1
|
Olkowski C, Fernandes B, Griffiths GL, Lin F, Choyke PL. Preclinical Imaging of Prostate Cancer. Semin Nucl Med 2023; 53:644-662. [PMID: 36882335 PMCID: PMC10440231 DOI: 10.1053/j.semnuclmed.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 03/07/2023]
Abstract
Prostate cancer remains a major cause of mortality and morbidity, affecting millions of men, with a large percentage expected to develop the disease as they reach advanced ages. Treatment and management advances have been dramatic over the past 50 years or so, and one aspect of these improvements is reflected in the multiple advances in diagnostic imaging techniques. Much attention has been focused on molecular imaging techniques that offer high sensitivity and specificity and can now more accurately assess disease status and detect recurrence earlier. During development of molecular imaging probes, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) must be evaluated in preclinical models of the disease. If such agents are to be translated to the clinic, where patients undergoing these imaging modalities are injected with a molecular imaging probe, these agents must first be approved by the FDA and other regulatory agencies prior to their adoption in clinical practice. Scientists have worked assiduously to develop preclinical models of prostate cancer that are relevant to the human disease to enable testing of these probes and related targeted drugs. Challenges in developing reproducible and robust models of human disease in animals are beset with practical issues such as the lack of natural occurrence of prostate cancer in mature male animals, the difficulty of initiating disease in immune-competent animals and the sheer size differences between humans and conveniently smaller animals such as rodents. Thus, compromises in what is ideal and what can be achieved have had to be made. The workhorse of preclinical animal models has been, and remains, the investigation of human xenograft tumor models in athymic immunocompromised mice. Later models have used other immunocompromised models as they have been found and developed, including the use of directly derived patient tumor tissues, completely immunocompromised mice, orthotopic methods for inducing prostate cancer within the mouse prostate itself and metastatic models of advanced disease. These models have been developed in close parallel with advances in imaging agent chemistries, radionuclide developments, computer electronics advances, radiometric dosimetry, biotechnologies, organoid technologies, advances in in vitro diagnostics, and overall deeper understandings of disease initiation, development, immunology, and genetics. The combination of molecular models of prostatic disease with radiometric-based studies in small animals will always remain spatially limited due to the inherent resolution sensitivity limits of PET and SPECT decay processes, fundamentally set at around a 0.5 cm resolution limit. Nevertheless, it is central to researcher's efforts and to successful clinical translation that the best animal models are adopted, accepted, and scientifically verified as part of this truly interdisciplinary approach to addressing this important disease.
Collapse
Affiliation(s)
- Colleen Olkowski
- Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, Bethesda MD
| | - Bruna Fernandes
- Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, Bethesda MD
| | - Gary L Griffiths
- Clinical Research Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD
| | - Frank Lin
- Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, Bethesda MD
| | - Peter L Choyke
- Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, Bethesda MD.
| |
Collapse
|
2
|
Pranata A, Yamada S, Weththasinghe S, Caldwell K, Zahra PW, Karamatic SL, Gardiner MG, McLeod MD. The in vivo metabolism of Jungle Warfare in greyhounds. Steroids 2023; 190:109150. [PMID: 36511323 DOI: 10.1016/j.steroids.2022.109150] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/15/2022] [Accepted: 11/22/2022] [Indexed: 11/28/2022]
Abstract
Δ6-Methyltestosterone was reported as the main active ingredient of the purported "dietary supplement" Jungle Warfare. This compound is structurally similar to 17α-methyltestosterone, containing an additional Δ6 double bond, and is reported to possess notable androgenic activity, raising concerns over the potential for abuse of Jungle Warfare in sport. The in vivo metabolism of Δ6-methyltestosterone in greyhounds was investigated. Urinary phase I (unconjugated) and phase II (glucuronide) metabolites were detected following oral administration using liquid chromatography-mass spectrometry. No phase II sulfate metabolites were detected. The major phase I metabolite was confirmed as 16α,17β-dihydroxy-17α-methylandrosta-4,6-dien-3-one by comparison with a synthetically-derived reference material. Minor amounts of the parent drug were also confirmed. Glucuronide conjugated metabolites were also observed, but were found to be resistant to hydrolysis using the Escherichia coli β-glucuronidase enzyme. Qualitative excretion profiles, limits of detection, and extraction recoveries were determined for the parent drug and the major phase I metabolite. These results provide a method for the detection of Jungle Warfare abuse in greyhounds suitable for incorporation into routine screening methods conducted by anti-doping laboratories.
Collapse
Affiliation(s)
- Andy Pranata
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Sean Yamada
- Racing Analytical Services Limited, Flemington, VIC 3031, Australia
| | - Sumudu Weththasinghe
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Karen Caldwell
- Queensland Racing Integrity Commission, Albion, QLD 4010, Australia
| | - Paul W Zahra
- Racing Analytical Services Limited, Flemington, VIC 3031, Australia
| | | | - Michael G Gardiner
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Malcolm D McLeod
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia.
| |
Collapse
|
3
|
Parent EE, Fowler AM. Nuclear Receptor Imaging In Vivo-Clinical and Research Advances. J Endocr Soc 2022; 7:bvac197. [PMID: 36655003 PMCID: PMC9838808 DOI: 10.1210/jendso/bvac197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Indexed: 01/01/2023] Open
Abstract
Nuclear receptors are transcription factors that function in normal physiology and play important roles in diseases such as cancer, inflammation, and diabetes. Noninvasive imaging of nuclear receptors can be achieved using radiolabeled ligands and positron emission tomography (PET). This quantitative imaging approach can be viewed as an in vivo equivalent of the classic radioligand binding assay. A main clinical application of nuclear receptor imaging in oncology is to identify metastatic sites expressing nuclear receptors that are targets for approved drug therapies and are capable of binding ligands to improve treatment decision-making. Research applications of nuclear receptor imaging include novel synthetic ligand and drug development by quantifying target drug engagement with the receptor for optimal therapeutic drug dosing and for fundamental research into nuclear receptor function in cells and animal models. This mini-review provides an overview of PET imaging of nuclear receptors with a focus on radioligands for estrogen receptor, progesterone receptor, and androgen receptor and their use in breast and prostate cancer.
Collapse
Affiliation(s)
- Ephraim E Parent
- Mayo Clinic Florida, Department of Radiology, Jacksonville, Florida 32224, USA
| | - Amy M Fowler
- Correspondence: Amy M. Fowler, MD, PhD, Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252, USA.
| |
Collapse
|
4
|
Cai H, Liu G. Exploring the Learning Psychology Mobilization of Music Majors Through Innovative Teaching Methods Under the Background of New Curriculum Reform. Front Psychol 2022; 12:751234. [PMID: 35126231 PMCID: PMC8814414 DOI: 10.3389/fpsyg.2021.751234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
The research expects to explore the psychological mobilization of innovative teaching methods of Music Majors under the new curriculum reform. The relevant theories of college students’ innovative teaching methods are analyzed under deep learning together with the innovation and construction of music courses. Thereupon, college students’ psychological mobilization is studied. Firstly, the relationship between innovation and entrepreneurship teaching and deep learning is obtained through a literature review. Secondly, the music classroom model is designed based on the deep learning theory, and the four dimensions of the music curriculum are defined to innovate and optimize the music teaching model. Finally, the Questionnaire Survey (QS) is used to analyze the design classroom model. Only 15% of the 180 respondents understand the concept of deep learning, 32% like interactive music learning, and 36% like competitive comparative music classroom learning. And the students who study instrumental music have higher significant differences in learning motivation than those who study vocal music. In addition to classroom learning, 16% of people improve their music skills through music equipment. College students like interactive music classes and competitive comparison classes that can give more play to their subjective initiative. After the new curriculum reform, the music curriculum based on deep learning can stimulate students’ interest in learning and participate in the mobilization of students’ learning psychology. Therefore, in the future of music education and teaching, there is a need to pay more attention to students’ psychological status. The research results can provide references and practical significance for the innovative teaching activities of music classrooms after the new curriculum reform.
Collapse
Affiliation(s)
- Haiqin Cai
- College of Music, Gannan Normal University, Ganzhou, China
- Graduate School, Khon Kaen University, Khon Kaen, Thailand
- *Correspondence: Haiqin Cai,
| | - Guangliang Liu
- Graduate School, Khon Kaen University, Khon Kaen, Thailand
| |
Collapse
|
5
|
Horváth A, Bolla K, Wachtler A, Maksó L, Papp M, Mahó S, Dubrovay Z, Kóti J, Skoda-Földes R. A Temperature-Controlled Switch between Fürst-Plattner Rule and Anti-Fürst-Plattner Rule Ring Opening of 2,3-Epoxy-steroids with Various Halide Sources in the Presence of Imidazolium Ionic Liquids. ACS OMEGA 2021; 6:26846-26856. [PMID: 34693106 PMCID: PMC8529608 DOI: 10.1021/acsomega.1c02470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
The ring opening of 2α,3α- and 2β,3β-epoxy-5α-androstan-17-one with halide reagents (AlCl3, TMSCl, LiCl, and LiBr) was investigated using imidazolium ionic liquids in the dual role of solvent and catalyst. The application of the ionic liquid was shown to result in an increase in the amount of the unusual diequatorial halohydrins especially at temperatures above 100 °C. With a careful choice of reaction conditions, the latter derivatives could be produced with 43-96% selectivity depending on the nature of the halide ion. Moreover, the usual diaxial products could also be isolated in 70-85% yields by a proper change in the reaction conditions. The reusability of the ionic liquid was demonstrated in both types of reactions. The structures of the products were proved unequivocally by nuclear magnetic resonance (NMR) measurements including two-dimensional (2D) techniques as well as high-resolution mass spectrometry (HRMS). Based on quantum chemical calculations, the effect of the ionic liquid could be explained by the stabilization of the transition state leading to the diequatorial product.
