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Zhang T, Ma X, Xu M, Cai J, Cai J, Cao Y, Zhang Z, Ji X, He J, Cabrera GOF, Wu X, Zhao W, Wu Z, Xie J, Li Z. Chelator boosted tumor-retention and pharmacokinetic properties: development of 64Cu labeled radiopharmaceuticals targeting neurotensin receptor. Eur J Nucl Med Mol Imaging 2024:10.1007/s00259-024-06754-2. [PMID: 38771516 DOI: 10.1007/s00259-024-06754-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/05/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE Accumulating evidence suggests that neurotensin (NTS) and neurotensin receptors (NTSRs) play key roles in lung cancer progression by triggering multiple oncogenic signaling pathways. This study aims to develop Cu-labeled neurotensin receptor 1 (NTSR1)-targeting agents with the potential for both imaging and therapeutic applications. METHOD A series of neurotensin receptor antagonists (NRAs) with variable propylamine (PA) linker length and different chelators were synthesized, including [64Cu]Cu-CB-TE2A-iPA-NRA ([64Cu]Cu-4a-c, i = 1, 2, 3), [64Cu]Cu-NOTA-2PA-NRA ([64Cu]Cu-4d), [64Cu]Cu-DOTA-2PA-NRA ([64Cu]Cu-4e, also known as [64Cu]Cu-3BP-227), and [64Cu]Cu-DOTA-VS-2PA-NRA ([64Cu]Cu-4f). The series of small animal PET/CT were conducted in H1299 lung cancer model. The expression profile of NTSR1 was also confirmed by IHC using patient tissue samples. RESULTS For most of the compounds studied, PET/CT showed prominent tumor uptake and high tumor-to-background contrast, but the tumor retention was strongly influenced by the chelators used. For previously reported 4e, [64Cu]Cu-labeled derivative showed initial high tumor uptake accompanied by rapid tumor washout at 24 h. The newly developed [64Cu]Cu-4d and [64Cu]Cu-4f demonstrated good tumor uptake and tumor-to-background contrast at early time points, but were less promising in tumor retention. In contrast, our lead compound [64Cu]Cu-4b demonstrated 9.57 ± 1.35, 9.44 ± 2.38 and 9.72 ± 4.89%ID/g tumor uptake at 4, 24, and 48 h p.i., respectively. Moderate liver uptake (11.97 ± 3.85, 9.80 ± 3.63, and 7.72 ± 4.68%ID/g at 4, 24, and 48 h p.i.) was observed with low uptake in most other organs. The PA linker was found to have a significant effect on drug distribution. Compared to [64Cu]Cu-4b, [64Cu]Cu-4a had a lower background, including a greatly reduced liver uptake, while the tumor uptake was only moderately reduced. Meanwhile, [64Cu]Cu-4c showed increased uptake in both the tumor and the liver. The clinical relevance of NTSR1 was also demonstrated by the elevated tumor expression in patient tissue samples. CONCLUSIONS Through the side-by-side comparison, [64Cu]Cu-4b was identified as the lead agent for further evaluation based on its high and sustained tumor uptake and moderate liver uptake. It can not only be used to efficiently detect NTSR1 expression in lung cancer (for diagnosis, patient screening, and treatment monitoring), but also has the great potential to treat NTSR-positive lesions once chelating to the beta emitter 67Cu.
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Affiliation(s)
- Tao Zhang
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA.
- Department of Radiopharmaceuticals, Nuclear Medicine Clinical Transformation Center, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China.
- Department of Nuclear Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China.
| | - Xinrui Ma
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, Raleigh, NC, North Carolina State University, NC 27599, USA
| | - Muyun Xu
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Jinghua Cai
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Jianhua Cai
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Yanguang Cao
- Division of Pharmacotherapy and Experimental Therapeutics, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Zhihao Zhang
- Department of Radiopharmaceuticals, Nuclear Medicine Clinical Transformation Center, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Xin Ji
- Department of Radiopharmaceuticals, Nuclear Medicine Clinical Transformation Center, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Jian He
- Department of Nuclear Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - German Oscar Fonseca Cabrera
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Xuedan Wu
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Weiling Zhao
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Zhanhong Wu
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA
| | - Jin Xie
- Department of Chemistry, University of Georgia, 302 East Campus Road, Athens, GA, 30602, USA.
| | - Zibo Li
- Department of Radiology, Biomedical Research Imaging Center, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina , 27599, USA.
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Lin W, Aluicio-Sarduy E, Houson HA, Barnhart TE, Tekin V, Jeffery JJ, Weichmann AM, Barrett KE, Lapi SE, Engle JW. Theranostic cobalt-55/58m for neurotensin receptor-mediated radiotherapy in vivo: A pilot study with dosimetry. Nucl Med Biol 2023; 118-119:108329. [PMID: 36805869 PMCID: PMC10121947 DOI: 10.1016/j.nucmedbio.2023.108329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023]
Abstract
Neurotensin receptor 1 (NTSR1) can stimulate tumor proliferation through neurotensin (NTS) activation and are overexpressed by a variety of cancers. The high binding affinity of NTS/NTSR1 makes radiolabeled NTS derivatives interesting for cancer diagnosis and staging. Internalization of NTS/NTSR1 also suggests therapeutic application with high LET alpha particles and low energy electrons. We investigated the therapeutic efficacy of [58mCo]Co-NOTA-NT-20.3 in vivo using murine models xenografted with NTSR1-positive HT29 human colorectal adenocarcinoma cells, and utilized [55Co]Co-NOTA-NT-20.3 for dosimetry. METHODS Targeting properties and cytotoxicity of [55/58mCo]Co-NOTA-NT-20.3 were assessed with HT29 cells. Female nude mice were xenografted with HT29 tumors and administered [55Co or 58mCo]Co-NOTA-NT-20.3 to evaluate pharmacokinetics or for therapy, respectively. Dosimetry calculations followed the Medical Internal Radiation Dose (MIRD) formalism and human absorbed dose rate per unit activity were obtained from OpenDose. The pilot therapy study consisted of two groups (each N = 3) receiving 110 ± 15 MBq and 26 ± 6 MBq [58mCo]Co-NOTA-NT-20.3 one week after tumor inoculation, and control (N = 3). Tumor sizes and masses were measured twice a week after therapy. Complete blood count and kidney histology were also performed to assess toxicity. RESULTS HPLC measured radiochemical purity of [55,58mCo]Co-NOTA-NT-20.3 > 99 %. Labeled compounds retained NTS targeting properties. [58mCo]Co-NOTA-NT-20.3 exhibited cytotoxicity for HT29 cells and was >15× more potent than [58mCo]CoCl2. Xenografted tumors responded modestly to administered doses, but mice showed no signs of radiotoxicity. Absorbed dose to tumor and kidney with 110 MBq [58mCo]Co-NOTA-NT-20.3 were 0.6 Gy and 0.8 Gy, respectively, and other organs received less than half of the absorbed dose to tumor. Off-target radiation dose from cobalt-58g was small but reduces the therapeutic window. CONCLUSION The enhanced in vitro cytotoxicity and high tumor-to-background led us to investigate the therapeutic efficacy of [58mCo]Co-NOTA-NT-20.3 in vivo. Although we were unable to induce tumor response commensurate with [177Lu]Lu-NT127 (NLys-Lys-Pro-Tyr-Tle-Leu) studies involving similar time-integrated activity, the absence of observed toxicity may constitute an opportunity for targeting vectors with improved uptake and/or retention to avoid the aftereffects of other high-LET radioactive emissions. Future studies with higher uptake, activity and/or multiple dosing regimens are warranted. The theranostic approach employed in this work was crucial for dosimetry analysis.
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Affiliation(s)
- Wilson Lin
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States.
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Hailey A Houson
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Volkan Tekin
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Justin J Jeffery
- University of Wisconsin Carbone Cancer Center, Madison, WI 53705, United States
| | - Ashley M Weichmann
- University of Wisconsin Carbone Cancer Center, Madison, WI 53705, United States
| | - Kendall E Barrett
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States; Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53792, United States
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Cadima-Couto I, Tauzin A, Freire JM, Figueira TN, Silva RDM, Pérez-Peinado C, Cunha-Santos C, Bártolo I, Taveira N, Gano L, Correia JDG, Goncalves J, Mammano F, Andreu D, Castanho MARB, Veiga AS. Anti-HIV-1 Activity of pepRF1, a Proteolysis-Resistant CXCR4 Antagonist Derived from Dengue Virus Capsid Protein. ACS Infect Dis 2021; 7:6-22. [PMID: 33319557 DOI: 10.1021/acsinfecdis.9b00507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is an urgent need for the development of new anti-HIV drugs that can complement existing medicines to be used against resistant strains. Here, we report the anti-HIV-1 peptide pepRF1, a human serum-resistant peptide derived from the Dengue virus capsid protein. In vitro, pepRF1 shows a 50% inhibitory concentration of 1.5 nM with a potential therapeutic window higher than 53 000. This peptide is specific for CXCR4-tropic strains, preventing viral entry into target cells by binding to the viral coreceptor CXCR4, acting as an antagonist of this receptor. pepRF1 is more effective than T20, the only peptide-based HIV-1 entry inhibitor approved, and excels in inhibiting a HIV-1 strain resistant to T20. Potentially, pepRF1 can be used alone or in combination with other anti-HIV drugs. Furthermore, one can also envisage its use as a novel therapeutic strategy for other CXCR4-related diseases.
