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Teodoro R, Gündel D, Deuther-Conrad W, Kazimir A, Toussaint M, Wenzel B, Bormans G, Hey-Hawkins E, Kopka K, Brust P, Moldovan RP. Synthesis, Structure-Activity Relationships, Radiofluorination, and Biological Evaluation of [ 18F]RM365, a Novel Radioligand for Imaging the Human Cannabinoid Receptor Type 2 (CB2R) in the Brain with PET. J Med Chem 2023; 66:13991-14010. [PMID: 37816245 PMCID: PMC10614203 DOI: 10.1021/acs.jmedchem.3c01035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Indexed: 10/12/2023]
Abstract
The development of cannabinoid receptor type 2 (CB2R) PET radioligands has been intensively explored due to the pronounced CB2R upregulation under various pathological conditions. Herein, we report on the synthesis of a series of CB2R affine fluorinated indole-2-carboxamide ligands. Compound RM365 was selected for PET radiotracer development due to its high CB2R affinity (Ki = 2.1 nM) and selectivity over CB1R (factor > 300). Preliminary in vitro evaluation of [18F]RM365 indicated species differences in the binding to CB2R (KD of 2.32 nM for the hCB2R vs KD > 10,000 nM for the rCB2R). Metabolism studies in mice revealed a high in vivo stability of [18F]RM365. PET imaging in a rat model of local hCB2R(D80N) overexpression in the brain demonstrates the ability of [18F]RM365 to reach and selectively label the hCB2R(D80N) with a high signal-to-background ratio. Thus, [18F]RM365 is a very promising PET radioligand for the imaging of upregulated hCB2R expression under pathological conditions.
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Affiliation(s)
- Rodrigo Teodoro
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
| | - Daniel Gündel
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
| | - Winnie Deuther-Conrad
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
| | - Aleksandr Kazimir
- Faculty
of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | - Magali Toussaint
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
| | - Barbara Wenzel
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
| | - Guy Bormans
- Radiopharmaceutical
Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, BE-3000 Leuven, Belgium
| | - Evamarie Hey-Hawkins
- Faculty
of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | - Klaus Kopka
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
- Faculty
of Chemistry and Food Chemistry, School of Science, TU Dresden, 01069 Dresden, Germany
| | - Peter Brust
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
- The
Lübeck Institute of Experimental Dermatology, University Medical Center Schleswig-Holstein, 23562 Lübeck, Germany
| | - Rareş-Petru Moldovan
- Institute
of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals,
Research Site Leipzig, Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), 04318 Leipzig, Germany
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Mukomura J, Nonaka H, Sato H, Kishimoto M, Arai M, Kotoku N. Anti-Mycobacterial N-(2-Arylethyl)quinolin-3-amines Inspired by Marine Sponge-Derived Alkaloid. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248701. [PMID: 36557834 PMCID: PMC9781020 DOI: 10.3390/molecules27248701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/03/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022]
Abstract
The synthesis and evaluation of simplified analogs of marine sponge-derived alkaloid 3-(phenethylamino)demethyl(oxy)aaptamine were performed to develop novel anti-mycobacterial substances. Ring truncation of the tricyclic benzo[de][1,6]-naphthyridine skeleton effectively weakened the cytotoxicity of the natural product, and the resulting AC-ring analog exhibited good anti-mycobacterial activity. A structure-activity relationship (SAR) study, synthesizing and evaluating some analogs, demonstrated the specificity and importance of the N-(2-arylethyl)quinolin-3-amine skeleton as a promising scaffold for anti-mycobacterial lead compounds.
