the stromal tissue to reach the epithelial cells. We have focused our efforts on examining the regulation of this important epididymal region by evaluating the impact of the androgen disrupter cimetidine on the epithelial–stromal androgenic microenvironment. Male rats received 100 mg/kg cimetidine (CMTG) or saline (CG) for 50 days, serum testosterone levels were measured and the epididymal cauda region was processed for light and transmission electron microscopy. In the proximal cauda region, the duct diameter was measured and birefringent collagen in the stroma was quantified. TUNEL-labeled epithelial cells were quantified, and androgen receptor (AR), karyopherin alpha (KPNA) and sex hormone-binding globulin (SHBG) levels were analyzed by immunofluorescence and Western blot. CMTG showed reduced duct diameter and high number of apoptotic epithelial cells. In the epithelium, the total AR concentration and the KPNA immunoreactivity were reduced, and a weak/absent AR nuclear immunofluorescence was observed in contrast to the enhanced AR immunolabeling observed in the cytoplasm of the epithelial cells. A significant reduction of collagen and SHBG levels in the stroma was also observed. Cimetidine treatment impairs AR nuclear import in the epithelium, causing androgenic dysfunction and subsequent epithelial cell apoptosis and duct atrophy. The connective tissue atrophy and reduction of SHBG stromal levels associated with epithelial androgenic dysfunction indicate a possible role of stromal SHBG in the androgenic supply of the sperm storage region of the epididymis.
Collapse
|
3
|
Wang K, Ruan H, Xu T, Liu L, Liu D, Yang H, Zhang X, Chen K. Recent advances on the progressive mechanism and therapy in castration-resistant prostate cancer. Onco Targets Ther 2018; 11:3167-3178. [PMID: 29881290 PMCID: PMC5983013 DOI: 10.2147/ott.s159777] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Background Although there have been great advances in mechanisms and therapeutic methods of prostate cancer, the mortality rate of prostate cancer remains high. The castration-resistant prostate cancer (CRPC), which develops from hormone-sensitive prostate cancer, foreshadows a more dismal outcome. Concomitant with the researches in the mechanism of CRPC and therapy for CRPC, more and more landmark progress has been made in recent years. Methods A number of clinical and experimental studies were reviewed to indicate the novel advancement in the progressive mechanism and therapy of CRPC. Results The androgen receptor (AR) is still a vital driver in the progression of CRPC, while other multiple mechanisms also contribute to this progression, such as tumor immunity, cancer stem cells, epithelial–mesenchymal transition and DNA repair disorder. In terms of the therapeutic methods of CRPC, chemotherapy with drugs, such as docetaxel, has been the first-line therapy for CRPC for many years. Besides, newer agents, which target some of the above mechanisms, show additional overall survival benefits for CRPC patients. These therapies include drugs targeting the androgen axis pathway (androgen synthesis, androgen receptor splice variants, coactivators of AR and so on), PI3K-AKT pathway, WNT pathway, DNA repair, rearrangement of ETS gene, novel chemotherapy and immunotherapy, bone metastasis therapy and so on. Understanding these novel findings on the mechanisms of CRPC and the latest potential CRPC therapies will direct us for further exploration of CRPC. Conclusion Through comprehensive consideration, the predominant mechanism of CRPC might be the AR signal axis concomitant with tumor microenvironment, stress, immunity, tumor microenvironment and so on. For CRPC therapy, targeting the AR axis pathway and chemotherapy are the first-line treatments at present. However, with the advancements in CRPC therapy made by the researchers, other novel potential methods will occupy more and more important position in the treatment of CRPC, especially the therapies targeting the tumor microenviroment, tumor immunity and DNA repair and so on.
