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Schirrmacher R, Wängler B, Bailey J, Bernard-Gauthier V, Schirrmacher E, Wängler C. Small Prosthetic Groups in 18F-Radiochemistry: Useful Auxiliaries for the Design of 18F-PET Tracers. Semin Nucl Med 2017; 47:474-492. [PMID: 28826522 DOI: 10.1053/j.semnuclmed.2017.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Prosthetic group (PG) applications in 18F-radiochemistry play a pivotal role among current 18F-labeling techniques for the development and availability of 18F-labeled imaging probes for PET (Wahl, 2002) (1). The introduction and popularization of PGs in the mid-80s by pioneers in 18F-radiochemistry has profoundly changed the landscape of available tracers for PET and has led to a multitude of new imaging agents based on simple and efficiently synthesized PGs. Because of the chemical nature of anionic 18F- (apart from electrophilic low specific activity 18F-fluorine), radiochemistry before the introduction of PGs was limited to simple nucleophilic substitutions of leaving group containing precursor molecules. These precursors were not always available, and some target compounds were either hard to synthesize or not obtainable at all. Even with the advent of recently introduced "late-stage fluorination" techniques for the 18F-fluorination of deactivated aromatic systems, PGs will continue to play a central role in 18F-radiochemistry because of their robust and almost universal usability. The importance of PGs in radiochemistry is shown by its current significance in tracer development and exemplified by an overview of selected methodologies for PG attachment to PET tracer molecules. Especially, click-chemistry approaches to PG conjugation, while furthering the historical evolution of PGs in PET tracer design, play a most influential role in modern PG utilization. All earlier and recent multifaceted approaches in PG development have significantly enriched the contingent of modern 18F-radiochemistry procedures and will continue to do so.
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Affiliation(s)
- Ralf Schirrmacher
- Medical Isotope and Cyclotron Facility, Cross Cancer Institute, University of Alberta, Alberta, Canada.
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Germany
| | - Justin Bailey
- Medical Isotope and Cyclotron Facility, Cross Cancer Institute, University of Alberta, Alberta, Canada
| | - Vadim Bernard-Gauthier
- Medical Isotope and Cyclotron Facility, Cross Cancer Institute, University of Alberta, Alberta, Canada
| | - Esther Schirrmacher
- Medical Isotope and Cyclotron Facility, Cross Cancer Institute, University of Alberta, Alberta, Canada
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Germany
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Parent MJ, Cyr M, Aliaga A, Kostikov A, Schirrmacher E, Soucy JP, Mechawar N, Rosa-Neto P, Bedard MA. Concordance between in vivo and postmortem measurements of cholinergic denervation in rats using PET with [18F]FEOBV and choline acetyltransferase immunochemistry. EJNMMI Res 2013; 3:70. [PMID: 24103360 PMCID: PMC3852759 DOI: 10.1186/2191-219x-3-70] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 10/01/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fluorine-18 fluoroethoxybenzovesamicol ([18F]FEOBV) is a radioligand for the selective imaging of the vesicular acetylcholine transporter with positron emission tomography (PET). The current study demonstrates that pathological cortical cholinergic deafferentation can be quantified in vivo with [18F]FEOBV PET, yielding analogous results to postmortem histological techniques. METHODS Fifteen male rats (3 months old) underwent a cerebral infusion of 192 IgG-saporin at the level of the nucleus basalis magnocellularis. They were scanned using [18F]FEOBV PET, then sacrificed, and their brain tissues collected for immunostaining and quantification of cholinergic denervation using optical density (OD). RESULTS For both PET binding and postmortem OD, the highest losses were found in the cortical areas, with the highest reductions in the orbitofrontal, sensorimotor, and cingulate cortices. In addition, OD quantification in the affected areas accurately predicts [18F]FEOBV uptake in the same regions when regressed linearly. CONCLUSIONS These findings support [18F]FEOBV as a reliable imaging agent for eventual use in human neurodegenerative conditions in which cholinergic losses are an important aspect.
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Affiliation(s)
- Maxime J Parent
- Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada
- Université du Québec à Montreal (UQAM), Montreal, QC H3C 3P8, Canada
| | - Marilyn Cyr
- Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada
- Université du Québec à Montreal (UQAM), Montreal, QC H3C 3P8, Canada
| | - Antonio Aliaga
- Montreal Neurological Institute (MNI), Montreal, QC H3A 2B4, Canada
| | - Alexey Kostikov
- Montreal Neurological Institute (MNI), Montreal, QC H3A 2B4, Canada
| | | | - Jean-Paul Soucy
- Montreal Neurological Institute (MNI), Montreal, QC H3A 2B4, Canada
| | - Naguib Mechawar
- Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada
| | - Pedro Rosa-Neto
- Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada
- Montreal Neurological Institute (MNI), Montreal, QC H3A 2B4, Canada
| | - Marc-Andre Bedard
- Université du Québec à Montreal (UQAM), Montreal, QC H3C 3P8, Canada
- Montreal Neurological Institute (MNI), Montreal, QC H3A 2B4, Canada
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Kostikov AP, Chin J, Orchowski K, Schirrmacher E, Niedermoser S, Jurkschat K, Iovkova-Berends L, Wängler C, Wängler B, Schirrmacher R. Synthesis of [(18)F]SiFB: a prosthetic group for direct protein radiolabeling for application in positron emission tomography. Nat Protoc 2012; 7:1956-63. [PMID: 23037310 DOI: 10.1038/nprot.2012.110] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
N-Succinimidyl 3-(di-tert-butyl[(18)F]fluorosilyl)benzoate ([(18)F]SiFB) is a highly reactive prosthetic group for radiolabeling of proteins for use in positron emission tomography (PET). It is similar to N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB), the 'gold-standard' prosthetic group for protein (18)F-labeling, but can be synthesized using a much shorter and technically easier procedure. A recently reported simple procedure to obtain anhydrous (18)F- by avoiding time-consuming azeotropic drying is applied with a slight modification to prevent basic hydrolysis of the active N-hydroxysuccinimide (NHS) ester moiety of [(18)F]SiFB. The labeling of [(18)F]SiFB is performed by a fast (18)F-(19)F isotopic exchange (IE) reaction at room temperature (20-25 °C) within 30 min. [(18)F]SiFB is purified using a C18 cartridge instead of HPLC, further decreasing the overall time required for protein labeling. High specific activities > 18.5 GBq μmol(-1) (> 500 Ci mmol(-1)) can be obtained. Finally, incubation of [(18)F]SiFB with the desired protein in an aqueous solution at pH 9, followed by HPLC purification, provides the final solution of the labeled protein ready for in vivo applications.
