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Neelamegam R, Chaly T, Dileep Kumar J. Radiosynthesis and in vivo imaging of [11C]BTFP, a potent inhibitor of VEGFR2. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Bolcaen J, Nair S, Driver CHS, Boshomane TMG, Ebenhan T, Vandevoorde C. Novel Receptor Tyrosine Kinase Pathway Inhibitors for Targeted Radionuclide Therapy of Glioblastoma. Pharmaceuticals (Basel) 2021; 14:626. [PMID: 34209513 PMCID: PMC8308832 DOI: 10.3390/ph14070626] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022] Open
Abstract
Glioblastoma (GB) remains the most fatal brain tumor characterized by a high infiltration rate and treatment resistance. Overexpression and/or mutation of receptor tyrosine kinases is common in GB, which subsequently leads to the activation of many downstream pathways that have a critical impact on tumor progression and therapy resistance. Therefore, receptor tyrosine kinase inhibitors (RTKIs) have been investigated to improve the dismal prognosis of GB in an effort to evolve into a personalized targeted therapy strategy with a better treatment outcome. Numerous RTKIs have been approved in the clinic and several radiopharmaceuticals are part of (pre)clinical trials as a non-invasive method to identify patients who could benefit from RTKI. The latter opens up the scope for theranostic applications. In this review, the present status of RTKIs for the treatment, nuclear imaging and targeted radionuclide therapy of GB is presented. The focus will be on seven tyrosine kinase receptors, based on their central role in GB: EGFR, VEGFR, MET, PDGFR, FGFR, Eph receptor and IGF1R. Finally, by way of analyzing structural and physiological characteristics of the TKIs with promising clinical trial results, four small molecule RTKIs were selected based on their potential to become new therapeutic GB radiopharmaceuticals.
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Affiliation(s)
- Julie Bolcaen
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town 7131, South Africa;
| | - Shankari Nair
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town 7131, South Africa;
| | - Cathryn H. S. Driver
- Radiochemistry, South African Nuclear Energy Corporation, Pelindaba, Brits 0240, South Africa;
- Pre-Clinical Imaging Facility, Nuclear Medicine Research Infrastructure, Pelindaba, Brits 0242, South Africa;
| | - Tebatso M. G. Boshomane
- Department of Nuclear Medicine, University of Pretoria Steve Biko Academic Hospital, Pretoria 0001, South Africa;
| | - Thomas Ebenhan
- Pre-Clinical Imaging Facility, Nuclear Medicine Research Infrastructure, Pelindaba, Brits 0242, South Africa;
- Department of Nuclear Medicine, University of Pretoria Steve Biko Academic Hospital, Pretoria 0001, South Africa;
- Preclinical Drug Development Platform, Department of Science and Technology, North West University, Potchefstroom 2520, South Africa
| | - Charlot Vandevoorde
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town 7131, South Africa;
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The Role of VEGF Receptors as Molecular Target in Nuclear Medicine for Cancer Diagnosis and Combination Therapy. Cancers (Basel) 2021; 13:cancers13051072. [PMID: 33802353 PMCID: PMC7959315 DOI: 10.3390/cancers13051072] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/13/2021] [Accepted: 02/24/2021] [Indexed: 12/17/2022] Open
Abstract
Simple Summary The rapid development of diagnostic and therapeutic methods of the cancer treatment causes that these diseases are becoming better known and the fight against them is more and more effective. Substantial contribution in this development has nuclear medicine that enables very early cancer diagnosis and early start of the so-called targeted therapy. This therapeutic concept compared to the currently used chemotherapy, causes much fewer undesirable side effects, due to targeting a specific lesion in the body. This review article discusses the possible applications of radionuclide-labelled tracers (peptides, antibodies or synthetic organic molecules) that can visualise cancer cells through pathological blood vessel system in close tumour microenvironment. Hence, at a very early step of oncological disease, targeted therapy can involve in tumour formation and growth. Abstract One approach to anticancer treatment is targeted anti-angiogenic therapy (AAT) based on prevention of blood vessel formation around the developing cancer cells. It is known that vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) play a pivotal role in angiogenesis process; hence, application of angiogenesis inhibitors can be an effective approach in anticancer combination therapeutic strategies. Currently, several types of molecules have been utilised in targeted VEGF/VEGFR anticancer therapy, including human VEGF ligands themselves and their derivatives, anti-VEGF or anti-VEGFR monoclonal antibodies, VEGF binding peptides and small molecular inhibitors of VEGFR tyrosine kinases. These molecules labelled with diagnostic or therapeutic radionuclides can become, respectively, diagnostic or therapeutic receptor radiopharmaceuticals. In targeted anti-angiogenic therapy, diagnostic radioagents play a unique role, allowing the determination of the emerging tumour, to monitor the course of treatment, to predict the treatment outcomes and, first of all, to refer patients for AAT. This review provides an overview of design, synthesis and study of radiolabelled VEGF/VEGFR targeting and imaging agents to date. Additionally, we will briefly discuss their physicochemical properties and possible application in combination targeted radionuclide tumour therapy.
