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Wilson EM, Eskander RN, Binder PS. Recent Therapeutic Advances in Gynecologic Oncology: A Review. Cancers (Basel) 2024; 16:770. [PMID: 38398161 PMCID: PMC10887183 DOI: 10.3390/cancers16040770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Gynecologic malignancies have high incidence rates both nationally and internationally, and cervical, endometrial, and ovarian cancers account for high mortality rates worldwide. Significant research is ongoing to develop targeted therapies to address unmet needs in the field and improve patient outcomes. As tumors mutate and progress through traditional lines of treatment, new therapies must be developed to overcome resistance and target cancer-specific receptors and mutations. Recent advances in the development of immunotherapy and antibody-drug conjugates have resulted in compelling and clinically meaningful results in cervical, endometrial, and ovarian cancers. In the last decade, several immunotherapy agents have received FDA approval or NCCN guideline recommendation for the treatment of gynecologic malignancies, including dostarlimab for advanced or recurrent endometrial cancer and pembrolizumab for advanced or recurrent cervical and endometrial cancers. Several other immunotherapeutic agents are under active investigation. Development of antibody-drug conjugates including tisotumab vedotin in cervical cancer, mirvetuximab soravtansine in ovarian cancer, and trastuzumab deruxtecan in multiple gynecologic cancers has translated into exciting efficacy signals, prompting full drug approvals and additional investigation. This article aims to review recent novel advances in targeted treatments for gynecologic malignancies, highlighting the trials and data underlying these novel interventions.
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Affiliation(s)
| | | | - Pratibha S. Binder
- Moores Cancer Center, Division of Gynecologic Oncology, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, San Diego, CA 92037, USA; (E.M.W.); (R.N.E.)
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Wilson EM, Stock E, Kuroki L, Fuh K, Thaker P, Hagemann A. 25 Comparison of three testing strategies for germline genetic testing for homologous recombination deficiency mutations in women with epithelial ovarian cancer. Gynecol Oncol Rep 2022. [DOI: 10.1016/s2352-5789(22)00237-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Zamorano AS, Wilson EM, Liu J, Leon A, Kuroki LM, Thaker PH, McCourt CK, Fuh KC, Powell MA, Mutch DG, Evanoff BA, Colditz GA, Hagemann AR. Text-message-based behavioral weight loss for endometrial cancer survivors with obesity: A randomized controlled trial. Gynecol Oncol 2021; 162:770-777. [PMID: 34140179 DOI: 10.1016/j.ygyno.2021.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the ability of a personalized text-message-based intervention to increase weight loss among endometrial cancer survivors with obesity. METHODS In this randomized, controlled trial, endometrial cancer survivors with obesity (BMI ≥30 kg/m2) were randomized to a personalized SMS text-message-based weight loss intervention or enhanced usual care. Primary outcome was weight loss at 6 months; secondary outcomes were weight loss at 12 months and changes in psychosocial measures. We also compared clinical characteristics and weight change between trial participants and non-participants. RESULTS Between May 18 and December 31, 2017, 80 endometrial cancer survivors with obesity consented to participate in the randomized trial. There were no differences in clinical characteristics between the two arms. Weight changes were similar in the two arms (P = 0.08). At 6 months, no differences in quality of life, physical activity, or body image were noted. Of 358 eligible patients, 80 became trial participants and 278, non-participants. Trial participants were younger (59.3 vs. 63.4 years, P < 0.001), more likely non-white (P = 0.02), on fewer medications (4 vs. 7, P < 0.001), and had a higher median BMI (38.7 vs. 37.6 kg/m2, P = 0.01) than non-participants. Weight change was similar between participants and non-participants (P = 0.85). At 6 months, similar percentages of participants and non-participants (47.7% vs. 44.4%) had gained weight, and similar percentages (9.2% vs. 11.2%) had lost at least 5% of their body weight. CONCLUSIONS This text-message-based intervention did not increase weight loss among endometrial cancer survivors with obesity, nor did participation in the trial. Other weight management interventions should be promoted to increase weight loss. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, www.clinicaltrials.gov, NCT03169023.
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Affiliation(s)
- Abigail S Zamorano
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Elise M Wilson
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Jingxia Liu
- Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Andrea Leon
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Lindsay M Kuroki
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Premal H Thaker
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Carolyn K McCourt
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Katherine C Fuh
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Matthew A Powell
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - David G Mutch
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Bradley A Evanoff
- Division of General Medical Sciences, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Graham A Colditz
- Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Andrea R Hagemann
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States of America.
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4
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Wilson EM, Zamorano AS, Liu J, Morris D, Leon A, Kuroki LM, Thaker PH, McCourt CK, Fuh KC, Powell MA, Mutch DG, Colditz GA, Hagemann AR. Obese endometrial cancer survivors' perceptions of weight loss strategies and characteristics that may influence participation in behavioral interventions. Gynecol Oncol Rep 2021; 36:100719. [PMID: 33665293 PMCID: PMC7907756 DOI: 10.1016/j.gore.2021.100719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 01/08/2023] Open
Abstract
Endometrial cancer (EC) survivors have attempted many methods to lose weight. EC survivors rarely choose bariatric surgery, physical therapy, or psychologic support services to lose weight. EC survivors without recurrence were more likely to enroll in a weight loss intervention trial than those with recurrence.
We aimed to evaluate obese endometrial cancer (EC) survivors' perceptions of weight loss barriers and previously attempted weight loss methods and to identify characteristics that predicted willingness to enroll in a behavioral intervention trial. We administered a 27-question baseline survey at an academic institution to EC survivors with body mass index ≥ 30 kg/m2. Survivors were asked about their lifestyles, previous weight loss attempts, perceived barriers, and were offered enrollment into an intervention trial. Data was analyzed using Fisher’s Exact, Kruskal-Wallis, and univariate and multivariate regressions. 155 of 358 (43%) eligible obese EC survivors were surveyed. Nearly all (n = 148, 96%) had considered losing weight, and 77% (n = 120) had tried two or more strategies. Few had undergone bariatric surgery (n = 5, 3%), psychologic counseling (n = 2, 1%), or met with physical therapists (n = 9, 6%). Lower income was associated with difficulty in accessing interventions. Survivors commented that negative self-perceptions and difficulties with follow-through were barriers to weight loss, and fear of complications and self-perceived lack of qualification were deterrents to bariatric surgery. 80 (52%) of those surveyed enrolled in the trial. In a multivariate model, adjusting for race and stage, survivors without recurrence were 4.3 times more likely to enroll than those with recurrence. Most obese EC survivors have tried multiple strategies to lose weight, but remain interested in weight loss interventions, especially women who have never experienced recurrence. Providers should encourage weight loss interventions early, at the time of initial diagnosis, and promote underutilized strategies such as psychological counseling, physical therapy, and bariatric surgery.
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Affiliation(s)
- Elise M Wilson
- Department of Obstetrics & Gynecology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Abigail S Zamorano
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Jingxia Liu
- Division of Public Health Sciences, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - David Morris
- Siteman Cancer Center Psychology Service, Barnes-Jewish Hospital, St. Louis, MO, United States
| | - Andrea Leon
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Lindsay M Kuroki
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Premal H Thaker
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Carolyn K McCourt
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Katherine C Fuh
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Matthew A Powell
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - David G Mutch
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Graham A Colditz
- Division of Public Health Sciences, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Andrea R Hagemann
- Division of Gynecologic Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
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Wilson CE, Dickie AP, Schreiter K, Wehr R, Wilson EM, Bial J, Scheer N, Wilson ID, Riley RJ. The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice. Arch Toxicol 2018; 92:1953-1967. [PMID: 29721588 DOI: 10.1007/s00204-018-2212-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/25/2018] [Indexed: 11/30/2022]
Abstract
The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.