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Affiliation(s)
- Junya Mukomura
- College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
| | - Hiroki Nonaka
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiromasa Sato
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Maho Kishimoto
- College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
| | - Masayoshi Arai
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Naoyuki Kotoku
- College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Correspondence: ; Tel.: +81-77-561-4920
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Attili B, Celen S, Ahamed M, Koole M, Haute CVD, Vanduffel W, Bormans G. Preclinical evaluation of [ 18 F]MA3: a CB 2 receptor agonist radiotracer for PET. Br J Pharmacol 2019; 176:1481-1491. [PMID: 30588600 DOI: 10.1111/bph.14564] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 10/31/2018] [Accepted: 11/16/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Non-invasive in vivo imaging of cannabinoid CB2 receptors using PET is pursued to study neuroinflammation. The purpose of this study is to evaluate the in vivo binding specificity of [18 F]MA3, a CB2 receptor agonist, in a rat model with local overexpression of human (h) CB2 receptors. METHODS [18 F]MA3 was produced with good radiochemical yield and radiochemical purity. The radiotracer was evaluated in rats with local overexpression of hCB2 receptors and in a healthy non-human primate using PET. KEY RESULTS Ex vivo autoradiography demonstrated CB2 -specific binding of [18 F]MA3 in rat hCB2 receptor vector injected striatum. In a PET study, increased tracer binding in the hCB2 receptor vector-injected striatum compared to the contralateral control vector-injected striatum was observed. Binding in hCB2 receptor vector-injected striatum was blocked with a structurally non-related CB2 receptor inverse agonist, and a displacement study confirmed the reversibility of tracer binding. This study identified the utility of mutated inactive vector model for evaluation of CB2 receptor agonist PET tracers. [18 F]MA3 PET scans in the non-human primate showed good uptake and fast washout from brain, but no CB2 receptor-specific binding was observed. CONCLUSION AND IMPLICATIONS Evaluation of [18 F]MA3 in a rat model with local overexpression of hCB2 receptors showed CB2 receptor-specific and reversible tracer binding. [18 F]MA3 showed good brain uptake and subsequent washout in a healthy non-human primate, but no specific binding was observed. Further clinical evaluation of [18 F]MA3 in patients with neuroinflammation is warranted. LINKED ARTICLES This article is part of a themed section on 8th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc.
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Affiliation(s)
- Bala Attili
- Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Sofie Celen
- Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Muneer Ahamed
- Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Department of Nuclear Medicine and Molecular Imaging, UZ Gasthuisberg, Leuven, Belgium
| | - Chris Van Den Haute
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Wim Vanduffel
- Laboratory for Neuro- and Psychophysiology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
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5
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Xu JH, Fan YL, Zhou J. Quinolone-Triazole Hybrids and their Biological Activities. J Heterocycl Chem 2018. [DOI: 10.1002/jhet.3234] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jun-Hao Xu
- Key Laboratory of Drug Prevention and Control Technology of Zhejiang Province; Zhejiang Police College; Hangzhou People's Republic of China
| | - Yi-Lei Fan
- Key Laboratory of Drug Prevention and Control Technology of Zhejiang Province; Zhejiang Police College; Hangzhou People's Republic of China
| | - Jin Zhou
- Key Laboratory of Drug Prevention and Control Technology of Zhejiang Province; Zhejiang Police College; Hangzhou People's Republic of China
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Can Astrocytes Be a Target for Precision Medicine? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1007:111-128. [DOI: 10.1007/978-3-319-60733-7_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Pang Y, An B, Lou L, Zhang J, Yan J, Huang L, Li X, Yin S. Design, Synthesis, and Biological Evaluation of Novel Selenium-Containing Isocombretastatins and Phenstatins as Antitumor Agents. J Med Chem 2017; 60:7300-7314. [DOI: 10.1021/acs.jmedchem.7b00480] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Yanqing Pang
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Baijiao An
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Lanlan Lou
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Junsheng Zhang
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jun Yan
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Ling Huang
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xingshu Li
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Sheng Yin
- School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
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Qi C, Guo T, Xiong W, Wang L, Jiang H. Silver-Promoted Coupling of Carbon Dioxide,o-Alkynylanilines and Diaryliodonium Salts: Straightforward Access to 4-Aryloxy-2-quinolinones. ChemistrySelect 2017. [DOI: 10.1002/slct.201701045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chaorong Qi
- Key Lab of Functional Molecular Engineering of Guangdong Province; School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou 510640 P.R. China
- State Key Lab of Luminescent Materials and Devices; South China University of Technology; Guangzhou 510640 P.R. China
| | - Tianzuo Guo
- Key Lab of Functional Molecular Engineering of Guangdong Province; School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou 510640 P.R. China