Collapse
Affiliation(s)
- Anita Horváth
- Chemical
Works of Gedeon Richter Plc., 1103 Budapest, Gyömrői
út 19-21, Hungary
| | - Kristóf Bolla
- Department
of Organic Chemistry, University of Pannonia, 8200 Veszprém, Egyetem u. 10, Hungary
| | - Alexandra Wachtler
- Department
of Organic Chemistry, University of Pannonia, 8200 Veszprém, Egyetem u. 10, Hungary
| | - Lilla Maksó
- Department
of Organic Chemistry, University of Pannonia, 8200 Veszprém, Egyetem u. 10, Hungary
| | - Máté Papp
- ELTE
Eötvös Loránd University, Institute of Chemistry, 1117 Budapest, Pázmány Péter sétány
1/A, Hungary
| | - Sándor Mahó
- Chemical
Works of Gedeon Richter Plc., 1103 Budapest, Gyömrői
út 19-21, Hungary
| | - Zsófia Dubrovay
- Chemical
Works of Gedeon Richter Plc., 1103 Budapest, Gyömrői
út 19-21, Hungary
| | - János Kóti
- Chemical
Works of Gedeon Richter Plc., 1103 Budapest, Gyömrői
út 19-21, Hungary
| | - Rita Skoda-Földes
- Department
of Organic Chemistry, University of Pannonia, 8200 Veszprém, Egyetem u. 10, Hungary
| |
Collapse
|
6
|
Katzenellenbogen JA. PET Imaging Agents (FES, FFNP, and FDHT) for Estrogen, Androgen, and Progesterone Receptors to Improve Management of Breast and Prostate Cancers by Functional Imaging. Cancers (Basel) 2020; 12:E2020. [PMID: 32718075 PMCID: PMC7465097 DOI: 10.3390/cancers12082020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/30/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022] Open
Abstract
Many breast and prostate cancers are driven by the action of steroid hormones on their cognate receptors in primary tumors and in metastases, and endocrine therapies that inhibit hormone production or block the action of these receptors provide clinical benefit to many but not all of these cancer patients. Because it is difficult to predict which individuals will be helped by endocrine therapies and which will not, positron emission tomography (PET) imaging of estrogen receptor (ER) and progesterone receptor (PgR) in breast cancer, and androgen receptor (AR) in prostate cancer can provide useful, often functional, information on the likelihood of endocrine therapy response in individual patients. This review covers our development of three PET imaging agents, 16α-[18F]fluoroestradiol (FES) for ER, 21-[18F]fluoro-furanyl-nor-progesterone (FFNP) for PgR, and 16β-[18F]fluoro-5α-dihydrotestosterone (FDHT) for AR, and the evolution of their clinical use. For these agents, the pathway from concept through development tracks with an emerging understanding of critical performance criteria that is needed for successful PET imaging of these low-abundance receptor targets. Progress in the ongoing evaluation of what they can add to the clinical management of breast and prostate cancers reflects our increased understanding of these diseases and of optimal strategies for predicting the success of clinical endocrine therapies.
Collapse
Affiliation(s)
- John A Katzenellenbogen
- Department of Chemistry and Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
7
|
Zhu Z, Chung YM, Sergeeva O, Kepe V, Berk M, Li J, Ko HK, Li Z, Petro M, DiFilippo FP, Lee Z, Sharifi N. Loss of dihydrotestosterone-inactivation activity promotes prostate cancer castration resistance detectable by functional imaging. J Biol Chem 2018; 293:17829-17837. [PMID: 30262668 PMCID: PMC6240862 DOI: 10.1074/jbc.ra118.004846] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/17/2018] [Indexed: 11/06/2022] Open
Abstract
Androgens such as testosterone and dihydrotestosterone are a critical driver of prostate cancer progression. Cancer resistance to androgen deprivation therapies ensues when tumors engage metabolic processes that produce sustained androgen levels in the tissue. However, the molecular mechanisms involved in this resistance process are unclear, and functional imaging modalities that predict impending resistance are lacking. Here, using the human LNCaP and C4-2 cell line models of prostate cancer, we show that castration treatment-sensitive prostate cancer cells that normally have an intact glucuronidation pathway that rapidly conjugates and inactivates dihydrotestosterone and thereby limits androgen signaling, become glucuronidation deficient and resistant to androgen deprivation. Mechanistically, using CRISPR/Cas9-mediated gene ablation, we found that loss of UDP glucuronosyltransferase family 2 member B15 (UGT2B15) and UGT2B17 is sufficient to restore free dihydrotestosterone, sustained androgen signaling, and development of castration resistance. Furthermore, loss of glucuronidation enzymatic activity was also detectable with a nonsteroid glucuronidation substrate. Of note, glucuronidation-incompetent cells and the resultant loss of intracellular conjugated dihydrotestosterone were detectable in vivo by 18F-dihydrotestosterone PET. Together, these findings couple a mechanism with a functional imaging modality to identify impending castration resistance in prostate cancers.
Collapse
Affiliation(s)
- Ziqi Zhu
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | - Yoon-Mi Chung
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | | | | | - Michael Berk
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | - Jianneng Li
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | - Hyun-Kyung Ko
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | - Zhenfei Li
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | - Marianne Petro
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute
| | | | - Zhenghong Lee
- Departments of Radiology; Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44124
| | - Nima Sharifi
- From the Genitourinary Malignancies Research Center, Department of Cancer Biology, Lerner Research Institute; Department of Urology, Glickman Urological and Kidney Institute; Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio 44195.
| |
Collapse
|
8
|
Zolottsev VA, Ponomarev GV, Taratynova MO, Morozevich GE, Novikov RA, Timofeev VP, Solyev PN, Zavialova MG, Zazulina OV, Tkachev YV, Misharin AY. Conjugates of 17-substituted testosterone and epitestosterone with pyropheophorbide a differing in the length of linkers. Steroids 2018; 138:82-90. [PMID: 30033342 DOI: 10.1016/j.steroids.2018.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/05/2018] [Accepted: 06/08/2018] [Indexed: 12/13/2022]
Abstract
Conjugates of 17α-substituted testosterone (1 and 2) and 17β-substituted epitestosterone (3 and 4) with pyropheophorbide a were synthesized. The scheme consisted of synthesis of 17α-hydroxy-3-oxopregn-4-en-21-oic and 17β-hydroxy-3-oxopregn-4-en-21-oic acids, and their coupling with pyropheophorbide a by means of either ethylene diamine, or 1,5-diamino pentane linkers. Mutual influence of steroidal and macrocyclic fragments in conjugates molecules was dependent on configuration of C17 and length of linker, that was established by analysis of 1H NMR spectra and molecular models of conjugates. Studies of interaction of conjugates with prostate carcinoma cells revealed that their uptake and internalization were independent on the androgen receptor activity, but dependent on the structure of conjugates, decreasing in the following row: 3 > 4 ≥ 1 > 2. Conjugates significantly decreased the LNCaP and PC-3 cells growth at 96 h incubation. Epitestosterone derivatives 3 and 4 also showed superior anti-proliferative activity versus testosterone ones. Conformationally more rigid conjugates 1 and 3, comprising short linkers, were more active than those with long linkers; conjugate 3 was the most potent.
Collapse
Affiliation(s)
| | | | | | | | - Roman A Novikov
- Engelhardt Institute of Molecular Biology RAS, Moscow, Russia
| | | | - Pavel N Solyev
- Engelhardt Institute of Molecular Biology RAS, Moscow, Russia
| | | | - Olga V Zazulina
- Orekhovich Institute of Biomedical Chemistry, Moscow, Russia
| | | | | |
Collapse
|
9
|
Zolottsev VA, Kostin VA, Novikov RA, Tkachev YV, Zavialova MG, Taratynova MO, Latysheva AS, Zazulina OV, Timofeev VP, Misharin AY. Synthesis of nitrogen-containing derivatives of 17(20)-pregnenoic, 17β-hydroxypregnanoic, and 17α-hydroxypregnanoic acids as new potential antiandrogens. Russ Chem Bull 2018. [DOI: 10.1007/s11172-018-2121-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
10
|
Production of diverse PET probes with limited resources: 24 18F-labeled compounds prepared with a single radiosynthesizer. Proc Natl Acad Sci U S A 2017; 114:11309-11314. [PMID: 29073049 DOI: 10.1073/pnas.1710466114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
New radiolabeled probes for positron-emission tomography (PET) are providing an ever-increasing ability to answer diverse research and clinical questions and to facilitate the discovery, development, and clinical use of drugs in patient care. Despite the high equipment and facility costs to produce PET probes, many radiopharmacies and radiochemistry laboratories use a dedicated radiosynthesizer to produce each probe, even if the equipment is idle much of the time, to avoid the challenges of reconfiguring the system fluidics to switch from one probe to another. To meet growing demand, more cost-efficient approaches are being developed, such as radiosynthesizers based on disposable "cassettes," that do not require reconfiguration to switch among probes. However, most cassette-based systems make sacrifices in synthesis complexity or tolerated reaction conditions, and some do not support custom programming, thereby limiting their generality. In contrast, the design of the ELIXYS FLEX/CHEM cassette-based synthesizer supports higher temperatures and pressures than other systems while also facilitating flexible synthesis development. In this paper, the syntheses of 24 known PET probes are adapted to this system to explore the possibility of using a single radiosynthesizer and hot cell for production of a diverse array of compounds with wide-ranging synthesis requirements, alongside synthesis development efforts. Most probes were produced with yields and synthesis times comparable to literature reports, and because hardware modification was unnecessary, it was convenient to frequently switch among probes based on demand. Although our facility supplies probes for preclinical imaging, the same workflow would be applicable in a clinical setting.
