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Jernberg E, Bergh A, Wikström P. Clinical relevance of androgen receptor alterations in prostate cancer. Endocr Connect 2017; 6:R146-R161. [PMID: 29030409 PMCID: PMC5640574 DOI: 10.1530/ec-17-0118] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 09/19/2017] [Indexed: 12/20/2022]
Abstract
Prostate cancer (PC) remains a leading cause of cancer-related deaths among men worldwide, despite continuously improved treatment strategies. Patients with metastatic disease are treated by androgen deprivation therapy (ADT) that with time results in the development of castration-resistant prostate cancer (CRPC) usually established as metastases within bone tissue. The androgen receptor (AR) transcription factor is the main driver of CRPC development and of acquired resistance to drugs given for treatment of CRPC, while a minority of patients have CRPC that is non-AR driven. Molecular mechanisms behind epithelial AR reactivation in CRPC include AR gene amplification and overexpression, AR mutations, expression of constitutively active AR variants, intra-tumoural and adrenal androgen synthesis and promiscuous AR activation by other factors. This review will summarize AR alterations of clinical relevance for patients with CRPC, with focus on constitutively active AR variants, their possible association with AR amplification and structural rearrangements as well as their ability to predict patient resistance to AR targeting drugs. The review will also discuss AR signalling in the tumour microenvironment and its possible relevance for metastatic growth and therapy.
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Affiliation(s)
- Emma Jernberg
- Department of Medical biosciencesUmeå University, Umeå, Sweden
| | - Anders Bergh
- Department of Medical biosciencesUmeå University, Umeå, Sweden
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2
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Wu JP, Huang WB, Zhou H, Xu LW, Zhao JH, Zhu JG, Su JH, Sun HB. Intensity of stromal changes is associated with tumor relapse in clinically advanced prostate cancer after castration therapy. Asian J Androl 2015; 16:710-4. [PMID: 24875819 PMCID: PMC4215666 DOI: 10.4103/1008-682x.129131] [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] [Indexed: 11/25/2022] Open
Abstract
Reactive stromal changes in prostate cancer (PCa) are likely involved in the emergence of castration-resistant PCa (CRPC). This study was designed to investigate stromal changes in patients with clinically advanced PCa and analyze their prognostic significance. Prostate needle biopsies obtained from 148 patients before castration therapy were analyzed by Masson trichrome staining and immunohistochemical analysis of vimentin and desmin. Reactive stroma grading was inversely correlated with Gleason score. Stroma grade (Masson stain 82.8% vs 45.6%, P < 0.001) and vimentin expression (P = 0.005) were significantly higher, and desmin expression (P = 0.004) significantly lower, in reactive stroma of tumors with a Gleason score of 6–7 than in adjacent peritumoral tissue. Kaplan-Meier analysis showed a significant association between reactive stroma grade in tumors and the occurrence of CRPC in patients with a Gleason score of 6–7 (P = 0.009). Furthermore, patients with higher vimentin or lower desmin expression had a shorter disease-free period. In multivariate analysis, only vimentin expression was a significant predictor of tumor relapse (hazard ratio 1.78, 95% confidence interval 1.12–10.26, P = 0.012). These findings indicate that the intensity of reactive stroma is associated with castration responsiveness, especially in patients with a lower Gleason score where the abundant stroma component is most frequently found. High expression of vimentin in tumor stroma was independently associated with poor outcomes in patients with Gleason scores of 6–7, and may serve as a new prognostic marker in daily practice.
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Affiliation(s)
| | | | | | | | | | | | | | - Hong-Bin Sun
- Department of Urology, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, China
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3
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Vander Griend DJ, Litvinov IV, Isaacs JT. Conversion of androgen receptor signaling from a growth suppressor in normal prostate epithelial cells to an oncogene in prostate cancer cells involves a gain of function in c-Myc regulation. Int J Biol Sci 2014; 10:627-42. [PMID: 24948876 PMCID: PMC4062956 DOI: 10.7150/ijbs.8756] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/12/2014] [Indexed: 12/22/2022] Open
Abstract
In normal prostate, androgen-dependent androgen receptor (AR) signaling within prostate stromal cells induces their secretion of paracrine factors, termed “andromedins” which stimulate growth of the epithelial cells. The present studies demonstrate that androgen-dependent andromedin-driven growth stimulation is counter-balanced by androgen-induced AR signaling within normal adult prostate epithelial cells resulting in terminal G0 growth arrest coupled with terminal differentiation into ΔNp63-negative, PSA-expressing secretory luminal cells. This cell autonomous AR-driven terminal differentiation requires DNA-binding of the AR protein, is associated with decreases in c-Myc m-RNA and protein, are coupled with increases in p21, p27, and SKP-2 protein expression, and does not require functional p53. These changes result in down-regulation of Cyclin D1 protein and RB phosphoryation. shRNA knockdown documents that neither RB, p21, p27 alone or in combination are required for such AR-induced G0 growth arrest. Transgenic expression of a constitutive vector to prevent c-Myc down-regulation overrides AR-mediated growth arrest in normal prostate epithelial cells, which documents that AR-induced c-Myc down-regulation is critical in terminal growth arrest of normal prostate epithelial cells. In contrast, in prostate cancer cells, androgen-induced AR signaling paradoxically up-regulates c-Myc expression and stimulates growth as documented by inhibition of both of these responses following exposure to the AR antagonist, bicalutamide. These data document that AR signaling is converted from a growth suppressor in normal prostate epithelial cells to an oncogene in prostate cancer cells during prostatic carcinogenesis and that this conversion involves a gain of function for regulation of c-Myc expression.