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Affiliation(s)
- C E Wilson
- Nestlé Skin Health R&D, Les Templiers, Route des Colles, BP 87, 06902, Sophia-Antipolis, France.
| | - A P Dickie
- Evotec (UK) Ltd, 114 Innovation Drive, Abingdon, Oxfordshire, OX14 4RZ, UK
| | - K Schreiter
- Evotec International GmbH, Manfred Eigen Campus, Essener Bogen 7, Hamburg, Germany
| | - R Wehr
- Evotec International GmbH, Manfred Eigen Campus, Essener Bogen 7, Hamburg, Germany
| | - E M Wilson
- Yecuris Corporation, PO Box 4645, Tualatin, OR, 97062, USA
| | - J Bial
- Yecuris Corporation, PO Box 4645, Tualatin, OR, 97062, USA
| | - N Scheer
- CEVEC Pharmaceuticals GmbH, Gottfried-Hagen-Str. 60-62, 51105, Cologne, Germany
| | - I D Wilson
- Department of Surgery and Cancer, Imperial College, Exhibition Rd, South Kensington, London, SW7 2AZ, UK
| | - R J Riley
- Evotec (UK) Ltd, Alderley Park, Nether Alderley, Cheshire, SK10 4TG, UK
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Burd CJ, Petre CE, Moghadam H, Wilson EM, Knudsen KE. Cyclin D1 binding to the androgen receptor (AR) NH2-terminal domain inhibits activation function 2 association and reveals dual roles for AR corepression. Mol Endocrinol 2004; 19:607-20. [PMID: 15539430 DOI: 10.1210/me.2004-0266] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The androgen receptor (AR) is a member of the nuclear receptor superfamily, the activity of which is critical for the development and progression of prostate cancer. We and others have previously demonstrated that cyclin D1 is a potent corepressor of the AR. Although cyclin D1 is suspected to recruit histone deacetylases to the AR complex, previous studies have demonstrated that this activity alone is insufficient for cyclin D1 function. Here, we uncover a novel, secondary means of cyclin D1-mediated repression, through modulation of AR amino-carboxy terminal interactions. We show that cyclin D1 predominantly binds the N-terminal domain of the AR, dependent on the AR 23FxxLF27 motif. Through this motif, cyclin D1 abrogates the ability of the AR N-terminal domain to interact with the C terminus. Secondary amino-terminal domain sites capable of fostering interaction with the C terminus were refractory to cyclin D1 action, indicating that the ability of cyclin D1 to modulate AR amino-carboxy terminal interactions is specific to 23FxxLF27. Deletion of the N-terminal cyclin D1 binding site severely compromised AR activity (due to loss of FxxLF) but unmasked a repressor action through interaction with the AR C terminus. In summary, these data reveal novel, unexpected mechanisms of cyclin D1 activity and demonstrate that this function of cyclin D1 is critical for AR modulation.
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Affiliation(s)
- C J Burd
- Department of Cell Biology, University of Cincinnati College of Medicine, P.O. Box 670521, 3125 Eden Avenue, Cincinnati, Ohio 45267-0521, USA
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Munro JF, MacCuish AC, Wilson EM, Duncan LJ. Comparison of continuous and intermittent anorectic therapy in obesity. Br Med J 2004; 1:352-4. [PMID: 15508204 PMCID: PMC1984840 DOI: 10.1136/bmj.1.5588.352] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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8
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Wilson EM. Three-dimensional conformal radiotherapy in the radical treatment of non-small cell lung cancer. Clin Oncol (R Coll Radiol) 2003; 15:412-9. [PMID: 14570090 DOI: 10.1016/s0936-6555(03)00116-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Patients with locally advanced, inoperable, non-small cell lung cancer (NSCLC) have a poor prognosis mainly due to failure of local control after treatment with radical radiotherapy. This overview addresses the role of three-dimensional conformal radiotherapy (3D CRT) in trying to improve survival and reduce toxicity for patients with NSCLC. Current techniques of 3D CRT are analysed and discussed. They include imaging, target volume definition, optimisation of the delivery of radiotherapy through improvement of set-up inaccuracy and reduction of organ motion, dosimetry and implementation and verification issues; the overview concludes with the clinical results of 3D CRT.
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Affiliation(s)
- E M Wilson
- Specialist Registrar in Clinical Oncology, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, UK.
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Affiliation(s)
- M Liao
- Loeb Health Research Institute, University of Ottawa, Ottawa, Ontario, Canada
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10
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Abstract
The progression of left ventricular (LV) dysfunction is often accompanied by changes in LV geometry and myocardial architecture that can be defined as LV myocardial remodelling. An important event in LV myocardial remodelling is alterations in the extracellular matrix (ECM). A family of zinc-dependent proteases implicated in facilitating myocardial tissue remodelling by degrading components of the ECM are the matrix metalloproteinases (MMPs). The temporal expression of MMPs and the local tissue inhibitors of MMPs (TIMPs) appear to be differentially regulated in several cardiovascular disease states such as myocardial infarction, LV hypertrophy, and dilated cardiomyopathy. Both pharmacological and genetic modulation of myocardial MMP expression has been demonstrated to alter the course of LV myocardial remodelling and LV dysfunction. The induction of MMPs within the myocardium during the heart failure process probably results in liberation of bioactive molecules, proteolytic degradation of ECM structural proteins, and alterations in cell-cell contact and adhesion. Modifying MMP expression and activation may reduce this turmoil within the myocardial interstitium and, in turn, prove to be a useful therapeutic paradigm for heart failure treatment.
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Affiliation(s)
- E M Wilson
- Medical University of South Carolina, Charleston, USA
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11
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Abstract
Activation domains in the 114 kDa androgen receptor (AR) NH(2)- and carboxyl-terminal regions are thought to contribute to different extents to AR-mediated transactivation. We investigated using anti-peptide antibodies whether smaller AR forms that migrate like the previously described 87 kDa AR-A occur in vivo resulting in constitutive or increased gene activation. Immunoblots of prostate cancer and fibroblast cell culture extracts revealed 114 and 84 kDa AR forms. Antibody mapping indicated the 84 kDa AR lacked the ligand-binding domain and comigrated with the constitutively active AR fragment AR1-660. AR expressed in COS cells was 114 and 92 kDa. Migration of the 92 kDa AR was slightly slower than that of a 90 kDa expressed fragment that was designed to initiate at the second methionine (residue 189) and lacked the NH(2)-terminal FxxLF interaction sequence. The 92 kDa AR did not result from alternative initiation since it was observed when the second methionine was changed to alanine. Optimization of extraction conditions indicated that both 84 and 92 kDa forms resulted from in vitro proteolytic cleavage and that cleavage by caspase-3 could account for the 92 kDa form. The results suggest that AR forms with gel mobility similar to that of the previously described 87 kDa AR-A result from in vitro proteolytic cleavage of NH(2)- or carboxyl-terminal regions during cell extraction and storage and that smaller forms with increased transcriptional activity do not occur in vivo.
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Affiliation(s)
- C W Gregory
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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He B, Bowen NT, Minges JT, Wilson EM. Androgen-induced NH2- and COOH-terminal Interaction Inhibits p160 coactivator recruitment by activation function 2. J Biol Chem 2001; 276:42293-301. [PMID: 11551963 DOI: 10.1074/jbc.m107492200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The androgen receptor undergoes an androgen-specific NH(2)- and COOH-terminal interaction between NH(2)-terminal motif FXXLF and activation function 2 in the ligand binding domain. We demonstrated previously that activation function 2 forms overlapping binding sites for the androgen receptor FXXLF motif and the LXXLL motifs of p160 coactivators. Here we investigate the influence of the NH(2)- and COOH-terminal interaction on androgen receptor function. Specificity and relative potency of the motif interactions were evaluated by ligand dissociation rate and the stability of chimeras of transcriptional intermediary factor 2 with full-length and truncated androgen or glucocorticoid receptor. The results indicate that the androgen receptor activation function 2 interacts specifically and with greater avidity with the single FXXLF motif than with the LXXLL motif region of p160 coactivators, whereas this region of the glucocorticoid receptor interacts preferentially with the LXXLL motifs. Expression of the LXXLL motifs as a fusion protein with the glucocorticoid receptor resulted in loss of agonist-induced receptor destabilization and increased half-time of ligand dissociation. The NH(2)- and COOH-terminal interaction inhibited binding and activation by transcriptional intermediary factor 2. We conclude that the androgen receptor NH(2)- and COOH-terminal interaction reduces the dissociation rate of bound androgen, stabilizes the receptor, and inhibits p160 coactivator recruitment by activation function 2.
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Affiliation(s)
- B He
- Department of Biochemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Curtin D, Jenkins S, Farmer N, Anderson AC, Haisenleder DJ, Rissman E, Wilson EM, Shupnik MA. Androgen suppression of GnRH-stimulated rat LHbeta gene transcription occurs through Sp1 sites in the distal GnRH-responsive promoter region. Mol Endocrinol 2001; 15:1906-17. [PMID: 11682622 DOI: 10.1210/mend.15.11.0723] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Steroids may regulate LH subunit gene transcription by modulating hypothalamic GnRH pulse patterns or by acting at the pituitary gonadotrope to alter promoter activity. We tested direct pituitary effects of the androgen dihydrotestosterone (DHT) to modulate the rat LHbeta promoter in transfected LbetaT2 clonal gonadotrope cells and in pituitaries of transgenic mice expressing LHbeta-luciferase. The LHbeta promoter (-617 to +44 bp)-luciferase construct was stimulated in LbetaT2 cells 7- to 10-fold by GnRH. Androgen treatment had little effect on basal promoter activity but suppressed GnRH stimulation by approximately 75%. GnRH stimulation of LHbeta was also suppressed by DHT in isolated pituitary cells from male or female mice with functional nuclear ARs, but not in male littermates with mutant AR. GnRH stimulation of the LHbeta promoter requires interactions between a complex distal response element containing two specificity protein-1 (Sp1) binding sites and a CArG box, and a proximal element with two bipartite binding sites for steroidogenic factor-1 and early growth response protein-1 (Egr-1). DHT effectively suppressed promoter constructs with an intact distal response element. The distal response element does not bind AR, but AR reduces Sp1 binding to this region. Glutathione-S-transferase pull-down studies demonstrated direct interactions of AR with Sp1, which requires the DNA-binding domain of AR, and weaker interactions with Egr-1. We conclude that androgen suppression of the rat LHbeta promoter occurs primarily through direct interaction of AR with Sp1, with some possible role through binding to Egr-1. These interactions result in interference with GnRH-stimulated gene transcription by reducing cooperation between the distal and proximal GnRH response elements.