Collapse
|
11
|
Synthesis and basic evaluation of 7α-(3-[ 18F]fluoropropyl)-testosterone and 7α-(3-[ 18F]fluoropropyl)-dihydrotestosterone. Ann Nucl Med 2016; 31:53-62. [PMID: 27680022 DOI: 10.1007/s12149-016-1130-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 09/23/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE 7α-Substituted androgen derivatives may have the potential to visualize androgen receptors with positron emission tomography. In the present study, we synthesized fluoropropyl derivatives of 7α-(3-[18F]fluoropropyl)-testosterone ([18F]7) and 7α-(3-[18F]fluoropropyl)-dihydrotestosterone ([18F]15), and characterized their in vitro binding, in vivo biodistribution, and performed blocking studies in mature androgen deprived male rats. METHODS We synthesized [18F]7 and [18F]15. In vitro binding to recombinant rat AR ligand binding domain protein was determined using a competitive radiometric ligand-binding assay with the high-affinity synthetic androgen [17α-methyl-3H]-methyltrienolone ([3H]R1881). In vivo biodistribution was performed in mature male rats treated with diethylstilbestrol (chemical castration). A blocking study was performed by co-administration of dihydrotestosterone (36 µg/animal). RESULTS 7α-(3-Fluoropropyl)-testosterone (7) and 7α-(3-fluoropropyl)-dihydrotestosterone (15) showed competitive binding to recombinant rat AR ligand binding domain protein. The IC50 value of 15 (13.0 ± 3.3 nM) was higher than 7 (47.8 ± 10.0 nM). In contrast to the AR binding affinity, the ventral prostate uptake of [18F]7 and [18F]15 at 2 h post-injection was similar (0.07 % injected dose/g of tissue). A blocking study indicated that specific binding of [18F]15 is observed in the ventral prostate. [18F]7 and [18F]15 showed moderate levels of bone uptake, which indicates moderate metabolic de-fluorination in rodents. CONCLUSION [18F]15 is better than [18F]7 in terms of radiochemical yield, in vitro binding affinity, prostate specific binding and stability against in vivo metabolic de-fluorination. However, the net uptake level of [18F]15 in prostate might be insufficient for in vivo visualization. Although [18F]7 and [18F]15 improved in vivo stability against de-fluorination, other basic characterization data in rodents were not superior to the current standard tracer 16β-[18F]fluoro-5α-dihydrotestosterone. It is also revealed that the shorter side chain length of 7α-[18F]fluoromethyl-dihydrotestosterone is superior to the longer three carbon chain in [18F]15, in terms of net prostate uptake and in vivo metabolic stability.
Collapse
|
12
|
Lazari M, Lyashchenko SK, Burnazi EM, Lewis JS, van Dam RM, Murphy JM. Fully-automated synthesis of 16β-(18)F-fluoro-5α-dihydrotestosterone (FDHT) on the ELIXYS radiosynthesizer. Appl Radiat Isot 2015; 103:9-14. [PMID: 26046518 DOI: 10.1016/j.apradiso.2015.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/30/2015] [Accepted: 05/18/2015] [Indexed: 01/30/2023]
Abstract
Noninvasive in vivo imaging of androgen receptor (AR) levels with positron emission tomography (PET) is becoming the primary tool in prostate cancer detection and staging. Of the potential (18)F-labeled PET tracers, (18)F-FDHT has clinically shown to be of highest diagnostic value. We demonstrate the first automated synthesis of (18)F-FDHT by adapting the conventional manual synthesis onto the fully-automated ELIXYS radiosynthesizer. Clinically-relevant amounts of (18)F-FDHT were synthesized on ELIXYS in 90 min with decay-corrected radiochemical yield of 29±5% (n=7). The specific activity was 4.6 Ci/µmol (170 GBq/µmol) at end of formulation with a starting activity of 1.0 Ci (37 GBq). The formulated (18)F-FDHT yielded sufficient activity for multiple patient doses and passed all quality control tests required for routine clinical use.
Collapse
Affiliation(s)
- Mark Lazari
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Serge K Lyashchenko
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Eva M Burnazi
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jason S Lewis
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Radiochemistry and Imaging Sciences Service, Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Jennifer M Murphy
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
| |
Collapse
|
13
|
Bertolini R, Goepfert C, Andrieu T, Nichols S, Walter MA, Frey FJ, McCammon JA, Frey BM. 18F-RB390: innovative ligand for imaging the T877A androgen receptor mutant in prostate cancer via positron emission tomography (PET). Prostate 2015; 75:348-59. [PMID: 25358634 DOI: 10.1002/pros.22919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 09/17/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Detecting prostate cancer before spreading or predicting a favorable therapy are challenging issues for impacting patient's survival. Presently, 2-[(18) F]-fluoro-2-deoxy-D-glucose ((18) F-FDG) and/or (18) F-fluorocholine ((18) F-FCH) are the generally used PET-tracers in oncology yet do not emphasize the T877A androgen receptor (AR) mutation being exclusively present in cancerous tissue and escaping androgen deprivation treatment. METHODS We designed and synthesized fluorinated 5α-dihydrotestosterone (DHT) derivatives to target T877A-AR. We performed binding assays to select suitable candidates using COS-7 cells transfected with wild-type or T877A AR (WT-AR, T877A-AR) expressing plasmids and investigated cellular uptake of candidate (18) F-RB390. Stability, biodistribution analyses and PET-Imaging were assessed by injecting (18) F-RB390 (10MBq), with and without co-injection of an excess of unlabeled DHT in C4-2 and PC-3 tumor bearing male SCID mice (n = 12). RESULTS RB390 presented a higher relative binding affinity (RBA) (28.1%, IC50 = 32 nM) for T877A-AR than for WT-AR (1.7%, IC50 = 357 nM) related to DHT (RBA = 100%). A small fraction of (18) F-RB390 was metabolized when incubated with murine liver homogenate or human blood for 3 hr. The metabolite of RB390, 3-hydroxysteroid RB448, presented similar binding characteristics as RB390. (18) F-RB390 but not (18) F-FDG or (18) F-FCH accumulated 2.5× more in COS-7 cells transfected with pSG5AR-T877A than with control plasmid. Accumulation was reduced with an excess of DHT. PET/CT imaging and biodistribution studies revealed a significantly higher uptake of (18) F-RB390 in T877A mutation positive xenografts compared to PC-3 control tumors. This effect was blunted with DHT. CONCLUSION Given the differential binding capacity and the favorable radioactivity pattern, (18) F-RB390 represents the portrayal of the first imaging ligand with predictive potential for mutant T877A-AR in prostate cancer for guiding therapy. Prostate 75:348-359, 2015. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Reto Bertolini
- Department of Nephrology & Hypertension and Clinical Pharmacology, University of Berne, Berne, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Zhou D, Lin M, Yasui N, Al-Qahtani MH, Dence CS, Schwarz S, Katzenellenbogen JA. Optimization of the preparation of fluorine-18-labeled steroid receptor ligands 16alpha-[18F]fluoroestradiol (FES), [18F]fluoro furanyl norprogesterone (FFNP), and 16beta-[18F]fluoro-5alpha-dihydrotestosterone (FDHT) as radiopharmaceuticals. J Labelled Comp Radiopharm 2014; 57:371-7. [PMID: 24861984 DOI: 10.1002/jlcr.3191] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/20/2014] [Accepted: 01/23/2014] [Indexed: 12/24/2022]
Abstract
Fluorine-18-labeled steroid receptor tracers, 16α-[(18)F]fluoroestradiol (FES), [(18)F]fluoro furanyl norprogesterone (FFNP), and 16β-[(18)F]fluoro-5α-dihydrotestosterone (FDHT), are important imaging tools for studies of breast and prostate cancers using positron emission tomography (PET). The automated production of these ligands with high specific activity (SA) as radiopharmaceuticals requires modification and optimization of the currently reported methods. [(18)F]FES with high SA was synthesized in over 60% radiochemical yield (RCY) at the end of synthesis (EOS) using a small amount of precursor (1) (as low as 0.3 mg) and 1 M H2SO4 for deprotection of the intermediate (2). [(18)F]FFNP was synthesized in up to 77% RCY at EOS using the triflate precursor (4) at room temperature or in 25% RCY using the mesylate precursor (6) at 65°C. Both methods are highly reproducible and afford high SA. [(18)F]FDHT was synthesized by radiofluoride incorporation at room temperature, reduction with NaBH4 , and deprotection with HCl/acetone, giving [(18)F]FDHT in up to 75% yield (RCY). All of these methods can be easily translated to automated production. The information provided here will aid in the development of automated production of these steroid receptor tracers with high or improved yields, optimal SA, and ease of processing for research and clinical use.