| | - Wenfang Xiong
- Key Lab of Functional Molecular Engineering of Guangdong Province; School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou 510640 P.R. China
| | - Lu Wang
- Key Lab of Functional Molecular Engineering of Guangdong Province; School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou 510640 P.R. China
| | - Huanfeng Jiang
- Key Lab of Functional Molecular Engineering of Guangdong Province; School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou 510640 P.R. China
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Kwak SH, Kang JA, Kim M, Lee SD, Park JH, Park SG, Ko H, Kim YC. Discovery and structure–activity relationship studies of quinolinone derivatives as potent IL-2 suppressive agents. Bioorg Med Chem 2016; 24:5357-5367. [DOI: 10.1016/j.bmc.2016.08.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 08/25/2016] [Accepted: 08/27/2016] [Indexed: 12/20/2022]
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10
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Poutiainen P, Jaronen M, Quintana FJ, Brownell AL. Precision Medicine in Multiple Sclerosis: Future of PET Imaging of Inflammation and Reactive Astrocytes. Front Mol Neurosci 2016; 9:85. [PMID: 27695400 PMCID: PMC5023680 DOI: 10.3389/fnmol.2016.00085] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 08/30/2016] [Indexed: 12/29/2022] Open
Abstract
Non-invasive molecular imaging techniques can enhance diagnosis to achieve successful treatment, as well as reveal underlying pathogenic mechanisms in disorders such as multiple sclerosis (MS). The cooperation of advanced multimodal imaging techniques and increased knowledge of the MS disease mechanism allows both monitoring of neuronal network and therapeutic outcome as well as the tools to discover novel therapeutic targets. Diverse imaging modalities provide reliable diagnostic and prognostic platforms to better achieve precision medicine. Traditionally, magnetic resonance imaging (MRI) has been considered the golden standard in MS research and diagnosis. However, positron emission tomography (PET) imaging can provide functional information of molecular biology in detail even prior to anatomic changes, allowing close follow up of disease progression and treatment response. The recent findings support three major neuroinflammation components in MS: astrogliosis, cytokine elevation, and significant changes in specific proteins, which offer a great variety of specific targets for imaging purposes. Regardless of the fact that imaging of astrocyte function is still a young field and in need for development of suitable imaging ligands, recent studies have shown that inflammation and astrocyte activation are related to progression of MS. MS is a complex disease, which requires understanding of disease mechanisms for successful treatment. PET is a precise non-invasive imaging method for biochemical functions and has potential to enhance early and accurate diagnosis for precision therapy of MS. In this review we focus on modulation of different receptor systems and inflammatory aspect of MS, especially on activation of glial cells, and summarize the recent findings of PET imaging in MS and present the most potent targets for new biomarkers with the main focus on experimental MS research.
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Affiliation(s)
- Pekka Poutiainen
- Athinoula A Martinos Biomedical Imaging Center, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolCharlestown, MA, USA
| | - Merja Jaronen
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical SchoolBoston, MA, USA
| | - Francisco J. Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical SchoolBoston, MA, USA
| | - Anna-Liisa Brownell
- Athinoula A Martinos Biomedical Imaging Center, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolCharlestown, MA, USA
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11
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Thokala R, Olivares S, Mi T, Maiti S, Deniger D, Huls H, Torikai H, Singh H, Champlin RE, Laskowski T, McNamara G, Cooper LJN. Redirecting Specificity of T cells Using the Sleeping Beauty System to Express Chimeric Antigen Receptors by Mix-and-Matching of VL and VH Domains Targeting CD123+ Tumors. PLoS One 2016; 11:e0159477. [PMID: 27548616 PMCID: PMC4993583 DOI: 10.1371/journal.pone.0159477] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/10/2016] [Indexed: 12/20/2022] Open
Abstract
Adoptive immunotherapy infusing T cells with engineered specificity for CD19 expressed on B- cell malignancies is generating enthusiasm to extend this approach to other hematological malignancies, such as acute myelogenous leukemia (AML). CD123, or interleukin 3 receptor alpha, is overexpressed on most AML and some lymphoid malignancies, such as acute lymphocytic leukemia (ALL), and has been an effective target for T cells expressing chimeric antigen receptors (CARs). The prototypical CAR encodes a VH and VL from one monoclonal antibody (mAb), coupled to a transmembrane domain and one or more cytoplasmic signaling domains. Previous studies showed that treatment of an experimental AML model with CD123-specific CAR T cells was therapeutic, but at the cost of impaired myelopoiesis, highlighting the need for systems to define the antigen threshold for CAR recognition. Here, we show that CARs can be engineered using VH and VL chains derived from different CD123-specific mAbs to generate a panel of CAR+ T cells. While all CARs exhibited specificity to CD123, one VH and VL combination had reduced lysis of normal hematopoietic stem cells. This CAR’s in vivo anti-tumor activity was similar whether signaling occurred via chimeric CD28 or CD137, prolonging survival in both AML and ALL models. Co-expression of inducible caspase 9 eliminated CAR+ T cells. These data help support the use of CD123-specific CARs for treatment of CD123+ hematologic malignancies.