Collapse
Affiliation(s)
- Keshan Wang
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Hailong Ruan
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Tianbo Xu
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Lei Liu
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Di Liu
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Hongmei Yang
- Department of Pathogenic Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoping Zhang
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ke Chen
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| |
Collapse
|
4
|
Johnston PA, Nguyen MM, Dar JA, Ai J, Wang Y, Masoodi KZ, Shun T, Shinde S, Camarco DP, Hua Y, Huryn DM, Wilson GM, Lazo JS, Nelson JB, Wipf P, Wang Z. Development and Implementation of a High-Throughput High-Content Screening Assay to Identify Inhibitors of Androgen Receptor Nuclear Localization in Castration-Resistant Prostate Cancer Cells. Assay Drug Dev Technol 2017; 14:226-39. [PMID: 27187604 DOI: 10.1089/adt.2016.716] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Patients with castration-resistant prostate cancer (CRPC) can be treated with abiraterone, a potent inhibitor of androgen synthesis, or enzalutamide, a second-generation androgen receptor (AR) antagonist, both targeting AR signaling. However, most patients relapse after several months of therapy and a majority of patients with relapsed CRPC tumors express the AR target gene prostate-specific antigen (PSA), suggesting that AR signaling is reactivated and can be targeted again to inhibit the relapsed tumors. Novel small molecules capable of inhibiting AR function may lead to urgently needed therapies for patients resistant to abiraterone, enzalutamide, and/or other previously approved antiandrogen therapies. Here, we describe a high-throughput high-content screening (HCS) campaign to identify small-molecule inhibitors of AR nuclear localization in the C4-2 CRPC cell line stably transfected with GFP-AR-GFP (2GFP-AR). The implementation of this HCS assay to screen a National Institutes of Health library of 219,055 compounds led to the discovery of 3 small molecules capable of inhibiting AR nuclear localization and function in C4-2 cells, demonstrating the feasibility of using this cell-based phenotypic assay to identify small molecules targeting the subcellular localization of AR. Furthermore, the three hit compounds provide opportunities to develop novel AR drugs with potential for therapeutic intervention in CRPC patients who have relapsed after treatment with antiandrogens, such as abiraterone and/or enzalutamide.
Collapse
Affiliation(s)
- Paul A Johnston
- 1 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh , Pittsburgh, Pennsylvania.,2 University of Pittsburgh Cancer Institute , Pittsburgh, Pennsylvania
| | - Minh M Nguyen
- 3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Javid A Dar
- 3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,4 Central Laboratory, College of Science, King Saud University , Riyadh, Saudi Arabia
| | - Junkui Ai
- 3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Yujuan Wang
- 3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Khalid Z Masoodi
- 3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,5 Transcriptomics and Proteomics Lab, Centre for Plant Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K) , Shalimar, Srinagar, India
| | - Tongying Shun
- 6 Pittsburgh Specialized Application Center, University of Pittsburgh Drug Discovery Institute , Pittsburgh, Pennsylvania
| | - Sunita Shinde
- 6 Pittsburgh Specialized Application Center, University of Pittsburgh Drug Discovery Institute , Pittsburgh, Pennsylvania
| | - Daniel P Camarco
- 1 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Yun Hua
- 1 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Donna M Huryn
- 1 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh , Pittsburgh, Pennsylvania.,7 University of Pittsburgh Chemical Diversity Center , Pittsburgh, Pennsylvania
| | - Gabriela Mustata Wilson
- 8 Department of Health Services and Health Administration, College of Nursing and Health Professions, University of Southern Indiana , Evansville, Indiana
| | - John S Lazo
- 9 Departments of Pharmacology and Chemistry, University of Virginia , Charlottesville, Virginia
| | - Joel B Nelson
- 2 University of Pittsburgh Cancer Institute , Pittsburgh, Pennsylvania.,3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Peter Wipf
- 1 Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh , Pittsburgh, Pennsylvania.,2 University of Pittsburgh Cancer Institute , Pittsburgh, Pennsylvania.,7 University of Pittsburgh Chemical Diversity Center , Pittsburgh, Pennsylvania.,10 Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Zhou Wang
- 2 University of Pittsburgh Cancer Institute , Pittsburgh, Pennsylvania.,3 Department of Urology, School of Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,11 Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania
| |
Collapse
|
5
|
Masoodi KZ, Xu Y, Dar JA, Eisermann K, Pascal LE, Parrinello E, Ai J, Johnston PA, Nelson JB, Wipf P, Wang Z. Inhibition of Androgen Receptor Nuclear Localization and Castration-Resistant Prostate Tumor Growth by Pyrroloimidazole-based Small Molecules. Mol Cancer Ther 2017; 16:2120-2129. [PMID: 28655783 DOI: 10.1158/1535-7163.mct-17-0176] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/19/2017] [Accepted: 06/19/2017] [Indexed: 01/01/2023]
Abstract
The androgen receptor (AR) is a ligand-dependent transcription factor that controls the expression of androgen-responsive genes. A key step in androgen action, which is amplified in castration-resistant prostate cancer (CRPC), is AR nuclear translocation. Small molecules capable of inhibiting AR nuclear localization could be developed as novel therapeutics for CRPC. We developed a high-throughput screen and identified two structurally-related pyrroloimidazoles that could block AR nuclear localization in CRPC cells. We show that these two small molecules, 3-(4-ethoxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (EPPI) and 3-(4-chlorophenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (CPPI) can inhibit the nuclear localization and transcriptional activity of AR and reduce the proliferation of AR-positive but not AR-negative prostate cancer cell lines. EPPI and CPPI did not inhibit nuclear localization of the glucocorticoid receptor or the estrogen receptor, suggesting they selectively target AR. In LNCaP tumor xenografts, CPPI inhibited the proliferation of relapsed LNCaP tumors. These findings suggest that EPPI and CPPI could serve as lead structures for the development of therapeutic agents for CRPC. Mol Cancer Ther; 16(10); 2120-9. ©2017 AACR.