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Affiliation(s)
- Iris Cadima-Couto
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Alexandra Tauzin
- INSERM UMR 1124, Université de Paris, 45 rue des Saints Pères, F-75006 Paris, France
| | - João M. Freire
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Tiago N. Figueira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Rúben D. M. Silva
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Clara Pérez-Peinado
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Catarina Cunha-Santos
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Inês Bártolo
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Nuno Taveira
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Prof. Gama Pinto, 1649-003 Lisboa, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Monte de Caparica, Portugal
| | - Lurdes Gano
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - João D. G. Correia
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Joao Goncalves
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Fabrizio Mammano
- INSERM UMR 1124, Université de Paris, 45 rue des Saints Pères, F-75006 Paris, France
| | - David Andreu
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Ana Salomé Veiga
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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Rečnik LM, Kandioller W, Mindt TL. 1,4-Disubstituted 1,2,3-Triazoles as Amide Bond Surrogates for the Stabilisation of Linear Peptides with Biological Activity. Molecules 2020; 25:E3576. [PMID: 32781656 PMCID: PMC7465391 DOI: 10.3390/molecules25163576] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/20/2022] Open
Abstract
Peptides represent an important class of biologically active molecules with high potential for the development of diagnostic and therapeutic agents due to their structural diversity, favourable pharmacokinetic properties, and synthetic availability. However, the widespread use of peptides and conjugates thereof in clinical applications can be hampered by their low stability in vivo due to rapid degradation by endogenous proteases. A promising approach to circumvent this potential limitation includes the substitution of metabolically labile amide bonds in the peptide backbone by stable isosteric amide bond mimetics. In this review, we focus on the incorporation of 1,4-disubstituted 1,2,3-triazoles as amide bond surrogates in linear peptides with the aim to increase their stability without impacting their biological function(s). We highlight the properties of this heterocycle as a trans-amide bond surrogate and summarise approaches for the synthesis of triazole-containing peptidomimetics via the Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC). The impacts of the incorporation of triazoles in the backbone of diverse peptides on their biological properties such as, e.g., blood serum stability and affinity as well as selectivity towards their respective molecular target(s) are discussed.
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Affiliation(s)
- Lisa-Maria Rečnik
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital Vienna, 1090 Vienna, Austria;
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria;
- Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, 1090 Vienna, Austria
| | - Wolfgang Kandioller
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria;
| | - Thomas L. Mindt
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital Vienna, 1090 Vienna, Austria;
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria;
- Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, 1090 Vienna, Austria
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Structural modifications of amino acid sequences of radiolabeled peptides for targeted tumor imaging. Bioorg Chem 2020; 99:103802. [DOI: 10.1016/j.bioorg.2020.103802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/19/2020] [Accepted: 03/25/2020] [Indexed: 12/18/2022]
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Schindler L, Bernhardt G, Keller M. Modifications at Arg and Ile Give Neurotensin(8-13) Derivatives with High Stability and Retained NTS 1 Receptor Affinity. ACS Med Chem Lett 2019; 10:960-965. [PMID: 31223455 DOI: 10.1021/acsmedchemlett.9b00122] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/10/2019] [Indexed: 12/16/2022] Open
Abstract
Due to its expression in various malignant tumors, the neurotensin receptor 1 (NTS1R) has been suggested and explored as a target for tumor diagnosis and therapy. Animal model-based investigations of various radiolabeled NTS1R ligands derived from the hexapeptide neurotensin(8-13) (NT(8-13)), e.g. 68Ga- and 18F-labeled compounds for PET diagnostics, give rise to optimize such radiotracers for clinical use. As NT(8-13) is rapidly degraded in vivo; structural modifications are required in terms of increased metabolic stability. In this study, the stabilization of the peptide backbone of NT(8-13) against enzymatic degradation was systematically explored by performing an N-methyl scan, replacing Ile12 by tert-butylglycine12 (Tle12) and N-terminal acylation. N-Methylation of either arginine, Arg8, or Arg9, combined with the Ile12/Tle12 exchange, proved to be most favorable with respect to NTS1R affinity (K i < 2 nM) and stability in human plasma (t 1/2 > 48 h), a valuable result regarding the development of radiopharmaceuticals derived from NT(8-13).
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Affiliation(s)
- Lisa Schindler
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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Deng H, Wang H, Zhang H, Wang M, Giglio B, Ma X, Jiang G, Yuan H, Wu Z, Li Z. Imaging Neurotensin Receptor in Prostate Cancer With 64Cu-Labeled Neurotensin Analogs. Mol Imaging 2018; 16:1536012117711369. [PMID: 28849698 PMCID: PMC6081756 DOI: 10.1177/1536012117711369] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Neurotensin receptor 1 (NTR-1) is expressed and activated in prostate cancer cells. In this study, we explore the NTR expression in normal mouse tissues and study the positron emission tomography (PET) imaging of NTR in prostate cancer models. MATERIALS AND METHODS Three 64Cu chelators (1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid [DOTA], 1,4,7-triazacyclononane-N,N',N″-triacetic acid [NOTA], or AmBaSar) were conjugated to an NT analog. Neurotensin receptor binding affinity was evaluated using cell binding assay. The imaging profile of radiolabeled probes was compared in well-established NTR+ HT-29 tumor model. Stability of the probes was tested. The selected agents were further evaluated in human prostate cancer PC3 xenografts. RESULTS All 3 NT conjugates retained the majority of NTR binding affinity. In HT-29 tumor, all agents demonstrated prominent tumor uptake. Although comparable stability was observed, 64Cu-NOTA-NT and 64Cu-AmBaSar-NT demonstrated improved tumor to background contrast compared with 64Cu-DOTA-NT. Positron emission tomography/computed tomography imaging of the NTR expression in PC-3 xenografts showed high tumor uptake of the probes, correlating with the in vitro Western blot results. Blocking experiments further confirmed receptor specificity. CONCLUSIONS Our results demonstrated that 64Cu-labeled neurotensin analogs are promising imaging agents for NTR-positive tumors. These agents may help us identify NTR-positive lesions and predict which patients and individual tumors are likely to respond to novel interventions targeting NTR-1.
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Affiliation(s)
- Huaifu Deng
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,2 PET/CT Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Hui Wang
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - He Zhang
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,3 Department of Radiology, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China
| | - Mengzhe Wang
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ben Giglio
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Xiaofen Ma
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,4 Department of Medical Imaging, Provincial People's Hospital, Guangzhou, China
| | - Guihua Jiang
- 4 Department of Medical Imaging, Provincial People's Hospital, Guangzhou, China
| | - Hong Yuan
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zhanhong Wu
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zibo Li
- 1 Department of Radiology, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Korbecki J, Gutowska I, Kojder I, Jeżewski D, Goschorska M, Łukomska A, Lubkowska A, Chlubek D, Baranowska-Bosiacka I. New extracellular factors in glioblastoma multiforme development: neurotensin, growth differentiation factor-15, sphingosine-1-phosphate and cytomegalovirus infection. Oncotarget 2018; 9:7219-7270. [PMID: 29467963 PMCID: PMC5805549 DOI: 10.18632/oncotarget.24102] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/02/2018] [Indexed: 11/25/2022] Open
Abstract
Recent years have seen considerable progress in understanding the biochemistry of cancer. For example, more significance is now assigned to the tumor microenvironment, especially with regard to intercellular signaling in the tumor niche which depends on many factors secreted by tumor cells. In addition, great progress has been made in understanding the influence of factors such as neurotensin, growth differentiation factor-15 (GDF-15), sphingosine-1-phosphate (S1P), and infection with cytomegalovirus (CMV) on the 'hallmarks of cancer' in glioblastoma multiforme. Therefore, in the present work we describe the influence of these factors on the proliferation and apoptosis of neoplastic cells, cancer stem cells, angiogenesis, migration and invasion, and cancer immune evasion in a glioblastoma multiforme tumor. In particular, we discuss the effect of neurotensin, GDF-15, S1P (including the drug FTY720), and infection with CMV on tumor-associated macrophages (TAM), microglial cells, neutrophil and regulatory T cells (Treg), on the tumor microenvironment. In order to better understand the role of the aforementioned factors in tumoral processes, we outline the latest models of intratumoral heterogeneity in glioblastoma multiforme. Based on the most recent reports, we discuss the problems of multi-drug therapy in treating glioblastoma multiforme.