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Tegnebratt T, Lu L, Eksborg S, Chireh A, Damberg P, Nikkhou-Aski S, Foukakis T, Rundqvist H, Holmin S, Kuiper RV, Samen E. Treatment response assessment with (R)-[ 11CPAQ PET in the MMTV-PyMT mouse model of breast cancer. EJNMMI Res 2018; 8:25. [PMID: 29616369 PMCID: PMC5882477 DOI: 10.1186/s13550-018-0380-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/23/2018] [Indexed: 02/07/2023] Open
Abstract
Background The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[11C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models. Methods MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[11C]PAQ PET as standardized uptake value (SUV)mean, SUVmax relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[11C]PAQ radiotracer uptake and therapy response biomarkers. Results The (R)-[11C]PAQ SUVmax in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUVmax change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[11C]PAQ SUVmax change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups. Conclusions The results of this study are promising. However, additional studies are necessary before (R)-[11C]PAQ can be approved as a predictive radiotracer for cancer therapy response.
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Affiliation(s)
- T Tegnebratt
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden. .,Department of Neuroradiology, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden.
| | - L Lu
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.,Department of Comparative Medicine, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden
| | - S Eksborg
- Department of Women's and Children's Health, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - A Chireh
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - P Damberg
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.,Department of Comparative Medicine, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden
| | - S Nikkhou-Aski
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.,Department of Comparative Medicine, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden
| | - T Foukakis
- Department of Oncology-Pathology, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - H Rundqvist
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - S Holmin
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.,Department of Neuroradiology, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden
| | - R V Kuiper
- Core Facility for Morphologic Phenotype Analysis, Laboratory Medicine, Karolinska Institutet, SE-14183, Huddinge, Sweden
| | - E Samen
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.,Department of Neuroradiology, Karolinska Experimental Research and Imaging Center, Karolinska University Hospital, SE-17176, Stockholm, Sweden
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Two anti-angiogenic TKI-PET tracers, [(11)C]axitinib and [(11)C]nintedanib: Radiosynthesis, in vivo metabolism and initial biodistribution studies in rodents. Nucl Med Biol 2016; 43:612-24. [PMID: 27497236 DOI: 10.1016/j.nucmedbio.2016.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 07/06/2016] [Accepted: 07/12/2016] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Tyrosine kinase inhibitors (TKIs) are very attractive targeted drugs, although a large portion of patients remains unresponsive. PET imaging with EGFR targeting TKIs ([(11)C]erlotinib and [(18)F]afatinib) showed promise in identifying treatment sensitive tumors. The aim of this study was to synthesize two anti-angiogenic TKI tracers, [(11)C]axitinib and [(11)C]nintedanib, and to evaluate their potential for PET. METHODS Following successful tracer synthesis, biodistribution studies in VU-SCC-OE and FaDu xenograft bearing mice were performed. Furthermore, tracer stability studies in mice were performed employing (radio-)HPLC and LC-MS/MS techniques. For [(11)C]nintedanib an LC-MS/MS method was developed to detect the primary carboxylic acid metabolite, resulting from methylester cleavage, in plasma and tumors, because this metabolite is postulated to be important for nintedanib efficacy. LC-MS/MS was also explored to assess the metabolic fate of [(11)C]axitinib in vivo, since axitinib has an isomerizable double bond. RESULTS [(11)C]axitinib and [(11)C]nintedanib were successfully synthesized with 10.5±2.6% and 25.6±3.3% radiochemical yield (corrected for decay), respectively. Biodistribution studies only demonstrated tumor uptake of [(11)C]nintedanib in FaDu xenografts of 1.66±0.02% ID/g at 60min p.i. In vivo stability analysis of [(11)C]axitinib at 45min p.i. revealed the formation of predominantly non-polar metabolites (36.6±6.8% vs 47.1±8.4% of parent tracer and 16.3±2.1% of polar metabolites), while for [(11)C]nintedanib mostly polar metabolites were found (70.9±4.1 vs 26.7±3.9% of parent tracer and only 2.4±1.6 of a non-polar metabolites). No isomerization of [(11)C]axtinib was observed in vivo; however, a sulfoxide metabolite could be detected using LC-MS/MS. For [(11)C]nintedanib, LC-MS/MS revealed formation of the reported primary carboxylic acid metabolite when in vitro plasma incubations were performed, with large differences in plasmas from different species. In vivo metabolite analysis, however, did not demonstrate the presence of the carboxylic acid in plasma or tumor tissue. CONCLUSIONS Reliable syntheses of [(11)C]axitinib and [(11)C]nintedanib were successfully developed. Tumor uptake was observed for [(11)C]nintedanib, albeit modest. The metabolic profiles of the tracers suggest that rapid metabolism is partly responsible for the modest tumor targeting observed.