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Affiliation(s)
- Alexey P Kostikov
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Parent M, Bedard MA, Aliaga A, Soucy JP, Landry St-Pierre E, Cyr M, Kostikov A, Schirrmacher E, Massarweh G, Rosa-Neto P. PET imaging of cholinergic deficits in rats using [18F]fluoroethoxybenzovesamicol ([18F]FEOBV). Neuroimage 2012; 62:555-61. [DOI: 10.1016/j.neuroimage.2012.04.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 04/04/2012] [Accepted: 04/12/2012] [Indexed: 11/28/2022] Open
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Tomaszowski KH, Schirrmacher R, Schirrmacher E, Kaina B. Abstract B63: Targeting cancer cells with a glucose-conjugated DNA repair inhibitor. Mol Cancer Ther 2011. [DOI: 10.1158/1535-7163.targ-11-b63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Alkylating agents are important chemotherapeutic drugs used for the treatment of several types of cancers, including brain tumors, melanoma and lymphoma. These chemotherapeutic agents have a strong affinity towards oxygen atoms in DNA giving rise to the important genotoxic DNA lesions O6-methylguanine and O6-chloroethylguanine, which are responsible for the cytotoxic effects of several alkylating anticancer drugs (e.g. temozolomide and lomustine). The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is considered as an important player of drug resistance because it removes these DNA adducts from the DNA. The MGMT protein restores guanine in the DNA by a suicide repair reaction leading to irreversible inactivation and degradation of the protein. Therefore depletion of MGMT renders cells more susceptible to treatment with alkylating anticancer drugs. There has been numerous attempts to inactivate MGMT with different inhibitors like O6-benzylguanine (O6-BG) or O6-(4-bromothenyl) guanine (O6-BTG, lomeguatrib) in glioblastoma and malignant melanoma cells. These strategies however have failed thus far, mainly due to the severe side effects associated with the systemic sensitization of the patients to chemotherapeutic agents. The application of targeting strategies for MGMT inhibitors therefore should improve chemotherapy by selective inhibition of MGMT in the tumor. In our previous work we have shown that O6-BG and O6-BTG bound to glucose is efficient in inhibiting MGMT on enzyme level and in the cell, causing sensitization to DNA alkylating N-nitrosoureas (Kaina et. al., 2004; 2010). Here we show, using a quantitative MGMT assay, that intracellular uptake of O6-benzylguanine-C8-glucose (O6-BG-Glu) occurs by a transporter-dependent mechanism and not through passive diffusion. We observed differences in the transport kinetics between several cell lines. Most cancer cell lines are able to take up the inhibitor, whereas normal cells only show marginal uptake of the glucose-conjugated inhibitor. The uptake is probably not depended on the glucose transporter GLUT since blocking of GLUT does not abolishes MGMT inhibition. Uptake of the glucose conjugated inhibitors in cancer cells leads to an increased DNA damage response, induction of apoptosis and significant decrease in surviving fraction after treatment with alkylating anticancer drugs, pointing to the usefulness of the glucose-mediated MGMT inhibitor targeting strategy. References: Kaina et al., J. Pharmacol. Expt. Therap., 311, 585–593 (2004); Kaina et al., Cell. Mol. Life Sci., 67, 3663–3681 (2010)
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B63.