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Affiliation(s)
- Jan Korbecki
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland.,Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, University of Bielsko-Biała, 43-309 Bielsko-Biała, Poland
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, 71-460 Szczecin, Poland
| | - Ireneusz Kojder
- Department of Applied Neurocognitivistics, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland.,Department of Neurosurgery, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Dariusz Jeżewski
- Department of Applied Neurocognitivistics, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland.,Department of Neurosurgery, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Marta Goschorska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Agnieszka Łukomska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, 71-460 Szczecin, Poland
| | - Anna Lubkowska
- Department of Functional Diagnostics and Physical Medicine, Pomeranian Medical University in Szczecin, 71-210 Szczecin, Poland
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
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Maschauer S, Prante O. Radiopharmaceuticals for imaging and endoradiotherapy of neurotensin receptor-positive tumors. J Labelled Comp Radiopharm 2018; 61:309-325. [DOI: 10.1002/jlcr.3581] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 10/13/2017] [Accepted: 10/24/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Simone Maschauer
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine; Friedrich Alexander University Erlangen-Nürnberg (FAU); Erlangen Germany
| | - Olaf Prante
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine; Friedrich Alexander University Erlangen-Nürnberg (FAU); Erlangen Germany
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Emrarian I, Sadeghzadeh N, Abedi SM, Abediankenari S. New neurotensin analogue radiolabeled by 99m-technetium as a potential agent for tumor identification. Chem Biol Drug Des 2017; 91:304-313. [DOI: 10.1111/cbdd.13082] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/24/2017] [Accepted: 07/27/2017] [Indexed: 01/20/2023]
Affiliation(s)
- Iman Emrarian
- Department of Radiopharmacy; Faculty of Pharmacy; Mazandaran University of Medical Sciences; Sari Iran
| | - Nourollah Sadeghzadeh
- Department of Radiopharmacy; Faculty of Pharmacy; Mazandaran University of Medical Sciences; Sari Iran
| | - Seyed Mohammad Abedi
- Department of Radiology; Faculty of Medicine; Mazandaran University of Medical Sciences; Sari Iran
| | - Saeid Abediankenari
- Immunogenetics Research Center; Mazandaran University of Medical Sciences; Sari Iran
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11
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Garg PK, Nazih R, Wu Y, Grinevich VP, Garg S. Selective targeting of melanoma using N-(2-diethylaminoethyl) 4-[ 18F]fluoroethoxy benzamide (4-[ 18F]FEBZA): a novel PET imaging probe. EJNMMI Res 2017; 7:61. [PMID: 28791653 PMCID: PMC5548701 DOI: 10.1186/s13550-017-0311-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/25/2017] [Indexed: 02/04/2023] Open
Abstract
Background The purpose of this study was to develop a positron emission tomography (PET) imaging probe that is easy to synthesize and selectively targets melanoma in vivo. Herein, we report the synthesis and preclinical evaluation of N-(2-diethylaminoethyl) 4-[18F]Fluoroethoxy benzamide (4-[18F]FEBZA). A one-step synthesis was developed to prepare 4-[18F]FEBZA in high radiochemical yields and specific activity. The binding affinity, the in vitro binding, and internalization studies were performed using B16F1 melanoma cell line. The biodistribution studies were performed in C57BL/6 normal mice, C57BL/6 mice bearing B16F1 melanoma tumor xenografts, and nu/nu athymic mice bearing HT-29 human adenocarcinoma tumor and C-32 amelanotic melanoma tumor xenografts. MicroPET studies were performed in mice bearing B16F1 and HT-29 tumor xenografts. Results 4-[18F]FEBZA was prepared in 53 ± 14% radiochemical yields and a specific activity of 8.7 ± 1.1 Ci/μmol. The overall synthesis time for 4-[18F]FEBZA was 54 ± 7 min. The in vitro binding to B16F1 cells was 60.03 ± 0.48% after 1 h incubation at 37 °C. The in vivo biodistribution studies show a rapid and high uptake of F-18 in B16F1 tumor with 8.66 ± 1.02%IA/g in this tumor at 1 h. In contrast, the uptake at 1 h in HT-29 colorectal adenocarcinoma and C-32 amelanotic melanoma tumors was significantly lower with 3.68 ± 0.47%IA/g and 3.91 ± 0.23%IA/g in HT-29 and C-32 tumors, respectively. On microPET images, the melanoma tumor was clearly visible by 10 min post-injection and the intensity in the tumor continued to increase with time. In contrast, the HT-29 tumor was not visible on the microPET scans. Conclusions A rapid and facile synthesis of 4-[18F]FEBZA is developed. This method offers a reliable production of 4-[18F]FEBZA in high radiochemical yields and specific activity. A high binding affinity to melanoma cells and high uptake in tumor was noted. The microPET scan clearly delineates the melanoma tumor by 10 min post-injection. The results from these preclinical studies support the potential of 4-[18F]FEBZA as an effective probe to image melanoma.
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Affiliation(s)
- Pradeep K Garg
- Wake Forest University Health Sciences, Winston Salem, NC, USA. .,Center for Molecular Imaging and Therapy, Biomedical Research Foundation, 1505 Kings Highway, Shreveport, LA, 71133, USA.
| | - Rachid Nazih
- Wake Forest University Health Sciences, Winston Salem, NC, USA.,Center for Molecular Imaging and Therapy, Biomedical Research Foundation, 1505 Kings Highway, Shreveport, LA, 71133, USA
| | - Yanjun Wu
- Center for Molecular Imaging and Therapy, Biomedical Research Foundation, 1505 Kings Highway, Shreveport, LA, 71133, USA
| | - Vladimir P Grinevich
- Current Address: Asinex Corporation, 10 N. Chestnut Street, St 104, Winston Salem, NC, 27101, USA
| | - Sudha Garg
- Wake Forest University Health Sciences, Winston Salem, NC, USA.,Center for Molecular Imaging and Therapy, Biomedical Research Foundation, 1505 Kings Highway, Shreveport, LA, 71133, USA
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12
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Simeth NA, Bause M, Dobmeier M, Kling RC, Lachmann D, Hübner H, Einsiedel J, Gmeiner P, König B. NTS2-selective neurotensin mimetics with tetrahydrofuran amino acids. Bioorg Med Chem 2017; 25:350-359. [DOI: 10.1016/j.bmc.2016.10.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/20/2016] [Accepted: 10/31/2016] [Indexed: 01/10/2023]
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13
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Garg PK, Nazih R, Wu Y, Singh R, Garg S. 4- 11C-Methoxy N-(2-Diethylaminoethyl) Benzamide: A Novel Probe to Selectively Target Melanoma. J Nucl Med 2016; 58:827-832. [PMID: 27980051 DOI: 10.2967/jnumed.116.184564] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/07/2016] [Indexed: 01/25/2023] Open
Abstract
We report the synthesis and preclinical evaluation of a 11C-labeled probe to target melanoma using PET. Methods: The target compound 4-11C-methoxy N-(2-diethylaminoethyl) benzamide (4-11C-MBZA) was prepared via the 11C-methylation of 4-hydroxy N-(2-diethylaminoethyl) benzamide (4-HBZA). The in vitro binding was performed using B16F1 (melanoma cells), MCF-10A (breast epithelial cells), and MDA-MB 231 (breast cancer cells). The internalization studies were conducted using B16F1 cells. In vivo biodistribution and small-animal PET imaging were performed in mice bearing B16F1 melanoma tumor xenografts. Results: The target compound 4-11C-MBZA was prepared in 46% ± 7% radiochemical yields by reacting 11C-methyltriflate with 4-HBZA followed by high-performance liquid chromatography purification. The specific activity of this compound was 853 ± 29.6 GBq/μmol (23 ± 0.8 Ci/μmol). The binding of 4-11C-MBZA to B16F1, MCF-10A, and MDA-MB-231 cells was 6.41% ± 1.28%, 1.51% ± 0.17%, and 0.30% ± 0.17%, respectively. Internalization studies using B16F1 melanoma cells show 60.7% of the cell-bound activity was internalized. Results from biodistribution studies show a rapid and high uptake of radioactivity in the tumor, with uptake levels reaching 5.85 ± 0.79 and 8.13 ± 1.46 percentage injected dose per gram at 10 and 60 min, respectively. Low uptake in normal tissues in conjunction with high tumor uptake resulted in high tumor-to-tissue ratios. On small-animal PET images, the tumor was clearly delineated soon after 4-11C-MBZA injection and tumor uptake reached 4.2 percentage injected dose per gram by 20 min. These preclinical evaluations show a high propensity of 4-11C-MBZA toward melanoma tumor. Conclusion: We successfully developed 4-11C-MBZA as a PET imaging probe, displaying properties advantageous over those for its 18F analogs. These preclinical evaluation results demonstrate the clinical potential of this probe to selectively target melanoma.
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Affiliation(s)
- Pradeep K Garg
- Department of Radiology, Wake Forest University Medical Center, Winston Salem, North Carolina .,Biomedical Research Foundation, Shreveport, Louisiana; and
| | - Rachid Nazih
- Department of Radiology, Wake Forest University Medical Center, Winston Salem, North Carolina.,Biomedical Research Foundation, Shreveport, Louisiana; and
| | - Yanjun Wu
- Biomedical Research Foundation, Shreveport, Louisiana; and
| | - Ravi Singh
- Department of Radiology, Wake Forest University Medical Center, Winston Salem, North Carolina.,Department of Cancer Biology, Wake Forest University Medical Center, Winston Salem, North Carolina
| | - Sudha Garg
- Department of Radiology, Wake Forest University Medical Center, Winston Salem, North Carolina .,Biomedical Research Foundation, Shreveport, Louisiana; and
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14
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Maschauer S, Einsiedel J, Hübner H, Gmeiner P, Prante O. 18F- and 68Ga-Labeled Neurotensin Peptides for PET Imaging of Neurotensin Receptor 1. J Med Chem 2016; 59:6480-92. [DOI: 10.1021/acs.jmedchem.6b00675] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Simone Maschauer
- Department
of Nuclear Medicine, Molecular Imaging and Radiochemistry, Friedrich-Alexander University (FAU), Schwabachanlage 6, 91054 Erlangen, Germany
| | - Jürgen Einsiedel
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University (FAU), Schuhstraße 19, 91052 Erlangen, Germany
| | - Harald Hübner
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University (FAU), Schuhstraße 19, 91052 Erlangen, Germany
| | - Peter Gmeiner
- Department
of Chemistry and Pharmacy, Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University (FAU), Schuhstraße 19, 91052 Erlangen, Germany
| | - Olaf Prante
- Department
of Nuclear Medicine, Molecular Imaging and Radiochemistry, Friedrich-Alexander University (FAU), Schwabachanlage 6, 91054 Erlangen, Germany
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15
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Mascarin A, Valverde IE, Mindt TL. Structure-Activity Relationship Studies of Amino Acid Substitutions in Radiolabeled Neurotensin Conjugates. ChemMedChem 2015; 11:102-7. [PMID: 26593062 DOI: 10.1002/cmdc.201500468] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Indexed: 11/06/2022]
Abstract
Radiolabeled derivatives of the peptide neurotensin (NT) and its binding sequence NT(8-13) have been studied as potential imaging probes and therapeutics for NT-1-receptor-positive cancer. However, a direct comparison of reported NT analogues, even if radiolabeled with the same radionuclide, is difficult because different techniques and models have been used for preclinical evaluations. In an effort to identify a suitable derivative of NT(8-13) for radiotracer development, we herein report a side-by-side in vitro comparison of radiometallated NT derivatives bearing some of the most commonly reported amino acid substitutions in their sequence. Performed investigations include cell internalization experiments, determinations of receptor affinity, measurements of the distribution coefficient, and blood serum stability studies. Of the [(177)Lu]-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-labeled examples studied, analogues of NT(8-13) containing a short hydrophilic tetraethylene glycol (PEG4 ) spacer between the peptide and the radiometal complex, and a minimum number of substitutions of amino acid residues, exhibited the most promising properties in vitro.
