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Abstract
The androgen receptor (AR) plays a key role in the maintenance of muscle and bone and the support of male sexual-related functions, as well as in the progression of prostate cancer. Accordingly, AR-targeted therapies have been developed for the treatment of related human diseases and conditions. AR agonists are an important class of drugs in the treatment of bone loss and muscle atrophy. AR antagonists have also been developed for the treatment of prostate cancer, including metastatic castration-resistant prostate cancer (mCRPC). Additionally, selective AR degraders (SARDs) have been reported. More recently, heterobifunctional degrader molecules of AR have been developed, and four such compounds are now in clinical development for the treatment of human prostate cancer. This review attempts to summarize the different types of compounds designed to target AR and the current frontiers of research on this important therapeutic target.
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Affiliation(s)
- Weiguo Xiang
- Departments of Internal Medicine, Pharmacology and Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Shaomeng Wang
- Departments of Internal Medicine, Pharmacology and Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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2
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Fontana F, Limonta P. Dissecting the Hormonal Signaling Landscape in Castration-Resistant Prostate Cancer. Cells 2021; 10:1133. [PMID: 34067217 PMCID: PMC8151003 DOI: 10.3390/cells10051133] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023] Open
Abstract
Understanding the molecular mechanisms underlying prostate cancer (PCa) progression towards its most aggressive, castration-resistant (CRPC) stage is urgently needed to improve the therapeutic options for this almost incurable pathology. Interestingly, CRPC is known to be characterized by a peculiar hormonal landscape. It is now well established that the androgen/androgen receptor (AR) axis is still active in CRPC cells. The persistent activity of this axis in PCa progression has been shown to be related to different mechanisms, such as intratumoral androgen synthesis, AR amplification and mutations, AR mRNA alternative splicing, increased expression/activity of AR-related transcription factors and coregulators. The hypothalamic gonadotropin-releasing hormone (GnRH), by binding to its specific receptors (GnRH-Rs) at the pituitary level, plays a pivotal role in the regulation of the reproductive functions. GnRH and GnRH-R are also expressed in different types of tumors, including PCa. Specifically, it has been demonstrated that, in CRPC cells, the activation of GnRH-Rs is associated with a significant antiproliferative/proapoptotic, antimetastatic and antiangiogenic activity. This antitumor activity is mainly mediated by the GnRH-R-associated Gαi/cAMP signaling pathway. In this review, we dissect the molecular mechanisms underlying the role of the androgen/AR and GnRH/GnRH-R axes in CRPC progression and the possible therapeutic implications.
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Affiliation(s)
| | - Patrizia Limonta
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milano, Italy;
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3
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Mukhamejanova Z, Tong Y, Xiang Q, Xu F, Pang J. Recent Advances in the Design and Development of Anticancer Molecules based on PROTAC Technology. Curr Med Chem 2021; 28:1304-1327. [PMID: 32164504 DOI: 10.2174/0929867327666200312112412] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/24/2020] [Accepted: 03/05/2020] [Indexed: 11/22/2022]
Abstract
PROTAC (Proteolysis Targeting Chimera) degraders based on protein knockdown technology are now suggested as a novel option for the treatment of various diseases. Over the last couple of years, the application of PROTAC technology has spread in a wide range of disorders, and plenty of PROTAC molecules with high potency have been reported. Mostly developing for anticancer therapy, these molecules showed high selectivities to target proteins, the ability to significantly induce degradation of oncoproteins, good in vitro and in vivo results. In this review, we summarized the recent development of PROTAC technology in the anticancer therapy field, including molecular design, types of targeted proteins, in vitro and in vivo results. Additionally, we also discuss the prospects and challenges for the application of candidates based on PROTAC strategy in clinical trials.