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Affiliation(s)
| | | | | | - Bernd Kaina
- 1University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Soucy JP, Rosa P, Massarweh G, Aliaga A, Schirrmacher E, Bédard MA, Sanchez-Legaspi M, Gravel P, Reader A. P1‐388: Imaging of cholinergic terminals in the non‐human primate brain using 18F‐FEOBV PET: Development of a tool to assess cholinergic losses in Alzheimer's disease. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Pedro Rosa
- Montreal Neurological InstituteMontreal QC Canada
| | | | | | | | | | | | - Paul Gravel
- Montreal Neurological InstituteMontreal QC Canada
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Fottner C, Mettler E, Goetz M, Schirrmacher E, Anlauf M, Strand D, Schirrmacher R, Klöppel G, Delaney P, Schreckenberger M, Galle PR, Neurath MF, Kiesslich R, Weber MM. In vivo molecular imaging of somatostatin receptors in pancreatic islet cells and neuroendocrine tumors by miniaturized confocal laser-scanning fluorescence microscopy. Endocrinology 2010; 151:2179-88. [PMID: 20233796 DOI: 10.1210/en.2009-1313] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The aim of the study was to evaluate real time in vivo molecular imaging of somatostatin receptors (sstrs) using a handheld miniaturized confocal laser scan microscope (CLM) in conjunction with fluorescein-labeled octreotate (OcF) in healthy mice and murine models of neuroendocrine tumors. For CLM a small rigid probe (diameter 7 mm) with an integrated single line laser (488 nm) was used (optical slice thickness 7 mum; lateral resolution 0.7 mum). OcF was synthesized via Fmoc solid-phase peptide synthesis and purified by HPLC showing high-affinity binding to the sstr2 (IC(50) 6.2 nmol). For in vitro evaluation, rat and human pancreatic cancer cells were used and characterized with respect to its sstr subtype expression and functional properties. For in vivo confocal imaging, healthy mouse pancreatic islet and renal tubular cells as well as immunoincompetent nude mice harboring sstr-expressing tumors were evaluated. Incubation of sstr-positive cells with OcF showed a specific time- and dose-dependent staining of sstr-positive cells. CLM showed rapid internalization and homogenous cytoplasmatic distribution. After systemic application to mice (n = 8), specific time-dependent internalization and cytoplasmatic distribution into pancreatic islet cells and tubular cells of the renal cortex was recorded. After injection in tumor-harboring nude mice (n = 8), sstr-positive cells selectively displayed a cell surface and cytoplasmatic staining. CLM-targeted biopsies detected sstr-positive tumor cells with a sensitivity of 87.5% and a specificity of 100% as correlated with ex vivo immunohistochemistry. CLM with OcF permits real-time molecular, functional, and morphological imaging of sstr-expressing cell structures, allowing the specific visualization of pancreatic islet cells and neuroendocrine tumors in vivo.
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Affiliation(s)
- C Fottner
- Department of Endocrinology and Metabolism, I. Medical Clinic, University of Mainz, Mainz, Germany
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Mueller C, Klega A, Buchholz HG, Rolke R, Magerl W, Schirrmacher R, Schirrmacher E, Birklein F, Treede RD, Schreckenberger M. Basal opioid receptor binding is associated with differences in sensory perception in healthy human subjects: A [18F]diprenorphine PET study. Neuroimage 2010; 49:731-7. [DOI: 10.1016/j.neuroimage.2009.08.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 08/12/2009] [Accepted: 08/16/2009] [Indexed: 01/26/2023] Open
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Massaweh G, Schirrmacher E, la Fougere C, Kovacevic M, Wängler C, Jolly D, Gravel P, Reader AJ, Thiel A, Schirrmacher R. Improved work-up procedure for the production of [(18)F]flumazenil and first results of its use with a high-resolution research tomograph in human stroke. Nucl Med Biol 2009; 36:721-7. [PMID: 19720284 DOI: 10.1016/j.nucmedbio.2009.05.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 05/19/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The central benzodiazepine receptor (cBZR)-gamma-aminobutyric acid (GABA(A)) receptor complex in the human brain plays an important role in many neurological and psychiatric disorders. (18)F-Labeled flumazenil ([(18)F]FZ) provides a potentially useful tracer to investigate those disorders by means of positron emission tomography (PET). METHODS [(18)F]Flumazenil was synthesized from its nitro-precursor Ro 15-2344 in DMF at high temperatures between 150 degrees C and 160 degrees C. Other solvents like acetonitrile and dimethylsulfoxide were also investigated as reaction media. A new HPLC method for the final purification of [(18)F]FZ was developed to circumvent some difficulties associated with a previously published procedure sometimes led to a contamination of [(18)F]FZ with Ro 15-2344. The final purification of the radiotracer was achieved using a Waters Symmetry Prep C18 HPLC column with elution with 0.05 M sodium acetate (NaOAc) buffer (pH 5)/THF/MeOH (80:10:10). RESULTS [(18)F]FZ could be synthesized in reproducible radiochemical yields (RCYs) of 15-20% (decay corrected to EOB) after 80 min overall synthesis time. The synthesized [(18)F]FZ was applied for the first time in a human PET study in a patient with ischemic right middle cerebral artery stroke using the HRRT high-resolution research scanner (Siemens Medical Solution, Knoxville, TN, USA). CONCLUSIONS [(18)F]FZ is a potentially useful GABA receptor-binding PET ligand. A modified procedure for its preparation in reproducibly high radiochemical yields has been described and the [(18)F]FZ thus produced has been used successfully in a pilot clinical study.
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Affiliation(s)
- Gassan Massaweh
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Rosa-Neto P, Wängler B, Iovkova L, Boening G, Reader A, Jurkschat K, Schirrmacher E. [18F]SiFA-isothiocyanate: a new highly effective radioactive labeling agent for lysine-containing proteins. Chembiochem 2009; 10:1321-4. [PMID: 19422010 DOI: 10.1002/cbic.200900132] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A highly efficient (18)F-labeling synthon for universal protein labeling is reported. Diverse (18)F-labeled proteins of 66-144 kDa were prepared with [(18)F]SiFA-isothiocyanate synthesized by an isotopic (19)F for (18)F exchange at the silicon atom. Overall preparative radiochemical yields were 20-40 % after 40-50 min. No bone uptake of (18)F radioactivity was detected until 90 min post-injection of (18)F-SiFA-RSA; this demonstrates the metabolic stability of the [(18)F]SiFA moiety.
