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Gaspar N, Handula M, Stroet MCM, Marella-Panth K, Haeck J, Kirkland TA, Hall MP, Encell LP, Dalm S, Lowik C, Seimbille Y, Mezzanotte L. A Novel Luciferase-Based Reporter Gene Technology for Simultaneous Optical and Radionuclide Imaging of Cells. Int J Mol Sci 2024; 25:8206. [PMID: 39125775 PMCID: PMC11312113 DOI: 10.3390/ijms25158206] [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: 06/13/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 08/12/2024] Open
Abstract
Multimodality reporter gene imaging combines the sensitivity, resolution and translational potential of two or more signals. The approach has not been widely adopted by the animal imaging community, mainly because its utility in this area is unproven. We developed a new complementation-based reporter gene system where the large component of split NanoLuc luciferase (LgBiT) presented on the surface of cells (TM-LgBiT) interacts with a radiotracer consisting of the high-affinity complementary HiBiT peptide labeled with a radionuclide. Radiotracer uptake could be imaged in mice using SPECT/CT and bioluminescence within two hours of implanting reporter-gene-expressing cells. Imaging data were validated by ex vivo biodistribution studies. Following the demonstration of complementation between the TM-LgBiT protein and HiBiT radiotracer, we validated the use of the technology in the highly specific in vivo multimodal imaging of cells. These findings highlight the potential of this new approach to facilitate the advancement of cell and gene therapies from bench to clinic.
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Affiliation(s)
- Natasa Gaspar
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
- Department of Molecular Genetics, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Maryana Handula
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Marcus C. M. Stroet
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
- Department of Molecular Genetics, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Kranthi Marella-Panth
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
- Department of Molecular Genetics, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Joost Haeck
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | | | | | | | - Simone Dalm
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Clemens Lowik
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Yann Seimbille
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
| | - Laura Mezzanotte
- Department of Radiology and Nuclear Medicine, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
- Department of Molecular Genetics, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands
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Bowden GD, Stotz S, Dunkel G, Haas S, Kimmerle E, Schaller M, Weigelin B, Herfert K, Pichler BJ, Maurer A. [ 18F] pFBC, a Covalent CLIP-Tag Radiotracer for Detection of Viral Reporter Gene Transfer in the Murine Brain. Bioconjug Chem 2024; 35:254-264. [PMID: 38308817 DOI: 10.1021/acs.bioconjchem.3c00551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024]
Abstract
Preclinical models of neurological diseases and gene therapy are essential for neurobiological research. However, the evaluation of such models lacks reliable reporter systems for use with noninvasive imaging methods. Here, we report the development of a reporter system based on the CLIP-tag enzyme and [18F]pFBC, an 18F-labeled covalent CLIP-tag-ligand synthesized via a DoE-optimized and fully automated process. We demonstrated its specificity using a subcutaneous xenograft model and a model of viral vector-mediated brain gene transfer by engineering HEK293 cells and striatal neurons to express membrane-tethered CLIP-tag protein. After in vitro characterization of the reporter, mice carrying either CLIP-tag expressing or control subcutaneous xenografts underwent dynamic [18F]pFBC PET imaging. The CLIP-tag expressing xenografts showed a significantly higher uptake than control xenografts (tumor-to-muscle ratio 5.0 vs 1.7, p = 0.0379). In vivo, metabolite analysis by radio-HPLC from plasma and brain homogenates showed only one radio-metabolite in plasma and none in the brain. In addition, [18F]pFBC showed fast uptake and rapid clearance from the brain in animals injected with adeno-associated virus (AAV)-CLIP in the right striatum but no right-to-left (R-L) uptake difference in the striata in the acquired PET data. In contrast, autoradiography showed a clear accumulation of radioactivity in the AAV-CLIP-injected right striatum compared to the sham-injected left striatum control. CLIP-tag expression and brain integrity were verified by immunofluorescence and light sheet microscopy. In conclusion, we established a novel reporter gene system for PET imaging of gene expression in the brain and periphery and demonstrated its potential for a wide range of applications, particularly for neurobiological research and gene therapy with viral vectors.