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Affiliation(s)
| | - Yichen Tong
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Qi Xiang
- Institute of Biomedicine & Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China
| | - Fang Xu
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), Guangzhou City Key Laboratory of Precision Chemical Drug Development, School of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Jiyan Pang
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
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4
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Current Status and Future Perspectives of Androgen Receptor Inhibition Therapy for Prostate Cancer: A Comprehensive Review. Biomolecules 2021; 11:biom11040492. [PMID: 33805919 PMCID: PMC8064397 DOI: 10.3390/biom11040492] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/12/2021] [Accepted: 03/23/2021] [Indexed: 12/13/2022] Open
Abstract
The androgen receptor (AR) is one of the main components in the development and progression of prostate cancer (PCa), and treatment strategies are mostly directed toward manipulation of the AR pathway. In the metastatic setting, androgen deprivation therapy (ADT) is the foundation of treatment in patients with hormone-sensitive prostate cancer (HSPC). However, treatment response is short-lived, and the majority of patients ultimately progress to castration-resistant prostate cancer (CRPC). Surmountable data from clinical trials have shown that the maintenance of AR signaling in the castration environment is accountable for disease progression. Study results indicate multiple factors and survival pathways involved in PCa. Based on these findings, the alternative molecular pathways involved in PCa progression can be manipulated to improve current regimens and develop novel treatment modalities in the management of CRPC. In this review, the interaction between AR signaling and other molecular pathways involved in tumor pathogenesis and its clinical implications in metastasis and advanced disease will be discussed, along with a thorough overview of current and ongoing novel treatments for AR signaling inhibition.
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5
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Wu H, Ren J, Zhao L, Li Z, Ye W, Yang Y, Wang J, Bian J. Identification of novel androgen receptor degrading agents to treat advanced prostate cancer. Eur J Med Chem 2021; 217:113376. [PMID: 33756125 DOI: 10.1016/j.ejmech.2021.113376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/25/2021] [Accepted: 03/07/2021] [Indexed: 12/21/2022]
Abstract
Prostate cancer (PCa) is one of the most common malignancies affecting men worldwide. Androgen receptor (AR) has been a target of PCa treatment for nearly six decades. AR antagonists/degraders can effectively treat PCa caused by increased AR overexpression. However, all approved AR antagonists have similar chemical structures and exhibit the same mode of action on the protein. Although initially effective, resistance to these AR antagonists usually develops. Therefore, this calls for the identification of novel chemical structures of AR antagonists to overcome the resistance. Herein, we employed the synergetic combination of virtual and experimental screening to identify a flavonoid compound which not only effectively inhibits AR transcriptional activity, but also induces the degradation of the protein. Based on this compound, we designed and synthesized a series of derivatives. We discovered that the most potent compound 10e could effectively inhibit AR transcriptional activity, and possessed a profound ability to cause degradation of both full length- and ARv7 truncated forms of human AR. Notably, 10e efficiently inhibited the growth of ARv7 dependent prostate cancer cell-lines, which are completely resistant to all current anti-androgens. Compound 10e also showed strong antitumor activity in the LNCaP (androgen dependent prostate cancer cell line) in vivo xenograft model. These results provide a foundation for the development of a new class of AR antagonists.
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Affiliation(s)
- Hongxi Wu
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jie Ren
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Lulu Zhao
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Zhiyu Li
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Wanli Ye
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yong Yang
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jubo Wang
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jinlei Bian
- Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
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6
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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.
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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
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7
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Management of men with metastatic castration-resistant prostate cancer following potent androgen receptor inhibition: a review of novel investigational therapies. Prostate Cancer Prostatic Dis 2020; 24:301-309. [PMID: 33168966 DOI: 10.1038/s41391-020-00299-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Androgen-targeted therapy and chemotherapy are currently the mainstay of treatment in metastatic castration resistant prostate cancer (mCRPC). When progression occurs despite these therapeutic strategies, additional FDA-approved treatment options are lacking. However, there is a vast amount of emerging data surrounding novel investigational therapies in this space. METHODS We reviewed and summarized the body of literature surrounding the current treatment options for mCRPC. Medline and Pubmed as well as abstracts from international congresses were utilized to gather relevant literature surrounding investigational treatment of mCRPC. We highlight the results of recent trials investigating the use of novel strategies to treat mCRPC. RESULTS Androgen-targeted therapy and chemotherapy will remain foundational in the treatment of mCRPC. However, heavily pretreated patients who have developed resistance may benefit from novel therapeutic strategies. The use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) has now gained FDA approval for patients with homologous recombination repair (HRR) gene mutations. Novel androgen receptor (AR) degraders and the use of radioligand therapy (RLT) with Lu-PSMA-617 (Lu-PSMA) are under investigation. Immune-directed therapies, including programmed death (PD-1) inhibition, bi-specific T-cell engager (BiTE) technology, and chimeric antigen receptor (CAR) T-cell therapy, have shown promise in early phase trials. Further understanding of resistance mechanisms has led to additional therapeutic targets, including targeting the PI3K-Akt-mTOR pathway and enhancer of zester homolog 2 (EZH2). CONCLUSIONS Based on our review of the literature, exciting new therapeutic strategies exist for the treatment of mCRPC. In particular, PARPi, AR degraders, PSMA-targeted therapies, immune-directed therapies, and agents targeting resistance mechanisms as monotherapy or in combination could improve patient outcomes. Additional data from randomized trials are necessary to understand the efficacy and tolerability of these treatment strategies.