Collapse
Affiliation(s)
- Dong Zhou
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Peng Z, Maxwell D, Sun D, Ying Y, Schuber PT, Bhanu Prasad BA, Gelovani J, Yung WKA, Bornmann WG. Design and Synthesis of an Inositol Phosphate Analog Based on Computational Docking Studies. Tetrahedron 2014; 70:984-990. [PMID: 25110363 DOI: 10.1016/j.tet.2013.11.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A virtual library of 54 inositol analog mimics of In(1,4,5)P3 has been docked, scored, and ranked within the binding site of human inositol 1,4,5-trisphosphate 3-kinase A (IP3-3KA). Chemical synthesis of the best scoring structure that also met distance criteria for 3'-OH to -P in Phosphate has been attempted along with the synthesis of (1S,2R,3S,4S)-3-fluoro-2,4-dihydroxycyclohexanecarboxylic acid as an inositol analog, useful for non-invasive visualization and quantitation of IP3-3KA enzymatic activity.
Collapse
Affiliation(s)
- Zhenghong Peng
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - David Maxwell
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Duoli Sun
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Yunming Ying
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Paul T Schuber
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Basvoju A Bhanu Prasad
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Juri Gelovani
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Wai-Kwan Alfred Yung
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - William G Bornmann
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| |
Collapse
|
16
|
Nickisch K, Nair HB, Kesavaram N, Das B, Garfield R, Shi SQ, Bhaskaran SS, Grimm SL, Edwards DP. Synthesis and antiprogestational properties of novel 17-fluorinated steroids. Steroids 2013; 78:909-19. [PMID: 23607964 DOI: 10.1016/j.steroids.2013.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 03/14/2013] [Accepted: 04/06/2013] [Indexed: 11/25/2022]
Abstract
Progesterone receptor (PR) plays a key role in reproductive functions, and compounds that inhibit progesterone action (antiprogestins) have potential use in the treatment of estrogen- and progesterone-dependent diseases, including uterine leiomyomas and breast cancer. In the present study, we chemically synthesized novel 17-fluorinated steroids and evaluated the cytotoxicity profiles of these compounds in T47D breast cancer cells compared to the activity of known antiprogestins, including ZK230 211, RU-486, CDB2914, CDB4124 and ORG33628. We analyzed in vitro receptor-binding assays and PR-transactivation assays to establish the antiprogestational activity of these molecules. The representative antiprogestin EC304 was found to inhibit in vitro tumorigenicity in a dose-dependent fashion in T47D cells by a colony formation assay at 1 and 10nM concentrations. The potent in vivo antiprogestational activity of EC304 was also demonstrated in an antinidation assay for the interruption of early pregnancy in rats. The strong antiprogestational activity and absence of antiglucocorticoid activity in EC compounds may demonstrate their utility in the treatment of leiomyoma, endometriosis and breast cancer.
Collapse
|
17
|
Affiliation(s)
- Franck Le Bideau
- Institut de Chimie de Strasbourg (UMR 7177), CNRS-Université de Strasbourg , Strasbourg 67000, France
| | | |
Collapse
|
18
|
Nickisch K, Elger W, Cessac J, Kesavaram N, Das B, Garfield R, Shi SQ, Amelkina O, Meister R. Synthesis and biological evaluation of partially fluorinated antiprogestins and mesoprogestins. Steroids 2013. [PMID: 23178161 DOI: 10.1016/j.steroids.2012.09.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A series of antiprogestins have been synthesized by partially fluorinating the steroid molecule in positions relevant for receptor binding. By introducing fluorine at the exo-methylene of the 17 spirofuran ring, we obtained partial agonists (mesoprogestins) with significant applications for antiproliferative and antiovulatory treatment strategies in gynecological therapy such as uterine fibroids, endometriosis and heavy menstrual bleeding. Compared to the standard drug RU486, our synthesized compounds exhibited considerable dissociation between antiprogestational and antiglucocorticoid PR receptors. Furthermore, our studies have shown that pure antiprogestins can be generated by partially fluorinating the 17 propenyl and propynl group or by substituting the 4' acetyl phenyl group in the 11 position using trifluromethyl group.
Collapse
|
19
|
Bruno RD, Vasaitis TS, Gediya LK, Purushottamachar P, Godbole AM, Ates-Alagoz Z, Brodie AMH, Njar VCO. Synthesis and biological evaluations of putative metabolically stable analogs of VN/124-1 (TOK-001): head to head anti-tumor efficacy evaluation of VN/124-1 (TOK-001) and abiraterone in LAPC-4 human prostate cancer xenograft model. Steroids 2011; 76:1268-79. [PMID: 21729712 PMCID: PMC3171567 DOI: 10.1016/j.steroids.2011.06.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/08/2011] [Accepted: 06/14/2011] [Indexed: 12/15/2022]
Abstract
In a continuing study of our clinical candidate 5 VN/124-1 (TOK-001) and analogs as potential agents for prostate cancer therapy, putative metabolites (10, 15 and 18) of compound 5 were rationally designed and synthesized. However, none of these agents were as efficacious as 5 in several in vitro studies. Using western blot analysis, we have generated a preliminary structure-activity relationship (SAR) of 5 and related analogs as androgen receptor ablative agents (ARAAs). In vivo using the androgen-dependent LAPC-4 prostate cancer xenograft model, we demonstrated for the first time that 5 is more efficacious than the 17-lyase inhibitor 3 (abiraterone)/4 (abiraterone acetate) that is currently in phase III clinical trials. In our desire to optimize the potency of 5, compounds 6 (3ξ-fluoro-) and 9 (3β-sulfamate-) designed to increase the stability and oral bioavailability of 5, respectively were evaluated in vivo. We showed, that on equimolar basis, compound 6 was ∼2-fold more efficacious versus LAPC-4 xenografts than 5, but the toxicity observed with 6 is of concern. These studies further demonstrate the efficacy of 5 in a clinically relevant prostate cancer model and justify its current clinical development as a potential treatment of prostate cancer.
Collapse
Affiliation(s)
- Robert D. Bruno
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Tadas S. Vasaitis
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Lalji K. Gediya
- Department of Pharmaceutical Sciences, Jefferson School of Pharmacy, Thomas Jefferson University, 130 South 9 Street, Philadelphia 19107, PA, USA
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Puranik Purushottamachar
- Department of Pharmaceutical Sciences, Jefferson School of Pharmacy, Thomas Jefferson University, 130 South 9 Street, Philadelphia 19107, PA, USA
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Abhijit M. Godbole
- Department of Pharmaceutical Sciences, Jefferson School of Pharmacy, Thomas Jefferson University, 130 South 9 Street, Philadelphia 19107, PA, USA
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Zeynep Ates-Alagoz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, 06100Tandogan, Ankara-Turkey
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, University of the Sciences, Philadelphia, PA 19104, USA
| | - Angela M. H. Brodie
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Vincent C. O. Njar
- Department of Pharmaceutical Sciences, Jefferson School of Pharmacy, Thomas Jefferson University, 130 South 9 Street, Philadelphia 19107, PA, USA
- Kimmel Cancer Center, Thomas Jefferson University, 130 South 9 Street, Philadelphia 19107, PA, USA
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
- Corresponding author: Tel: (215) 503 7468, Fax: (215) 503 9052;
| |
Collapse
|
20
|
Rice SL, Roney CA, Daumar P, Lewis JS. The next generation of positron emission tomography radiopharmaceuticals in oncology. Semin Nucl Med 2011; 41:265-82. [PMID: 21624561 DOI: 10.1053/j.semnuclmed.2011.02.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although (18)F-fluorodeoxyglucose ((18)F-FDG) is still the most widely used positron emission tomography (PET) radiotracer, there are a few well-known limitations to its use. The last decade has seen the development of new PET probes for in vivo visualization of specific molecular targets, along with important technical advances in the production of positron-emitting radionuclides and their related labeling methods. As such, a broad range of new PET tracers are in preclinical development or have recently entered clinical trials. The topics covered in this review include labeling methods, biological targets, and the most recent preclinical or clinical data of some of the next generation of PET radiopharmaceuticals. This review, which is by no means exhaustive, has been separated into sections related to the PET radionuclide used for radiolabeling: fluorine-18, for the labeling of agents such as FACBC, FDHT, choline, and Galacto-RGD; carbon-11, for the labeling of choline; gallium-68, for the labeling of peptides such as DOTATOC and bombesin analogs; and the long-lived radionuclides iodine-124 and zirconium-89 for the labeling of monoclonal antibodies cG250, and J591 and trastuzumab, respectively.