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Recent Advances in the Development and Application of Radiolabeled Kinase Inhibitors for PET Imaging. Molecules 2015; 20:22000-27. [PMID: 26690113 PMCID: PMC6332294 DOI: 10.3390/molecules201219816] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/18/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022] Open
Abstract
Over the last 20 years, intensive investigation and multiple clinical successes targeting protein kinases, mostly for cancer treatment, have identified small molecule kinase inhibitors as a prominent therapeutic class. In the course of those investigations, radiolabeled kinase inhibitors for positron emission tomography (PET) imaging have been synthesized and evaluated as diagnostic imaging probes for cancer characterization. Given that inhibitor coverage of the kinome is continuously expanding, in vivo PET imaging will likely find increasing applications for therapy monitoring and receptor density studies both in- and outside of oncological conditions. Early investigated radiolabeled inhibitors, which are mostly based on clinically approved tyrosine kinase inhibitor (TKI) isotopologues, have now entered clinical trials. Novel radioligands for cancer and PET neuroimaging originating from novel but relevant target kinases are currently being explored in preclinical studies. This article reviews the literature involving radiotracer design, radiochemistry approaches, biological tracer evaluation and nuclear imaging results of radiolabeled kinase inhibitors for PET reported between 2010 and mid-2015. Aspects regarding the usefulness of pursuing selective vs. promiscuous inhibitor scaffolds and the inherent challenges associated with intracellular enzyme imaging will be discussed.
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Abstract
Targeted therapy is gaining prominence in the management of different cancers. Given different mechanism of action compared with traditional chemoradiotherapy, selection of patients for targeted therapy and monitoring response to these agents is difficult with conventional imaging. Various new PET radiopharmaceuticals have been evaluated for molecular imaging of these targets to achieve specific patient selection and response monitoring. These PET/computed tomography (CT) agents target the cell surface receptors, hormone receptors, receptor tyrosine kinases, or angiogenesis components. This article reviews the established and potential role of PET/CT with new radiopharmaceuticals for guiding targeted therapy.
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Theragnostic imaging using radiolabeled antibodies and tyrosine kinase inhibitors. ScientificWorldJournal 2015; 2015:842101. [PMID: 25874259 PMCID: PMC4385703 DOI: 10.1155/2015/842101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/22/2014] [Accepted: 08/22/2014] [Indexed: 01/22/2023] Open
Abstract
During the past decade, the efficacy of new molecular targeted drugs such as tyrosine kinase inhibitors (TKIs) and monoclonal antibodies has been proven worldwide, and molecular targeted therapies have become the mainstream in cancer therapy. However, clinical use of these new drugs presents unexpected adverse effects or poor therapeutic effects. Therefore, we require diagnostic tools to estimate the target molecule status in cancer tissues and predict therapeutic efficacy and adverse effects. Although immunohistochemical, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) analyses of biopsy samples are conventional and popular for this diagnostic purpose, molecular imaging modalities such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) are also useful for noninvasive estimation of gene and protein expression and drug pharmacokinetics. In this review, we introduce new radiolabeled TKIs, antibodies, and their clinical application in molecular targeted therapy and discuss the issues of these imaging probes.