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Affiliation(s)
- Pedro Rosa-Neto
- Montreal Neurological Institute, McGill University, Douglas Research Institute, Montreal, H3A 2B4, Canada
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Wängler B, Quandt G, Iovkova L, Schirrmacher E, Wängler C, Boening G, Hacker M, Schmoeckel M, Jurkschat K, Bartenstein P, Schirrmacher R. Kit-like 18F-labeling of proteins: synthesis of 4-(di-tert-butyl[18F]fluorosilyl)benzenethiol (Si[18F]FA-SH) labeled rat serum albumin for blood pool imaging with PET. Bioconjug Chem 2009; 20:317-21. [PMID: 19132825 DOI: 10.1021/bc800413g] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Radiosyntheses of 18F-radiopharmaceuticals for positron emission tomography (PET) normally require an extraordinarily high effort of technical equipment and specially trained personnel. We recently reported a novel method for the introduction of fluorine-18 into peptides for PET-imaging based on silicon-18F-chemistry (SiFA technique). We herewith introduce the first SiFA-based Kit-like radio-fluorination of a protein (rat serum albumin,RSA) and demonstrate its usefulness for in vivo imaging with microPET in normal rats as well as in a rat heterotropic transplanted heart model. As a labeling agent, we prepared 4-(di-tert-butyl[18F]fluorosilyl)benzenethiol (Si[18F]FASH)by simple isotopic exchange in 40-60% radiochemical yield (RCY) and coupled it directly to a Sulfo-SMCC derivatized RSA in an overall RCY of 12% within 20-30 min. The technically simple labeling procedure does not require any elaborated purification procedures and is a straightforward example of a successful application of Si-18F chemistry for in vivo imaging with PET.
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Affiliation(s)
- Björn Wängler
- Department of Nuclear Medicine, Hospital of the Ludwig-Maximilians-University, Munich, Germany.
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12
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Iovkova L, Wängler B, Schirrmacher E, Schirrmacher R, Quandt G, Boening G, Schürmann M, Jurkschat K. para-Functionalized aryl-di-tert-butylfluorosilanes as potential labeling synthons for (18)F radiopharmaceuticals. Chemistry 2009; 15:2140-7. [PMID: 19156812 DOI: 10.1002/chem.200802266] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Broad spectrum: Novel para-functionalized aryl-di-tert-butylfluorosilanes, p-(tBu(2)FSi)C(6)H(4)X (X=functional group), have been made available and broaden the spectrum of silicon-based (18)F acceptors (SiFAs) for potential PET applications. For example, the [(18)F]maleimido derivative 1 has been employed for the synthesis of [(18)F]1- labeled rat serum albumin (RSA), the applicability of which for PET has been verified by in vivo experiments.The syntheses of the functionalized triorganofluorosilanes tBu(2)(p-XC(6)H(4))SiF (3 a, X=SH; 4 a, X=NCS; 4 b, X=NCO; 5, X=NC(4)H(2)O(2); 7, X=COOH; 8 a, X=COONC(4)H(4)O(2); 8 b, X=COOC(6)F(5)) are reported. These compounds display potential as silicon-based fluoride acceptors (SiFAs). The molecular structures of compounds 5, 7, and 8 a have been determined by single-crystal X-ray diffraction studies. With the exception of compounds 8 a and 8 b, all of the compounds could be (18)F-labeled by isotopic exchange in good to high radiochemical yields (RCY) with good to excellent specific activities. As proof of applicability, the maleimido-functionalized SiFA derivative 5, which is specific for thiol groups, has been used for the labeling of rat serum albumin (RSA) that had been derivatized with 2-iminothiolane. The incorporation of [(18)F]5 into the derivatized RSA reached a maximum yield after 30 min at ambient temperature. After purification, the [(18)F]RSA was evaluated in a healthy rat by means of muPET and displayed an expedient in vivo stability over 180 min.
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Affiliation(s)
- Ljuba Iovkova
- Lehrstuhl für Anorganische Chemie II, Technische Universität Dortmund, 44221 Dortmund, Germany
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Rius M, Stresemann C, Keller D, Brom M, Schirrmacher E, Keppler D, Lyko F. Human concentrative nucleoside transporter 1-mediated uptake of 5-azacytidine enhances DNA demethylation. Mol Cancer Ther 2009; 8:225-31. [PMID: 19139132 DOI: 10.1158/1535-7163.mct-08-0743] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The DNA methyltransferase inhibitors 5-azacytidine (5-azaCyd) and 5-aza-2'-deoxycytidine have found increasing use for the treatment of myeloid leukemias and solid tumors. Both nucleoside analogues must be transported into cells and phosphorylated before they can be incorporated into DNA and inactivate DNA methyltransferases. The members of the human equilibrative and concentrative nucleoside transporter families mediate transport of natural nucleosides and some nucleoside analogues into cells. However, the molecular identity of the transport proteins responsible for mediating the uptake of 5-azanucleosides has remained unknown. To this end, we have generated a stably transfected Madin-Darby canine kidney strain II cell line expressing recombinant hCNT1. An antiserum directed against hCNT1 specifically detected the protein in the apical membrane of hCNT1-expressing Madin-Darby canine kidney cells. Using [14C]5-azaCyd, we show here that hCNT1 mediated the Na+-dependent uptake of this drug with a Km value of 63 micromol/L. Na+-dependent transport of radiolabeled cytidine, uridine, and 5-fluoro-5'-deoxyuridine further showed the functionality of the transporter. hCNT1-expressing cells were significantly more sensitive to 5-azaCyd, and drug-dependent covalent trapping of DNA methyltransferase 1 was substantially more pronounced. Importantly, these results correlated with a significant sensitization of hCNT1-expressing cells toward the demethylating effects of 5-azaCyd and 5-aza-2'-deoxycytidine. In conclusion, our study identifies 5-azaCyd as a novel substrate for hCNT1 and provides direct evidence that hCNT1 is involved in the DNA-demethylating effects of this drug.