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Affiliation(s)
- Alba Mascarin
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Ibai E Valverde
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Thomas L Mindt
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland. .,Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
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16
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Mascarin A, Valverde IE, Vomstein S, Mindt TL. 1,2,3-Triazole Stabilized Neurotensin-Based Radiopeptidomimetics for Improved Tumor Targeting. Bioconjug Chem 2015; 26:2143-52. [DOI: 10.1021/acs.bioconjchem.5b00444] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alba Mascarin
- Division
of Radiopharmaceutical
Chemistry, University of Basel Hospital, Petersgraben 4, 4031 Basel, Switzerland
| | - Ibai E. Valverde
- Division
of Radiopharmaceutical
Chemistry, University of Basel Hospital, Petersgraben 4, 4031 Basel, Switzerland
| | - Sandra Vomstein
- Division
of Radiopharmaceutical
Chemistry, University of Basel Hospital, Petersgraben 4, 4031 Basel, Switzerland
| | - Thomas L. Mindt
- Division
of Radiopharmaceutical
Chemistry, University of Basel Hospital, Petersgraben 4, 4031 Basel, Switzerland
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17
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Deng H, Wang H, Wang M, Li Z, Wu Z. Synthesis and Evaluation of 64Cu-DOTA-NT-Cy5.5 as a Dual-Modality PET/Fluorescence Probe to Image Neurotensin Receptor-Positive Tumor. Mol Pharm 2015; 12:3054-61. [PMID: 26162008 DOI: 10.1021/acs.molpharmaceut.5b00325] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Overexpression of neurotensin receptors (NTRs) has been suggested to play important roles in the growth and survival of a variety of tumor types. The aim of this study is to develop a dual-modality probe (64Cu -DOTA-NT-Cy5.5) for imaging NTR1 expression in vivo with both positron emission tomography (PET) and fluorescence. In this approach, the thiol group and N terminal amino group of neurotensin analogue (Cys-NT) were chemically modified with Cy5.5 dye and DOTA chelator, respectively. After radiolabeling with 64Cu, the resulting probe (64Cu-DOTA-NT-Cy5.5) was evaluated in NTR1 positive HT-29 tumor model. Small animal PET quantification analysis demonstrated that the tumor uptake was 1.91±0.22 and 1.79±0.16%ID/g at 1 and 4 h postinjection (p.i.), respectively. The tumor-to-muscle ratio was 17.44±3.25 at 4 h p.i. based on biodistribution. Receptor specificity was confirmed by the successful blocking experiment at 4 h p.i. (0.42±0.05%ID/g). In parallel with PET experiment, fluorescence imaging was also performed, which demonstrated prominent tumor uptake in HT-29 model. As a proof of concept, an imaging guided surgery was performed to the fluorescent moiety of this probe and could provide potential surgery guidance for NTR positive patients. In summary, our results clearly indicated that the dual-modality probe, 64Cu-DOTA-NT-Cy5.5, could serve as a promising agent to image NTR positive tumors in vivo.
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Affiliation(s)
- Huaifu Deng
- †Biomedical Research Imaging Center and Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,‡PET/CT Center, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510230, China
| | - Hui Wang
- †Biomedical Research Imaging Center and Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mengzhe Wang
- †Biomedical Research Imaging Center and Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Zibo Li
- †Biomedical Research Imaging Center and Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Zhanhong Wu
- †Biomedical Research Imaging Center and Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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18
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Khoshbakht S, Kobarfard F, Beiki D, Sabzevari O, Amini M, Mehrnejad F, Tabib K, Shahhosseini S. HYNIC a bifunctional prosthetic group for the labelling of peptides with 99mTc and 18FDG. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4259-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Körner M, Waser B, Strobel O, Büchler M, Reubi JC. Neurotensin receptors in pancreatic ductal carcinomas. EJNMMI Res 2015; 5:17. [PMID: 25859423 PMCID: PMC4388205 DOI: 10.1186/s13550-015-0094-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/26/2015] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The frequent expression of neurotensin receptors (NT-R) in primaries of pancreatic ductal carcinomas has triggered the development of radioactive neurotensin analogs for possible in vivo targeting of these tumors. However, the complete lack of information regarding NT-R in liver metastases of pancreatic cancer and pancreatic intraepithelial neoplasia (PanIN) makes an in vitro study of NT-R in these tissues indispensable. METHODS Using in vitro receptor autoradiography with (125)I-[Tyr(3)]-neurotensin, NT-R were investigated in 18 primaries and 23 liver metastases of pancreatic ductal carcinomas as well as in 19 PanIN lesions. RESULTS We report here that 13 of 18 ductal carcinoma primaries and 14 of 23 liver metastases expressed NT-R. Moreover, none of the six PanIN 1B cases expressed NT-R, while two of six PanIN 2 and five of seven PanIN 3 expressed NT-R. Binding was fully displaced by the type 1 NT-R-selective antagonist SR48692, indicating that the NT-R in the tumors are of the type 1 NT-R subtype. CONCLUSIONS These in vitro data extend the currently available information on NT-R in invasive and non-invasive pancreatic ductal tumors. They suggest that type 1 NT-R may be a novel, specific marker of PanIN of higher degree. The high expression of NT-R in primaries and metastases of invasive cancer strongly support the need to develop radioactive neurotensin analogs for the diagnosis and therapy of this tumor type.
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Affiliation(s)
- Meike Körner
- Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, PO Box 62, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Beatrice Waser
- Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, PO Box 62, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Oliver Strobel
- Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Markus Büchler
- Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Jean Claude Reubi
- Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, PO Box 62, Murtenstrasse 31, CH-3010 Berne, Switzerland
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20
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Richter S, Wuest F. 18F-Labeled Peptides: The Future Is Bright. Molecules 2014; 19:20536-20556. [PMID: 25493636 PMCID: PMC6271677 DOI: 10.3390/molecules191220536] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/24/2014] [Accepted: 11/28/2014] [Indexed: 01/10/2023] Open
Abstract
Radiolabeled peptides have been the subject of intense research efforts for targeted diagnostic imaging and radiotherapy over the last 20 years. Peptides offer several advantages for receptor imaging and targeted radiotherapy. The low molecular weight of peptides allows for rapid clearance from the blood and non-target tissue, which results in favorable target-to-non-target ratios. Moreover, peptides usually display good tissue penetration and they are generally non-immunogenic. A major drawback is their potential low metabolic stability. The majority of currently used radiolabeled peptides for targeted molecular imaging and therapy of cancer is labeled with various radiometals like 99mTc, 68Ga, and 177Lu. However, over the last decade an increasing number of 18F-labeled peptides have been reported. Despite of obvious advantages of 18F like its ease of production in large quantities at high specific activity, the low β+ energy (0.64 MeV) and the favorable half-life (109.8 min), 18F-labeling of peptides remains a special challenge. The first part of this review will provide a brief overview on chemical strategies for peptide labeling with 18F. A second part will discuss recent technological advances for 18F-labeling of peptides with special focus on microfluidic technology, automation, and kit-like preparation of 18F-labeled peptides.
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Affiliation(s)
- Susan Richter
- Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada.
| | - Frank Wuest
- Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada.
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21
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Wu Z, Li L, Liu S, Yakushijin F, Yakushijin K, Horne D, Conti PS, Li Z, Kandeel F, Shively JE. Facile Preparation of a Thiol-Reactive (18)F-Labeling Agent and Synthesis of (18)F-DEG-VS-NT for PET Imaging of a Neurotensin Receptor-Positive Tumor. J Nucl Med 2014; 55:1178-84. [PMID: 24854793 DOI: 10.2967/jnumed.114.137489] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/17/2014] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Accumulating evidence suggests that neurotensin receptors (NTRs) play key roles in cancer growth and survival. In this study, we developed a simple and efficient method to radiolabel neurotensin peptide with (18)F for NTR-targeted imaging. METHODS The thiol-reactive reagent (18)F-(2-(2-(2-fluoroethoxy)ethoxy)ethylsulfonyl)ethane ((18)F-DEG-VS) was facilely prepared through 1-step radiofluorination. After high-pressure liquid chromatography purification, (18)F-DEG-VS was incubated with the c(RGDyC) and c(RGDyK) peptide mixture to evaluate its specificity toward the reactive thiol. Thiolated neurotensin peptide was then labeled with (18)F using this novel synthon, and the resulting imaging probe was subjected to receptor-binding assay and small-animal PET studies in a murine xenograft model. The imaging results and metabolic stability of (18)F-DEG-VS-NT were compared with the thiol-specific maleimide derivative N-[2-(4-(18)F-fluorobenzamido)ethyl]maleimide-neurotensin ((18)F-FBEM-NT). RESULTS (18)F-DEG-VS was obtained in high labeling yield. The reaction of (19)F-DEG-VS was highly specific for thiols at neutral pH, whereas the lysine of c(RGDyK) reacted at a pH greater than 8.5. (18)F-DEG-VS-c(RGDyC) was the preferred product when both c(RGDyK) and c(RGDyC) were incubated together with (18)F-DEG-VS. Thiolated neurotensin peptide (Cys-NT) efficiently reacted with (18)F-DEG-VS, with a 95% labeling yield (decay-corrected). The radiochemical purity of the (18)F-DEG-VS-NT was greater than 98%, and the specific activity was about 19.2 ± 4.3 TBq/mmol. Noninvasive small-animal PET demonstrated that (18)F-DEG-VS-NT had an NTR-specific tumor uptake in subcutaneous HT-29 xenografts. The tumor-to-muscle, tumor-to-liver, and tumor-to-kidney ratios reached 30.65 ± 22.31, 11.86 ± 1.98, and 1.91 ± 0.43 at 2 h after injection, respectively, based on the biodistribution study. Receptor specificity was demonstrated by blocking experiment. Compared with (18)F-FBEM-NT, (18)F-DEG-VS-NT was synthesized with fewer steps and provided significantly improved imaging quality in vivo. CONCLUSION We have established a facile (18)F-labeling method for site-specific labeling of the Cys-NT. Using this method, we synthesized an NTR-targeted PET agent, which demonstrated high tumor-to-background contrast.