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8
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Takwale AD, Jo SH, Jeon YU, Kim HS, Shin CH, Lee HK, Ahn S, Lee CO, Du Ha J, Kim JH, Hwang JY. Design and characterization of cereblon-mediated androgen receptor proteolysis-targeting chimeras. Eur J Med Chem 2020; 208:112769. [PMID: 32961381 DOI: 10.1016/j.ejmech.2020.112769] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/17/2023]
Abstract
Proteolysis-targeting chimera (PROTAC)-mediated protein degradation is a rapidly emerging therapeutic intervention that induces the degradation of targeted proteins. Herein, we report the design and biological evaluation of a series of androgen receptor (AR) PROTAC degraders for the treatment of metastatic castration-resistant prostate cancer. Predominantly, instead of thalidomide, we utilized the TD-106 scaffold, a novel cereblon (CRBN) binder that was identified in our previous study. Our results suggest that the linker position in the TD-106 CRBN binder is critical for the efficiency of AR degradation. The compounds attached to the 6-position of TD-106 promoted better degradation of AR than those at the 5- and 7-positions. Among the synthesized AR PROTACs, the representative degrader 33c (TD-802) effectively induced AR protein degradation, with a degradation concentration 50% of 12.5 nM and a maximum degradation of 93% in LNCaP prostate cancer cells. Additionally, most AR PROTAC degraders, including TD-802, displayed good liver microsomal stability and in vivo pharmacokinetic properties. Finally, we showed that TD-802 effectively inhibited tumor growth in an in vivo xenograft study.
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Affiliation(s)
- Akshay D Takwale
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea; Department of Medicinal Chemistry and Pharmacology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Seung-Hyun Jo
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea; Department of Functional Genomics, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Yeong Uk Jeon
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea
| | - Hyung Soo Kim
- Department of Chemistry, Korea Univeristy, Seoul, 02841, Republic of Korea
| | - Choong Hoon Shin
- Department of Chemistry, Sogang Univeristy, Seoul, 04107, Republic of Korea
| | - Heung Kyoung Lee
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea
| | - Sunjoo Ahn
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea
| | - Chong Ock Lee
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea
| | - Jae Du Ha
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea.
| | - Jeong-Hoon Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea; Department of Functional Genomics, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea.
| | - Jong Yeon Hwang
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, 305-606, Republic of Korea; Department of Medicinal Chemistry and Pharmacology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea.
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9
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Roles of Splicing Factors in Hormone-Related Cancer Progression. Int J Mol Sci 2020; 21:ijms21051551. [PMID: 32106418 PMCID: PMC7084890 DOI: 10.3390/ijms21051551] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 02/20/2020] [Indexed: 12/19/2022] Open
Abstract
Splicing of mRNA precursor (pre-mRNA) is a mechanism to generate multiple mRNA isoforms from a single pre-mRNA, and it plays an essential role in a variety of biological phenomena and diseases such as cancers. Previous studies have demonstrated that cancer-specific splicing events are involved in various aspects of cancers such as proliferation, migration and response to hormones, suggesting that splicing-targeting therapy can be promising as a new strategy for cancer treatment. In this review, we focus on the splicing regulation by RNA-binding proteins including Drosophila behavior/human splicing (DBHS) family proteins, serine/arginine-rich (SR) proteins and heterogeneous nuclear ribonucleoproteins (hnRNPs) in hormone-related cancers, such as breast and prostate cancers.