Collapse
Affiliation(s)
- Samuel L Rice
- Radiochemistry Service, Department of Radiology and Program in Molecular Pharmacology and Chemistry, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, USA
| | | | | | | |
Collapse
|
21
|
Andrieu T, Bertolini R, Nichols SE, Setoud R, Frey FJ, Baker ME, Frey BM. A novel steroidal antiandrogen targeting wild type and mutant androgen receptors. Biochem Pharmacol 2011; 82:1651-62. [PMID: 21907706 DOI: 10.1016/j.bcp.2011.08.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/24/2011] [Accepted: 08/24/2011] [Indexed: 11/17/2022]
Abstract
Prostate cancer (PCa) progression is enhanced by androgen and treatment with antiandrogens represents an alternative to castration. While patients initially respond favorably to androgen ablation therapy, most experience a relapse of the disease within 1-2 years by expressing androgen receptor (AR) mutants. Such mutations, indeed, promote unfavorable agonistic behavior from classical antagonists. Here, we have synthesized and screened 37 novel compounds derived from dihydrotestosterone (DHT), cyanolutamide and hydroxyflutamide. These derivatives were tested for their potential antagonistic activity using a luciferase reporter gene assay and binding properties were determined for wild type (WT) and mutant ARs (T877A, W741C, W741L, H874Y). In the absence and presence of antiandrogens, androgen dependent cellular proliferation and prostate specific antigen (PSA) expression were assayed in the prostate cancer cell line LNCaP by crystal violet, real time PCR and by Western blots. Also, cellular proliferation and PSA expression were assayed in 22Rv1. A novel compound RB346, derived from DHT, was found to be an antagonist for all tested AR forms, preventing DHT induced proliferation and PSA expression in LNCaP and 22Rv1 cells. RB346 displayed no agonistic activity, in contrast to the non-steroidal antiandrogen bicalutamide (Casodex) with unfavorable agonistic activity for W741L-AR. Additionally, RB346 has a slightly higher binding affinity for WT-AR, T877A-AR and H874Y-AR than bicalutamide. Thus, RB346 is the first potent steroidal antiandrogen with efficacy for WT and various AR mutants.
Collapse
Affiliation(s)
- Thomas Andrieu
- Department of Nephrology & Hypertension, University of Berne, Berne, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
22
|
Ampt KAM, Aspers RLEG, Jaeger M, Geutjes PETJ, Honing M, Wijmenga SS. Application of fluorine NMR for structure identification of steroids. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2011; 49:221-230. [PMID: 21387404 DOI: 10.1002/mrc.2737] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/13/2011] [Accepted: 01/14/2011] [Indexed: 05/30/2023]
Abstract
Fluorinated steroids were examined using 1D and 2D homo- and heteronuclear (19)F NMR, such as (19)F-(1) H and (19)F-(13)C. The utilization of fluorine NMR accounted for spectral simplification and resulted in a straightforward pathway for the determination of structures including the configuration of these compounds; these steroids present an illustrative example for other types of fluorinated compounds, which are increasingly encountered in drug discovery. The potential of (19)F NMR is elaborated on in detail for two compounds containing diastereotopic fluorines with different coupling patterns. The analysis of the coupling patterns and the through-space interactions resulted in the determination of the structure and configuration. Heteronuclear correlation experiments, i.e. (19)F-(1)H HETCOR, (19)F-(13)C HMQC and HMBC, and (19)F-(1)H HOESY, were applied to determine first the relative stereochemistry and then the molecular configuration at C4 and C5 of a steroidal compound bearing a fused three-membered ring with two fluorine substituents. These examples proved (19)F NMR to be a useful addition to the extensively used (1)H and (13)C NMR within structure elucidation and configuration determination of small molecules.
Collapse
Affiliation(s)
- Kirsten A M Ampt
- Institute of Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Prostate cancer is biologically and clinically a heterogeneous disease and its imaging evaluation will need to be tailored to the specific phases of the disease in a patient-specific, risk-adapted manner. We first present a brief overview of the natural history of prostate cancer before discussing the role of various imaging tools, including opportunities and challenges, for different clinical phases of this common disease in men. We then review the preclinical and clinical evidence on the potential and emerging role of positron emission tomography with various radiotracers in the imaging evaluation of men with prostate cancer.
Collapse
Affiliation(s)
- Hossein Jadvar
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
24
|
Kortylewicz ZP, Nearman J, Baranowska-Kortylewicz J. Radiolabeled 5-iodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridine and its 5'-monophosphate for imaging and therapy of androgen receptor-positive cancers: synthesis and biological evaluation. J Med Chem 2010; 52:5124-43. [PMID: 19653647 DOI: 10.1021/jm9005803] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High levels of androgen receptor (AR) are often indicative of recurrent, advanced, or metastatic cancers. These conditions are also characterized by a high proliferative fraction. 5-Radioiodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridine 8 and 5-radioiodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridin-5'-yl monophosphate 13 target AR. They are also degraded intracellularly to 5-radioiodo-2'-deoxyuridine 1 and its monophosphate 20, respectively, which can participate in the DNA synthesis. Both drugs were prepared at the no-carrier-added level. Precursors and methods are readily adaptable to radiolabeling with various radiohalides suitable for SPECT and PET imaging, as well as endoradiotherapy. In vitro and in vivo studies confirm the AR-dependent interactions. Both drugs bind to sex hormone binding globulin. This binding significantly improves their stability in serum. Biodistribution and imaging studies show preferential uptake and retention of 8 and 13 in ip xenografts of human ovarian adenocarcinoma cells NIH:OVCAR-3, which overexpress AR. When these drugs are administered at therapeutic dose levels, a significant tumor growth arrest is observed.
Collapse
Affiliation(s)
- Zbigniew P Kortylewicz
- Department of Radiation Oncology, J. Bruce Henriksen Cancer Research Laboratories, University of Nebraska Medical Center, 986850 Nebraska Medical Center, Omaha, Nebraska 68198-6850, USA.
| | | | | |
Collapse
|
25
|
Gunther JR, Parent AA, Katzenellenbogen JA. Alternative inhibition of androgen receptor signaling: peptidomimetic pyrimidines as direct androgen receptor/coactivator disruptors. ACS Chem Biol 2009; 4:435-40. [PMID: 19441848 DOI: 10.1021/cb900043e] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Compounds that directly disrupt the androgen receptor/steroid receptor coactivator interaction could function as novel inhibitors of androgen signaling that would remain effective in the treatment of prostate cancer that is resistant to conventional endocrine therapies. A structure-based peptidomimetic approach was used to design and synthesize such compounds, based on a pyrimidine-core system. Using fluorescence resonance energy transfer and reporter gene assays, we identified members of this library that disrupt the androgen receptor/steroid receptor coactivator interaction selectively, without affecting the estrogen receptor/steroid receptor coactivator interaction. Unlike the activity of traditional androgen receptor antagonists, such as flutamide and bicalutamide, inhibition by these coactivator binding inhibitors is insurmountable by increased concentrations of androgen agonists and maintains effectiveness even on a mutant androgen receptor that is resistant to traditional antagonists. These findings support the feasibility of targeting the coactivator binding groove of the androgen receptor as an alternative approach to treatment-resistant prostate cancer therapy.
Collapse
Affiliation(s)
- Jillian R. Gunther
- Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
| | - Alexander A. Parent
- Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
| | | |
Collapse
|
26
|
Top S, Thibaudeau C, Vessières A, Brulé E, Le Bideau F, Joerger JM, Plamont MA, Samreth S, Edgar A, Marrot J, Herson P, Jaouen G. Synthesis and Structure Activity Relationship of Organometallic Steroidal Androgen Derivatives. Organometallics 2009. [DOI: 10.1021/om800698y] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Siden Top
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Céline Thibaudeau
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Anne Vessières
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Emilie Brulé
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Franck Le Bideau
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Jean-Michel Joerger
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Marie-Aude Plamont
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Soth Samreth
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Alan Edgar
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Jérôme Marrot
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Patrick Herson
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| | - Gérard Jaouen
- Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Charles Friedel, UMR 7223, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France, Laboratoire Fournier, 50 Rue de Dijon, 21121 Daix, France, Institut Lavoisier de Versailles, UMR 8180, Université de Versailles-Saint-Quentin-en-Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France, and Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05,
| |
Collapse
|
27
|
Mankoff DA, Link JM, Linden HM, Sundararajan L, Krohn KA. Tumor receptor imaging. J Nucl Med 2008; 49 Suppl 2:149S-63S. [PMID: 18523071 DOI: 10.2967/jnumed.107.045963] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Tumor receptors play an important role in carcinogenesis and tumor growth and have been some of the earliest targets for tumor-specific therapy, for example, the estrogen receptor in breast cancer. Knowledge of receptor expression is key for therapy directed at tumor receptors and traditionally has been obtained by assay of biopsy material. Tumor receptor imaging offers complementary information that includes evaluation of the entire tumor burden and characterization of the heterogeneity of tumor receptor expression. The nature of the ligand-receptor interaction poses a challenge for imaging--notably, the requirement for a low molecular concentration of the imaging probe to avoid saturating the receptor and increasing the background because of nonspecific uptake. For this reason, much of the work to date in tumor receptor imaging has been done with radionuclide probes. In this overview of tumor receptor imaging, aspects of receptor biochemistry and biology that underlie tumor receptor imaging are reviewed, with the estrogen-estrogen receptor system in breast cancer as an illustrative example. Examples of progress in radionuclide receptor imaging for 3 receptor systems--steroid receptors, somatostatin receptors, and growth factor receptors-are highlighted, and recent investigations of receptor imaging with other molecular imaging modalities are reviewed.