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Affiliation(s)
- Zhanhong Wu
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute of the City of Hope, Duarte, California
| | - Lin Li
- Department of Immunology, Beckman Research Institute of the City of Hope, Duarte, California
| | - Shuanglong Liu
- Department of Radiology, Molecular Imaging Center, University of Southern California, Los Angeles, California; and
| | - Fumiko Yakushijin
- Department of Molecular Medicine, Beckman Research Institute of the City of Hope, Duarte, California
| | - Kenichi Yakushijin
- Department of Molecular Medicine, Beckman Research Institute of the City of Hope, Duarte, California
| | - David Horne
- Department of Molecular Medicine, Beckman Research Institute of the City of Hope, Duarte, California
| | - Peter S Conti
- Department of Radiology, Molecular Imaging Center, University of Southern California, Los Angeles, California; and
| | - Zibo Li
- Department of Radiology, Molecular Imaging Center, University of Southern California, Los Angeles, California; and
| | - Fouad Kandeel
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute of the City of Hope, Duarte, California
| | - John E Shively
- Department of Immunology, Beckman Research Institute of the City of Hope, Duarte, California
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Ahrabi NZ, Erfani M, Parivar K, Beiki D, Jalilian AR. Preparation and evaluation of a new neurotensin analog labeled with 99mTc for targeted imaging of neurotensin receptor positive tumors. J Radioanal Nucl Chem 2013. [DOI: 10.1007/s10967-013-2795-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Accardo A, Ringhieri P, Tesauro D, Morelli G. Liposomes derivatized with tetrabranched neurotensin peptides via click chemistry reactions. NEW J CHEM 2013. [DOI: 10.1039/c3nj00596h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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24
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Richter S, Bouvet V, Wuest M, Bergmann R, Steinbach J, Pietzsch J, Neundorf I, Wuest F. 18F-Labeled phosphopeptide-cell-penetrating peptide dimers with enhanced cell uptake properties in human cancer cells. Nucl Med Biol 2012; 39:1202-12. [DOI: 10.1016/j.nucmedbio.2012.06.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 05/14/2012] [Accepted: 06/02/2012] [Indexed: 10/28/2022]
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25
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White JB, Hausner SH, Carpenter RD, Sutcliffe JL. Optimization of the solid-phase synthesis of [18F] radiolabeled peptides for positron emission tomography. Appl Radiat Isot 2012; 70:2720-9. [PMID: 23041391 DOI: 10.1016/j.apradiso.2012.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 07/08/2012] [Accepted: 08/09/2012] [Indexed: 11/30/2022]
Abstract
Establishing improved methods for the radiolabeling of peptides with fluorine-18 via solid-phase peptide synthesis (SPPS) is desirable for the efficient synthesis of peptide-based molecular imaging agents. This work focuses on the development of a standardized platform to facilitate the reliable and efficient synthesis of high-purity fluorine-18 radiolabeled peptides for in vivo imaging with positron emission tomography (PET). Seven commercially available resins were selected for solid-phase radiolabeling of the model peptide VQAAIDYING with 4-[(18)F]fluorobenzoic acid ([(18)F]FBA). A wide range of radiochemical yields (18.8 ± 1.5% to 41.2 ± 5.3%) was obtained using standard conditions (coupling: 3 eq amino acid, 3 eq HATU, 6 eq DIPEA, 1.5 h, r.t.; cleavage: 94% TFA, 3 h, r.t.). After modification of coupling reagents and employing heated reactions to 37°C, radiochemical yields were improved by as much as 35.3% over standard conditions. When the optimized conditions were applied to the synthesis of [(18)F]FBA-PEG(28)-A20FMDV2, which targets the α(v)β(6) integrin in vivo, radiochemical yields improved by as much as 73.4% over those obtained using standard coupling and cleavage conditions. This platform can be utilized to improve the synthesis of peptide-based molecular probes for molecular imaging with PET.
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Affiliation(s)
- Jason B White
- Department of Biomedical Engineering, University of California, Davis, USA
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Thonon D, Goblet D, Goukens E, Kaisin G, Paris J, Aerts J, Lignon S, Franci X, Hustinx R, Luxen A. Fully automated preparation and conjugation of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) with RGD peptide using a GE FASTlab™ synthesizer. Mol Imaging Biol 2012; 13:1088-95. [PMID: 21267662 DOI: 10.1007/s11307-011-0470-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE The aim of this work was to automate the radiosynthesis of [(18)F]SFB, a widely used reagent for the labeling of biomolecules with (18)F on a new generation commercial synthesis module (FASTLab™, GE Healthcare). PROCEDURES Two synthesis approaches were implemented on this module: the classical "two-pot radiosynthesis" and the more recently described "one-pot" method. RESULTS The "two-pot" approach affords [(18)F]SFB with a 42% decay-corrected yield in 57 min (n = 24) with a chemical purity sufficient to avoid an intermediate HPLC purification. The recently established "one-pot" method, afforded a product with a lower chemical purity, in the conditions used in this report. The lower d.c. yield obtained (32% (n = 15)) was related to the low (18)F labeling yields obtained in MeCN compared with DMSO. The subsequent conjugation step with a RGD (PRGD2) peptide was also successfully automated. CONCLUSIONS The formulated [(18)F]FPRGD2 was obtained without any operator manipulation with a d.c. yield of 13% ± 3% (n = 13) in 130 min, a radiochemical purity >98% and a specific activity of 140 ± 40 TBq/mmol.
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Affiliation(s)
- David Thonon
- Cyclotron Research Center, Liege University, Liege, Belgium.
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Hou S, Phung DL, Lin WY, Wang MW, Liu K, Shen CKF. Microwave-assisted one-pot synthesis of N-succinimidyl-4[ ¹⁸F]fluorobenzoate ([¹⁸F]SFB). J Vis Exp 2011:2755. [PMID: 21730951 DOI: 10.3791/2755] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Biomolecules, including peptides¹⁻⁹, proteins¹⁰⁻¹¹, and antibodies and their engineered fragments¹²⁻¹⁴, are gaining importance as both potential therapeutics and molecular imaging agents. Notably, when labeled with positron-emitting radioisotopes (e.g., Cu-64, Ga-68, or F-18), they can be used as probes for targeted imaging of many physiological and pathological processes.¹⁵⁻¹⁸ Therefore, significant effort has devoted to the synthesis and exploration of ¹⁸F-labeled biomolecules. Although there are elegant examples of the direct ¹⁸F-labeling of peptides,¹⁹⁻²² the harsh reaction conditions (i.e., organic solvent, extreme pH, high temperature) associated with direct radiofluorination are usually incompatible with fragile protein samples. To date, therefore, the incorporation of radiolabeled prosthetic groups into biomolecules remains the method of choice.²³(,)²⁴ N-Succinimidyl-4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB),²⁵⁻³⁷ a Bolton-Hunter type reagent that reacts with the primary amino groups of biomolecules, is a very versatile prosthetic group for the ¹⁸F-labeling of a wide spectrum of biological entities, in terms of its evident in vivo stability and high radiolabeling yield. After labeling with [¹⁸F]SFB, the resulting [F]fluorobenzoylated biomolecules could be explored as potential PET tracers for in vivo imaging studies.¹ Most [¹⁸F]SFB radiosyntheses described in the current literatures require two or even three reactors and multiple purifications by using either solid phase extraction (SPE) or high-performance liquid chromatography (HPLC). Such lengthy processes hamper its routine production and widespread applications in the radiolabeling of biomolecules. Although several module-assisted [¹⁸F]SFB syntheses have been reported²⁹⁻³²,⁴¹⁻⁴² they are mainly based on complicated and lengthy procedures using costly commercially-available radiochemistry boxes (Table 1). Therefore, further simplification of the radiosynthesis of [¹⁸F]SFB using a low-cost setup would be very beneficial for its adaption to an automated process. Herein, we report a concise preparation of [¹⁸F]SFB, based on a simplified one-pot microwave-assisted synthesis (Figure 1). Our approach does not require purification between steps or any aqueous reagents. In addition, microwave irradiation, which has been used in the syntheses of several PET tracers,³⁸⁻⁴¹ can gives higher RCYs and better selectivity than the corresponding thermal reactions or they provide similar yields in shorter reaction times.³⁸Most importantly, when labeling biomolecules, the time saved could be diverted to subsequent bioconjugation or PET imaging step. ²⁸(,)⁴³The novelty of our improved [¹⁸F]SFB synthesis is two-fold: (1) the anhydrous deprotection strategy requires no purification of intermediate(s) between each step and (2) the microwave-assisted radiochemical transformations enable the rapid, reliable production of [¹⁸F]SFB.