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Affiliation(s)
- Donald J Vander Griend
- 1. Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. ; 3. The Brady Urological Institute, Johns Hopkins
| | - Ivan V Litvinov
- 1. Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. ; 2. Cellular and Molecular Medicine Graduate Program at Johns Hopkins
| | - John T Isaacs
- 1. Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. ; 2. Cellular and Molecular Medicine Graduate Program at Johns Hopkins. ; 3. The Brady Urological Institute, Johns Hopkins
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Matuszak EA, Kyprianou N. Androgen regulation of epithelial-mesenchymal transition in prostate tumorigenesis. Expert Rev Endocrinol Metab 2011; 6:469-482. [PMID: 23667383 PMCID: PMC3648215 DOI: 10.1586/eem.11.32] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Prostate cancer patient mortality is ascribed to the spread of cancerous cells to areas outside the prostate gland and the inability of current treatment strategies to effectively block progression to metastasis. Understanding the cellular mechanisms contributing to the dissemination of malignant cells and metastasis is critically significant to the generation of effective therapeutic modalities for improved patient survival while combating therapeutic resistance. In recent years, the phenomenon of epithelial-mesenchymal transitions (EMTs) has received considerable attention due to accumulating evidence indicating a role for this developmentally conserved process in tumorigenesis. Cancer cells at the invasive edges of tumors undergo EMT under the influence of contextual signals that they receive from the microenvironment, such as TGF-β. Also derived from developmental studies is the fact that EMT induction is reversible; thus, upon removal of EMT-inducing signals, cells occasionally revert to the epithelial state of their cellular ancestors via the process of mesenchymal-epithelial transition. This article discusses the current evidence supporting a central role for EMT and its reverse process, mesenchymal-epithelial transition, in the metastatic progression of prostate cancer to advanced disease and the involvement of androgen signaling in its regulation towards the development of castration-resistant prostate cancer.
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Affiliation(s)
- Emily A Matuszak
- Department of Toxicology, University of Kentucky College of Medicine, Lexington, KY 40536, USA
- Department of Surgery/Urology, University of Kentucky College of Medicine, KY, USA
| | - Natasha Kyprianou
- Department of Toxicology, University of Kentucky College of Medicine, Lexington, KY 40536, USA
- Department of Surgery/Urology, University of Kentucky College of Medicine, KY, USA
- Department of Pathology, University of Kentucky College of Medicine, Lexington, KY, USA
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, USA
- Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, USA
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Johansson A, Rudolfsson S, Hammarsten P, Halin S, Pietras K, Jones J, Stattin P, Egevad L, Granfors T, Wikström P, Bergh A. Mast cells are novel independent prognostic markers in prostate cancer and represent a target for therapy. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:1031-41. [PMID: 20616342 DOI: 10.2353/ajpath.2010.100070] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mast cells affect growth in various human tumors, but their role in prostate cancer (PC) is unclear. Here, we identify mast cells as independent prognostic markers in PC using a large cohort of untreated PC patients with a long follow-up. By analyzing mast cells in different tissue compartments, our data indicate that intratumoral and peritumoral mast cells have anti- opposed to protumor properties. Intratumoral mast cells negatively regulate angiogenesis and tumor growth, whereas peritumoral mast cells stimulate the expansion of human prostate tumors. We also observed mast cell recruitment particularly to the peritumoral compartment in men during the formation of castrate-resistant prostate tumors. In our ortothopic rat model, mast cells accumulated in the peritumoral tissue where they enhanced angiogenesis and tumor growth. In line with this, prostate mast cells expressed high levels of the angiogenic factor FGF-2. Similar to the situation in men, mast cells infiltrated rat prostate tumors that relapsed after initially effective castration treatment, concurrent with a second wave of angiogenesis and an up-regulation of FGF-2. We conclude that mast cells are novel independent prognostic markers in PC and affect tumor progression in animals and patients. In addition, peritumoral mast cells provide FGF-2 to the tumor micro environment, which may contribute to their stimulating effect on angiogenesis.
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Affiliation(s)
- Anna Johansson
- Department of Medical Biosciences, Umeå University, Umeå, Sweden.