Collapse
Affiliation(s)
- David A Mankoff
- Division of Nuclear Medicine, University of Washington, Seattle, Washington, USA.
| | | | | | | | | |
Collapse
|
28
|
Parent EE, Dence CS, Sharp TL, Welch MJ, Katzenellenbogen JA. 7α-18F-Fluoromethyl-Dihydrotestosterone and 7α-18F-Fluoromethyl-Nortestosterone: Ligands to Determine the Role of Sex Hormone–Binding Globulin for Steroidal Radiopharmaceuticals. J Nucl Med 2008; 49:987-94. [DOI: 10.2967/jnumed.107.048926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
|
29
|
Guha C, Alfieri A, Blaufox MD, Kalnicki S. Tumor biology-guided radiotherapy treatment planning: gross tumor volume versus functional tumor volume. Semin Nucl Med 2008; 38:105-13. [PMID: 18243845 DOI: 10.1053/j.semnuclmed.2007.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This issue of Seminars in Nuclear Medicine deals with a watershed event in cancer treatment -- the combined use of functional and anatomical information to guide therapeutic interventions. The use of positron emission tomography/computed tomography (PET/CT) in radiation treatment planning and tumor response evaluation brings a paradigm change in the development of image-guided therapies into routine clinical practice. The implications, as seen in the following articles, are not only promising but also groundbreaking. And, as in every new scientific breakthrough, each step forward generates a myriad of additional important clinical and research questions. Functional imaging takes advantage of the subtle differences between normal and malignant tissues at the cellular level to reveal in vivo unique functional characteristics of neoplasms. The ultimate goal of the partnership between nuclear medicine physicians and radiation oncologists is to use this information with absolute clarity in target definition for radiation treatment planning and therapy, as well as response evaluation. Functional imaging can provide metabolic information and behavioral correlation along with the anatomical imaging for correlative target delineation. Additionally, as a purely diagnostic instrument, PET/CT provides a tool for oncologists to make critical decisions regarding radiation treatment planning modifications secondary to changes in tumor staging (up or down), treatment field modifications, localized control, sites of residual and/or metastatic disease and post therapy response evaluation. The articles in this issue of the seminars provide insights into the current state-of-the-art of functional imaging techniques, mostly centered on the use of (18)F-fluorodeoxyglucose PET/CT in image guided oncologic therapies. Because it is a novel science, the future of image-guided functional treatment planning is bright with technologic and biologic innovations, translational research and new clinical applications.
Collapse
Affiliation(s)
- Chandan Guha
- Department Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10467, USA.
| | | | | | | |
Collapse
|
30
|
Pantaleo MA, Nannini M, Maleddu A, Fanti S, Ambrosini V, Nanni C, Boschi S, Biasco G. Conventional and novel PET tracers for imaging in oncology in the era of molecular therapy. Cancer Treat Rev 2007; 34:103-21. [PMID: 18055120 DOI: 10.1016/j.ctrv.2007.10.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 10/03/2007] [Accepted: 10/06/2007] [Indexed: 01/18/2023]
Abstract
In the last ten years, the development of several novel targeted drugs and the refinement of state of the art technologies such as the genomics and proteomics and their introduction to clinical practice have revolutionized the management of patients affected by cancer. However, everyday practice points out several clinical questions: the difficulty of response assessment to new drugs especially using standard RECIST criteria that do not provide information on biological, vascular or metabolic variations; the inadequate selection of patients who are likely to benefit from a targeted therapy excluding those with breast cancer and gastrointestinal stromal tumours; the need to know the global biological background of diseases especially in metastatic setting using repeatable non-invasive procedures. Molecular imaging could provide information on in vivo distribution of biological markers in response to targeted therapy and could improve the selection of patients before therapies. The aim of this review is to analyze the current role of conventional and innovative positron emission tomography (PET) radiotracers in clinical practice and to explore the promising perspectives of molecular imaging in cancer research.
Collapse
Affiliation(s)
- M A Pantaleo
- Institute of Hematology and Medical Oncology L. & A. Seragnoli, Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Parent EE, Dence CS, Sharp TL, Welch MJ, Katzenellenbogen JA. Synthesis and biological evaluation of a fluorine-18-labeled nonsteroidal androgen receptor antagonist, N-(3-[18F]fluoro-4-nitronaphthyl)-cis-5-norbornene-endo-2,3-dicarboxylic imide. Nucl Med Biol 2006; 33:615-24. [PMID: 16843836 DOI: 10.1016/j.nucmedbio.2006.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 04/05/2006] [Accepted: 04/15/2006] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Androgen receptor (AR), which is overexpressed in most prostate cancers, is the target of androgen ablation and antiandrogen therapies: it is also the target for the receptor-mediated imaging of AR-positive prostate cancer using radiolabeled ligands. Previous AR imaging agents were based on a steroidal core labeled with fluorine. To develop a novel class of nonsteroidal imaging agents, with binding and pharmacological characteristics that are more similar to those of clinically used AR antagonists, we synthesized N-(3-fluoro-4-nitronaphthyl)-cis-5-norbornene-endo-2,3-dicarboxylic imide (3-F-NNDI), an analog of recently reported AR antagonist ligands. METHODS 3-F-NNDI was synthesized in six steps starting with 1-nitronaphthalene, with fluorine incorporation as the final step. The labeling of 3-F-NNDI with fluorine-18 was achieved through a novel, extremely mild, S(N)Ar displacement reaction of an o-nitro-activated arene trimethylammonium salt, and 3-[(18)F]F-NNDI was prepared in high specific activity. RESULTS AND DISCUSSION 3-F-NNDI was found to have an AR-binding affinity similar to that of its parent compound. In vitro assays demonstrated high stability of the labeled compound under physiological conditions in buffer and in the blood. Androgen target tissue uptake in diethylstilbestrol-pretreated male rats, however, was minimal, probably because of extensive metabolic defluorination the radiolabeled ligand. CONCLUSIONS This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents that are alternatives to steroidal AR agonist-based imaging agents. Although 3-[(18)F]F-NNDI has significant affinity for AR, it showed limited promise as a PET imaging agent because of its poor target tissue distribution properties.
Collapse
Affiliation(s)
- Ephraim E Parent
- Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | | |
Collapse
|
32
|
Du H, Liu K, Li W. Catalytic Hydrogenation of Halosteroidal Derivatives by Bipyridine or Phenanthroline Complexes of Copper(II) in Hydrazine Aqueous Media. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397910500408522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Huang‐Chi Du
- a Institute of Chemistry, Academia Sinica , Taipei, Taiwan
| | - Kung‐Cheng Liu
- a Institute of Chemistry, Academia Sinica , Taipei, Taiwan
| | - Wen‐Shan Li
- a Institute of Chemistry, Academia Sinica , Taipei, Taiwan
| |
Collapse
|
33
|
Parent EE, Jenks C, Sharp T, Welch MJ, Katzenellenbogen JA. Synthesis and biological evaluation of a nonsteroidal bromine-76-labeled androgen receptor ligand 3-[76Br]bromo-hydroxyflutamide. Nucl Med Biol 2006; 33:705-13. [PMID: 16934689 DOI: 10.1016/j.nucmedbio.2006.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 05/25/2006] [Accepted: 05/30/2006] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Androgen receptors (ARs) are overexpressed in normal tissues and in most primary and metastatic prostate cancers. In our efforts to develop a nonsteroidal AR-specific imaging agent, we synthesized (+/-)-3-[(76)Br]bromo-hydroxyflutamide ((76)Br-), an analog of hydroxyflutamide, the active metabolite of the AR antagonist ligand flutamide. MATERIALS AND METHODS (76)Br- was synthesized in three steps, starting with commercially available compounds. Labeling of (76)Br- was achieved through the nucleophilic opening of an epoxide intermediate, and a labeled compound was obtained in high specific activity and good radiochemical yield. RESULTS AND DISCUSSION (+/-)-3-Bromo-hydroxyflutamide has a significantly higher affinity for ARs compared to hydroxyflutamide, its parent compound. The androgen target-tissue uptake of (76)Br- in diethylstilbestrol-treated male rats was examined; however, AR-mediated uptake was minimal due most likely to the rapid metabolic debromination of the radiolabeled ligand. CONCLUSIONS This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents, which are alternatives to steroidal AR agonist-based imaging agents. Although (76)Br- has a significant affinity for ARs, it showed limited promise as a PET imaging agent because of its poor target-tissue distribution properties.
Collapse
Affiliation(s)
- Ephraim E Parent
- Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | | |
Collapse
|
34
|
Deluca D, Möller G, Rosinus A, Elger W, Hillisch A, Adamski J. Inhibitory effects of fluorine-substituted estrogens on the activity of 17beta-hydroxysteroid dehydrogenases. Mol Cell Endocrinol 2006; 248:218-24. [PMID: 16406285 DOI: 10.1016/j.mce.2005.11.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In search for new inhibitors of human 17beta-hydroxysteroid dehydrogenase type 1 (h17beta-HSD1) a specific group of steroids with interesting properties including novel compounds was investigated. Several estratriene derivatives with fluorine-substitution in position 17 of the steroidal scaffold were synthesised and tested in vitro towards recombinant h17beta-HSD1, 2, 4, 5 and 7. Moderate, mostly unselective inhibitors of h17beta-HSD1 and h17beta-HSD2 and a selective inhibitor of h17beta-HSD5 were identified. The structure-activity relationship with respect to inhibitory strengths and selectivity of these compounds on five h17beta-HSDs is discussed.