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Affiliation(s)
- Shuang Hou
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, CA, USA
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Podstawka-Proniewicz E, Kudelski A, Kim Y, Proniewicz LM. Structure and Binding of Specifically Mutated Neurotensin Fragments on a Silver Substrate: Vibrational Studies. J Phys Chem B 2011; 115:7097-108. [DOI: 10.1021/jp201316n] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
| | - Andrzej Kudelski
- Faculty of Chemistry, University of Warsaw, ul. L. Pasteura 1, 02-093 Warsaw, Poland
| | - Younkyoo Kim
- Department of Chemistry, Hankuk University of Foreign Studies, Yongin, Kyunggi-Do 449-791, Korea
| | - Leonard M. Proniewicz
- Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
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Röhrich A, Bergmann R, Kretzschmann A, Noll S, Steinbach J, Pietzsch J, Stephan H. A novel tetrabranched neurotensin(8-13) cyclam derivative: synthesis, 64Cu-labeling and biological evaluation. J Inorg Biochem 2011; 105:821-32. [PMID: 21497581 DOI: 10.1016/j.jinorgbio.2011.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 01/21/2011] [Accepted: 02/21/2011] [Indexed: 12/11/2022]
Abstract
New macrocyclic 1,4,8,11-tetraazacyclotetradecane (cyclam) derivatives with 1, 2 and 4 neurotensin(8-13) units 4, 5 and 7 have been synthesized. Compounds 4 and 5 were prepared by the reaction of non-stabilized neurotensin(8-13) and cyclamtetrapropionic acid 2 using 1-ethyl-3-(3-dimethylaminocarbonyl)carbodiimide-hydrochloride and N-hydroxysulfosuccinimide. The tetrameric compound 7 was synthesized by Michael addition of neurotensin(8-13) acrylamide 6 and cyclam 1. The copper(II) complexation behavior of 4, 5 and 7 was investigated by UV/visible spectrophotometry and shows that the metal center resides inside the N4 chromophore with additional apical interactions established with pendant arms. The novel tetrabranched NT(8-13) cyclam 7 with nanomolar neurotensin receptor 1 binding affinity was efficiently radiolabeled with (64)Cu under mild conditions. (64)Cu⊂7 showed slow transchelation in the presence of a large amount of cyclam as competing ligand, while it completely remains intact in the presence of EDTA. The in vivo behavior of (64)Cu⊂7 was studied in rats and mice. The metabolic stability in rodent models was high with a half-life of intact (64)Cu⊂7 in plasma of 34 min in rats and 60 min in the mice, respectively. The binding affinity was high enough to demonstrate in vivo binding of (64)Cu⊂7 to NTR1 overexpressing HT-29 tumor xenotransplants in nude mice. Regarding elimination, (64)Cu⊂7 showed a substantial renal and reticuloendothelial accumulation. On the other hand, metabolization of the compound in vivo with a resulting metabolite-postulated to be the (64)Cu-cyclam-tetraarginine complex-also showed long retention in the circulating blood, preventing a better contrast of tumor imaging.
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Affiliation(s)
- Anika Röhrich
- Institute of Radiopharmacy, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
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Chen K, Conti PS. Target-specific delivery of peptide-based probes for PET imaging. Adv Drug Deliv Rev 2010; 62:1005-22. [PMID: 20851156 DOI: 10.1016/j.addr.2010.09.004] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/08/2010] [Accepted: 09/08/2010] [Indexed: 12/19/2022]
Abstract
Positron emission tomography (PET) is one of the most rapidly growing areas of medical imaging, with many applications in the clinical management of patients with various diseases. The principal goal of PET imaging is to visualize, characterize, and measure biological processes at the cellular, subcellular, and molecular level in living subjects with non-invasive procedures. PET imaging takes advantage of the traditional diagnostic imaging techniques and introduces positron-emitting probes to determine the expression of indicative molecular targets at different stages of disease. During the last decade, advances in molecular biology have revealed an increasing number of potential molecular targets, including peptide receptors and peptide-related biomolecules. With the help of sophisticated bioconjugation and radiolabeling techniques, numerous peptide-based agents have been developed and evaluated for delivery of PET radionuclides to the specific molecular targets in preclinical and clinical studies. As compared to macromolecules, such as proteins or antibodies, low-molecular-weight peptides have their distinctive advantages and predominantly demonstrate their favorable pharmacokinetics for in vivo PET applications. This review summarizes the criteria of peptide-based PET probes design, the selection of radioisotopes, labeling methods, and provides an overview of the current status and trends in the development of target-specific peptide-based probes with respect to their unique PET imaging applications.
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Synthesis of neurotensin(8–13)–phosphopeptide heterodimers via click chemistry. Bioorg Med Chem Lett 2010; 20:3306-9. [DOI: 10.1016/j.bmcl.2010.04.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 04/07/2010] [Accepted: 04/12/2010] [Indexed: 11/19/2022]
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Roehn U, Becaud J, Mu L, Srinivasan A, Stellfeld T, Fitzner A, Graham K, Dinkelborg L, Schubiger AP, Ametamey SM. Nucleophilic ring-opening of activated aziridines: A one-step method for labeling biomolecules with fluorine-18. J Fluor Chem 2009. [DOI: 10.1016/j.jfluchem.2009.07.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Alshoukr F, Rosant C, Maes V, Abdelhak J, Raguin O, Burg S, Sarda L, Barbet J, Tourwé D, Pelaprat D, Gruaz-Guyon A. Novel neurotensin analogues for radioisotope targeting to neurotensin receptor-positive tumors. Bioconjug Chem 2009; 20:1602-10. [PMID: 19610615 DOI: 10.1021/bc900151z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The increased expression of the neurotensin (NT) receptor NTS1 by different cancer cells, such as pancreatic adenocarcinoma and ductal breast cancer cells, as compared to normal epithelium, offers the opportunity to target these tumors with radiolabeled neurotensin analogues for diagnostic or therapeutic purposes. The aim of the present study was to design and synthesize new neurotensin radioligands and to select a lead molecule with high in vivo tumor selectivity for further development. Two series of neurotensin analogues bearing DTPA were tested: a series of NT(8-13) analogues, with DTPA coupled to the α-NH(2), sharing the same peptide sequence with analogues previously developed for radiolabeling with technetium or rhenium, as well as an NT(6-13) series in which DTPA was coupled to the ε-NH(2) of Lys(6). Changes were introduced to stabilize the bonds between Arg(8)-Arg(9), Pro(10)-Tyr(11), and Tyr(11)-Ile(12) to provide metabolic stability. Structure-activity studies of NT analogues have shown that the attachment of DTPA induces an important loss of affinity unless the distance between the chelator and the NT(8-13) sequence, which binds to the NTS1 receptor, is increased. The doubly stabilized DTPA-NT-20.3 exhibits a high affinity and an elevated stability to enzymatic degradation. It shows specific tumor uptake and high tumor to blood, to liver, and to intestine activity uptake ratios and affords high-contrast planar and SPECT images in an animal model. The DTPA-NT-20.3 peptide is a promising candidate for imaging neurotensin receptor-positive tumors, such as pancreatic adenocarcinoma and invasive ductal breast cancer. Analogues carrying DOTA are being developed for yttrium-90 or lutetium-177 labeling.
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Glaser M, Årstad E, Luthra SK, Robins EG. Two-step radiosynthesis of [18F]N-succinimidyl-4-fluorobenzoate ([18F]SFB). J Labelled Comp Radiopharm 2009. [DOI: 10.1002/jlcr.1601] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Speranza A, Ortosecco G, Castaldi E, Nardelli A, Pace L, Salvatore M. Fully automated synthesis procedure of 4-[18F]fluorobenzaldehyde by commercial synthesizer: amino-oxi peptide labelling prosthetic group. Appl Radiat Isot 2009; 67:1664-9. [PMID: 19443231 DOI: 10.1016/j.apradiso.2009.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 04/02/2009] [Accepted: 04/09/2009] [Indexed: 10/20/2022]
Abstract
Automatic synthesis of 4-[18F]fluorobenzaldehyde has been developed by a commercially available TRACERlab FX(F-N) synthesis module to be used as prosthetic group for amino-oxy functionalized peptide labelling in clinical routine application. In addition a handmade purification device (HPD) has been setup to perform automatic cartridge purification as well as to back-up the reactor where one-pot synthesis is not applicable. Cartridges for solid phase extraction such as C18, C8, phenyl has been tested to best perform purification as well as activity recovery. Radiochemical yield (RCY) at end of synthesis (EOS) was in average 67% after about 45 min (90% decay corrected at EOB). The RCY of the entire procedure was 54% with a radiochemical purity above 99%.
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36
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Orwig KS, Lassetter MR, Hadden MK, Dix TA. Comparison of N-Terminal Modifications on Neurotensin(8−13) Analogues Correlates Peptide Stability but Not Binding Affinity with in Vivo Efficacy. J Med Chem 2009; 52:1803-13. [DOI: 10.1021/jm801072v] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kevin S. Orwig
- Department of Pharmaceutical Sciences, Medical University of South Carolina, 280 Calhoun Street, P.O. Box 250140, Charleston, South Carolina 29425, Argolyn Bioscience Inc., 530 Meridian Parkway, Suite 200, Durham, North Carolina 27713
| | - McKensie R. Lassetter
- Department of Pharmaceutical Sciences, Medical University of South Carolina, 280 Calhoun Street, P.O. Box 250140, Charleston, South Carolina 29425, Argolyn Bioscience Inc., 530 Meridian Parkway, Suite 200, Durham, North Carolina 27713
| | - M. Kyle Hadden
- Department of Pharmaceutical Sciences, Medical University of South Carolina, 280 Calhoun Street, P.O. Box 250140, Charleston, South Carolina 29425, Argolyn Bioscience Inc., 530 Meridian Parkway, Suite 200, Durham, North Carolina 27713
| | - Thomas A. Dix
- Department of Pharmaceutical Sciences, Medical University of South Carolina, 280 Calhoun Street, P.O. Box 250140, Charleston, South Carolina 29425, Argolyn Bioscience Inc., 530 Meridian Parkway, Suite 200, Durham, North Carolina 27713
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37
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Falciani C, Pini A, Bracci L. Oligo-branched peptides for tumor targeting: from magic bullets to magic forks. Expert Opin Biol Ther 2009; 9:171-8. [DOI: 10.1517/14712590802620501] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Richter S, Bergmann R, Pietzsch J, Ramenda T, Steinbach J, Wuest F. Fluorine-18 labeling of phosphopeptides: A potential approach for the evaluation of phosphopeptide metabolism in vivo. Biopolymers 2009; 92:479-88. [DOI: 10.1002/bip.21263] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wuest F, Köhler L, Berndt M, Pietzsch J. Systematic comparison of two novel, thiol-reactive prosthetic groups for 18F labeling of peptides and proteins with the acylation agent succinimidyl-4-[18F]fluorobenzoate ([18F]SFB). Amino Acids 2008; 36:283-95. [PMID: 18414978 DOI: 10.1007/s00726-008-0065-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Accepted: 03/21/2008] [Indexed: 11/29/2022]
Abstract
A systematic comparison of 4-[18F]fluorobenzaldehyde-O-(2-{2-[2-(pyrrol-2,5-dione-1-yl)ethoxy]-ethoxy}-ethyl)oxime ([18F]FBOM) and 4-[18F]fluorobenzaldehyde-O-[6-(2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-hexyl]oxime ([18F]FBAM) as prosthetic groups for the mild and efficient 18F labeling of cysteine-containing peptides and proteins with the amine-group reactive acylation agent, succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), is described. All three prosthetic groups were prepared in a remotely controlled synthesis module. Synthesis of [18F]FBOM and [18F]FBAM was accomplished via oxime formation through reaction of appropriate aminooxy-functionalized labeling precursors with 4-[18F]fluorobenzaldehyde. The obtained radiochemical yields were 19% ([18F]FBOM) and 29% ([18F]FBAM), respectively. Radiolabeling involving [18F]FBAM and [18F]FBOM was exemplified by the reaction with cysteine-containing tripeptide glutathione (GSH), a cysteine-containing dimeric neurotensin derivative, and human native low-density lipoprotein (nLDL) as model compounds. Radiolabeling with the acylation agent [18F]SFB was carried out using a dimeric neurotensin derivative and nLDL. Both thiol-group reactive prosthetic groups show significantly better labeling efficiencies for the peptides in comparison with the acylation agent [18F]SFB. The obtained results demonstrate that [18F]FBOM is especially suited for the labeling of hydrophilic cysteine-containing peptides, whereas [18F]FBAM shows superior labeling performance for higher molecular weight compounds as exemplified for nLDL apolipoprotein constituents. However, the acylation agent [18F]SFB is the preferred prosthetic group for labeling nLDL under physiological conditions.