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10
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Petrylak DP, Vogelzang NJ, Chatta K, Fleming MT, Smith DC, Appleman LJ, Hussain A, Modiano M, Singh P, Tagawa ST, Gore I, McClay EF, Mega AE, Sartor AO, Somer B, Wadlow R, Shore ND, Olson WC, Stambler N, DiPippo VA, Israel RJ. PSMA ADC monotherapy in patients with progressive metastatic castration-resistant prostate cancer following abiraterone and/or enzalutamide: Efficacy and safety in open-label single-arm phase 2 study. Prostate 2020; 80:99-108. [PMID: 31742767 DOI: 10.1002/pros.23922] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/16/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND Prostate-specific membrane antigen (PSMA) is a well-established therapeutic and diagnostic target overexpressed in both primary and metastatic prostate cancers. PSMA antibody-drug conjugate (PSMA ADC) is a fully human immunoglobulin G1 anti-PSMA monoclonal antibody conjugated to monomethylauristatin E, which binds to PSMA-positive cells and induces cytotoxicity. In a phase 1 study, PSMA ADC was well tolerated and demonstrated activity as measured by reductions in serum prostate-specific antigen (PSA) and circulating tumor cells (CTCs). To further assess PSMA ADC, we conducted a phase 2 trial in metastatic castration-resistant prostate cancer (mCRPC) subjects who progressed following abiraterone/enzalutamide (abi/enz) therapy. METHODS A total of 119 (84 chemotherapy-experienced and 35 chemotherapy-naïve) subjects were administered PSMA ADC 2.5 or 2.3 mg/kg IV q3w for up to eight cycles. Antitumor activity (best percentage declines in PSA and CTCs from baseline and tumor responses through radiological imaging), exploratory biomarkers, and safety (monitoring of adverse events [AEs], clinical laboratory tests, and Eastern Cooperative Oncology Group performance status) were assessed. RESULTS PSA declines ≥50% occurred in 14% of all treated (n = 113) and 21% of chemotherapy-naïve subjects (n = 34). CTC declines ≥50% were seen in 78% of all treated (n = 77; number of subjects with ≥5 CTCs at baseline and a posttreatment result) and 89% of chemotherapy-naïve subjects (n = 19); 47% of all treated and 53% of chemotherapy-naïve subjects had a transition from ≥5 to less than 5 CTCs/7.5 mL blood at some point during the study. PSA and CTC reductions were associated with high PSMA expression (CTCs or tumor tissue) and low neuroendocrine serum markers. In the chemotherapy-experienced group, the best overall radiologic response to PSMA ADC treatment was stable disease in 51 (60.7%) subjects; 5.7% of subjects in the chemotherapy-naïve group had partial responses. The most common treatment-related AEs ≥Common Terminology Criteria for AE (CTCAE) grade 3 were neutropenia, fatigue, electrolyte imbalance, anemia, and neuropathy. The most common serious AEs were dehydration, hyponatremia, febrile neutropenia, and constipation. Two subjects who received 2.5 mg/kg died of sepsis. CONCLUSIONS PSMA ADC demonstrated some activity with respect to PSA declines, CTC conversions/reductions, and radiologic assessments in abi/enz treated mCRPC subjects. Clinically significant treatment-related AEs included neutropenia and neuropathy.