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Mammatas LH, Verheul HMW, Hendrikse NH, Yaqub M, Lammertsma AA, Menke-van der Houven van Oordt CW. Molecular imaging of targeted therapies with positron emission tomography: the visualization of personalized cancer care. Cell Oncol (Dordr) 2014; 38:49-64. [PMID: 25248503 DOI: 10.1007/s13402-014-0194-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2014] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION Molecular imaging has been defined as the visualization, characterization and measurement of biological processes at the molecular and cellular level in humans and other living systems. In oncology it enables to visualize (part of) the functional behaviour of tumour cells, in contrast to anatomical imaging that focuses on the size and location of malignant lesions. Available molecular imaging techniques include single photon emission computed tomography (SPECT), positron emission tomography (PET) and optical imaging. In PET, a radiotracer consisting of a positron emitting radionuclide attached to the biologically active molecule of interest is administrated to the patient. Several approaches have been undertaken to use PET for the improvement of personalized cancer care. For example, a variety of radiolabelled ligands have been investigated for intratumoural target identification and radiolabelled drugs have been developed for direct visualization of the biodistibution in vivo, including intratumoural therapy uptake. First indications of the clinical value of PET for target identification and response prediction in oncology have been reported. This new imaging approach is rapidly developing, but uniformity of scanning processes, standardized methods for outcome evaluation and implementation in daily clinical practice are still in progress. In this review we discuss the available literature on molecular imaging with PET for personalized targeted treatment strategies. CONCLUSION Molecular imaging with radiolabelled targeted anticancer drugs has great potential for the improvement of personalized cancer care. The non-invasive quantification of drug accumulation in tumours and normal tissues provides understanding of the biodistribution in relation to therapeutic and toxic effects.
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Affiliation(s)
- Lemonitsa H Mammatas
- Dept of Medical Oncology VUmc Cancer Center Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
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Wang M, Gao M, Zheng QH. The first radiosynthesis of [ 11 C]AZD8931 as a new potential PET agent for imaging of EGFR, HER2 and HER3 signaling. Bioorg Med Chem Lett 2014; 24:4455-4459. [DOI: 10.1016/j.bmcl.2014.07.092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 11/26/2022]
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Visualization of angiogenesis during cancer development in the polyoma middle T breast cancer model: molecular imaging with (R)-[11C]PAQ. EJNMMI Res 2014; 4:17. [PMID: 24670127 PMCID: PMC3986910 DOI: 10.1186/2191-219x-4-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/16/2014] [Indexed: 01/08/2023] Open
Abstract
Background Vascular endothelial growth factor receptor 2 (VEGFR2) is a crucial mediator of tumour angiogenesis. High expression levels of the receptor have been correlated to poor prognosis in cancer patients. Reliable imaging biomarkers for stratifying patients for anti-angiogenic therapy could therefore be valuable for increasing treatment success rates. The aim of this study was to investigate the pharmacokinetics and angiogenesis imaging abilities of the VEGFR2-targeting positron emission tomography (PET) tracer (R)-[11C]PAQ. Methods (R)-[11C]PAQ was evaluated in the mouse mammary tumour virus-polyoma middle T (MMTV-PyMT) model of metastatic breast cancer. Mice at different stages of disease progression were imaged with (R)-[11C]PAQ PET, and results were compared to those obtained with [18 F]FDG PET and magnetic resonance imaging. (R)-[11C]PAQ uptake levels were also compared to ex vivo immunofluorescence analysis of tumour- and angiogenesis-specific biomarkers. Additional pharmacokinetic studies were performed in rat and mouse. Results A heterogeneous uptake of (R)-[11C]PAQ was observed in the tumorous mammary glands. Ex vivo analysis confirmed the co-localization of areas with high radioactivity uptake and areas with elevated levels of VEGFR2. In some animals, a high focal uptake was observed in the lungs. The lung uptake correlated to metastatic and angiogenic activity, but not to uptake of [18 F]FDG PET. The pharmacokinetic studies revealed a limited metabolism and excretion during the 1-h scan and a distribution of radioactivity mainly to the liver, kidneys and lungs. In rat, a high uptake was additionally observed in adrenal and parathyroid glands. Conclusion The results indicate that (R)-[11C]PAQ is a promising imaging biomarker for visualization of angiogenesis, based on VEGFR2 expression, in primary tumours and during metastasis development.