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Affiliation(s)
- Maria Rius
- Division of Tumor Biochemistry, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
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Schirrmacher R, Lakhrissi Y, Jolly D, Goodstein J, Lucas P, Schirrmacher E. Rapid in situ synthesis of [11C]methyl azide and its application in 11C click-chemistry. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.06.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Schreckenberger M, Klega A, Gründer G, Buchholz HG, Scheurich A, Schirrmacher R, Schirrmacher E, Müller C, Henriksen G, Bartenstein P. Opioid receptor PET reveals the psychobiologic correlates of reward processing. J Nucl Med 2008; 49:1257-61. [PMID: 18632824 DOI: 10.2967/jnumed.108.050849] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
UNLABELLED Little is known about the neurobiologic correlates of human personality. On the basis of the key role of the central opioidergic system in addiction and substance abuse, we investigated the relationship between certain personality traits that are supposed to be relevant in addiction and the opioid receptor status in healthy subjects. METHODS We investigated 23 healthy male volunteers who were extensively clinically tested to exclude substance abuse. All of the subjects underwent 1 PET scan with the subtype-nonselective opioidergic radioligand 18F-fluoroethyl-diprenorphine under resting conditions without sensory or cognitive stimulation. Subsequently, the subjects were psychologically tested for the personality traits novelty seeking, harm avoidance, reward dependence, and persistence, according to Cloninger's biosocial model of personality. The binding potential (BP) as a parameter of regional cerebral opioid receptor availability was computed by means of the modified Logan plot using the occipital cortex as a reference region. Further imaging data analysis was performed using statistical parametric mapping; after stereotactic normalization, the correlations were calculated between the regional BP and the psychologic scores on a voxel-by-voxel basis. RESULTS The correlation analysis between personality dimensions and opioid receptor availability showed a significant (P < 0.001) positive correlation between the scores of reward dependence and the BP of the bilateral ventral striatum with nucleus accumbens (z scores, 4.52 and 4.33, respectively). The additionally performed region-of-interest-based correlation analysis yielded correlation coefficients of r = 0.84 and r = 0.81 for the left and right ventral striata, respectively. No further significant correlations were detectable between the other personality dimensions and cerebral opioid receptor binding. CONCLUSION In healthy subjects, personality traits, which might be predisposing for addictive behavior, are correlated to the opioidergic neurotransmission in core structures of the human reward system.
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Schirrmacher E, Wängler B, Cypryk M, Bradtmöller G, Schäfer M, Eisenhut M, Jurkschat K, Schirrmacher R. Synthesis of p-(di-tert-butyl[(18)F]fluorosilyl)benzaldehyde ([(18)F]SiFA-A) with high specific activity by isotopic exchange: a convenient labeling synthon for the (18)F-labeling of N-amino-oxy derivatized peptides. Bioconjug Chem 2007; 18:2085-9. [PMID: 18030993 DOI: 10.1021/bc700195y] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The syntheses of different (18)F-labeled peptides using the highly effective labeling synthon p-(di- tert-butylfluorosilyl) benzaldehyde ([ (18)F]SiFA-A) for the development of (18)F-radiopharmaceuticals for oncological positron emission tomography (PET) is reported. The novel and mild labeling technique for the radiosynthesis of [ (18)F]SiFA-A, based on an unexpectedly efficient isotopic (19)F- (18)F exchange, yielded the (18)F-synthon [ (18)F]SiFA-A in almost quantitative yields in high specific activities between 225 and 680 GBq/micromol (6081-18 378 Ci/mmol) without applying HPLC purification. The [ (18)F]SiFA-A was finally used to label the N-terminal amino-oxy (N-AO) derivatized peptides AO-Tyr (3)-octreotate (AO-TATE), cyclo(fK(AO-N)RGD and N-AO-PEG 2-[D-Tyr-Gln-Trp-Ala-Val-betaAla-His-Thi-Nle-NH 2] (AO-BZH3, a bombesin derivative) in high radiochemical yields. Density functional theory (DFT) calculations confirmed high efficiency of the isotopic exchange, which is predicted to proceed via a pentacoordinate siliconate intermediate dissociating immediately to form the radiolabeled [ (18)F]SiFA-A.
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Affiliation(s)
- Esther Schirrmacher
- Lady Davis Institute, Jewish General Hospital, and Montreal Neurological Institute, McGill University, Montreal, Canada.
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Schirrmacher R, Bradtmöller G, Schirrmacher E, Thews O, Tillmanns J, Siessmeier T, Buchholz HG, Bartenstein P, Wängler B, Niemeyer CM, Jurkschat K. 18F-labeling of peptides by means of an organosilicon-based fluoride acceptor. Angew Chem Int Ed Engl 2007; 45:6047-50. [PMID: 16888726 DOI: 10.1002/anie.200600795] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ralf Schirrmacher
- Klinik und Poliklinik für Nuklearmedizin, Johannes Gutenberg Universität Mainz, 55131 Mainz, Germany.