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MESH Headings
- Animals
- Binding Sites
- Cells, Cultured
- Dihydrotestosterone/pharmacology
- Female
- Glycoprotein Hormones, alpha Subunit/genetics
- Glycoprotein Hormones, alpha Subunit/metabolism
- Gonadotropin-Releasing Hormone/metabolism
- Gonadotropin-Releasing Hormone/pharmacology
- Luteinizing Hormone/drug effects
- Luteinizing Hormone/genetics
- Luteinizing Hormone/metabolism
- Male
- Mice
- Mice, Transgenic
- Pituitary Gland/cytology
- Pituitary Gland/physiology
- Promoter Regions, Genetic
- Rats
- Receptors, Androgen/drug effects
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, LHRH/drug effects
- Receptors, LHRH/genetics
- Response Elements/drug effects
- Response Elements/genetics
- Sp1 Transcription Factor/metabolism
- Steroidogenic Factor 1
- Suppression, Genetic
- Transcription, Genetic
- Transfection
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Affiliation(s)
- D Curtin
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
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Tureckova J, Wilson EM, Cappalonga JL, Rotwein P. Insulin-like growth factor-mediated muscle differentiation: collaboration between phosphatidylinositol 3-kinase-Akt-signaling pathways and myogenin. J Biol Chem 2001; 276:39264-70. [PMID: 11500504 DOI: 10.1074/jbc.m104991200] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The differentiation and maturation of skeletal muscle require interactions between signaling pathways activated by hormones and growth factors and an intrinsic regulatory network controlled by myogenic transcription factors. Insulin-like growth factors (IGFs) play key roles in muscle development in the embryo and in regeneration in the adult. To study mechanisms of IGF action in muscle, we developed a myogenic cell line that overexpresses IGF-binding protein-5. C2BP5 cells remain quiescent in low serum differentiation medium until the addition of IGF-I. Here we use this cell line to identify signaling pathways controlling IGF-mediated differentiation. Induction of myogenin by IGF-I and myotube formation were prevented by the phosphatidylinositol (PI) 3-kinase inhibitor, LY294002, even when included 2 days after growth factor addition, whereas expression of active PI 3-kinase could promote differentiation in the absence of IGF-I. Differentiation also was induced by myogenin but was blocked by LY294002. The differentiation-promoting effects of IGF-I were mimicked by a modified membrane-targeted inducible Akt-1 (iAkt), and iAkt was able to stimulate differentiation of C2 myoblasts and primary mouse myoblasts incubated with otherwise inhibitory concentrations of LY294002. These results show that an IGF-regulated PI 3-kinase-Akt pathway controls muscle differentiation by mechanisms acting both upstream and downstream of myogenin.
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Affiliation(s)
- J Tureckova
- Oregon Health and Science University, Molecular Medicine Division, Department of Medicine, Portland, Oregon 97201-3098, USA
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Buckway CK, Wilson EM, Ahlsén M, Bang P, Oh Y, Rosenfeld RG. Mutation of three critical amino acids of the N-terminal domain of IGF-binding protein-3 essential for high affinity IGF binding. J Clin Endocrinol Metab 2001; 86:4943-50. [PMID: 11600567 DOI: 10.1210/jcem.86.10.7936] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The N-terminal domain is conserved in all members of the IGF-binding protein superfamily. Most recently, studies have demonstrated the importance of an IGF-binding protein N-terminal hydrophobic pocket for IGF binding. To examine more critically the amino acids important for IGF binding within the full-length IGF-binding protein-3 protein while minimizing changes in the tertiary structure, we targeted residues I56, L80, and L81 within the proposed hydrophobic pocket for mutation. With a single change at these sites to the nonconserved glycine there was a notable decrease in binding. A greater reduction was seen when both L80 and L81 were substituted with glycine, and complete loss of affinity for IGF-I and IGF-II occurred when all three targeted amino acids were changed to glycine. Furthermore, the ability of the IGF-binding protein-3 mutants to inhibit IGF-I-stimulated phosphorylation of its receptor was a reflection of their affinity for IGF, with the lowest affinity mutants having the least inhibitory effect. These studies, thus, support the hypothesis that an N-terminal hydrophobic pocket is the primary site of high affinity binding of IGF to IGF-binding protein-3. The mutants provide a tool for future studies directed at IGF-dependent and IGF-independent actions of IGF-binding protein-3.
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Affiliation(s)
- C K Buckway
- Department of Pediatrics, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97201, USA.
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16
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Wilson EM, Oh Y, Hwa V, Rosenfeld RG. Interaction of IGF-binding protein-related protein 1 with a novel protein, neuroendocrine differentiation factor, results in neuroendocrine differentiation of prostate cancer cells. J Clin Endocrinol Metab 2001; 86:4504-11. [PMID: 11549700 DOI: 10.1210/jcem.86.9.7845] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Neuroendocrine cells have been implicated in many cancers, including small cell lung, cervical, breast, and prostate carcinomas. The increase in neuroendocrine cell number in prostate cancer has been reported to correlate with poor prognosis, progressive tumors, and androgen insensitivity. The mechanisms involved in this differentiation remain unknown. IGF-binding protein-related protein 1 is a member of the IGF-binding protein superfamily and has recently been shown to exhibit differentiation and tumor suppression activity in prostate cancer cell lines stably overexpressing IGF-binding protein-related protein 1. From a yeast two-hybrid screen, a novel IGF-binding protein-related protein 1-interacting protein was identified. Immunocytochemical techniques indicate that this protein, 25.1, and intracellular IGF-binding protein-related protein 1 colocalize in the nucleus. When 25.1 is transiently expressed in a stable prostate cancer cell line overexpressing IGF-binding protein-related protein 1, cells assume a neuritic-like morphology with long dendritic-like processes and express the neuroendocrine markers chromogranin A and neuron-specific enolase. We propose that 25.1 (neuroendocrine differentiation factor) together with IGF-binding protein-related protein 1 can induce neuroendocrine cell differentiation in prostate cancer cells.
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Affiliation(s)
- E M Wilson
- Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201, USA
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17
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Walker GE, Wilson EM, Powell D, Oh Y. Butyrate, a histone deacetylase inhibitor, activates the human IGF binding protein-3 promoter in breast cancer cells: molecular mechanism involves an Sp1/Sp3 multiprotein complex. Endocrinology 2001; 142:3817-27. [PMID: 11517158 DOI: 10.1210/endo.142.9.8380] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Specific cell growth stimulators and inhibitors regulate IGF binding protein-3 (IGFBP-3), where in turn IGFBP-3 mediates their biological effects. The molecular mechanism(s) by which these factors regulate IGFBP-3 are unknown. Sodium butyrate, a histone deacetylase inhibitor causing growth arrest and differentiation, increases IGFBP-3 expression. We investigated the molecular mechanism of this induction using an IGFBP-3 promoter reporter system in MCF-7 and Hs578T breast cancer cells. IGFBP-3 promoter activity was induced up to 40-fold following a 24-h treatment with sodium butyrate and 46-fold in cells treated with trichostatin A, a pure histone deacetylase inhibitor. Deletion analysis of the IGFBP-3 promoter identified key sodium butyrate-responsive element(s) to a 45-bp region containing consensus binding sites for Sp1 and activating protein-2. Sp1 binding to the Sp1 site and Sp3 to the activating protein-2/GA-box played a functional role in sodium butyrate's activation of the IGFBP-3 promoter, however, with no change in binding direct sodium butyrate regulation was attributed to cofactors. The histone acetyltransferase p300 and histone deacetylase-1 were identified in multiprotein complexes containing DNA bound Sp1 and Sp3, with p300 accumulating following sodium butyrate treatment. Taken together, these data suggest that sodium butyrate increases IGFBP-3 expression by activating the IGFBP-3 promoter via an Sp1/Sp3 multiprotein complex, a mechanism that may be important for other key regulators of IGFBP-3.