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MESH Headings
- Aged
- Aged, 80 and over
- Androstenes/administration & dosage
- Antibodies, Monoclonal, Humanized/adverse effects
- Antibodies, Monoclonal, Humanized/therapeutic use
- Antineoplastic Combined Chemotherapy Protocols/administration & dosage
- Benzamides
- Biomarkers, Tumor/blood
- Drug Resistance, Neoplasm
- Humans
- Immunotoxins/adverse effects
- Immunotoxins/therapeutic use
- Male
- Middle Aged
- Nitriles
- Phenylthiohydantoin/administration & dosage
- Phenylthiohydantoin/analogs & derivatives
- Prostatic Neoplasms, Castration-Resistant/blood
- Prostatic Neoplasms, Castration-Resistant/diagnostic imaging
- Prostatic Neoplasms, Castration-Resistant/drug therapy
- Survival Rate
- Treatment Outcome
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Affiliation(s)
| | | | - Kamal Chatta
- Virginia Mason Medical Center, Seattle, Washington
| | | | | | - Leonard J Appleman
- Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | | | | | | | - Ira Gore
- Alabama Oncology, Birmingham, Alabama
| | - Edward F McClay
- California Cancer Associates for Research and Excellence, Encinitas, California
| | | | - A Oliver Sartor
- School of Medicine, Tulane University, New Orleans, Louisiana
| | - Bradley Somer
- West Cancer Center and Research Institute, Memphis, Tennessee
| | | | - Neal D Shore
- Carolina Urologic Research Center, Myrtle Beach, South Carolina
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11
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Elshan NGRD, Rettig MB, Jung ME. Molecules targeting the androgen receptor (AR) signaling axis beyond the AR-Ligand binding domain. Med Res Rev 2019; 39:910-960. [PMID: 30565725 PMCID: PMC6608750 DOI: 10.1002/med.21548] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/21/2018] [Accepted: 10/09/2018] [Indexed: 02/06/2023]
Abstract
Prostate cancer (PCa) is the second most common cause of cancer-related mortality in men in the United States. The androgen receptor (AR) and the physiological pathways it regulates are central to the initiation and progression of PCa. As a member of the nuclear steroid receptor family, it is a transcription factor with three distinct functional domains (ligand-binding domain [LBD], DNA-binding domain [DBD], and transactivation domain [TAD]) in its structure. All clinically approved drugs for PCa ultimately target the AR-LBD. Clinically active drugs that target the DBD and TAD have not yet been developed due to multiple factors. Despite these limitations, the last several years have seen a rise in the discovery of molecules that could successfully target these domains. This review aims to present and comprehensively discuss such molecules that affect AR signaling through direct or indirect interactions with the AR-TAD or the DBD. The compounds discussed here include hairpin polyamides, niclosamide, marine sponge-derived small molecules (eg, EPI compounds), mahanine, VPC compounds, JN compounds, and bromodomain and extraterminal domain inhibitors. We highlight the significant in vitro and in vivo data found for each compound and the apparent limitations and/or potential for further development of these agents as PCa therapies.
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Affiliation(s)
| | - Matthew B. Rettig
- . Division of Hematology/Oncology, VA Greater Los Angeles Healthcare System West LA, Los Angeles, CA, United States
- . Departments of Medicine and Urology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
| | - Michael E. Jung
- . Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, United States
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12
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Han X, Wang C, Qin C, Xiang W, Fernandez-Salas E, Yang CY, Wang M, Zhao L, Xu T, Chinnaswamy K, Delproposto J, Stuckey J, Wang S. Discovery of ARD-69 as a Highly Potent Proteolysis Targeting Chimera (PROTAC) Degrader of Androgen Receptor (AR) for the Treatment of Prostate Cancer. J Med Chem 2019; 62:941-964. [PMID: 30629437 DOI: 10.1021/acs.jmedchem.8b01631] [Citation(s) in RCA: 241] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report herein the discovery of highly potent PROTAC degraders of androgen receptor (AR), as exemplified by compound 34 (ARD-69). ARD-69 induces degradation of AR protein in AR-positive prostate cancer cell lines in a dose- and time-dependent manner. ARD-69 achieves DC50 values of 0.86, 0.76, and 10.4 nM in LNCaP, VCaP, and 22Rv1 AR+ prostate cancer cell lines, respectively. ARD-69 is capable of reducing the AR protein level by >95% in these prostate cancer cell lines and effectively suppressing AR-regulated gene expression. ARD-69 potently inhibits cell growth in these AR-positive prostate cancer cell lines and is >100 times more potent than AR antagonists. A single dose of ARD-69 effectively reduces the level of AR protein in xenograft tumor tissue in mice. Further optimization of ARD-69 may ultimately lead to a new therapy for AR+, castration-resistant prostate cancer.
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