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Goetz M, Fottner C, Schirrmacher E, Delaney P, Gregor S, Schneider C, Strand D, Kanzler S, Memadathil B, Weyand E, Holtmann M, Schirrmacher R, Weber MM, Anlauf M, Klöppel G, Vieth M, Galle PR, Bartenstein P, Neurath MF, Kiesslich R. In-vivo confocal real-time mini-microscopy in animal models of human inflammatory and neoplastic diseases. Endoscopy 2007; 39:350-6. [PMID: 17427071 DOI: 10.1055/s-2007-966262] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND AND STUDY AIMS Although various improvements in tissue imaging modalities have recently been achieved, in-vivo molecular and subsurface imaging in the field of gastroenterology remains a technical challenge. In this study we evaluated a newly developed, handheld, miniaturized confocal laser microscopy probe for real-time in-vivo molecular and subsurface imaging in rodent models of human disease. MATERIALS AND METHODS The minimicroscope uses a 488-nm, single line laser for fluorophore excitation. The optical slice thickness is 7 microm, the lateral resolution 0.7 microm. The range of the z-axis is 0-250 microm below the tissue surface. Imaging was performed using different fluorescent staining protocols; 5-carboxyfluorescein-labeled octreotate was synthesized for targeted molecular imaging. RESULTS Cellular and subcellular details of the gastrointestinal tract could be visualized in vivo at high resolution. Confocal real-time microscopy allowed in-vivo identification of tumor vessels and liver metastases, as well as diagnosis of focal hepatic inflammation, necrosis, and associated perfusion anomalies. Somatostatin-receptor targeting permitted in-vivo molecular staining of AR42-J-induced carcinoma and pancreatic islet cells. CONCLUSIONS Confocal mini-microscopy allows rapid in-vivo molecular and subsurface imaging of normal and pathological tissue in the gastrointestinal tract at high resolution. Because this technology is applicable to humans, it might impact on future in-vivo microsocpic and molecular diagnosis of diseases such as cancer and inflammation.
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Affiliation(s)
- M Goetz
- Medical Clinic I, University of Mainz, Mainz, Germany.
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Schneider S, Überberg S, Schechinger W, Klein HH, Schwanstecher C, Schwanstecher M, Schirrmacher E. Synthesis and evaluation of a glibenclamide glucose-conjugate: A potential lead compound for substituted glibenclamide derivatives as islet imaging agents. Exp Clin Endocrinol Diabetes 2007. [DOI: 10.1055/s-2007-972443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Schneider S, Ueberberg S, Korobeynikov A, Schechinger W, Schwanstecher C, Schwanstecher M, Klein H, Schirrmacher E. Synthesis and evaluation of a glibenclamide glucose-conjugate: A potential new lead compound for substituted glibenclamide derivatives as islet imaging agents. ACTA ACUST UNITED AC 2007; 139:122-7. [DOI: 10.1016/j.regpep.2006.11.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 11/07/2006] [Accepted: 11/07/2006] [Indexed: 11/28/2022]
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Schirrmacher R, Bradtmöller G, Schirrmacher E, Thews O, Tillmanns J, Siessmeier T, Buchholz HG, Bartenstein P, Wängler B, Niemeyer CM, Jurkschat K. 18F-Markierung von Peptiden mithilfe eines Organosilicium-Fluoridacceptors. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600795] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Wängler B, Beck C, Wagner-Utermann U, Schirrmacher E, Bauer C, Rösch F, Schirrmacher R, Eisenhut M. Application of tris-allyl-DOTA in the preparation of DOTA–peptide conjugates. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Schirrmacher E, Beck C, Brueckner B, Schmitges F, Siedlecki P, Bartenstein P, Lyko F, Schirrmacher R. Synthesis and in Vitro Evaluation of Biotinylated RG108: A High Affinity Compound for Studying Binding Interactions with Human DNA Methyltransferases. Bioconjug Chem 2006; 17:261-6. [PMID: 16536454 DOI: 10.1021/bc050300b] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small-molecule inhibitors of DNA methyltransferases such as RG108 represent promising candidates for cancer drug development. We report the synthesis and in vitro analysis of a biotinylated RG108 conjugate, 2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-3-(5-[3-[5-(2-oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)pentanoylamino]propoxy]-1H-indol-3-yl)propionic acid (bio-RG108), for the evaluation of interactions with DNA methyltransferase enzymes. The structural design of the chemically modified inhibitor was aided by molecular modeling, which suggested the possibility for extensive chemical modifications at the 5-position of the tryptophan moiety in RG108. The inhibitory activity of the corresponding derivative was confirmed in a cell-free biochemical assay, where bio-RG108 showed an undiminished inhibition of DNA methyltransferase activity (IC50 = 40 nM). Bio-RG108 therefore represents a suitable bioconjugate for the elucidation of inhibitory mechanisms and for the affinity purification of RG108-associated proteins.
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Affiliation(s)
- Esther Schirrmacher
- Division of Epigenetics, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
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Fottner C, Schirrmacher E, Goetz M, Feilen P, Bartenstein P, Galle PR, Neurath MF, Weber MM, Kiesslich R. In vivo-molecular and morphological imaging of somatostatin receptors by real time confocal mini-microscopy. Exp Clin Endocrinol Diabetes 2006. [DOI: 10.1055/s-2006-932857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Schneider S, Feilen PJ, Schreckenberger M, Schwanstecher M, Schwanstecher C, Buchholz HG, Thews O, Oberholzer K, Korobeynikov A, Bauman A, Comagic S, Piel M, Schirrmacher E, Shiue CY, Alavi AA, Bartenstein P, Rösch F, Weber MM, Klein HH, Schirrmacher R. In vitro and in vivo evaluation of novel glibenclamide derivatives as imaging agents for the non-invasive assessment of the pancreatic islet cell mass in animals and humans. Exp Clin Endocrinol Diabetes 2005; 113:388-95. [PMID: 16025400 DOI: 10.1055/s-2005-865711] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Pancreatic islet cell mass (PICM) is a major determinant of the insulin secretory capacity in humans. Currently, the only method for accurate assessment of the PICM is an autopsy study. Thus, development of a technique allowing the non-invasive quantification of PICM is of great interest. The aim of this study was to develop such a non-invasive technique featuring novel fluorine- and (99m)Tc-labelled glibenclamide derivatives. Despite the structural modifications necessary to introduce fluorine into the glibenclamide molecule, all derivatives retained insulin stimulating capacity as well as high affinity binding to human SUR1 when compared to the original glibenclamide. Contrastingly, the lipophilicity of the fluorine-labelled derivatives was altered depending on the particular modification. In the human PET-study a constant but weak radioactive signal could be detected in the pancreas using a fluorine-labelled glibenclamide derivative. However, a reliable assessment and visualisation of the PICM could not be obtained. It can be assumed that the high uptake of the fluorine-labelled tracer e.g. into the the liver and the high plasma protein binding leads to a relatively low signal-to-noise ratio. In case of the presented fluorine-labelled glibenclamide based compounds this could be the result of their invariably high lipophilicity. The development of a (99 m)Tc-labelled glibenclamide derivative with a lower lipophilicity and differing in vivo behaviour, glibenclamide based compounds for non-invasive imaging of the pancreatic islet cell mass may be possible.