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MESH Headings
- Animals
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- CD28 Antigens/genetics
- CD28 Antigens/immunology
- Caspase 9/genetics
- Caspase 9/immunology
- Cytotoxicity, Immunologic
- Disease Models, Animal
- Gene Expression
- Genetic Engineering/methods
- Hematopoietic Stem Cells/immunology
- Hematopoietic Stem Cells/pathology
- Humans
- Immunotherapy, Adoptive/methods
- Interleukin-3 Receptor alpha Subunit/genetics
- Interleukin-3 Receptor alpha Subunit/immunology
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/immunology
- Leukemia, Myeloid, Acute/pathology
- Leukemia, Myeloid, Acute/therapy
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Molecular Targeted Therapy
- Plasmids
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/immunology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Single-Domain Antibodies/genetics
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/transplantation
- Transfection
- Tumor Necrosis Factor Receptor Superfamily, Member 9/genetics
- Tumor Necrosis Factor Receptor Superfamily, Member 9/immunology
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Affiliation(s)
- Radhika Thokala
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas, United States of America
| | - Simon Olivares
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Tiejuan Mi
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Sourindra Maiti
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Drew Deniger
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Helen Huls
- Intrexon Corporation, Germantown, Maryland, United States of America
| | - Hiroki Torikai
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Harjeet Singh
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Richard E. Champlin
- Stem Cell Transplantation and Cellular Therapy, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Tamara Laskowski
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - George McNamara
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Laurence J. N. Cooper
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Ziopharm Oncology Inc., Boston, Massachusetts, United States of America
- * E-mail:
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Saccomanni G, Pascali G, Carlo SD, Panetta D, De Simone M, Bertini S, Burchielli S, Digiacomo M, Macchia M, Manera C, Salvadori PA. Design, synthesis and preliminary evaluation of (18)F-labelled 1,8-naphthyridin- and quinolin-2-one-3-carboxamide derivatives for PET imaging of CB2 cannabinoid receptor. Bioorg Med Chem Lett 2015; 25:2532-5. [PMID: 25956416 DOI: 10.1016/j.bmcl.2015.04.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/15/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022]
Abstract
In the present work, we report the synthesis of new aryliodonium salts used as precursors of single-stage nucleophilic (18)F radiofluorination. The corresponding unlabelled fluorinated derivatives showed to be CB2 cannabinoid receptor specific ligands, with Ki values in the low nanomolar range and high CB2/CB1 selectivity. The radiolabelled compound [(18)F]CB91, was successfully formulated for in vivo administration, and its preliminary biodistribution was assessed with microPET/CT. This tracer presented a reasonable in vivo stability and a preferential extraction in the tissues that constitutionally express CB2 cannabinoid receptor. The results obtained indicate [(18)F]CB91 as a possible candidate marker of CB2 cannabinoid receptor distribution. This study would open the way to further validation of this tracer for assessing pathologies for which the expression of this receptor is modified.