Collapse
Affiliation(s)
- Dominga Deluca
- GSF-National Research Center for Environment and Health, Institute of Experimental Genetics, Genome Analysis Center, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | | | | | | | | | | |
Collapse
|
35
|
Yang J, Bohl CE, Nair VA, Mustafa SM, Hong SS, Miller DD, Dalton JT. Preclinical Pharmacology of a Nonsteroidal Ligand for Androgen Receptor-Mediated Imaging of Prostate Cancer. J Pharmacol Exp Ther 2006; 317:402-8. [PMID: 16434567 DOI: 10.1124/jpet.105.094334] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Proper management of prostate cancer patients is highly dependent on the spread of the disease. High expression levels of the androgen receptor (AR) in prostate tumor offer a target for identifying cancer metastasis. We investigated the use of nonsteroidal AR ligands for receptor-mediated imaging as a diagnostic tool for prostate cancer staging. Compound S-26 [S-3-(4-fluorophenoxy)-2-hydroxy-2-methyl-N-(4-cyano-3-iodophenyl)-propionamide]was identified from a series of iodinated ether-linked derivatives of bicalutamide due to its high-AR binding affinity of 3.3 nM (which is similar to testosterone and approximately 25% of the binding affinity of dihydrotestosterone) in an in vitro competitive binding assay using rat prostate cytosol. Furthermore, S-26 exhibited a greater binding affinity (K(i) = 4.4 nM) in a whole-cell binding assay using COS-7 cells transfected with human AR than testosterone (K(i) = 32.9 nM) and dihydrotestosterone (K(i) = 45.4 nM). We also confirmed that sex hormone-binding globulin (SHBG), a plasma protein that binds steroids with high affinity, does not bind with S-26. Cotransfection studies with the estrogen, progesterone, and glucocorticoid receptor indicated that S-26 does not cross-react with other members of the steroid hormone receptor family. The nonsteroidal structure, high-AR binding affinity, specificity, and lack of binding to SHBG indicate that S-26 exhibits favorable properties for further development as an imaging agent for prostate cancer.
Collapse
Affiliation(s)
- Jun Yang
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, USA
| | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Although most clinical diagnostic imaging studies employ anatomic techniques such as computed tomography (CT) and magnetic resonance (MR) imaging, much of radiology research currently focuses on adapting these conventional methods to physiologic imaging as well as on introducing new techniques and probes for studying processes at the cellular and molecular levels in vivo, i.e. molecular imaging. Molecular imaging promises to provide new methods for the early detection of cancer and support for personalized cancer therapy. Although molecular imaging has been practiced in various incarnations for over 20 years in the context of nuclear medicine, other imaging modalities have only recently been applied to the noninvasive assessment of physiology and molecular events. Nevertheless, there has been sufficient experience with specifically targeted contrast agents and high-resolution techniques for MR imaging and other modalities that we must begin moving these new technologies from the laboratory to the clinic. This brief review outlines several of the more promising areas of pursuit in molecular imaging for oncology with an emphasis on those that show the most immediate likelihood for clinical translation.
Collapse
Affiliation(s)
- Martin G Pomper
- The Russell H Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD 21287-2182, USA.
| |
Collapse
|
37
|
Van Den Bossche B, Van de Wiele C. Receptor Imaging in Oncology by Means of Nuclear Medicine: Current Status. J Clin Oncol 2004; 22:3593-607. [PMID: 15337810 DOI: 10.1200/jco.2004.10.216] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
To date, our understanding of the role of receptors and their cognate ligands in cancer is being successfully translated into the design and development of an arsenal of new, less toxic, and more specific anticancer drugs. Because most of these novel drugs are cytostatic, objective response as measured by morphologic imaging modalities (eg, computed tomography or magnetic resonance imaging) cannot be used as a surrogate marker for drug development or for clinical decision making. Positron emission tomography (PET) can be used to image and quantify the in vivo distribution of positron-emitting radioisotopes such as oxygen-15, carbon-11, and fluorine-18 that can be substituted or added into biologically relevant and specific receptor radioligands. Similarly, single-photon emission computed tomography (SPECT) can be used to image and quantify the in vivo distribution of receptor targeting compounds labeled with indium-111, technetium-99m, and iodine-123. By virtue of their whole-body imaging capacity and the absence of errors of sampling and tissue manipulation as well as preparation, both techniques have the potential to address locoregional receptor status noninvasively and repetitively. This article reviews available data on the in vivo evaluation of receptor systems by means of PET or SPECT for identifying and monitoring patients with sufficient receptor overexpression for tailored therapeutic interventions, and also for depicting tumor tissue and determining the currently largely unknown heterogeneity in receptor expression among different tumor lesions within and between patients.
Collapse
|
38
|
Ali H, Rousseau J, Ahmed N, Guertin V, Hochberg RB, van Lier JE. Synthesis of the 7alpha-cyano-(17alpha,20E/Z)-[125I]iodovinyl-19-nortestosterones: potential radioligands for androgen and progesterone receptors. Steroids 2003; 68:1163-71. [PMID: 14643878 DOI: 10.1016/j.steroids.2003.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We report the preparation of the 7alpha-cyano derivative of the isomeric (17alpha,20E/Z)-[125I]iodovinyl-19-nortestosterones (IVNT) together with their binding affinity for the androgen receptor (AR) and their biodistribution in two different animal models. The cyano group was introduced at the 7alpha-position by hydrocyanation of 4,6-estradien-17beta-ol-3-one with diethylaluminum cyanide. Selective protection of the A-ring enone system as the dienol ether followed by ethynylation and deprotection under base and acid hydrolysis condition gave 7alpha-cyano-17alpha-ethynyl-19-nortestosterone. The stannyl derivatives were prepared by addition of tri-n-butylstannyl hydride and converted stereospecifically to the corresponding [125I]iodovinyl analog using [125I]NaI and H2O2. The [125I]iodovinylsteroids were intravenously administered to male rats and estrogen-primed immature female rats and tissue uptake was measured up to 6h post-injection. Co-administration of NLP-004 or ORG-2058, highly selective ligands for the progesterone receptor, to the female rats did not affect uterus uptake of the 125I-ligands. However co-injection of testosterone to DES-primed male rats induced a marked increase in prostate uptake of the 20Z-isomer of 7alpha-cyano-[125I]-IVNT. The relative binding affinity (RBA) of either 7alpha-cyano-(17alpha,20E/Z)-IVNT isomer for the AR is low (RBA=4 and 3, respectively, versus 100 for 5alpha-dihydrotestosterone (DHT)), suggesting the absence of a possible role of the AR in the localization process. These findings contrast previously reported data for the analogous 7alpha-methyl-[125I]-IVNT where co-administration of testosterone was shown to result in a 50% drop in prostate uptake. These data indicate that the addition of an electron withdrawing 7alpha-cyano group to 123I-labeled nortestosterone derivatives does not improve their potential to serve as SPECT agents for the imaging of AR densities in the prostate.
Collapse
Affiliation(s)
- Hasrat Ali
- Department of Nuclear Medicine and Radiobiology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Que., Canada J1H 5N4
| | | | | | | | | | | |
Collapse
|
39
|
A selective Cu(II)/Fe(III)-mediated hydrogenation of steroidal haloalkenes in the presence of hydrazine. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(02)02875-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
40
|
Abstract
Positron emission tomography (PET) scanning is evolving as a unique tool for drug development in oncology for improving both the efficacy of established treatment and in evaluating novel anticancer agents. As a non-invasive functional imaging modality, PET has an unrivalled sensitivity when monitoring the pharmacokinetics and pharmacodynamics of drugs and biochemicals when radiolabelled with short living positron-emitting radioisotopes. This is of particular relevance in assessing newer molecular-targeted therapy where conventional evaluation criteria (maximum tolerated dose and tumour shrinkage for example) may be inappropriate. PET has already been applied to a wide number of drugs to demonstrate activity in vivo from standard chemotherapy such as 5-fluorouracil (5-FU) [J Clin Oncol 17 (1999) 1580], to novel molecular agents such as those involved in tumour angiogenesis [Br J Cancer 83 (2000) P6] and antivascular therapy [Proc Annu Meet Am Soc Clin Oncol 19 (2000) 179a]. This review will evaluate the achievements of PET in the drug development process, an approach that promises to facilitate the rapid translation of scientific research into current clinical practice.
Collapse
Affiliation(s)
- N Gupta
- Cancer Research UK PET Oncology Group, Section of Cancer Therapeutics, Imperial College of Science, Technology and Medicine, MRC Cyclotron Unit, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK
| | | | | |
Collapse
|
41
|
Katzenellenbogen JA. Steroids labeled with 18F for imaging tumors by positron emission tomography. J Fluor Chem 2001. [DOI: 10.1016/s0022-1139(01)00379-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
42
|
Abstract
The origins of positron emission tomography (PET) date back 70 years. Since the 1970s, however, its use has increased exponentially in the fields of neurology, cardiology and oncology. [18F]-Fluorodeoxyglucose (FDG) whole-body scanning is by far the most widely utilised and recognised application of PET in oncology. However, PET is a very versatile and powerful imaging modality capable of helping bridge the gap between the laboratory and the clinic. This article reviews the history and current applications of PET in oncology and then explores some of the newer applications and potential future uses of this versatile technology particularly in the area of cancer research.
