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Regter S, Hedayati M, Zhang Y, Zhou H, Dalrymple S, Koch CJ, Isaacs JT, DeWeese TL. Androgen withdrawal fails to induce detectable tissue hypoxia in the rat prostate. Prostate 2014; 74:805-10. [PMID: 24677180 PMCID: PMC4332785 DOI: 10.1002/pros.22803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/05/2014] [Indexed: 01/17/2023]
Abstract
BACKGROUND It has been reported that significant hypoxia may occur in the rat prostate following androgen deprivation (AD). It is well known that hypoxia substantially reduces radiation sensitivity of cells both in vitro and in vivo. Given that contemporary management of men with intermediate and high-risk prostate cancer includes the use of neoadjuvant androgen suppression and radiation, AD-induced hypoxia in the prostate could result in suboptimal therapeutic results. Given this concern, we fully investigate possible AD-induced hypoxia in the ventral prostate (VP) of adult rats by two independent methods. METHODS Tissue pO2 levels in the VP of adult Spraque-Dawley rats were evaluated prior to and at various time points following castration by two independent techniques. First, an Oxylab tissue oxygen monitor with a 240 μm probe was used for quantitative monitoring of global VP oxygenation. Second, fluorescence immunohistochemistry using the hypoxia marker EF5, known to be metabolically activated by hypoxic cells, was used to evaluate cell-to-cell variation in hypoxia at various days post-castration. RESULTS Neither the oxygen probe nor EF5 method demonstrate any substantive change in pO2 levels in the rat VP at any time point post-castration. CONCLUSIONS We find no evidence that the rat VP becomes hypoxic at any point following castration using an animal model that closely mimics the human prostate. These data are in contrast to previous reports suggesting prostatic hypoxia occurs following AD and provide assurance that our present therapeutic strategy of neoadjuvant AD followed by radiation is not compromised by AD-induced tissue hypoxia.
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Affiliation(s)
- Sietze Regter
- Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mohammad Hedayati
- Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yonggang Zhang
- Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Haoming Zhou
- Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Susan Dalrymple
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Cameron J. Koch
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John T. Isaacs
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Theodore L. DeWeese
- Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Correspondence to: Theodore L. DeWeese, Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
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Bristow RG, Berlin A, Dal Pra A. An arranged marriage for precision medicine: hypoxia and genomic assays in localized prostate cancer radiotherapy. Br J Radiol 2014; 87:20130753. [PMID: 24588670 DOI: 10.1259/bjr.20130753] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Prostate cancer (CaP) is the most commonly diagnosed malignancy in males in the Western world with one in six males diagnosed in their lifetime. Current clinical prognostication groupings use pathologic Gleason score, pre-treatment prostatic-specific antigen and Union for International Cancer Control-TNM staging to place patients with localized CaP into low-, intermediate- and high-risk categories. These categories represent an increasing risk of biochemical failure and CaP-specific mortality rates, they also reflect the need for increasing treatment intensity and justification for increased side effects. In this article, we point out that 30-50% of patients will still fail image-guided radiotherapy or surgery despite the judicious use of clinical risk categories owing to interpatient heterogeneity in treatment response. To improve treatment individualization, better predictors of prognosis and radiotherapy treatment response are needed to triage patients to bespoke and intensified CaP treatment protocols. These should include the use of pre-treatment genomic tests based on DNA or RNA indices and/or assays that reflect cancer metabolism, such as hypoxia assays, to define patient-specific CaP progression and aggression. More importantly, it is argued that these novel prognostic assays could be even more useful if combined together to drive forward precision cancer medicine for localized CaP.
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Affiliation(s)
- R G Bristow
- Princess Margaret Cancer Center (University Health Network), Toronto, ON, Canada
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53
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Improving outcomes in high-risk prostate cancer with radiotherapy. Rep Pract Oncol Radiother 2013; 18:333-7. [PMID: 24416574 DOI: 10.1016/j.rpor.2013.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/15/2013] [Indexed: 11/23/2022] Open
Abstract
There have been significant improvements in the radiotherapeutic management of patients with high risk prostate cancer. Randomized trials have clearly demonstrated improved outcomes with the combination of radiotherapy in conjunction with androgen deprivation. While these trials have utilized low doses of radiotherapy in the range of 70 Gy, recent studies have suggested that significant benefits of combined androgen deprivation therapy with dose escalated radiotherapy are also observed. The use of high radiation dose levels in the setting of high risk prostate cancer is important, and strategies which combine external beam radiotherapy with a brachytherapy boost may provide an opportunity for even greater intensification of the radiation dose to the prostate target. Systemic therapies, second generation anti-androgen therapy and novel targeted agents integrated with radiotherapy will open up new vistas and challenges for further improved outcomes in patients with high-risk disease.