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Affiliation(s)
- Frank Wuest
- Research Center Dresden-Rossendorf, Institute for Radiopharmacy, PF 510 119, 01314 Dresden, Germany.
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40
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Janssen PJJM, de Visser M, Verwijnen SM, Bernard BF, Srinivasan A, Erion JL, Breeman WAP, Vulto AG, Krenning EP, de Jong M. Five Stabilized 111In-labeled neurotensin analogs in nude mice bearing HT29 tumors. Cancer Biother Radiopharm 2007; 22:374-81. [PMID: 17651043 DOI: 10.1089/cbr.2007.369.a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neurotensin (NT) receptors are overexpressed in different human tumors, such as human ductal pancreatic adenocarcinoma. New stable neurotensin analogs with high receptor affinity have been synthesized by replacing arginine residues with lysine and arginine derivatives. The aim of this study was to explore the biodistribution, tumor uptake, kidney localization, and stability characteristics of these new analogs in order to develop new diagnostic tools for exocrine pancreatic cancer. Four (111)In-labeled DTPA-chelated NT analogs and one (111)In-labeled DOTA-chelated NT analog were evaluated in NMRI nude mice bearing NT receptor-positive HT29 tumors. Experiments with a coinjection of unlabeled NT or lysine were performed to investigate receptor-mediated uptake and kidney protection, respectively. In addition, the in vivo serum stability of the most promising analog was analyzed. In the biodistribution study in mice, at 4 hours postinjection, a low percentage of the injected dose per gram (%ID/g) of tissue for all compounds was found in NT receptor-negative organs, such as the blood, spleen, pancreas, liver, muscle, and femur. A high uptake was found in the colon, intestine, kidneys, and in implanted HT29 tumors. The coinjection of excess unlabeled neurotensin significantly reduced tumor uptake, showing tumor uptake to be receptor-mediated. To a lesser extent, this was also observed for the colon, but not for other tissues. We concluded that DTPA-(Pip)Gly-Pro-(PipAm)Gly-Arg-Pro-Tyr-tBuGly-Leu-OH and the DOTA-linked counterpart have the most favorable biodistribution properties regarding tumor uptake.
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Falciani C, Fabbrini M, Pini A, Lozzi L, Lelli B, Pileri S, Brunetti J, Bindi S, Scali S, Bracci L. Synthesis and biological activity of stable branched neurotensin peptides for tumor targeting. Mol Cancer Ther 2007; 6:2441-8. [PMID: 17766836 DOI: 10.1158/1535-7163.mct-07-0164] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Receptors for endogenous regulatory peptides, like the neuropeptide neurotensin, are overexpressed in several human cancers and can be targets for peptide-mediated tumor-selective therapy. Peptides, however, have the main drawback of an extremely short half-life in vivo. We showed that neurotensin and other endogenous peptides, when synthesized as dendrimers, retain biological activity and become resistant to proteolysis. Here, we synthesized the neurotensin functional fragment NT(8-13) in a tetrabranched form linked to different units for tumor therapy or diagnosis. Fluorescent molecules were used to monitor receptor binding and internalization in HT29 human adenocarcinoma cells and receptor binding in HT29 tumor xenografts in nude mice. Linking of chemotherapic molecules like chlorin e6 and methotrexate to dendrimers resulted in a dramatic increase in drug selectivity, uptake of which by target cells became dependent on peptide receptor binding. When nude mice carrying human tumor xenografts were treated with branched NT(8-13)-methotrexate, a 60% reduction in tumor growth was observed with respect to mice treated with the free drug.
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Affiliation(s)
- Chiara Falciani
- Department of Molecular Biology, University of Siena, Siena, Italy 53100.
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Hultsch C, Berndt M, Bergmann R, Wuest F. Radiolabeling of multimeric neurotensin(8–13) analogs with the short-lived positron emitter fluorine-18. Appl Radiat Isot 2007; 65:818-26. [PMID: 17451963 DOI: 10.1016/j.apradiso.2007.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Accepted: 02/19/2007] [Indexed: 10/23/2022]
Abstract
Three methods for (18)F-labeling of dimeric and tetrameric neurotensin(8-13) derivatives were evaluated with respect to the labeling yield and the required peptide amounts. Labeling using N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB) gave low radiochemical yield for the dimeric peptides. Coupling of the tetramer with [(18)F]SFB was not successful. High yields were obtained for labeling of the aminooxy-functionalized neurotensin(8-13) dimer using 4-[(18)F]fluorobenzaldehyde ([(18)F]FBA) whilst coupling of the corresponding tetramer gave only low yields. Labeling of sulfydryl-functionalized neurotensin(8-13) derivatives using the maleinimide 4-[(18)F]fluorobenzaldehyde-O-[6-(2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-hexyl]-oxime ([(18)F]FBAM) resulted in high radiochemical yields for both, the dimer and the tetramer. Therefore, [(18)F]FBAM seems to be the most suitable (18)F-labeling agent for multivalent neurotensin(8-13) derivatives.
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Affiliation(s)
- Christina Hultsch
- Institute of Radiopharmacy, Research Center Rossendorf, P.O. Box 51 01 19, D-01314 Dresden, Germany
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Prante O, Einsiedel J, Haubner R, Gmeiner P, Wester HJ, Kuwert T, Maschauer S. 3,4,6-Tri-O-acetyl-2-deoxy-2-[18F]fluoroglucopyranosyl phenylthiosulfonate: a thiol-reactive agent for the chemoselective 18F-glycosylation of peptides. Bioconjug Chem 2007; 18:254-62. [PMID: 17226980 DOI: 10.1021/bc060340v] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
3,4,5-Tri-O-acetyl-2-[18F]fluoro-2-deoxy-d-glucopyranosyl 1-phenylthiosulfonate (Ac3-[18F]FGlc-PTS) was developed as a thiol-reactive labeling reagent for the site-specific 18F-glycosylation of peptides. Taking advantage of highly accessible 1,3,4,6-tetra-O-acetyl-2-deoxy-2-[18F]fluoroglucopyranose, a three-step radiochemical pathway was investigated and optimized, providing Ac3-[18F]FGlc-PTS in a radiochemical yield of about 33% in 90 min (decay-corrected and based on starting [18F]fluoride). Ac3-[18F]FGlc-PTS was reacted with the model pentapeptide CAKAY, confirming chemoselectivity and excellent conjugation yields of >90% under mild reaction conditions. The optimized method was adopted to the 18F-glycosylation of the alphavbeta3-affine peptide c(RGDfC), achieving high conjugation yields (95%, decay-corrected). The alphavbeta3 binding affinity of the glycosylated c(RGDfC) remained uninfluenced as determined by competition binding studies versus 125I-echistatin using both isolated alphavbeta3 and human umbilical vein endothelial cells (Ki = 68 +/- 10 nM (alphavbeta3) versus Ki = 77 +/- 4 nM (HUVEC)). The whole radiosynthetic procedure, including the preparation of the 18F-glycosylating reagent Ac3-[18F]FGlc-PTS, peptide ligation, and final HPLC purification, provided a decay-uncorrected radiochemical yield of 13% after a total synthesis time of 130 min. Ac3-[18F]FGlc-PTS represents a novel 18F-labeling reagent for the mild chemoselective 18F-glycosylation of peptides indicating its potential for the design and development of 18F-labeled bioactive S-glycopeptides suitable to study their pharmacokinetics in vivo by positron emission tomography (PET).
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Affiliation(s)
- Olaf Prante
- Laboratory of Molecular Imaging, Clinic of Nuclear Medicine, Friedrich-Alexander University, 91054 Erlangen, Germany.
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Wester HJ, Schottelius M. Fluorine-18 labeling of peptides and proteins. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2007:79-111. [PMID: 17172153 DOI: 10.1007/978-3-540-49527-7_4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The pool of promising peptides worthy of investigation and evaluation for clinical use is continuously filled from different sources. Driven by the promising results obtained with peptides addressing somatostatin-2 receptor positive (sst2+) neuroendocrine tumours, other peptides targeting further receptor systems are being studied and evaluated. Progress in profiling the density and incidence of peptide hormone receptors in human cancer has initiated and will further promote research on the corresponding peptidic binders. In addition, industrial pharmaceutical research will be another significant source of peptides in the future. A recent prognosis revealed that about 50% of the drugs entering clinical trials in the next years will be peptides. The extensive research activities in genomics and proteomics will point out and quantify new and already known target structures upregulated in specific diseases. Based on the knowledge of their endogenous ligands or via selection of suitable candidates by phage display, suitable peptide ligands for e.g. membrane associated receptors can be identified and thus allow targeting of such binding sites. Thus, bioactive peptides specifically addressing relevant molecular targets are expected to become an important class of tracers, also due to the possibility of bridging imaging with therapeutic approaches. In this brief overview a summary of methods and strategies for the 18F-labeling of peptides and proteins is given.