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Radiosynthesis of 10-(2-[18F]fluoroethoxy)-20(S)-camptothecin as a potential positron emission tomography tracer for the imaging of topoisomerase I in cancers. J Radioanal Nucl Chem 2013. [DOI: 10.1007/s10967-013-2862-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Synthesis of (Z)-2-((1H-indazol-3-yl)methylene)-6-[11C]methoxy-7-(piperazin-1-ylmethyl)benzofuran-3(2H)-one as a new potential PET probe for imaging of the enzyme PIM1. Bioorg Med Chem Lett 2013; 23:4342-6. [DOI: 10.1016/j.bmcl.2013.05.091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 05/22/2013] [Accepted: 05/28/2013] [Indexed: 12/23/2022]
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Wang M, Gao M, Miller KD, Zheng QH. Synthesis of 2,6-difluoro-N-(3-[11C]methoxy-1H-pyrazolo[3,4-b]pyridine-5-yl)-3-(propylsulfonamidio)benzamide as a new potential PET agent for imaging of B-RafV600E in cancers. Bioorg Med Chem Lett 2013; 23:1017-21. [DOI: 10.1016/j.bmcl.2012.12.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 11/27/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
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The first synthesis of [11C]J147, a new potential PET agent for imaging of Alzheimer’s disease. Bioorg Med Chem Lett 2013; 23:524-7. [DOI: 10.1016/j.bmcl.2012.11.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 10/27/2012] [Accepted: 11/07/2012] [Indexed: 11/23/2022]
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Prabhakaran J, Arango V, Majo VJ, Simpson NR, Kassir SA, Underwood MD, Polavarapu H, Bruce JN, Canoll P, Mann JJ, Kumar JSD. Synthesis and in vitro evaluation of [18F](R)-FEPAQ: a potential PET ligand for VEGFR2. Bioorg Med Chem Lett 2012; 22:5104-7. [PMID: 22749281 PMCID: PMC4818572 DOI: 10.1016/j.bmcl.2012.05.099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 05/25/2012] [Accepted: 05/29/2012] [Indexed: 12/19/2022]
Abstract
Synthesis and in vitro evaluation of [(18)F](R)-N-(4-bromo-2-fluorophenyl)-7-((1-(2-fluoroethyl)piperidin-3-yl)methoxy)-6-methoxyquinazolin-4-amine ((R)-[(18)F]FEPAQ or [(18)F]1), a potential imaging agent for the VEGFR2, using phosphor image autoradiography are described. Synthesis of 2, the desfluoroethyl precursor for (R)-FEPAQ was achieved from t-butyl 3-(hydroxymethyl)piperidine-1-carboxylate (3) in five steps and in 50% yield. [(18)F]1 was synthesized by reaction of sodium salt of compound 2 with [(18)F]fluoroethyl tosylate in DMSO. The yield of [(18)F]1 was 20% (EOS based on [(18)F]F(-)) with >99% radiochemical purity and specific activity of 1-2 Ci/μmol (n=10). The total synthesis time was 75 min. The radiotracer selectively labeled VEGFR2 in slide-mounted sections of human brain and higher binding was found in surgically removed human glioblastoma sections as demonstrated by in vitro phosphor imager studies. These findings suggest [(18)F]1 may be a promising radiotracer for imaging VEGFR2 in brain using PET.
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Affiliation(s)
- Jaya Prabhakaran
- Division of Molecular Imaging and Neuropathology, Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York, USA.
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Slobbe P, Poot AJ, Windhorst AD, van Dongen GAMS. PET imaging with small-molecule tyrosine kinase inhibitors: TKI-PET. Drug Discov Today 2012; 17:1175-87. [PMID: 22766374 DOI: 10.1016/j.drudis.2012.06.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/18/2012] [Accepted: 06/21/2012] [Indexed: 12/20/2022]
Abstract
The discovery and increased understanding of tumor targets has led to the development and approval of 12 small molecule tyrosine kinase inhibitors (TKIs). Despite tremendous efforts in TKI development, treatment efficacies with these therapeutics are still too low and improvements require a personalized medicine approach. Positron emission tomography (PET) with radiolabeled TKIs (TKI-PET) is a tracking, quantification and imaging method, which provides a unique understanding of the behavior of these drugs in vivo and of the interaction with their target(s). In this article we provide an overview of tracer synthesis and development because each TKI requires a tailor made approach. Moreover, we describe current preclinical work and the first proof-of-principle clinical studies on the application of TKI-PET, illustrating the potential of this approach for improving therapy efficacy and personalized cancer treatment.