Collapse
Affiliation(s)
- Khalid Z Masoodi
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Transcriptomics Lab, Division of Plant Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu and Kashmir, India
| | - Yadong Xu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Department of Urology, The Second Xiangya Hospital of Central South University, Hunan 410011, China.,The Third Xiangya Hospital of Central South University, Changsha 410013, China
| | - Javid A Dar
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Central Laboratory College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Kurtis Eisermann
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Laura E Pascal
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Erica Parrinello
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Junkui Ai
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Paul A Johnston
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joel B Nelson
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Peter Wipf
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Zhou Wang
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. .,University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.,Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| |
Collapse
|
6
|
Hu J, Wang G, Sun T. Dissecting the roles of the androgen receptor in prostate cancer from molecular perspectives. Tumour Biol 2017; 39:1010428317692259. [PMID: 28475016 DOI: 10.1177/1010428317692259] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Androgen receptor plays a pivotal role in prostate cancer progression, and androgen deprivation therapy to intercept androgen receptor signal pathway is an indispensable treatment for most advanced prostate cancer patients to delay cancer progression. However, the emerging of castration-resistant prostate cancer reminds us the alteration of androgen receptor, which includes androgen receptor mutation, the formation of androgen receptor variants, and androgen receptor distribution in cancer cells. In this review, we introduce the process of androgen receptor and also its variants' formation, translocation, and function alteration by protein modification or interaction with other pathways. We dissect the roles of androgen receptor in prostate cancer from molecular perspective to provide clues for battling prostate cancer, especially castration-resistant prostate cancer.
Collapse
Affiliation(s)
- Jieping Hu
- Department of Urology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Gongxian Wang
- Department of Urology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ting Sun
- Department of Urology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| |
Collapse
|
7
|
Yap TA, Smith AD, Ferraldeschi R, Al-Lazikani B, Workman P, de Bono JS. Drug discovery in advanced prostate cancer: translating biology into therapy. Nat Rev Drug Discov 2016; 15:699-718. [DOI: 10.1038/nrd.2016.120] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
8
|
Wang D, Nguyen MM, Masoodi KZ, Singh P, Jing Y, O'Malley K, Dar JA, Dhir R, Wang Z. Splicing Factor Prp8 Interacts With NES(AR) and Regulates Androgen Receptor in Prostate Cancer Cells. Mol Endocrinol 2015; 29:1731-42. [PMID: 26371515 DOI: 10.1210/me.2015-1112] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Androgen receptor (AR) plays a pivotal role in the development of primary as well as advanced castration-resistant prostate cancer. Previous work in our lab identified a novel nuclear export signal (NES) (NES(AR)) in AR ligand-binding domain essential for AR nucleocytoplasmic trafficking. By characterizing the localization of green fluorescence protein (GFP)-tagged NES(AR), we designed and executed a yeast mutagenesis screen and isolated 7 yeast mutants that failed to display the NES(AR) export function. One of those mutants was identified as the splicing factor pre-mRNA processing factor 8 (Prp8). We further showed that Prp8 could regulate NES(AR) function using short hairpin RNA knockdown of Prp8 coupled with a rapamycin export assay in mammalian cells and knockdown of Prp8 could induce nuclear accumulation of GFP-tagged AR in PC3 cells. Prp8 expression was decreased in castration-resistant LuCaP35 xenograft tumors as compared with androgen-sensitive xenografts. Laser capture microdissection and quantitative PCR showed Prp8 mRNA levels were decreased in human prostate cancer specimens with high Gleason scores. In prostate cancer cells, coimmunoprecipitation and deletion mutagenesis revealed a physical interaction between Prp8 and AR mainly mediated by NES(AR). Luciferase assay with prostate specific antigen promoter-driven reporter demonstrated that Prp8 regulated AR transcription activity in prostate cancer cells. Interestingly, Prp8 knockdown also increased polyubiquitination of endogenous AR. This may be 1 possible mechanism by which it modulates AR activity. These results show that Prp8 is a novel AR cofactor that interacts with NES(AR) and regulates AR function in prostate cancer cells.