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Vander Griend DJ, D’Antonio J, Gurel B, Antony L, DeMarzo AM, Isaacs JT. Cell-autonomous intracellular androgen receptor signaling drives the growth of human prostate cancer initiating cells. Prostate 2010; 70:90-9. [PMID: 19790235 PMCID: PMC2788041 DOI: 10.1002/pros.21043] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The lethality of prostate cancer is due to the continuous growth of cancer initiating cells (CICs) which are often stimulated by androgen receptor (AR) signaling. However, the underlying molecular mechanism(s) for such AR-mediated growth stimulation are not fully understood. Such mechanisms may involve cancer cell-dependent induction of tumor stromal cells to produce paracrine growth factors or could involve cancer cell autonomous autocrine and/or intracellular AR signaling pathways. METHODS We utilized clinical samples, animal models and a series of AR-positive human prostate cancer cell lines to evaluate AR-mediated growth stimulation of prostate CICs. RESULTS The present studies document that stromal AR expression is not required for prostate cancer growth, since tumor stroma surrounding AR-positive human prostate cancer metastases (N = 127) are characteristically AR-negative. This lack of a requirement for AR expression in tumor stromal cells is also documented by the fact that human AR-positive prostate cancer cells grow equally well when xenografted in wild-type versus AR-null nude mice. AR-dependent growth stimulation was documented to involve secretion, extracellular binding, and signaling by autocrine growth factors. Orthotopic xenograft animal studies documented that the cellautonomous autocrine growth factors which stimulate prostate CIC growth are not the andromedins secreted by normal prostate stromal cells. Such cell autonomous and extracellular autocrine signaling is necessary but not sufficient for the optimal growth of prostate CICs based upon the response to anti-androgen plus/or minus preconditioned media. CONCLUSIONS AR-induced growth stimulation of human prostate CICs requires AR-dependent intracellular pathways. The identification of such AR-dependent intracellular pathways offers new leads for the development of effective therapies for prostate cancer.
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Affiliation(s)
- Donald J. Vander Griend
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jason D’Antonio
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Bora Gurel
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lizamma Antony
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Angelo M. DeMarzo
- The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John T. Isaacs
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Abstract
The critical role played by stroma-epithelium crosstalk in carcinogenesis and progression of prostate cancer has been increasingly recognized. These interactions are mediated by a variety of paracrine factors secreted by cancer cells and/or stromal cells. In human prostate cancer, reactive stroma is characterized by an increase in myofibroblasts and a corresponding amplification of extracellular matrix production and angiogenesis. Permanent genetic mutations have been reported in stromal cells as well as in tumour cells. Transforming growth factor-beta, vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor signalling pathways are involved in the process of angiogenesis, whereas hepatocyte growth factor, insulin-like growth factor-1, epidermal growth factor, CXC12 and Interleukin-6 play active roles in the progression, androgen-independent conversion and distal metastasis of prostate cancer. Some soluble factors have reciprocal interactions with androgens and the androgen receptor (AR), and can even activate AR in the absence of the androgen ligand. In this article, we review the complex interactions between cancer cells and the surrounding microenvironment, and discuss the potential therapeutic targets in the stromal compartment of prostate cancer.
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Affiliation(s)
- Yi-Nong Niu
- Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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Koochekpour S, Lee TJ, Sun Y, Hu S, Grabowski GA, Liu Z, Garay J. Prosaposin is an AR-target gene and its neurotrophic domain upregulates AR expression and activity in prostate stromal cells. J Cell Biochem 2008; 104:2272-85. [PMID: 18481277 DOI: 10.1002/jcb.21786] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies have introduced prosaposin (PSAP) as a pleiotrophic growth factor for prostate cancer (PCa). We have previously reported that PSAP or one of its known active molecular derivatives, saposin C functions as an androgen-agonist and androgen-regulated gene (ARG) for androgen-sensitive (AS) PCa cell lines. Due to the potential significance of androgen receptor (AR)-expressing stroma in PCa, we evaluated a possible bi-directional paracrine regulatory interactions between DHT and PSAP in AR-positive prostate stromal (PrSt) cells. We report that saposin C in a ligand-independent manner increased AR expression, its nuclear content, and tyrosine phosphorylation. DHT treatment of PrSt cells increased PSAP expression. We also demonstrated both serum- and androgen-inducibility of a previously characterized hormone-responsive element (HRE) located in the proximal region of PSAP promoter. In addition, conditioned-media derived from PrSt cells and bone fibroblasts (i.e., MSF) differentially increased PSAP-promoter activity in androgen-independent (AI) PC-3 and AS LNCaP cells. Our data for the first time demonstrate that not only saposin C or PSAP regulates AR expression/activity, but also function as an ARG in PrSt. Ligand-independent activation of AR by PSAP or saposin C in PCa and stromal cells may contribute not only to prostate carcinogenesis at an early stage, but also in AI progression of the disease in an androgen-deprived tumor microenvironment.
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Affiliation(s)
- S Koochekpour
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
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Pathophysiologie und Therapie der benignen Prostata-Hyperplasie. Wien Klin Wochenschr 2008; 120:390-401. [DOI: 10.1007/s00508-008-0986-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 05/21/2008] [Indexed: 12/17/2022]
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