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Affiliation(s)
- Giuseppe Saccomanni
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Giancarlo Pascali
- CNR Istituto di Fisiologia Clinica, Via Moruzzi, 1, 56124 Pisa, Italy; ANSTO LifeSciences, PO Box M34, Camperdown 2050, Australia
| | - Sara Del Carlo
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Daniele Panetta
- CNR Istituto di Fisiologia Clinica, Via Moruzzi, 1, 56124 Pisa, Italy
| | | | - Simone Bertini
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | | | - Maria Digiacomo
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Marco Macchia
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Clementina Manera
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy.
| | - Piero A Salvadori
- CNR Istituto di Fisiologia Clinica, Via Moruzzi, 1, 56124 Pisa, Italy
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Design, syntheses, structure–activity relationships and docking studies of coumarin derivatives as novel selective ligands for the CB2 receptor. Eur J Med Chem 2015; 93:16-32. [DOI: 10.1016/j.ejmech.2015.01.054] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/21/2015] [Accepted: 01/26/2015] [Indexed: 12/15/2022]
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14
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Galli U, Travelli C, Aprile S, Arrigoni E, Torretta S, Grosa G, Massarotti A, Sorba G, Canonico PL, Genazzani AA, Tron GC. Design, Synthesis, and Biological Evaluation of Combretabenzodiazepines: A Novel Class of Anti-Tubulin Agents. J Med Chem 2015; 58:1345-57. [DOI: 10.1021/jm5016389] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ubaldina Galli
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Cristina Travelli
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Silvio Aprile
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Elena Arrigoni
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Simone Torretta
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Giorgio Grosa
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Alberto Massarotti
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Giovanni Sorba
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Pier Luigi Canonico
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Armando A. Genazzani
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
| | - Gian Cesare Tron
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale “A. Avogadro”, Largo Donegani 2, 28100 Novara, Italy
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15
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Kwak SH, Kim MJ, Lee SD, You H, Kim YC, Ko H. Solid-phase synthesis of quinolinone library. ACS COMBINATORIAL SCIENCE 2015; 17:60-9. [PMID: 25437883 DOI: 10.1021/co5001585] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Quinolinones have various biological activities, including antibacterial, anticancer, and antiviral properties. The 3-substituted amide quinolin-2(1H)-ones not only show antibacterial activity, but also act as immunomodulators, 5-HT4 receptor agonists, cannabinoid receptor inverse agonists, and AchE and, BuchE inhibitors. To investigate the potent biological activity of 3-substituted amide quinolin-2(1H)-ones, a large number of 3,5-amide substituted-2-oxoquinolinones were prepared by parallel solid-phase synthesis. The compound 5-amino-1-(4-methoxybenzyl)-2-oxo-1,2-dihydroquinoline-3-carboxylic acid was loaded onto 4-formyl-3,5-dimethoxyphenoxy (PL-FDMP) resin by reductive amination with high efficiency. Various building blocks were attached to the 3 and 5 positions to yield 3,5-disubstituted-2-oxoquinolinones with high purity and good yield. The ability some of these compound to inhibit the release of IL-1β, a cytokine involved in the immune response was measured, and they showed about 50% inhibition at 10 μM.
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Affiliation(s)
- Seung-hwa Kwak
- School
of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Min jeong Kim
- School
of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - So-Deok Lee
- School
of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Hyun You
- Department
of Medical System Engineering (DMSE), Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Yong-Chul Kim
- School
of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
- Department
of Medical System Engineering (DMSE), Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Hyojin Ko
- School
of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
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16