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Affiliation(s)
- Paul Slobbe
- Department of Nuclear Medicine and PET Research, VU University Medical Center, Amsterdam, The Netherlands.
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Wang H, Gao H, Guo N, Niu G, Ma Y, Kiesewetter DO, Chen X. Site-Specific Labeling of scVEGF with Fluorine-18 for Positron Emission Tomography Imaging. Theranostics 2012; 2:607-17. [PMID: 22768028 PMCID: PMC3388593 DOI: 10.7150/thno.4611] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 06/01/2012] [Indexed: 11/06/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is one of the most important mediators of angiogenesis. Single-chain (sc)-VEGF protein containing an N-terminal Cys-tag has been designed for site-specific modification with a variety of imaging and therapeutic moieties. Site-specific labeling of scVEGF with thiol-reactive prosthetic group, N-[2-(4-18F-fluorobenzamido) ethyl] maleimide ([18F]FBEM) for positron emission tomography (PET) imaging of VEFGR may provide a new tracer which has great potential for clinical translation. Methods: [18F]FBEM-scVEGF was synthesized by site-specific conjugation of 18F-FBEM to a thiol group in Cys-tag of scVEGF at room temperature. The functional activity after labeling was tested by immunofluorescence staining, cellular uptake and efflux. The tumor targeting and in vivo properties were evaluated by biodistribution and microPET studies in tumor-bearing mice. Results: The radiolabeling yield and specific activity of [18F]FBEM-scVEGF were 20.6 ± 15.1% (based on starting [18F]FBEM, uncorrected, n = 5) and 58.8 ± 12.4 GBq/µmol, respectively. Noninvasive microPET and direct tissue sampling experiments demonstrated that [18F]FBEM-scVEGF had VEGFR specific tumor uptake in MDA-MB-435, U87MG and 4T1 xenograft models. The optimal tumor uptake was achieved at 2 h p.i., which can be partially, but significantly blocked by co-injection of non-labeled scVEGF protein. Overall, [18F]FBEM-scVEGF showed VEGFR specific tumor uptake. Conclusion: The scVEGF was site-specifically labeled with 18F via [18F]FBEM prosthetic group and the tracer [18F]FBEM-scVEGF exhibited high receptor binding affinity and tumor targeting efficacy. Further study of [18F] FBEM-scVEGF to evaluate angiogenesis in cancer and other disease types is warranted.
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Abstract
Angiogenesis is a fundamental requirement for tumor growth and therefore it is a primary target for anti-cancer therapy. Molecular imaging of angiogenesis may provide novel opportunities for early diagnostic and for image-guided optimization and management of therapeutic regimens. Here we reviewed the advances in targeted imaging of key biomarkers of tumor angiogenesis, integrins and receptors for vascular endothelial growth factor (VEGF). Tracers for targeted imaging of these biomarkers in different imaging modalities are now reasonably well-developed and PET tracers for integrin imaging are currently in clinical trials. Molecular imaging of longitudinal responses to anti-angiogenic therapy in model tumor systems revealed a complex pattern of changes in targeted tracer accumulation in tumor, which reflects drug-induced tumor regression followed by vascular rebound. Further work will define the competitiveness of targeted imaging of key angiogenesis markers for early diagnostic and image-guided therapy.
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Backer MV, Backer JM. Imaging key biomarkers of tumor angiogenesis. Theranostics 2012; 2:502-15. [PMID: 22737188 PMCID: PMC3364556 DOI: 10.7150/thno.3623] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 01/07/2012] [Indexed: 11/05/2022] Open
Abstract
Angiogenesis is a fundamental requirement for tumor growth and therefore it is a primary target for anti-cancer therapy. Molecular imaging of angiogenesis may provide novel opportunities for early diagnostic and for image-guided optimization and management of therapeutic regimens. Here we reviewed the advances in targeted imaging of key biomarkers of tumor angiogenesis, integrins and receptors for vascular endothelial growth factor (VEGF). Tracers for targeted imaging of these biomarkers in different imaging modalities are now reasonably well-developed and PET tracers for integrin imaging are currently in clinical trials. Molecular imaging of longitudinal responses to anti-angiogenic therapy in model tumor systems revealed a complex pattern of changes in targeted tracer accumulation in tumor, which reflects drug-induced tumor regression followed by vascular rebound. Further work will define the competitiveness of targeted imaging of key angiogenesis markers for early diagnostic and image-guided therapy.
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