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Affiliation(s)
- S Schneider
- Medical Department I, University Hospital Bergmannsheil, University of Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany.
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Helisch A, Schirrmacher E, Thews O, Schirrmacher R, Buchholz HG, Dillenburg W, Höhnemann S, Tillmanns J, Wessler I, Buhl R, Rösch F, Bartenstein P. Demonstration of pulmonary β2-adrenergic receptor binding in vivo with [18F]fluoroethyl-fenoterol in a guinea pig model. Eur J Nucl Med Mol Imaging 2005; 32:1324-8. [PMID: 16133376 DOI: 10.1007/s00259-005-1914-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 07/14/2005] [Indexed: 11/25/2022]
Abstract
PURPOSE The new beta2 radioligand (R,R)(S,S) 5-(2-(2-[4-(2-[18F]fluoroethoxy)phenyl]-1-methylethylamino)-1-hydroxyethyl)-benzene-1,3-diol ([18F]FE-fenoterol; [18F]FEFE), a fluoroethylated derivative of racemic fenoterol, was evaluated in vivo and ex vivo using a guinea pig model. METHODS Dynamic PET studies over 60 min with [(18)F]FEFE were performed in nine Hartley guinea pigs in which a baseline (group 1, n=3), a predose (group 2, n=3; 2 mg/kg fenoterol 5 min prior to injection of [18F]FEFE) or a displacement study (group 3, n=3; 2 mg/kg fenoterol 5 min post injection of [18F]FEFE) was conducted. RESULTS In all animal groups, the lungs could be visualised and semi-quantified separately by calculating uptake ratios to non-specific binding in the neck area. Premedication with non-radioactive fenoterol and displacement tests showed significant reduction of lung uptake, by 94% and 76%, respectively. CONCLUSION These data demonstrate specific binding of the new radioligand to the pulmonary beta2-receptors in accordance with ex vivo measurements. Therefore, [18F]FEFE seems to be suitable for the in vivo visualisation and quantification of the pulmonary beta2-receptor binding in this animal model.
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Affiliation(s)
- A Helisch
- Department of Nuclear Medicine, University Hospital, Langenbeckstrasse 1, 55101 Mainz, Germany.
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Schirrmacher R, Schirrmacher E, Mühlhausen U, Kaina B, Wängler B. Synthetic Strategies Towards O6-Substituted Guanine Derivatives and their Application in Medicine. Curr Org Synth 2005. [DOI: 10.2174/1570179053545369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Wängler B, Schneider S, Thews O, Schirrmacher E, Comagic S, Feilen P, Schwanstecher C, Schwanstecher M, Shiue CY, Alavi A, Höhnemann S, Piel M, Rösch F, Schirrmacher R. Synthesis and evaluation of (S)-2-(2-[18F]fluoroethoxy)-4-([3-methyl-1-(2-piperidin-1-yl-phenyl)-butyl-carbamoyl]-methyl)-benzoic acid ([18F]repaglinide): a promising radioligand for quantification of pancreatic beta-cell mass with positron emission tomography (PET). Nucl Med Biol 2004; 31:639-47. [PMID: 15219283 DOI: 10.1016/j.nucmedbio.2004.01.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Revised: 01/25/2004] [Accepted: 01/25/2004] [Indexed: 11/20/2022]
Abstract
18F-labeled non-sulfonylurea hypoglycemic agent (S)-2-(2-[(18)F]fluoroethoxy)-4-((3-methyl-1-(2-piperidin-1-yl-phenyl)-butylcarbamoyl)-methyl)-benzoic acid ([(18)F]repaglinide), a derivative of the sulfonylurea-receptor (SUR) ligand repaglinide, was synthesized as a potential tracer for the non-invasive investigation of the sulfonylurea 1 receptor status of pancreatic beta-cells by positron emission tomography (PET) in the context of type 1 and type 2 diabetes. [(18)F]Repaglinide could be obtained in an overall radiochemical yield (RCY) of 20% after 135 min with a radiochemical purity higher than 98% applying the secondary labeling precursor 2-[(18)F]fluoroethyltosylate. Specific activity was in the range of 50-60 GBq/micromol. Labeling was conducted by exchanging the ethoxy-moiety into a 2-[(18)F]fluoroethoxy group. To characterize the properties of fluorinated repaglinide, the affinity of the analogous non-radioactive (19)F-compound for binding to the human SUR1 isoform was assessed. [(19)F]Repaglinide induced a complete monophasic inhibition curve with a Hill coefficient close to 1 (1.03) yielding a dissociation constant (K(D)) of 134 nM. Biological activity was proven via insulin secretion experiments on isolated rat islets and was comparable to that of repaglinide. Finally, biodistribution of [(18)F]repaglinide was investigated in rats by measuring the concentration of the compound in different organs after i.v. injection. Pancreatic tissue displayed a stable accumulation of approximately 0.12% of the injected dose from 10 min to 30 min p.i. 50% of the radioactive tracer could be displaced by additional injection of unlabeled repaglinide, indicating that [(18)F]repaglinide might be suitable for in vivo investigation with PET.