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Affiliation(s)
- H J Wester
- Nuklearmedizinische Klinik und Poliklinik und Institut für Radiochemie, Technische Universität Müchen, Germany.
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Prante O, Hamacher K, Coenen HH. Chemoenzymatic n.c.a synthesis of the coenzyme UDP-2-deoxy-2-[18F]fluoro-α-D-glucopyranose as substrate of glycosyltransferases. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1161] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bruus-Jensen K, Poethko T, Schottelius M, Hauser A, Schwaiger M, Wester HJ. Chemoselective hydrazone formation between HYNIC-functionalized peptides and (18)F-fluorinated aldehydes. Nucl Med Biol 2006; 33:173-83. [PMID: 16546671 DOI: 10.1016/j.nucmedbio.2005.10.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 10/13/2005] [Accepted: 10/17/2005] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Since the demand for (18)F-fluorinated peptides for quantitative in vivo receptor imaging using PET has increased, a new chemoselective two-step (18)F-labeling strategy based on hydrazone formation between an unprotected hydrazine-functionalized peptide and an (18)F-labeled aldehyde was developed. METHODS First, 4-[(18)F]fluorobenzaldehyde ([(18)F]FB-CHO) was prepared from 4-formyl-N,N,N-trimethylanilinium triflate via direct no-carrier-added (18)F-fluorination (dimethyl sulfoxide, 90 degrees C, 5 min) and purified by RP-HPLC. Hydrazone formation between [(18)F]FB-CHO and 6-hydrazinonicotinic acid (HYNIC) and the unprotected HYNIC-functionalized peptides (HYNIC-d-Phe(1))-Tyr(3)-Thr(8)-octreotide and (HYNIC-Arg(1))-substance P was evaluated with respect to the dependence of radiochemical yield on pH, precursor concentration and temperature. The stability of [(18)F]FB-CH=N-HYNIC-Tyr(3)-Thr(8)(NH(2))-octreotide in aqueous solution at various pH (4.0, 5.5 and 7.5) as well as the in vivo stability of [(18)F]FB-CH=N-HYNIC-Tyr(3)-Thr(8)-octreotide in mouse blood (30 min p.i.) was investigated. RESULTS Yields of the hydrazone formation were independent of pH between pH 0.5 and 5.5. Optimal labeling yields of 85% were obtained with a precursor concentration of 2.1 mM at 70 degrees C for 10 min. The labeling products were stable at pH 7.5 at 37 degrees C, while in more acidic media (pH 4.0) the product slowly decomposed to form up to 31+/-2% [(18)F]FB-CHO within 5 h. Metabolite studies showed no detectable degradation of [(18)F]FB-CH=N-HYNIC-Tyr(3)-Thr(8)-octreotide in mouse blood (30 min p.i.). CONCLUSIONS In conclusion, chemoselective hydrazone formation between unprotected HYNIC-functionalized peptides and [(18)F]FB-CHO is a fast and straightforward radiolabeling method leading to high yields under mild acidic conditions. In addition, it represents a powerful and versatile radiolabeling strategy that is applicable to a variety of radionuclides and peptide precursors already available for (99m)Tc labeling.
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Affiliation(s)
- Kjerstin Bruus-Jensen
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technischen Universität München, D-81675 Munich, Germany
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Hultsch C, Pawelke B, Bergmann R, Wuest F. Synthesis and evaluation of novel multimeric neurotensin(8–13) analogs. Bioorg Med Chem 2006; 14:5913-20. [PMID: 16735124 DOI: 10.1016/j.bmc.2006.05.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 05/02/2006] [Accepted: 05/15/2006] [Indexed: 10/24/2022]
Abstract
Neurotensin(8-13) is a hexapeptide with subnanomolar affinity to the neurotensin receptor 1 which is expressed with high incidence in several human tumor entities. Thus, radiolabeled neurotensin(8-13) might be used for tumor targeting. However, its application is limited by insufficient metabolic stability. The present study aims at improving metabolic stability by the synthesis of multimeric neurotensin(8-13) derivatives rather than commonly employed chemical modifications of the peptide itself. Thus, different dimeric and tetrameric peptides carrying C- or N-terminal attached neurotensin(8-13) moieties have been synthesized and their binding affinity toward the neurotensin receptor has been determined. The results demonstrate that branched compounds containing neurotensin(8-13) attached via its C-terminus only show low receptor affinities, whilst derivatives with neurotensin(8-13) attached via the N-terminus show IC50 values in the nanomolar range. Moreover, within the multimeric neurotensin(8-13) derivatives with neurotensin(8-13) attached via the N-terminus an increasing number of branching units lead to higher binding affinities toward the neurotensin receptor.
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Marik J, Hausner SH, Fix LA, Gagnon MKJ, Sutcliffe JL. Solid-Phase Synthesis of 2-[18F]Fluoropropionyl Peptides. Bioconjug Chem 2006; 17:1017-21. [PMID: 16848410 DOI: 10.1021/bc0600564] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 2-[(18)F]fluoropropionic (2-[(18)F]FPA) acid is used as a prosthetic group for radiolabeling proteins and peptides for targeted imaging using positron emission tomography (PET). Radiolabeling of compounds with more than one acylable functional group can lead to complex mixtures of products; however, peptides can be labeled regioselectively on the solid phase. We investigated the use of a solid-phase approach for the preparation of 2-[(18)F]fluoropropionyl peptides. [(18)F]FPA was prepared and conjugated to the peptides attached to the solid phase support. The (18)F-labeled peptides were obtained in 175 min with decay corrected yields of 10% (related to [(18)F]fluoride) and with a purity of 76-99% prior HPLC purification. The suitability of various coupling reagents and solid supports were tested for radiolabeling of several peptides of various lengths.
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Affiliation(s)
- Jan Marik
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
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Zhang K, An R, Gao Z, Zhang Y, Aruva MR. Radionuclide imaging of small-cell lung cancer (SCLC) using 99mTc-labeled neurotensin peptide 8-13. Nucl Med Biol 2006; 33:505-12. [PMID: 16720242 DOI: 10.1016/j.nucmedbio.2006.03.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Revised: 02/23/2006] [Accepted: 03/05/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To prepare 99m technetium (99mTc)-labeled neurotensin (NT) peptide and to evaluate the feasibility of imaging oncogene NT receptors overexpressed in human small-cell lung cancer (SCLC) cells. METHODS The NT analogue (Nalpha-His)Ac-NT(8-13) was synthesized such that histidine was attached at the N-terminus. The analogue was labeled with [99mTc(H2O)3(CO)3] at pH 7. 99mTc-(Nalpha-His)Ac-NT(8-13) in vitro stability was determined by challenging it with 100 times the molar excess of DTPA, human serum albumin (HSA) and cysteine. The affinity, 99mTc-(Nalpha-His)Ac-NT(8-13) binding to SCLC cell line NCI-H446, was studied in vitro. Biodistribution and imaging with 99mTc-(Nalpha-His)Ac-NT(8-13) were performed at 4 and 12 h postinjection, and tissue distribution and imaging after receptor blocking were carried out at 4 h in nude mice bearing human SCLC tumor. Blood clearance was determined in normal mice. RESULTS The affinity constant (Kd) of 99mTc-(Nalpha-His)Ac-NT(8-13) to SCLC cells was 0.56 nmol/L. When challenged with 100 times the molar excess of DTPA, HSA or cysteine, more than 97+/-1.8% radioactivity remained as 99mTc-(Nalpha-His)Ac-NT(8-13). Tumor-to-muscle ratio was 3.35+/-1.01 at 4 h and 4.20+/-1.35 at 12 h postinjection. The excretory route of 99mTc-(Nalpha-His)Ac-NT(8-13) was chiefly through the renal pathway. In the receptor-blocking group treated with unlabeled (Nalpha-His)Ac-NT(8-13), tumor-to-muscle ratio at 4 h was 1.25+/-0.55. CONCLUSION The results suggest that 99mTc-(Nalpha-His)Ac-NT(8-13) specifically binds to the SCLC cells and made 99mTc-(Nalpha-His)Ac-NT(8-13) a desirable compound for further studies in planar or SPECT imaging of oncogene receptors overexpressed in SCLC cells.
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Affiliation(s)
- Kaijun Zhang
- Department of Nuclear Medicine, Union Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
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Maes V, Garcia-Garayoa E, Bläuenstein P, Tourwé D. Novel99mTc-Labeled Neurotensin Analogues with Optimized Biodistribution Properties. J Med Chem 2006; 49:1833-6. [PMID: 16509599 DOI: 10.1021/jm051172f] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two new 99mTc-labeled neurotensin(8-13) analogues containing the retro-N(alpha)-carboxymethyl-histidine ((N(alpha)His)Ac) chelator were synthesized as potential radiopharmaceuticals for visualization of pancreatic carcinoma. To improve the pharmacokinetic properties, (N(alpha)His)Ac-Arg-NMeArg-Pro-Tyr-Tle-Leu (NT-XII), which is metabolically stabilized at two positions, was further modified. Shikimic acid (3,4,5-trihydroxy-1-cyclohexene-1-carboxylic acid) was introduced to obtain a more hydrophilic peptide (NT-XVIII), or Tyr11 was replaced by 2,6-dimethyltyrosine (Dmt) resulting in a triple-stabilized NT(8-13) analogue (NT-XIX). The latter has the best biodistribution profile.
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Affiliation(s)
- Veronique Maes
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
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