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Deniger DC, Maiti SN, Mi T, Switzer KC, Ramachandran V, Hurton LV, Ang S, Olivares S, Rabinovich BA, Huls MH, Lee DA, Bast RC, Champlin RE, Cooper LJN. Activating and propagating polyclonal gamma delta T cells with broad specificity for malignancies. Clin Cancer Res 2014; 20:5708-19. [PMID: 24833662 DOI: 10.1158/1078-0432.ccr-13-3451] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To activate and propagate populations of γδ T cells expressing polyclonal repertoire of γ and δ T-cell receptor (TCR) chains for adoptive immunotherapy of cancer, which has yet to be achieved. EXPERIMENTAL DESIGN Clinical-grade artificial antigen-presenting cells (aAPC) derived from K562 tumor cells were used as irradiated feeders to activate and expand human γδ T cells to clinical scale. These cells were tested for proliferation, TCR expression, memory phenotype, cytokine secretion, and tumor killing. RESULTS γδ T-cell proliferation was dependent upon CD137L expression on aAPC and addition of exogenous IL2 and IL21. Propagated γδ T cells were polyclonal as they expressed TRDV1, TRDV2-2, TRDV3, TRDV5, TRDV7, and TRDV8 with TRGV2, TRGV3F, TRGV7, TRGV8, TRGV9*A1, TRGV10*A1, and TRGV11 TCR chains. IFNγ production by Vδ1, Vδ2, and Vδ1(neg)Vδ2(neg) subsets was inhibited by pan-TCRγδ antibody when added to cocultures of polyclonal γδ T cells and tumor cell lines. Polyclonal γδ T cells killed acute and chronic leukemia, colon, pancreatic, and ovarian cancer cell lines, but not healthy autologous or allogeneic normal B cells. Blocking antibodies demonstrated that polyclonal γδ T cells mediated tumor cell lysis through combination of DNAM1, NKG2D, and TCRγδ. The adoptive transfer of activated and propagated γδ T cells expressing polyclonal versus defined Vδ TCR chains imparted a hierarchy (polyclonal>Vδ1>Vδ1(neg)Vδ2(neg)>Vδ2) of survival of mice with ovarian cancer xenografts. CONCLUSIONS Polyclonal γδ T cells can be activated and propagated with clinical-grade aAPCs and demonstrate broad antitumor activities, which will facilitate the implementation of γδ T-cell cancer immunotherapies in humans.
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Affiliation(s)
- Drew C Deniger
- Departments of Pediatrics, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | | | | | | | | | - Lenka V Hurton
- Departments of Pediatrics, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | | | | | | | | | - Dean A Lee
- Departments of Pediatrics, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | | | - Richard E Champlin
- Stem Cell Transplantation and Cellular Therapy, University of Texas MD Anderson Cancer Center; and
| | - Laurence J N Cooper
- Departments of Pediatrics, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
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Mu L, Slavik R, Müller A, Popaj K, Cermak S, Weber M, Schibli R, Krämer SD, Ametamey SM. Synthesis and Preliminary Evaluation of a 2-Oxoquinoline Carboxylic Acid Derivative for PET Imaging the Cannabinoid Type 2 Receptor. Pharmaceuticals (Basel) 2014; 7:339-52. [PMID: 24662272 PMCID: PMC3978495 DOI: 10.3390/ph7030339] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 02/21/2014] [Accepted: 02/27/2014] [Indexed: 11/27/2022] Open
Abstract
Cannabinoid receptor subtype 2 (CB2) has been shown to be up-regulated in activated microglia and therefore plays an important role in neuroinflammatory and neurodegenerative diseases such as multiple sclerosis, amyotrophic lateral sclerosis and Alzheimer’s disease. The CB2 receptor is therefore considered as a very promising target for therapeutic approaches as well as for imaging. A promising 2-oxoquinoline derivative designated KP23 was synthesized and radiolabeled and its potential as a ligand for PET imaging the CB2 receptor was evaluated. [11C]KP23 was obtained in 10%–25% radiochemical yield (decay corrected) and 99% radiochemical purity. It showed high stability in phosphate buffer, rat and mouse plasma. In vitro autoradiography of rat and mouse spleen slices, as spleen expresses a high physiological expression of CB2 receptors, demonstrated that [11C]KP23 exhibits specific binding towards CB2. High spleen uptake of [11C]KP23 was observed in dynamic in vivo PET studies with Wistar rats. In conclusion, [11C]KP23 showed promising in vitro and in vivo characteristics. Further evaluation with diseased animal model which has higher CB2 expression levels in the brain is warranted.
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Affiliation(s)
- Linjing Mu
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Department of Nuclear Medicine, University Hospital Zürich, CH-8091 Zürich, Switzerland.