Collapse
Affiliation(s)
- Dan Wang
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Minh M Nguyen
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Khalid Z Masoodi
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Prabhpreet Singh
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Yifeng Jing
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Katherine O'Malley
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Javid A Dar
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Rajiv Dhir
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| | - Zhou Wang
- Departments of Urology (D.W., M.M.N., K.Z.M., P.S., Y.J., K.O., J.A.D., Z.W.), Pharmacology and Chemical Biology (Z.W.), and Pathology (R.D., Z.W.) and University of Pittsburgh Cancer Institute (R.D., Z.W.), University of Pittsburgh, Pittsburgh, Pennsylvania 15232; and Department of Urology (Y.J.), The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200080, China
| |
Collapse
|
9
|
Poly (A) Binding Protein Cytoplasmic 1 Is a Novel Co-Regulator of the Androgen Receptor. PLoS One 2015; 10:e0128495. [PMID: 26176602 PMCID: PMC4503479 DOI: 10.1371/journal.pone.0128495] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/27/2015] [Indexed: 11/20/2022] Open
Abstract
The androgen receptor (AR) is a member of the steroid receptor superfamily that regulates gene expression in a ligand-dependent manner. The NTD of the AR plays a key role in AR transactivation including androgen-independent activation of the AR in castration-resistant prostate cancer (CRPC) cells. We recently reported that amino acids (a.a.) 50-250 of the NTD are capable of modulating AR nucleocytoplasmic trafficking. To further explore the mechanism associated with a.a. 50-250, GFP pull-down assays were performed in C4-2 CRPC cells transfected with GFP tagged a.a. 50-250 of the AR. Mass spectrometry analysis of the pulled down proteins identified poly (A) binding protein cytoplasmic 1 (PABPC1) interaction with this region of the AR. In silico analysis of gene expression data revealed PABPC1 up-regulation in prostate cancer tissue specimens and this up-regulation correlates to increased disease recurrence. Co-immunoprecipitation assays confirmed the association of PABPC1 with a.a. 50-250 of the NTD of the AR. Knockdown of PABPC1 decreased nuclear AR protein levels and inhibited androgen activation of the AR target PSA in LNCaP and C4-2 cells. Additionally, knockdown of PABPC1 inhibited transactivation of the PSA promoter by NAR (AR lacking the LBD) and attenuated proliferation of AR-positive prostate cancer cells. These findings suggest that PABPC1 is a novel co-regulator of the AR and may be a potential target for blocking activation of the AR in CRPC.
Collapse
|
10
|
Dar JA, Masoodi KZ, Eisermann K, Isharwal S, Ai J, Pascal LE, Nelson JB, Wang Z. The N-terminal domain of the androgen receptor drives its nuclear localization in castration-resistant prostate cancer cells. J Steroid Biochem Mol Biol 2014; 143:473-80. [PMID: 24662325 PMCID: PMC4127361 DOI: 10.1016/j.jsbmb.2014.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 02/14/2014] [Accepted: 03/14/2014] [Indexed: 10/25/2022]
Abstract
Androgen-independent nuclear localization is required for androgen receptor (AR) transactivation in castration-resistant prostate cancer (CRPC) and should be a key step leading to castration resistance. However, mechanism(s) leading to androgen-independent AR nuclear localization are poorly understood. Since the N-terminal domain (NTD) of AR plays a role in transactivation under androgen-depleted conditions, we investigated the role of the NTD in AR nuclear localization in CRPC. Deletion mutagenesis was used to identify amino acid sequences in the NTD essential for its androgen-independent nuclear localization in C4-2, a widely used CRPC cell line. Deletion mutants of AR tagged with green fluorescent protein (GFP) at the 5'-end were generated and their signal distribution was investigated in C4-2 cells by fluorescent microscopy. Our results showed that the region of a.a. 294-556 was required for androgen-independent AR nuclear localization whereas a.a. 1-293 mediates Hsp90 regulation of AR nuclear localization in CRPC cells. Although the region of a.a. 294-556 does not contain a nuclear import signal, it was able to enhance DHT-induced import of the ligand binding domain (LBD). Also, transactivation of the NTD could be uncoupled from its modulation of AR nuclear localization in C4-2 cells. These observations suggest an important role of the NTD in AR intracellular trafficking and androgen-independent AR nuclear localization in CRPC cells.
Collapse
Affiliation(s)
- Javid A Dar
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States; Central Laboratory College of Science, King Saud University, Riyadh KSA-11451, Saudi Arabia
| | - Khalid Z Masoodi
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Kurtis Eisermann
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Sudhir Isharwal
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Junkui Ai
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Laura E Pascal
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Joel B Nelson
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States; University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States
| | - Zhou Wang
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, United States; University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, United States.
| |
Collapse
|