Collapse
Affiliation(s)
- H Anderson
- CRC PET Oncology Group, MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Du Cane Road, W12 0NN, London, UK
| | | |
Collapse
|
43
|
Kuduk SD, Harris TC, Zheng FF, Sepp-Lorenzino L, Ouerfelli Q, Rosen N, Danishefsky SJ. Synthesis and evaluation of geldanamycin-testosterone hybrids. Bioorg Med Chem Lett 2000; 10:1303-6. [PMID: 10866406 DOI: 10.1016/s0960-894x(00)00208-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Geldanamycin (GDM) binds to the Hsp90 chaperone protein resulting in the degradation of several important signaling proteins. A series of GDM-testosterone linked hybrids has been synthesized and evaluated for activity against prostate cancer cell lines. The hybrid with the greatest activity exhibits potent and selective cytotoxicity against prostate cancer cells containing the androgen receptor.
Collapse
Affiliation(s)
- S D Kuduk
- Departement of Medicine, Sloan-Kettering Institute for Cancer Research, New York, NY 10021, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
There is an increasing realization of the role of non-invasive monitoring of drug pharmacology. In this review, we discuss the role of positron emission tomography in such monitoring of tumour and normal tissue drug pharmacokinetics as well as assessment of tumour response, drug-receptor interactions and mechanisms of drug action and resistance. These studies represent a multidisciplinary research effort involving radiochemists, imaging scientists, clinicians, pharmacologists and mathematical modellers. This review evaluates achievements in the field from assessment of commonly used therapeutic agents such as 5-fluorouracil to target specific molecules such as markers for gene expression. It is envisaged that application of this technology will facilitate rational drug design and rapid translation of new ideas to the bedside.
Collapse
Affiliation(s)
- A Saleem
- CRC PET Oncology Group, Section of Cancer Therapeutics, Imperial College School of Medicine, MRC Cyclotron Unit, Hammersmith Hospital, Du Cane Road, London, UK.
| | | | | |
Collapse
|
45
|
Varagnolo L, Stokkel MP, Mazzi U, Pauwels EK. 18F-labeled radiopharmaceuticals for PET in oncology, excluding FDG. Nucl Med Biol 2000; 27:103-12. [PMID: 10773538 DOI: 10.1016/s0969-8051(99)00109-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews possible use of (18)F-labelled radiopharmaceuticals in oncology with positron emission tomography. The characteristics of various (18)F-labelled compounds are proteins and peptides, those that bind to. receptors, agents to assess hypoxia, and agents to evaluate gene therapy are highlighted. Furthermore, different (18)F-labelled tissue specific agents are indicated for the detection and monitoring of various malignancies: melanoma, brain tumours, breast cancer, prostate cancer and colorectal cancer. (18)F-fluorodeoxyglucose has been excluded from this summary.
Collapse
Affiliation(s)
- L Varagnolo
- Division of Nuclear Medicine, Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | | | | |
Collapse
|
46
|
Sanz G, Robles JE, Giménez M, Arocena J, Sánchez D, Rodriguez-Rubio F, Rosell D, Richter JA, Berián JM. Positron emission tomography with 18fluorine-labelled deoxyglucose: utility in localized and advanced prostate cancer. BJU Int 1999; 84:1028-31. [PMID: 10571628 DOI: 10.1046/j.1464-410x.1999.00349.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To determine the role of the positron emission tomography (PET) with 18F-labelled deoxyglucose in the identification of prostatic cancer in the iliac and obturator lymphatic nodes before radical prostatectomy, and in the localization of relapse in patients in biochemical progression. PATIENTS AND METHODS Twenty-one patients were divided into two groups. Group A consisted of 11 men diagnosed with organ-confined prostate cancer, where attention was focused on the iliac and obturator lymphatic nodes, the results being compared with the pathological anatomy obtained from surgical procedures. Group B included 10 patients treated by radical prostatectomy, radiotherapy or orchidectomy and who were in biochemical progression, in whom the aim was to identify recurrence of the disease. RESULTS In none of the 11 patients of group A who had undergone radical prostatectomy were deposits of radiotracer identified in the area of the iliac and obturator nodes which would indicate node metastases. However, the histopathological analysis of these nodes showed tumour in three patients. In group B the PET scans showed recurrence of prostate cancer (by deposits of radiotracer) more clearly than did computed tomography (CT) in two patients (both with recurrence in soft tissue). In one patient bone scintigraphy identified a lesion compatible with prostatic disease in the bone; this was clinically confirmed but was not identified by PET. CONCLUSION PET, using deoxyglucose labelled with 18F, cannot reliably identify prostatic adenocarcinoma in the iliac and obturator lymph nodes before surgery; other tracers may give better results. To locate relapses in patients with biochemical progression, PET seems to have better sensitivity than CT when identifying diseases in soft tissues and is possibly inferior to bone scintigraphy in detecting bony metastases.
Collapse
Affiliation(s)
- G Sanz
- Department of Urology, University Hospital, School of Medicine, Pamplona, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Rao PN, Wang Z, Cessac JW, Rosenberg RS, Jenkins DJ, Diamandis EP. New 11 beta-aryl-substituted steroids exhibit both progestational and antiprogestational activity. Steroids 1998; 63:523-30. [PMID: 9800283 DOI: 10.1016/s0039-128x(98)00060-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The syntheses of three 11 beta-aryl-19-norpregna-4,9-dien-3-one derivatives with 17-spirolactone and 17 beta-hydroxy-17 alpha-cyanoethyl substitutions are described. The progesterone agonist/antagonist activities of the new compounds are investigated using a recently developed tissue culture system that relies on the progesterone agonist up-regulation of the prostate-specific antigen (PSA) gene in female breast tumor cell lines. Two of the newly synthesized compounds exhibit mixed agonistic/antagonistic progestational activity.
Collapse
Affiliation(s)
- P N Rao
- Department of Organic Chemistry, Southwest Foundation for Biomedical Research, San Antonio, Texas 78245-0549, USA
| | | | | | | | | | | |
Collapse
|
48
|
Wüst F, Scheller D, Spies H, Johannsen B. Synthesis of Oxorhenium(V) Complexes Derived from 7α-Functionalized Testosterone: First Rhenium-Containing Testosterone Derivatives. Eur J Inorg Chem 1998. [DOI: 10.1002/(sici)1099-0682(199806)1998:6<789::aid-ejic789>3.0.co;2-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
49
|
Visser GM, Krugers HJ, Luurtsema G, van Waarde A, Elsinga PH, deKloet ER, Groen MB, Bohus B, Go KG, Paans AM. Synthesis and organ distribution of [18F]fluoro-Org 6141 in the rat: a potential glucocorticoid receptor ligand for positron emission tomography. Nucl Med Biol 1995; 22:915-20. [PMID: 8547889 DOI: 10.1016/0969-8051(95)00030-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
For the synthesis of [18F]Fluoro-Org 6141 via a nucleophilic substitution reaction with 18F-, the tosyl group was chosen as the leaving group because of its stability and excellent leaving group ability. The biodistribution of the high affinity and moderate lipophilicity (log P = 2.66, calculated value) ligand [18F]Fluoro-Org 6141 (specific activity 8.2 to 37 TBq/mmol, yield 10% at EOB) was examined in sham adrenalectomized (sADX) and adrenalectomized (ADX) male Wistar rats. Two days after ADX or sADX, the animals were anesthetized and 0.37 to 1.85 MBq of [18F]Fluoro-Org 6141 was administered intravenously. Kinetics of 18F activity uptake were monitored for 3 h using a stationary double-headed positron emission tomography (PET) camera, and the biodistribution was assessed by ex vivo determination of radioactivity in several tissues and different brain areas. One hour after injection of the radioligand, the bladder, kidney, liver, trachea, and bone of sADX animals contained more concentration on a wet weight basis than blood. Three hours post injection, radioactivity was retained in bladder, trachea, and bone. The accumulation of radioactivity in brain corresponded to the concentration of activity in the blood within the first hours after injection. ADX animals showed a higher uptake of 18F activity in spleen, testes, and brain areas (hippocampus and brainstem) but a lower uptake in bone than sADX rats. PET scans suggested that 18F activity uptake in the brain had not yet reached a maximum at this interval. Although [18F]Fluoro-Org 6141 is not useful for PET studies of glucocorticoid receptors (GRs), the results obtained with this compound indicate a synthetic strategy suitable for the synthesis of high-affinity radioligands for GRs.
Collapse
Affiliation(s)
- G M Visser
- PET Center and Groningen Center for Catalysis and Synthesis, Groningen, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
Seven androgens, substituted with fluorine at C-6, were prepared as potential imaging agents for androgen receptor-positive prostate tumors and were evaluated in vitro in terms of their lipophilicity and their relative binding affinities (RBA, relative to R 1881 = 100) for the androgen receptor and for sex steroid binding protein. Introduction of a fluorine atom into the C-6 position of an androgen generally decreases binding affinity to the androgen receptor, except in the two cases: 6 alpha-fluoro-19-nor-testosterone (RBA = 41.6 versus 30.6 for the unsubstituted steroid) and 6 alpha-fluorotestosterone (RBA = 8.9 versus 6.6). Receptor binding of the C-6 fluoro-androgens is also stereospecific, showing higher binding affinities for the alpha-epimers compared to the corresponding beta-epimers (4:1-15:1). Binding affinity to sex steroid binding protein is the lowest with 19-nor-testosterone, which is also the least lipophilic androgen studied. Based on the binding properties of compounds in this series, 6 alpha-fluoro-19-nor-testosterone appears to have the most promise as a tumor imaging agent.
Collapse
Affiliation(s)
- Y S Choe
- Department of Chemistry, University of Illinois, Urbana 61801, USA
| | | |
Collapse
|