| | - Roger Slavik
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Adrienne Müller
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Kasim Popaj
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Department of Nuclear Medicine, University Hospital Zürich, CH-8091 Zürich, Switzerland
| | - Stjepko Cermak
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Markus Weber
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital St. Gallen, CH-9007 St. Gallen, Switzerland
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Department of Nuclear Medicine, University Hospital Zürich, CH-8091 Zürich, Switzerland
| | - Stefanie D Krämer
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Simon M Ametamey
- Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zürich, Switzerland
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Holland JP, Liang SH, Rotstein BH, Collier TL, Stephenson NA, Greguric I, Vasdev N. Alternative approaches for PET radiotracer development in Alzheimer's disease: imaging beyond plaque. J Labelled Comp Radiopharm 2013; 57:323-31. [PMID: 24327420 DOI: 10.1002/jlcr.3158] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 10/29/2013] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) and related dementias show increasing clinical prevalence, yet our understanding of the etiology and pathobiology of disease-related neurodegeneration remains limited. In this regard, noninvasive imaging with radiotracers for positron emission tomography (PET) presents a unique tool for quantifying spatial and temporal changes in characteristic biological markers of brain disease and for assessing potential drug efficacy. PET radiotracers targeting different protein markers are being developed to address questions pertaining to the molecular and/or genetic heterogeneity of AD and related dementias. For example, radiotracers including [(11) C]-PiB and [(18) F]-AV-45 (Florbetapir) are being used to measure the density of Aβ-plaques in AD patients and to interrogate the biological mechanisms of disease initiation and progression. Our focus is on the development of novel PET imaging agents, targeting proteins beyond Aβ-plaques, which can be used to investigate the broader mechanism of AD pathogenesis. Here, we present the chemical basis of various radiotracers which show promise in preclinical or clinical studies for use in evaluating the phenotypic or biochemical characteristics of AD. Radiotracers for PET imaging neuroinflammation, metal ion association with Aβ-plaques, tau protein, cholinergic and cannabinoid receptors, and enzymes including glycogen-synthase kinase-3β and monoamine oxidase B amongst others, and their connection to AD are highlighted.
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Affiliation(s)
- Jason P Holland
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Department of Radiology, Harvard Medical School, 55 Fruit St., White 427, Boston, Massachusetts, 02114, USA; Life Sciences, Australian Nuclear Science and Technology Organisation, Kirrawee, New South Wales, 2232, Australia
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Lueg C, Schepmann D, Günther R, Brust P, Wünsch B. Development of fluorinated CB2 receptor agonists for PET studies. Bioorg Med Chem 2013; 21:7481-98. [DOI: 10.1016/j.bmc.2013.09.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/12/2013] [Accepted: 09/16/2013] [Indexed: 10/26/2022]
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20
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Mu L, Bieri D, Slavik R, Drandarov K, Müller A, Cermak S, Weber M, Schibli R, Krämer SD, Ametamey SM. Radiolabeling and in vitro /in vivo evaluation of N-(1-adamantyl)-8-methoxy-4-oxo-1-phenyl-1,4-dihydroquinoline-3-carboxamide as a PET probe for imaging cannabinoid type 2 receptor. J Neurochem 2013; 126:616-24. [PMID: 23795580 DOI: 10.1111/jnc.12354] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/12/2013] [Accepted: 06/19/2013] [Indexed: 11/30/2022]
Abstract
The cannabinoid type 2 (CB2) receptor plays an important role in neuroinflammatory and neurodegenerative diseases such as multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer’s disease and is therefore a very promising target for therapeutic approaches as well as for imaging. Based on the literature, we identified one 4-oxoquinoline derivative(designated KD2) as the lead structure. It was synthesized, radiolabeled and evaluated as a potential imaging tracer for CB2. [11C]KD2 was obtained in 99% radiochemical purity.Moderate blood–brain barrier (BBB) passage was predicted for KD2 from an in vitro transport assay with P-glycoprotein-transfected Madin Darby canine kidney cells. No efflux of KD2 by P-glycoprotein was detected. In vitro autoradiography of rat and mouse spleen slices demonstrated that [11C]KD2 exhibits high specific binding towards CB2. High spleen uptake of [11C]KD2 was observed in dynamic positron emission tomography(PET) studies with Wistar rats and its specificity was confirmed by displacement study with a selective CB2 agonist, GW405833. A pilot autoradiography study with post-mortem spinal cord slices from amyotrophic lateral sclerosis (ALS)patients with [11C]KD2 suggested the presence of CB2 receptors under disease conditions. Specificity of [11C]KD2 binding could also be demonstrated on these human tissues. In conclusion, [11C]KD2 shows good in vitro and in vivo properties as a potential PET tracer for CB2.