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Affiliation(s)
- G E Walker
- Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201, USA
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18
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Jenkins R, Angus RA, McNatt H, Howell WM, Kemppainen JA, Kirk M, Wilson EM. Identification of androstenedione in a river containing paper mill effluent. Environ Toxicol Chem 2001; 20:1325-1331. [PMID: 11392143 DOI: 10.1897/1551-5028(2001)020<1325:ioaiar>2.0.co;2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Effluent from a paper mill discharging into the Fenholloway River, Taylor County, Florida, USA, contains chemicals that masculinize females of the resident population of eastern mosquitofish (Gambusia holbrooki), as evidenced in females by elongated anal fins, which is normally a male-specific trait. To identify androgenic components in the effluent, water collected from the Fenholloway River and a control tributary was fractionated using solid-phase extraction and reverse-phase high-performance-liquid chromatography. Two Fenholloway River fractions induced androgen receptor-dependent transcriptional activity in transient transfection cell culture assays. Of these, androstenedione was confirmed by liquid chromatography-mass spectrometry with multiple reaction monitoring.
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Affiliation(s)
- R Jenkins
- Biology Department, Samford University, Birmingham, Alabama 35229, USA
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19
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Gregory CW, He B, Johnson RT, Ford OH, Mohler JL, French FS, Wilson EM. A mechanism for androgen receptor-mediated prostate cancer recurrence after androgen deprivation therapy. Cancer Res 2001; 61:4315-9. [PMID: 11389051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The development and growth of prostate cancer depends on the androgen receptor and its high-affinity binding of dihydrotestosterone, which derives from testosterone. Most prostate tumors regress after therapy to prevent testosterone production by the testes, but the tumors eventually recur and cause death. A critical question is whether the androgen receptor mediates recurrent tumor growth after androgen deprivation therapy. Here we report that a majority of recurrent prostate cancers express high levels of the androgen receptor and two nuclear receptor coactivators, transcriptional intermediary factor 2 and steroid receptor coactivator 1. Overexpression of these coactivators increases androgen receptor transactivation at physiological concentrations of adrenal androgen. Furthermore, we provide a molecular basis for this activation and suggest a general mechanism for recurrent prostate cancer growth.
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Affiliation(s)
- C W Gregory
- Laboratory for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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20
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Gregory CW, Johnson RT, Mohler JL, French FS, Wilson EM. Androgen receptor stabilization in recurrent prostate cancer is associated with hypersensitivity to low androgen. Cancer Res 2001; 61:2892-8. [PMID: 11306464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The androgen receptor (AR) is highly expressed in androgen-dependent and recurrent prostate cancer (CaP) suggesting it has a role in the growth and progression of CaP. Previously proposed mechanisms for AR reactivation in recurrent CaP include altered growth factor signaling leading to protein phosphorylation and AR mutations that broaden ligand specificity. To further establish a role for AR in recurrent CaP, we compared several properties of AR in relation to the growth response to low levels of androgens in model systems of androgen-dependent and recurrent CaP. AR from all of the tumors and cell lines bound [3H]R1881 with similar high affinity (mean Kd, 0.12 nM). In the absence of androgen, AR in androgen-dependent LNCaP cells was unstable with a degradation half-time (t(1/2)) of 3 h at 37 degrees C. In contrast, AR was 2-4 times more stable in recurrent CWR22 tumors (t(1/2), >12 h) and CWR-R1 or LNCaP-C4-2 cell lines (t(1/2), 6-7 h) derived from recurrent prostate tumors. In the recurrent CWR22 tumor and its CWR-R1 cell line grown in the absence of androgen, AR immunostaining was entirely nuclear, whereas under the same conditions AR in LNCaP-C4-2 and LNCaP cells was predominantly nuclear but was also detected in the cytoplasm. High level expression, increased stability, and nuclear localization of AR in recurrent tumor cells were associated with an increased sensitivity to the growth-promoting effects of dihydrotestosterone in the femtomolar range. The concentration of dihydrotestosterone required for growth stimulation in CWR-R1 and LNCaP-C4-2 cells was four orders of magnitude lower than that required for androgen-dependent LNCaP cells. The results suggest that AR is transcriptionally active in recurrent CaP and can increase cell proliferation at the low circulating levels of androgen reported in castrated men.
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Affiliation(s)
- C W Gregory
- Department of Pediatrics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill 27599, USA.
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21
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Massaad C, Garlatti M, Wilson EM, Cadepond F, Barouki R. A natural sequence consisting of overlapping glucocorticoid-responsive elements mediates glucocorticoid, but not androgen, regulation of gene expression. Biochem J 2000; 350 Pt 1:123-9. [PMID: 10926835 PMCID: PMC1221233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Cytosolic aspartate aminotransferase (cAspAT) is regulated by glucocorticoids in rat liver and kidney. Part of this regulation is mediated by an unusual glucocorticoid-responsive element (GRE)-like sequence called GRE A. GRE A is composed of two overlapping imperfect GREs, each comprising a conserved half-site (half-sites 1 and 4 respectively) and a poorly conserved half-site (half-sites 2 and 3 respectively). The sequence binds co-operatively two dimers of the glucocorticoid receptor (GR) and mediates efficient glucocorticoid regulation of gene expression. Analysis of deletions of the cAspAT gene promoter and subcloning of GRE A upstream of the thymidine kinase promoter indicate that this sequence is responsive to glucocorticoids, but not to androgens. Electrophoretic mobility shift assays indicate that the GRE A unit does not bind the androgen receptor (AR). The modification of three nucleotides in the poorly conserved half-sites 2 and 3, converting GRE A into two overlapping high-affinity GREs (ov-cGRE), resulted in co-operative binding of the AR. Furthermore, ov-cGRE efficiently mediated androgen regulation of the thymidine kinase promoter. A single base modification in half-site 2 or 3 in GRE A allowed the binding of the AR as one or two dimers respectively, and restored transcriptional activation by androgens only in the latter case. Thus the poor affinity of the AR for half-sites 2 and 3 prevented its binding to GRE A, indicating that the overlapping GRE A sequence of the cAspAT gene promoter discriminates a glucocorticoid-mediated from an androgen-mediated response.
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Affiliation(s)
- C Massaad
- INSERM Unité 490, Université René Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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22
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He B, Kemppainen JA, Wilson EM. FXXLF and WXXLF sequences mediate the NH2-terminal interaction with the ligand binding domain of the androgen receptor. J Biol Chem 2000; 275:22986-94. [PMID: 10816582 DOI: 10.1074/jbc.m002807200] [Citation(s) in RCA: 308] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nuclear receptor superfamily members of eukaryotic transcriptional regulators contain a highly conserved activation function 2 (AF2) in the hormone binding carboxyl-terminal domain and, for some, an additional activation function 1 in the NH(2)-terminal region which is not conserved. Recent biochemical and crystallographic studies revealed the molecular basis of AF2 is hormone-dependent recruitment of LXXLL motif-containing coactivators, including the p160 family, to a hydrophobic cleft in the ligand binding domain. Our previous studies demonstrated that AF2 in the androgen receptor (AR) binds only weakly to LXXLL motif-containing coactivators and instead mediates an androgen-dependent interaction with the AR NH(2)-terminal domain required for its physiological function. Here we demonstrate in a mammalian two-hybrid assay, glutathione S-transferase fusion protein binding studies, and functional assays that two predicted alpha-helical regions that are similar, but functionally distinct from the p160 coactivator interaction sequence, mediate the androgen-dependent, NH(2)- and carboxyl-terminal interaction. FXXLF in the AR NH(2)-terminal domain with the sequence (23)FQNLF(27) mediates interaction with AF2 and is the predominant androgen-dependent interaction site. This FXXLF sequence and a second NH(2)-terminal WXXLF sequence (433)WHTLF(437) interact with different regions of the ligand binding domain to stabilize the hormone-receptor complex and may compete with AF2 recruitment of LXXLL motif-containing coactivators. The results suggest a unique mechanism for AR-mediated transcriptional activation.