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Affiliation(s)
- B Wängler
- Institute of Nuclear Chemistry, Johannes Gutenberg-University of Mainz, Fritz Strassmann-Weg 2, D-55128 Mainz, Germany
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Schirrmacher R, Comagic S, Schirrmacher E, Rösch F. Synthesis of a technetium-99m labelledL-tyrosine derivative with thefac-99mTc(I)(CO)3-core using a simple kit-procedure. J Labelled Comp Radiopharm 2004. [DOI: 10.1002/jlcr.831] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Schneider S, Wängler B, Thews O, Schirrmacher E, Comagic S, Feilen PJ, Schwanstecher C, Schwanstecher M, Piel M, Rösch F, Schirrmacher R, Weber MM. [18F]Repaglinide: A Novel Radioligand for estimation of pancreatic islet-cell mass in vivo with Positron Emission Tomography (PET). Exp Clin Endocrinol Diabetes 2004. [DOI: 10.1055/s-2004-819155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Schneider S, Schirrmacher E, Schreckenberger M, Schwanstecher M, Feilen PJ, Bucholz HG, Thews O, Oberholzer K, Shiue CY, Alavi A, Rösch F, Schirrmacher R, Weber MM. In-vitro and in-vivo evaluation of [18F]fluorethoxy-bromo-glibenclamide for the non invasive visualisation of the pancreatic islet cell mass in humans using PET. Exp Clin Endocrinol Diabetes 2004. [DOI: 10.1055/s-2004-819252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Schildan A, Schirrmacher R, Schirrmacher E, Samochocki M, Christner C, Maelicke A, Rösch F. Synthesis and evaluation of tritium labelled 10-methylgalanthamine iodide: a novel compound to examine the mechanism of interaction of galanthamine derivatives with the nicotinic acetylcholine receptors. J Labelled Comp Radiopharm 2003. [DOI: 10.1002/jlcr.744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schirrmacher E, Schirrmacher R, Thews O, Dillenburg W, Helisch A, Wessler I, Buhl R, Höhnemann S, Buchholz HG, Bartenstein P, Machulla HJ, Rösch F. Synthesis and preliminary evaluation of (R,R)(S,S) 5-(2-(2-[4-(2-[(18)F]fluoroethoxy)phenyl]-1-methylethylamino)-1-hydroxyethyl)-benzene-1,3-diol ([(18)F]FEFE) for the in vivo visualisation and quantification of the beta2-adrenergic receptor status in lung. Bioorg Med Chem Lett 2003; 13:2687-92. [PMID: 12873495 DOI: 10.1016/s0960-894x(03)00538-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The (18)F-labeled beta2-adrenergic receptor ligand (R,R)(S,S) 5-(2-(2-[4-(2-[(18)F]fluoroethoxy)phenyl]-1-methylethylamino)-1-hydroxyethyl)-benzene-1,3-diol, a derivative of the original highly selective racemic fenoterol, was synthesized in an overall radiochemical yield of 20% after 65 min with a radiochemical purity higher than 98%. The specific activity was in the range of 50-60 GBq/micromol. In vitro testing of the non-radioactive fluorinated fenoterol derivative with isolated guinea pig trachea was conducted to obtain an IC(50) value of 60 nM. Preliminary ex vivo organ distribution and in vivo experiments with positron emission tomography (PET) on guinea pigs were performed to study the biodistribution as well as the displacement of the radiotracer to prove specific binding to the beta2-receptor.
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Affiliation(s)
- Esther Schirrmacher
- Institute of Nuclear Chemistry, University of Mainz, Fritz Strassmann-Weg 2, D-55128, Mainz, Germany.
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Schirrmacher R, Mathiasch B, Schirrmacher E, Radnic D, Rösch F. Syntheses of novelN-([18F]fluoroalkyl)-N-nitroso-4-methyl-benzenesulfonamides and decomposition studies of corresponding19F- and bromo-analogues: potential new compounds for the18F-labelling of radiopharmaceuticals. J Labelled Comp Radiopharm 2003. [DOI: 10.1002/jlcr.729] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schirrmacher R, Wängler B, Schirrmacher E, August T, Rösch F. Dimethylpyridin-4-ylamine-Catalysed Alcoholysis of 2-Amino-N,N,N-Trimethyl-9H-purine-6-ylammonium Chloride: An Effective Route to O6-Substituted Guanine Derivatives from Alcohols with Poor Nucleophilicity. SYNTHESIS-STUTTGART 2002. [DOI: 10.1055/s-2002-20970] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Schirrmacher E, Schirrmacher R, Buhl R, Wessler I, Machulla HJ, Rösch F. Synthesis of [18F]-Fluoroethylfenoterol for imaging β2 receptor status in lung in vivo. J Labelled Comp Radiopharm 2001. [DOI: 10.1002/jlcr.25804401154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Schirrmacher E, Seifert J. [The Mannheim Peritonitis Index. Its reliability for the assessment of prognosis in peritonitis patients]. Fortschr Med 1988; 106:454-6. [PMID: 3220410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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