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Affiliation(s)
- Linjing Mu
- Department of Nuclear Medicine, Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, University Hospital Zürich, Zürich, Switzerland
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Jacobs AH, Tavitian B. Noninvasive molecular imaging of neuroinflammation. J Cereb Blood Flow Metab 2012; 32:1393-415. [PMID: 22549622 PMCID: PMC3390799 DOI: 10.1038/jcbfm.2012.53] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 03/05/2012] [Accepted: 03/23/2012] [Indexed: 12/23/2022]
Abstract
Inflammation is a highly dynamic and complex adaptive process to preserve and restore tissue homeostasis. Originally viewed as an immune-privileged organ, the central nervous system (CNS) is now recognized to have a constant interplay with the innate and the adaptive immune systems, where resident microglia and infiltrating immune cells from the periphery have important roles. Common diseases of the CNS, such as stroke, multiple sclerosis (MS), and neurodegeneration, elicit a neuroinflammatory response with the goal to limit the extent of the disease and to support repair and regeneration. However, various disease mechanisms lead to neuroinflammation (NI) contributing to the disease process itself. Molecular imaging is the method of choice to try to decipher key aspects of the dynamic interplay of various inducers, sensors, transducers, and effectors of the orchestrated inflammatory response in vivo in animal models and patients. Here, we review the basic principles of NI with emphasis on microglia and common neurologic disease mechanisms, the molecular targets which are being used and explored for imaging, and molecular imaging of NI in frequent neurologic diseases, such as stroke, MS, neurodegeneration, epilepsy, encephalitis, and gliomas.
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Affiliation(s)
- Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI) at the Westfalian Wilhelms-University of Münster (WWU), Münster, Germany.
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22
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Turkman N, Shavrin A, Paolillo V, Yeh HH, Flores L, Soghomonian S, Rabinovich B, Volgin A, Gelovani J, Alauddin M. Synthesis and preliminary evaluation of [18F]-labeled 2-oxoquinoline derivatives for PET imaging of cannabinoid CB2 receptor. Nucl Med Biol 2012; 39:593-600. [PMID: 22226022 DOI: 10.1016/j.nucmedbio.2011.10.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 09/27/2011] [Accepted: 10/25/2011] [Indexed: 10/14/2022]
Abstract
INTRODUCTION The cannabinoid receptor type 2 (CB(2)) is an important target for development of drugs and imaging agents for diseases, such as neuroinflammation, neurodegeneration and cancer. Recently, we reported synthesis and results of in vitro receptor binding of a focused library of fluorinated 2-oxoquinoline derivatives as CB(2) receptor ligands. Some of the compounds demonstrated to be good CB(2)-specific ligands with Ki values in the nanomolar to subnanomolar concentrations; therefore, we pursued the development of their (18)F-labeled analogues that should be useful for positron emission tomography (PET) imaging of CB(2) receptor expression. Here, we report the radiosynthesis of two (18)F-labeled 2-oxoquinoline derivatives and the preliminary in vitro and ex vivo evaluation of one compound as a CB(2)-specific radioligand. METHODS 4-[(18)F]fluorobenzyl amine [(18)F]-3 was prepared by radiofluorination of 4-cyano-N,N,N-trimethylanilinium triflate salt followed by reduction with LiAlH(4) and then coupled with acid chlorides 11 and 12 to afford [(18)F]-13 and [(18)F]-14. In vitro CB(2) receptor binding assay was performed using U87 cells transduced with CB(2) and CB(1) receptor. Ex vivo autoradiography was performed with [(18)F]-14 on spleen and on CB(2)- and CB(1)-expressing and wild-type U87 subcutaneous tumors grown in mice. RESULTS The radiochemical yields of [(18)F]-13 and [(18)F]-14 were 10%-15.0% with an average of 12% (n=10); radiochemical purity was >99% with specific activity 1200 mCi/μmol. The dissociation constant Kd for [(18)F]-14 was 3.4 nM. Ex vivo autoradiography showed accumulation of [(18)F]-14 in the CB(2)-expressing tumor. CONCLUSION Two new [(18)F]-labeled CB(2) ligands have been synthesized. Compound [(18)F]-14 appears to be a potential PET imaging agent for the assessment of CB(2) receptor expression; however, poor solubility restrain its use in vivo.
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