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Affiliation(s)
- B He
- Laboratories for Reproductive Biology, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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23
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Johnson BA, Wilson EM, Li Y, Moller DE, Smith RG, Zhou G. Ligand-induced stabilization of PPARgamma monitored by NMR spectroscopy: implications for nuclear receptor activation. J Mol Biol 2000; 298:187-94. [PMID: 10764590 DOI: 10.1006/jmbi.2000.3636] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nuclear receptors are ligand-dependent transcription factors that are mediators of the action of lipophilic hormones and other endogenous ligands and are the targets of drugs useful in a variety of therapeutic areas. Peroxisome proliferator-activated receptor (PPAR)gamma is a nuclear receptor that, acting as a heterodimer with RXR, mediates a variety of cellular effects including adipocyte-differentiation. Due to its role in modulating insulin sensitivity, it is the target of therapeutically active anti-diabetic agents such as rosiglitazone. We have assigned the chemical shifts of the backbone atoms of the 32 kDa ligand-binding domain of PPARgamma in the presence of bound rosiglitazone. Three-dimensional HNCO spectra of the apo ligand-binding domain (LBD) have less than half the expected number of cross-peaks. The missing cross-peaks are restored upon binding strong agonists such as rosiglitazone. The NMR results indicate that the apo-LBD of PPARgamma is in a conformationally mobile state, and that agonist binding is associated with a marked stabilization of the conformation. Mapping the missing peaks to the 3D X-ray crystallographic structure indicates the region of mobility is extensive and includes the ligand-binding region and the cofactor-binding site. This leads to the conclusion that activation of this nuclear receptor is a result of a population shift of a dynamic ensemble of conformations, rather than a two-state switch from an inactive to an active conformation. Our results have important implications for the mechanisms by which antagonists, partial agonists, and agonists of nuclear receptor function operate.
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Affiliation(s)
- B A Johnson
- Department of Endocrinology and Chemical Biology, Merck Research Laboratories, Rahway, NJ 07065, USA.
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24
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Wilson EM. A model for prehospital personnel continuing education. J Emerg Nurs 2000; 26:48-50. [PMID: 10657799 DOI: 10.1016/s0099-1767(00)90016-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- E M Wilson
- Department of Clinical Research, Connecticut Asthma and Allergy Center, West Hartford, Conn., USA
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25
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He B, Kemppainen JA, Voegel JJ, Gronemeyer H, Wilson EM. Activation function 2 in the human androgen receptor ligand binding domain mediates interdomain communication with the NH(2)-terminal domain. J Biol Chem 1999; 274:37219-25. [PMID: 10601285 DOI: 10.1074/jbc.274.52.37219] [Citation(s) in RCA: 267] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation function 2 in the ligand binding domain of nuclear receptors forms a hydrophobic cleft that binds the LXXLL motif of p160 transcriptional coactivators. Here we provide evidence that activation function 2 in the androgen receptor serves as the contact site for the androgen dependent NH(2)- and carboxyl-terminal interaction of the androgen receptor and only weakly interacts with p160 coactivators in an LXXLL-dependent manner. Mutagenesis studies indicate that it is the NH(2)-/carboxyl-terminal interaction that is required by activation function 2 to stabilize helix 12 and slow androgen dissociation critical for androgen receptor activity in vivo. The androgen receptor recruits p160 coactivators through its NH(2)-terminal and DNA binding domains in an LXXLL motif-independent manner. The results suggest a novel function for activation function 2 and a unique mechanism of nuclear receptor transactivation.
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Affiliation(s)
- B He
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina 27599-7500, USA
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26
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Wilson EM. The forgotten copper 7 - a circus tale. Br J Fam Plann 1999; 25:122-3. [PMID: 10567065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A forgotten Gravigard intra-uterine contraceptive device, in a woman with an itinerant lifestyle, caused pelvic actinomycosis, mimicking ovarian malignancy. This case illustrates that although rare, this complication can still occur.
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Affiliation(s)
- E M Wilson
- Gateshead Health NHS Trust, Low Fell, Gateshead, UK
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27
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Leon MD, Wilson EM. Development of a statewide protocol for the prehospital identification of DNR patients in Connecticut including new DNR regulations. Ann Emerg Med 1999; 34:263-74. [PMID: 10424934 DOI: 10.1016/s0196-0644(99)70242-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This article describes the development and implementation of a standardized protocol for the prehospital identification of terminally ill "do-not-resuscitate" (DNR) patients. This pilot program was initiated by members of the Connecticut College of Emergency Physicians and instituted on a voluntary basis statewide in July 1991. Key components of the program are discussed, including developmental rationale, formation of a DNR Coalition, educational rollout, and implementation activities. The second phase of this initiative involved passage of state legislation and development of new DNR regulations, which went into effect in July 1997. The regulations successfully addressed the limitations and difficulties encountered in the pilot program. Major modifications included applicability of the bracelet program to a broader group of DNR patients, development of a uniform system for interfacility transfer of DNR patients, and mandatory compliance by health care personnel.
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Affiliation(s)
- M D Leon
- Department of Traumatology and Emergency Medicine, University of Connecticut Health Center, Farmington, CT, USA.
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28
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Liao M, Zhou ZX, Wilson EM. Redox-dependent DNA binding of the purified androgen receptor: evidence for disulfide-linked androgen receptor dimers. Biochemistry 1999; 38:9718-27. [PMID: 10423251 DOI: 10.1021/bi990589i] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Full-length histidine-tagged, dihydrotestosterone-bound human androgen receptor (AR) was purified to homogeneity by affinity and gel-filtration chromatography for antibody production and analysis of AR dimerization and DNA binding properties. A monoclonal antibody was raised that recognized human and rat AR epitope (360)ArgAspTyrTyrAsnPheProLeuAla(368) in the NH(2)-terminal domain and slowed migration of AR-DNA complexes in mobility shift assays. AR binding to androgen response element DNA had a K(d) of 2.0 nM and a Hill coefficient of 2.1, indicating high-affinity, cooperative binding. AR solution dimerization was detected only at >/=0.2 microM AR, and DNA binding increased dimerization up to 30-fold. Slow- and fast-migrating AR-DNA complexes were detected under different reducing conditions that differed 5-fold in their dissociation rates from DNA. Treatment with the sulfhydryl oxidizing reagent diamide formed the faster migrating, slower dissociating complex, indicating it represents disulfide-linked AR dimers bound to DNA. The results indicate that high concentrations of purified AR are required for solution dimerization and that cooperative DNA binding stabilizes two dimer forms that differ in redox state.
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Affiliation(s)
- M Liao
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill 27599, USA
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29
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Kemppainen JA, Langley E, Wong CI, Bobseine K, Kelce WR, Wilson EM. Distinguishing androgen receptor agonists and antagonists: distinct mechanisms of activation by medroxyprogesterone acetate and dihydrotestosterone. Mol Endocrinol 1999; 13:440-54. [PMID: 10077001 DOI: 10.1210/mend.13.3.0255] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Natural and pharmacological androgen receptor (AR) ligands were tested for their ability to induce the AR NH2-terminal and carboxyl-terminal (N/C) interaction in a two-hybrid protein assay to determine whether N/C complex formation distinguishes in vivo AR agonists from antagonists. High-affinity agonists such as dihydrotestosterone, mibolerone, testosterone, and methyltrienolone at concentrations between 0.1 and 1 nM induce the N/C interaction more than 40-fold. The lower affinity anabolic steroids, oxandrolone and fluoxymesterone, require concentrations of 10-100 nM for up to 23-fold induction of the N/C interaction. However no N/C interaction was detected in the presence of the antagonists, hydroxyflutamide, cyproterone acetate, or RU56187, at concentrations up to 1 microM, or with 1 microM estradiol, progesterone, or medroxyprogesterone acetate; each of these steroids at 1-500 nM inhibited the dihydrotestosterone-induced N/C interaction, with medroxyprogesterone acetate being the most effective. In transient and stable cotransfection assays using the mouse mammary tumor virus reporter vector, all ligands displayed concentration-dependent AR agonist activity that paralleled induction of the N/C interaction, with antagonists and weaker agonists failing to induce the N/C interaction. AR dimerization and DNA binding in mobility shift assays and AR stabilization reflected, but were not dependent on, the N/C interaction. The results indicate that the N/C interaction facilitates agonist potency at low physiological ligand concentrations as detected in transcription, dimerization/DNA binding, and stabilization assays. However the N/C interaction is not required for agonist activity at sufficiently high ligand concentrations, nor does its inhibition imply antagonist activity.