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Bartek J, Mistrik M, Bartkova J. Androgen Receptor Signaling Fuels DNA Repair and Radioresistance in Prostate Cancer. Cancer Discov 2013; 3:1222-4. [DOI: 10.1158/2159-8290.cd-13-0679] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Goodwin JF, Schiewer MJ, Dean JL, Schrecengost RS, de Leeuw R, Han S, Ma T, Den RB, Dicker AP, Feng FY, Knudsen KE. A hormone-DNA repair circuit governs the response to genotoxic insult. Cancer Discov 2013; 3:1254-71. [PMID: 24027197 PMCID: PMC3823813 DOI: 10.1158/2159-8290.cd-13-0108] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Alterations in DNA repair promote tumor development, but the impact on tumor progression is poorly understood. Here, discovery of a biochemical circuit linking hormone signaling to DNA repair and therapeutic resistance is reported. Findings show that androgen receptor (AR) activity is induced by DNA damage and promotes expression and activation of a gene expression program governing DNA repair. Subsequent investigation revealed that activated AR promotes resolution of double-strand breaks and resistance to DNA damage both in vitro and in vivo. Mechanistically, DNA-dependent protein kinase catalytic subunit (DNAPKcs) was identified as a key target of AR after damage, controlling AR-mediated DNA repair and cell survival after genotoxic insult. Finally, DNAPKcs was shown to potentiate AR function, consistent with a dual role in both DNA repair and transcriptional regulation. Combined, these studies identify the AR-DNAPKcs circuit as a major effector of DNA repair and therapeutic resistance and establish a new node for therapeutic intervention in advanced disease. SIGNIFICANCE The present study identifies for the fi rst time a positive feedback circuit linking hormone action to the DNA damage response and shows the significant impact of this process on tumor progression and therapeutic response. These provocative findings provide the foundation for development of novel nodes of therapeutic intervention for advanced disease.
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Affiliation(s)
- Jonathan F. Goodwin
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Matthew J. Schiewer
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jeffry L. Dean
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Randy S. Schrecengost
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Renee de Leeuw
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sumin Han
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Teng Ma
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Robert B. Den
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Adam P. Dicker
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Felix Y. Feng
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, Michigan
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
- Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan*
| | - Karen E. Knudsen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Department of Urology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
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Polkinghorn WR, Parker JS, Lee MX, Kass EM, Spratt DE, Iaquinta PJ, Arora VK, Yen WF, Cai L, Zheng D, Carver BS, Chen Y, Watson PA, Shah NP, Fujisawa S, Goglia AG, Gopalan A, Hieronymus H, Wongvipat J, Scardino PT, Zelefsky MJ, Jasin M, Chaudhuri J, Powell SN, Sawyers CL. Androgen receptor signaling regulates DNA repair in prostate cancers. Cancer Discov 2013; 3:1245-53. [PMID: 24027196 DOI: 10.1158/2159-8290.cd-13-0172] [Citation(s) in RCA: 384] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
UNLABELLED We demonstrate that the androgen receptor (AR) regulates a transcriptional program of DNA repair genes that promotes prostate cancer radioresistance, providing a potential mechanism by which androgen deprivation therapy synergizes with ionizing radiation. Using a model of castration-resistant prostate cancer, we show that second-generation antiandrogen therapy results in downregulation of DNA repair genes. Next, we demonstrate that primary prostate cancers display a significant spectrum of AR transcriptional output, which correlates with expression of a set of DNA repair genes. Using RNA-seq and ChIP-seq, we define which of these DNA repair genes are both induced by androgen and represent direct AR targets. We establish that prostate cancer cells treated with ionizing radiation plus androgen demonstrate enhanced DNA repair and decreased DNA damage and furthermore that antiandrogen treatment causes increased DNA damage and decreased clonogenic survival. Finally, we demonstrate that antiandrogen treatment results in decreased classical nonhomologous end-joining. SIGNIFICANCE We demonstrate that the AR regulates a network of DNA repair genes, providing a potential mechanism by which androgen deprivation synergizes with radiotherapy for prostate cancer.
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Affiliation(s)
- William R Polkinghorn
- 1Human Oncology Pathogenesis Program, 2Developmental Biology Program, and 3Immunology Program; Departments of 4Radiation Oncology, 5Medicine, 6Surgery, and 7Pathology; 8Molecular Cytology Core Facility, Memorial Sloan-Kettering Cancer Center; 9Department of Genetics, Albert Einstein College of Medicine, New York, New York; 10Department of Genetics; and 11Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
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Démonstration biologique a posteriori du concept de l’association hormono-radiothérapie dans les cancers de la prostate. Bull Cancer 2013. [DOI: 10.1684/bdc.2013.1745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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