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Affiliation(s)
- J A Kemppainen
- Department of Pediatrics, University of North Carolina, Chapel Hill 27599, USA
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30
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Burren CP, Wilson EM, Hwa V, Oh Y, Rosenfeld RG. Binding properties and distribution of insulin-like growth factor binding protein-related protein 3 (IGFBP-rP3/NovH), an additional member of the IGFBP Superfamily. J Clin Endocrinol Metab 1999; 84:1096-103. [PMID: 10084601 DOI: 10.1210/jcem.84.3.5577] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The protein product of the novH oncogene, a member of the CCN family, is structurally related to the insulin-like growth factor (IGF) binding proteins (IGFBPs). We have characterized aspects of structure, function, and distribution of this protein, which, as IGFBP-related protein 3 (IGFBP-rP3), is a proposed member of the IGFBP Superfamily. Affinity cross-linking experiments performed with baculovirus synthesized recombinant human IGFBP-rP3 established that rhIGFBP-rP3 binds IGF-I, IGF-II, and insulin with low affinity. Specificity of binding was shown by competitive cross-linking experiments; binding to IGF-I and -II was also demonstrated by nondenaturing Western ligand blots. Northern blot analysis indicated the presence of IGFBP-rP3 messenger RNA (mRNA) in a broad range of human tissues. Western immunoblotting studies, using a polyclonal rabbit anti-rhIGFBP-rP3 antibody, demonstrated that IGFBP-rP3 protein is synthesized in vitro by several breast and prostate cancer cell lines: Hs578T, PC3, P69, and LNCaP cells. Western immunoblotting studies of human biological fluids identified that IGFBP-rP3 was present in normal serum, pregnancy serum, serum from patients with growth hormone receptor deficiency, cerebrospinal fluid, amniotic fluid, peritoneal fluid, and follicular fluid, while IGFBP-rP3 fragments were identified in cerebrospinal fluid, amniotic fluid, and prepubertal and pubertal urine samples. Our studies demonstrate that IGFBP-rP3 exhibits IGF binding, albeit at low affinity, and IGFBP-rP3 thus merits inclusion in the IGFBP Superfamily. The low affinity IGF binding suggests that IGFBP-rP3 may act primarily independently of the IGFs. The synthesis of IGFBP-rP3 by several malignant cell lines and its presence in human biological fluids suggest that this protein possesses other interesting roles, potentially in cell growth regulation.
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Affiliation(s)
- C P Burren
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland 97201, USA
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31
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Yamanaka Y, Fowlkes JL, Wilson EM, Rosenfeld RG, Oh Y. Characterization of insulin-like growth factor binding protein-3 (IGFBP-3) binding to human breast cancer cells: kinetics of IGFBP-3 binding and identification of receptor binding domain on the IGFBP-3 molecule. Endocrinology 1999; 140:1319-28. [PMID: 10067859 DOI: 10.1210/endo.140.3.6566] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor binding protein-3 (IGFBP-3) binds to specific membrane proteins located on human breast cancer cells, which may be responsible for mediating the IGF-independent growth inhibitory effects of IGFBP-3. In this study, we evaluated IGFBP-3 binding sites on breast cancer cell membranes by competitive binding studies with IGFBP-1 through -6 and various forms of IGFBP-3, including synthetic IGFBP-3 fragments. Scatchard analysis revealed the existence of high-affinity sites for IGFBP-3 in estrogen receptor-negative Hs578T human breast cancer cells (dissociation constant (Kd) = 8.19 +/- 0.97 x 10(-9) M and 4.92 +/- 1.51 x 10(5) binding sites/cell) and 30-fold fewer receptors in estrogen receptor-positive MCF-7 cells (Kd = 8.49 +/- 0.78 x 10(-9) M and 1.72 +/- 0.31 x 10(4) binding sites/cell), using a one-site model. These data demonstrate binding characteristics of typical receptor-ligand interactions, strongly suggesting an IGFBP-3:IGFBP-3 receptor interaction. Among IGFBPs, only IGFBP-5 showed weak competition, indicating that IGFBP-3 binding to breast cancer cell surfaces is specific and cannot be attributed to nonspecific interaction with glycosaminoglycans. This was confirmed by showing that synthetic IGFBP-3 peptides containing IGFBP-3 glycosaminoglycan-binding domains competed only weakly for IGFBP-3 binding to the cell surface. Rat IGFBP-3 was 20-fold less potent in its ability to compete with human IGFBP-3(Echerichia coli), as well as 10- to 20-fold less potent for cell growth inhibition than human IGFBP-3, suggesting the existence of species specificity in the interaction between IGFBP-3 and the IGFBP-3 receptor. When various IGFBP-3 fragments were evaluated for affinity for the IGFBP-3 receptor, only those fragments that contain the midregion of the IGFBP-3 molecule were able to inhibit 125I-IGFBP-3(Escherichia coli) binding, indicating that the midregion of the IGFBP-3 molecule is responsible for binding to its receptor. These observations demonstrate that specific, high-affinity IGFBP-3 receptors are located on breast cancer cell membranes. These receptors have properties that support the notion that they may mediate the IGF-independent inhibitory actions of IGFBP-3 in breast cancer cells.
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Affiliation(s)
- Y Yamanaka
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland 97201-3042, USA
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Affiliation(s)
- C S Choong
- Department of Pediatric Endocrinology, Mater Misericordiae Children's Hospital, South Brisbane, Queensland 4101, Australia
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Abstract
Steroid hormone receptors control fundamental events in embryonic development and sex differentiation through their function as ligand-inducible transcription factors. The consequences of disrupting these processes can be especially profound during development due to the crucial role hormones play in controlling transient and irreversible developmental processes. Several environmental chemicals, including metabolites of the fungicide vinclozolin and the pesticide DDT, disrupt male reproductive development and function by inhibiting androgen receptor mediated events. A variety of in vitro and in vivo approaches have been used to determine the molecular basis of environmental antiandrogen toxicity. These chemicals commonly bind androgen receptor with moderate affinity and act as antagonists by inhibiting transcription of androgen dependent genes.
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Affiliation(s)
- W R Kelce
- Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Abstract
Androgen effects mediated by the androgen receptor (AR) are essential for male reproductive development and virilization. Comparison of AR DNA coding sequence from five primate species, Homo sapiens (human), Pan troglodytes (chimpanzee), Papio hamadryas (baboon), Macaca fascicularis (macaque), and Eulemur fulvus collaris (collared brown lemur), supports their phylogeny with complete conservation of the DNA and steroid binding domain protein sequence. A linear increase in trinucleotide repeat expansion of homologous CAG and GGC sequences occurs in the NH2-terminal transcriptional activation region and is proportional to the time of species divergence. A serine phosphate/glutamine repeat interaction is observed where increasing CAG repeat length is associated with an increased rate of serine 94 phosphorylation. Disparity in the calculated and apparent molecular weight with CAG repeat expansion of an AR NH2-terminal fragment suggests self-aggregation with increasing glutamine repeat length into the pathological range. These results suggest that a CAG/glutamine repeat expanded during divergence of the higher primate species, which may have a direct effect on AR structure and support a common pathway in CAG trigenic diseases in the pathophysiology of neurodegeneration observed in X-linked spinal bulbar and muscular atrophy.
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Affiliation(s)
- C S Choong
- Laboratories for Reproductive Biology and Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599, USA
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35
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Yang DH, Kim HS, Wilson EM, Rosenfeld RG, Oh Y. Identification of glycosylated 38-kDa connective tissue growth factor (IGFBP-related protein 2) and proteolytic fragments in human biological fluids, and up-regulation of IGFBP-rP2 expression by TGF-beta in Hs578T human breast cancer cells. J Clin Endocrinol Metab 1998; 83:2593-6. [PMID: 9661651 DOI: 10.1210/jcem.83.7.5097] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Connective Tissue Growth Factor (CTGF) is a cysteine-rich peptide involved in human atherosclerosis and fibrotic disorders such as scleroderma. CTGF has considerable N-terminal sequence similarity with the insulin-like growth factor binding proteins (IGFBPs), including preservation of cysteines, and has been postulated to be a member of the IGFBP superfamily. Indeed, recent studies have shown that baculovirus generated CTGF, a secreted 38-kDa protein, binds IGFs in a specific manner, leading to the provisional renaming of CTGF as IGFBP-8 (or IGFBP-rP2). With immunoprecipitation and immunoblotting, using polyclonal anti-IGFBP-rP2 antibody generated against recombinant human IGFBP-rP2bac, IGFBP-rP2 can be identified in the serum-free conditioned media of Hs578T human breast cancer cells, as well as in various human biological fluids, such as normal sera, pregnancy sera, and cerebrospinal, amniotic, follicular and peritoneal fluids. Glycosylation studies with endoglycosidase F reveal that endogenous human IGFBP-rP2 is a secreted, glycosylated, approximately 32-38-kDa protein with 2-8-kDa of N-linked sugars and a 30-kDa core. There are 18- and 24-kDa proteins that appear to be IGFBP-rP2 degradation products. In Hs578T human breast cancer cells, transforming growth factor (TGF)-beta 2, a potent growth inhibitor for these cells, upregulates IGFBP-rP2 mRNA and protein levels. Expression of Hs578T IGFBP-rP2 is significantly increased by TGF-beta 2 treatment in a dose-dependent manner, with 2.5- and 6-fold increases in mRNA and protein levels, respectively, at a TGF-beta 2 concentration of 10 ng/ml. Our studies indicate that IGFBP-rP2 appears to be an important endocrine factor, and one of the critical downstream effectors of the critical downstream effectors of TGF-beta, similar to the role of IGFBP-3 in TGF-beta-induced growth inhibition in human breast cancer cells.
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Affiliation(s)
- D H Yang
- Dept. of Pediatrics NRC5, Oregon Health Sciences University, Portland 97201, USA
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36
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Wilson EM. Strokes, CVAs, or brain attacks: by any name they need quick attention. J Emerg Nurs 1998; 24:251-3. [PMID: 9775801 DOI: 10.1016/s0099-1767(98)90069-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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37
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Delbridge TR, Bailey B, Chew JL, Conn AK, Krakeel JJ, Manz D, Miller DR, O'Malley PJ, Ryan SD, Spaite DW, Stewart RD, Suter RE, Wilson EM. EMS agenda for the future: where we are ... where we want to be. EMS Agenda for the Future Steering Committee. Ann Emerg Med 1998; 31:251-63. [PMID: 9472190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the "EMS Agenda for the Future." Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are Integration of Health Services, EMS Research, Legislation and Regulation, System Finance, Human Resources, Medical Direction, Education Systems, Public Education, Prevention, Public Access, Communication Systems, Clinical Care, Information Systems, and Evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.
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Affiliation(s)
- T R Delbridge
- Department of Emergency Medicine, University of Pittsburgh, PA, USA
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38
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Langley E, Kemppainen JA, Wilson EM. Intermolecular NH2-/carboxyl-terminal interactions in androgen receptor dimerization revealed by mutations that cause androgen insensitivity. J Biol Chem 1998; 273:92-101. [PMID: 9417052 DOI: 10.1074/jbc.273.1.92] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Structural alignment of the human androgen receptor dimer was investigated by introducing steroid binding domain mutations that cause partial or complete androgen insensitivity into fusion proteins containing the full-length androgen receptor or the steroid binding domain. Most of the mutants had unchanged apparent equilibrium androgen binding affinity and increased dissociation rates of [3H]methyltrienolone and required increased dihydrotestosterone concentrations for transcriptional activation. In a 2-hybrid protein interaction assay in mammalian cells, the steroid binding domain interacts with an NH2-terminal-DNA binding domain fragment and with the full-length androgen receptor at physiological androgen concentrations in a dose-dependent manner. However, mutations at Val-889 and Arg-752 disrupt the NH2-/carboxyl-terminal interaction when introduced into the steroid binding domain fragment but not when present in the full-length androgen receptor. The N-C bimolecular interaction reduces the dissociation rate of bound androgen and slows the degradation rate of the carboxyl-terminal steroid binding domain fragment. The results suggest that steroid binding domain residues Val-889 and Arg-752 are critical to the NH2-/carboxyl-terminal interaction and that an intermolecular N-C interaction occurs during receptor dimerization that results in an antiparallel arrangement of androgen receptor monomers.
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Affiliation(s)
- E Langley
- Laboratories for Reproductive Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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40
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Delbridge TR, Bailey B, Chew JL, Conn AK, Krakeel JJ, Manz D, Miller DR, O'Malley PJ, Ryan SD, Spaite DW, Stewart RD, Suter RE, Wilson EM. EMS Agenda for the Future: where we are...where we want to be. PREHOSP EMERG CARE 1998; 2:1-12. [PMID: 9737400 DOI: 10.1080/10903129808958832] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the EMS Agenda for the Future. Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are integration of health services, EMS research, legislation and regulation, system finance, human resources, medical direction, education systems, public education, prevention, public access, communication systems, clinical care, information systems, and evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.
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Affiliation(s)
- T R Delbridge
- Department of Emergency Medicine, University of Pittsburgh, PA 15213, USA. delbridg+@pitt.edu
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41
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Abstract
The insulin-like growth factors (IGFs) are transported by a family of high-affinity binding proteins (IGFBPs) that protect IGFs from degradation, limit their binding to IGF receptors, and modulate IGF actions. The six classical IGFBPs have been believed to have no affinity for insulin. We now demonstrate that IGFBP-7/mac25, a newly identified member of the IGFBP superfamily that binds IGFs specifically with low affinity is a high-affinity insulin binding protein. IGFBP-7 blocks insulin binding to the insulin receptor and thereby inhibiting the earliest steps in insulin action, such as autophosphorylation of the insulin receptor beta subunit and phosphorylation of IRS-1, indicating that IGFBP-7 is a functional insulin-binding protein. The affinity of other IGFBPs for insulin can be enhanced by modifications that disrupt disulfide bonds or remove the conserved COOH terminus. Like IGFBP-7, an NH2-terminal fragment of IGFBP-3 (IGFBP-3((1-87))), also binds insulin with high affinity and blocks insulin action. IGFBPs with enhanced affinity for insulin might contribute to the insulin resistance of pregnancy, type II diabetes mellitus, and other pathological conditions.
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Affiliation(s)
- Y Yamanaka
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland, Oregon 97201, USA
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42
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Heckert LL, Wilson EM, Nilson JH. Transcriptional repression of the alpha-subunit gene by androgen receptor occurs independently of DNA binding but requires the DNA-binding and ligand-binding domains of the receptor. Mol Endocrinol 1997; 11:1497-506. [PMID: 9280065 PMCID: PMC1502414 DOI: 10.1210/mend.11.10.9996] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The pituitary glycoprotein hormones LH and FSH regulate the reproductive cycle and are sensitive to feedback by gonadal steroids. The common alpha-subunit shared by these hormones is transcriptionally repressed by androgen receptor (AR) in the presence of its ligand dihydrotestosterone. This identifies at least one mechanism that contributes to AR-dependent suppression of gonadotropin synthesis. Repression of alpha-subunit transcription by AR requires only the sequences within the first 480 bp of the promoter. While this region contains a high-affinity binding site for AR, this element does not mediate the suppressive effects of androgens. Instead, two other elements within the promoter-regulatory region (alpha-basal element and cAMP-regulatory element), which are important for expression of the alpha-subunit gene in gonadotropes, mediate the effects of AR. This suggests that AR inhibits activity of the alpha-subunit promoter by interfering with the transcriptional properties of the proteins that bind to alpha-basal element and the cAMP-regulatory elements. Furthermore, transfection analysis of various mutant ARs identified both the DNA-binding and ligand-binding domains of the receptor as critical for repression. Comparisons with the MMTV promoter revealed distinct structural requirements that underlie the transactivation and transrepression properties of AR.
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Affiliation(s)
- L L Heckert
- Department of Molecular and Integrative Physiology, The University of Kansas Medical Center, Kansas City 66160, USA
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43
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Tan J, Sharief Y, Hamil KG, Gregory CW, Zang DY, Sar M, Gumerlock PH, deVere White RW, Pretlow TG, Harris SE, Wilson EM, Mohler JL, French FS. Dehydroepiandrosterone activates mutant androgen receptors expressed in the androgen-dependent human prostate cancer xenograft CWR22 and LNCaP cells. Mol Endocrinol 1997; 11:450-9. [PMID: 9092797 DOI: 10.1210/mend.11.4.9906] [Citation(s) in RCA: 223] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An androgen receptor (AR) gene mutation identified in the androgen-dependent human prostate cancer xenograft, CWR22, changed codon 874 in the ligand-binding domain (exon H) from CAT for histidine to TAT for tyrosine and abolished a restriction site for the endonuclease SfaNI. SfaNI digestion of AR exon H DNA from normal but not from prostate cancer tissue indicated H874Y is a somatic mutation that occurred before the initial tumor transplant. CWR22, an epithelial cell tumor, expresses a 9.6-kb AR mRNA similar in size to the AR mRNA in human benign prostatic hyperplasia. AR protein is present in cell nuclei by immunostaining as in other androgen-responsive tissues. Transcriptional activity of recombinant H874Y transiently expressed in CV1 cells in the presence of testosterone or dihydrotestosterone was similar to that of wild type AR. With dihydrotestosterone at a near physiological concentration (0.01 nM), H874Y and wild type AR induced 2-fold greater luciferase activity than did the LNCaP mutant AR T877A. The adrenal androgen, dehydroepiandrosterone (10 and 100 nM) with H874Y stimulated a 3- to 8-fold greater response than with wild type AR and at 100 nM the response was similar with the LNCaP mutant. H874Y, like the LNCaP cell mutant, was more responsive to estradiol and progesterone than was wild type AR. The antiandrogen hydroxyflutamide (10 nM) had greater agonist activity (4- to 7-fold) with both mutant ARs than with wild type AR. AR mutations that alter ligand specificity may influence tumor progression subsequent to androgen withdrawal by making the AR more responsive to adrenal androgens or antiandrogens.
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Affiliation(s)
- J Tan
- Department of Pediatrics, School of Medicine, The University of North Carolina, Chapel Hill 27599, USA
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44
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Wilson EM, Oh Y, Rosenfeld RG. Generation and characterization of an IGFBP-7 antibody: identification of 31kD IGFBP-7 in human biological fluids and Hs578T human breast cancer conditioned media. J Clin Endocrinol Metab 1997; 82:1301-3. [PMID: 9100611 DOI: 10.1210/jcem.82.4.3983] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The cDNA encoding mac25 (IGFBP-7) was firsr derived from mRNA isolated from leptomeningial and senescent human mammary epithelial cells (1,2). The open reading frame was shown to predict a protein with homology to the amino terminus of the IGF binding proteins, (IGFBP)1-6. Studies in our laboratory have shown that baculovirus generated mac25 binds IGF-I and-II in a specific manner, leading to the renaming of mac25 as IGFBP-7 (3). Further studies at the cellular level, to identify the involvement of IGFBP-7 in IGF regulation and cell growth, require a specific antibody against the protein, which has yet to be identified in either cultured cells or in vivo. We have now generated three polyclonal antibodies against the purified baculovirus peptide and, by western immunoblots and immunoprecipitation, demonstrated the existence of a specific 31,000 dalton protein. It is a secreted protein, and can be identified in the conditioned media of Hs578T breast cancer cells, as well as in normal human urine, cerebrospinal fluid and amniotic fluid. Subsequent studies with these antibodies should help elucidate the physiological role(s) of this protein.
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Affiliation(s)
- E M Wilson
- Department of Pediatrics, Oregon Health Sciences University, Portland 97201, USA
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45
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Abstract
Industrial chemicals and environmental pollutants can disrupt reproductive development in wildlife and humans by mimicking or inhibiting the action of the gonadal steroid hormones, estradiol and testosterone. The toxicity of these so-called environmental endocrine disruptors is especially insidious during sex differentiation and development due to the crucial role of gonadal steroid hormones in regulating these processes. This review describes the mechanism of toxicity and clinical implications of a new class of environmental chemicals that inhibit androgen-mediated sex development. For several of these chemicals, including the agricultural fungicide vinclozolin and the ubiquitous and persistent 1,1,1-trichloro-2,2-bis (p-chlorophenyl)ethane metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene, the molecular mechanism of action and the adverse developmental effects on male sex differentiation have been elucidated and are used as examples. Environmental chemicals with antiandrogenic activity offer profound implications with regard to recent clinical observations that suggest an increasing incidence of human male genital tract malformations, male infertility, and female breast cancer. Finally, in light of increasing concern over the potential endocrine disrupting effects of environmental pollutants, an in vitro/in vivo investigational strategy is presented which has proved useful in identifying chemicals with antiandrogen activity and their mechanism of action.
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Affiliation(s)
- W R Kelce
- Reproductive Toxicology Division, United States Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Wilson AG, Wilson EM, Groves CR, Wallace RL. U.S. distribution of the Coeur d'Alene salamander (Plethodon idahoensis Slater and Slipp). ACTA ACUST UNITED AC 1997. [DOI: 10.5962/bhl.part.13088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Brooks BP, Paulson HL, Merry DE, Salazar-Grueso EF, Brinkmann AO, Wilson EM, Fischbeck KH. Characterization of an expanded glutamine repeat androgen receptor in a neuronal cell culture system. Neurobiol Dis 1997; 3:313-23. [PMID: 9173928 DOI: 10.1006/nbdi.1997.0126] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA) is an inherited form of lower motor neuron degeneration caused by expansion of a CAG repeat in the androgen receptor (AR) gene. To study the mechanism by which this mutation causes neuronal pathology, we stably transfected a motor neuron hybrid cell line with human AR cDNAs containing either 24 or 65 repeats (AR24 and AR65, respectively). Both forms of receptor were able to bind ligand and activate transcription of a reporter construct equally well. Likewise, the subcellular localizations of AR24 and AR65 were similar, in both the presence and the absence of ligand. AR24- and AR65-expressing clones were phenotypically indistinguishable. They survived equally well after differentiation and were equally susceptible to damage by oxidative stress. Our studies thus demonstrate that, in a neuronal system, the expanded repeat AR functions like the normal repeat AR in several important ways. Because levels of AR65 expression were consistently lower than levels of AR24 expression, we propose that the loss of function of AR seen in SBMA may be due to decreased levels of receptor expression rather than to a difference in intrinsic properties. The postulated gain of function responsible for neuronal degeneration remains to be determined.
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Affiliation(s)
- B P Brooks
- Department of Neurology, University of Pennsylvania School of Medicine, Room 250 CRB, 415 Curie Boulevard, Philadelphia, Pennsylvania, 19104, USA.
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48
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Affiliation(s)
- E M Wilson
- Office of Emergency Medical Services, Hartford, Connecticut, USA
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49
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Abstract
The molecular basis for partial androgen insensitivity associated with adult onset spinal/bulbar muscular atrophy was investigated by transient transfection of human androgen receptor (AR) expression vectors containing increasing CAG repeat lengths in the first exon. An inverse relationship was observed between CAG repeat length and AR mRNA and protein levels. Trinucleotide repeat lengths of 43 and 65 associated with spinal/bulbar muscular atrophy decreased AR mRNA and protein levels but did not alter equilibrium binding affinity for [3H]R1881 or inherent transcriptional activity of AR, expressed as androgen-dependent fold induction of a mouse mammary tumor virus promoter-luciferase reporter vector. The findings indicate that glutamine expansion up to 66 residues in the NH2-terminal domain of AR does not alter AR functional activity. Rather, CAG repeat expansion in the region of the first exon reduces AR mRNA and protein expression. The study reveals a previously unrecognized effect of CAG repeat length on AR mRNA expression and a novel molecular mechanism for androgen resistance.
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Affiliation(s)
- C S Choong
- Laboratories for Reproductive Biology, University of North Carolina, Chapel Hill 27599-7500, USA
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50
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Klus GT, Nakamura J, Li JS, Ling YZ, Son C, Kemppainen JA, Wilson EM, Brodie AM. Growth inhibition of human prostate cells in vitro by novel inhibitors of androgen synthesis. Cancer Res 1996; 56:4956-64. [PMID: 8895750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The long-standing strategy for the treatment of metastatic prostate cancer has been to reduce androgenic stimulation of tumor growth by removal of the testes, the primary site of testosterone synthesis. However, a low level of androgenic stimulation may continue, even after castration, by the conversion of adrenal androgens to 5alpha-dihydrotestosterone (DHT) in the prostate tumor cells. Two important enzymes of the androgen biosynthetic pathway are 17alpha-hydroxylase/C17,20-lyase, which regulates an early step in the synthesis of testosterone and other androgens in both the testes and adrenal glands, and 5alpha-reductase, which converts testosterone to the more potent androgen, DHT, in the prostate. We have identified new inhibitors of these enzymes that may be of use in achieving a more complete ablation of androgens in the treatment of metastatic prostate cancer. Three derivatives of androstene were shown to inhibit 17alpha-hydroxylase/C17,20-lyase with potencies 2-20-fold greater than that of ketoconazole, a previously established inhibitor of this enzyme. Derivatives of pregnane and pregnene displayed activities against 5alpha-reductase that were comparable to that of N-(1,1-dimethyl-ethyl)-3-oxo-4-aza-5alpha-androst-1-ene-17beta-car boxamide. All of the 5alpha-reductase inhibitors were able to at least partially inhibit the mitogenic effect of testosterone in either histocultures of human benign prostatic hypertrophic tissue or in cultures of the LNCaP human prostatic tumor cell line. For these compounds, it appears that this inhibition can be attributed to a reduction of DHT synthesis in these cultures, because no inhibitory effect was observed in DHT-treated cultures, and none of the compounds had a cytotoxic effect. Surprisingly, one of the inhibitors of 17alpha-hydroxylase/C17,20-lyase, 17beta-(4-imidazolyl)-5-pregnen-3beta-ol, was also able to inhibit the mitogenic effect of testosterone in both the histoculture and cell culture assays and had an effect against DHT as well. In transcriptional activation assays, it was found that this compound is an antagonist of both the wild-type androgen receptor and the mutant androgen receptor, which is present in LNCaP cells. In conclusion, the abilities of these compounds to inhibit androgen synthesis and, in some cases, to exert antiandrogen activity, did in fact translate to an inhibitory effect on the growth of human prostatic tissue in vitro, suggesting their potential utility in the treatment of prostatic cancer.
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Affiliation(s)
- G T Klus
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201, USA
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