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Affiliation(s)
- Gregory D Bowden
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
| | - Sophie Stotz
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
| | - Gina Dunkel
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
| | - Sabrina Haas
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
| | - Elena Kimmerle
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
| | - Martin Schaller
- Department of Dermatology, University Hospital Tuebingen, 72076 Tuebingen, Germany
| | - Bettina Weigelin
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
| | - Kristina Herfert
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
| | - Bernd J Pichler
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
| | - Andreas Maurer
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72076 Tuebingen, Germany
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3
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Nerella SG, Telu S, Liow JS, Jenkins MD, Zoghbi SS, Gomez JL, Michaelides M, Eldridge MAG, Richmond BJ, Innis RB, Pike VW. Synthesis and preclinical evaluation of [ 11C]uPSEM792 for PSAM 4-GlyR based chemogenetics. Sci Rep 2024; 14:1886. [PMID: 38253691 PMCID: PMC10803328 DOI: 10.1038/s41598-024-51307-0] [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: 07/03/2023] [Accepted: 01/01/2024] [Indexed: 01/24/2024] Open
Abstract
Chemogenetic tools are designed to control neuronal signaling. These tools have the potential to contribute to the understanding of neuropsychiatric disorders and to the development of new treatments. One such chemogenetic technology comprises modified Pharmacologically Selective Actuator Modules (PSAMs) paired with Pharmacologically Selective Effector Molecules (PSEMs). PSAMs are receptors with ligand-binding domains that have been modified to interact only with a specific small-molecule agonist, designated a PSEM. PSAM4 is a triple mutant PSAM derived from the α7 nicotinic receptor (α7L131G,Q139L,Y217F). Although having no constitutive activity as a ligand-gated ion channel, PSAM4 has been coupled to the serotonin 5-HT3 receptor (5-HT3R) and to the glycine receptor (GlyR). Treatment with the partner PSEM to activate PSAM4-5-HT3 or PSAM4-GlyR, causes neuronal activation or silencing, respectively. A suitably designed radioligand may enable selective visualization of the expression and location of PSAMs with positron emission tomography (PET). Here, we evaluated uPSEM792, an ultrapotent PSEM for PSAM4-GlyR, as a possible lead for PET radioligand development. We labeled uPSEM792 with the positron-emitter, carbon-11 (t1/2 = 20.4 min), in high radiochemical yield by treating a protected precursor with [11C]iodomethane followed by base deprotection. PET experiments with [11C]uPSEM792 in rodents and in a monkey transduced with PSAM4-GlyR showed low peak radioactivity uptake in brain. This low uptake was probably due to high polarity of the radioligand, as evidenced by physicochemical measurements, and to the vulnerability of the radioligand to efflux transport at the blood-brain barrier. These findings can inform the design of a more effective PSAM4 based PET radioligand, based on the uPSEM792 chemotype.
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Affiliation(s)
- Sridhar Goud Nerella
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Madeline D Jenkins
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Barry J Richmond
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
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4
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Chung T, Merrill JR, Lyons SK. CRISPR/Cas for PET Reporter Gene Engineering. Methods Mol Biol 2024; 2729:285-301. [PMID: 38006503 DOI: 10.1007/978-1-0716-3499-8_17] [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] [Indexed: 11/27/2023]
Abstract
The relatively recent discovery of CRISPR/Cas has led to a revolution in our ability to efficiently manipulate the genome of eukaryotic cells. We describe here a protocol that employs CRISPR technology to precisely knock-in a PET imaging reporter transgene into a specific genetic locus of interest. Resulting transcription of the targeted reporter will more accurately mimic physiologic expression of the endogenous allele than conventional approaches, and so this method has the potential to become an efficient way to generate a new generation of "gold-standard" reporter transgenes. We break down the protocol into three experimental stages: how to identify the genomic location that the reporter transgene will be inserted, how to practically insert the reporter transgene into the genome, and how to screen resultant clones for the correct targeted event.
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Affiliation(s)
- Taemoon Chung
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | | | - Scott K Lyons
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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Nerella SG, Michaelides M, Minamimoto T, Innis RB, Pike VW, Eldridge MAG. PET reporter systems for the brain. Trends Neurosci 2023; 46:941-952. [PMID: 37734962 PMCID: PMC10592100 DOI: 10.1016/j.tins.2023.08.007] [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: 04/04/2023] [Revised: 07/18/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023]
Abstract
Positron emission tomography (PET) can be used as a noninvasive method to longitudinally monitor and quantify the expression of proteins in the brain in vivo. It can be used to monitor changes in biomarkers of mental health disorders, and to assess therapeutic interventions such as stem cell and molecular genetic therapies. The utility of PET monitoring depends on the availability of a radiotracer with good central nervous system (CNS) penetration and high selectivity for the target protein. This review evaluates existing methods for the visualization of reporter proteins and/or protein function using PET imaging, focusing on engineered systems, and discusses possible approaches for future success in the development of high-sensitivity and high-specificity PET reporter systems for the brain.
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Affiliation(s)
- Sridhar Goud Nerella
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Takafumi Minamimoto
- Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
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6
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Ajenjo J, Seo JW, Foiret J, Wu B, Raie MN, Wang J, Fite BZ, Zhang N, Malek R, Beinat C, Malik N, Anders DA, Ferrara KW. PET imaging of focused-ultrasound enhanced delivery of AAVs into the murine brain. Theranostics 2023; 13:5151-5169. [PMID: 37908737 PMCID: PMC10614693 DOI: 10.7150/thno.85549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 09/19/2023] [Indexed: 11/02/2023] Open
Abstract
Rationale: Despite recent advances in the use of adeno-associated viruses (AAVs) as potential vehicles for genetic intervention of central and peripheral nervous system-associated disorders, gene therapy for the treatment of neuropathology in adults has not been approved to date. The currently FDA-approved AAV-vector based gene therapies rely on naturally occurring serotypes, such as AAV2 or AAV9, which display limited or no transport across the blood-brain barrier (BBB) if systemically administered. Recently developed engineered AAV variants have shown broad brain transduction and reduced off-target liver toxicity in non-human primates (NHPs). However, these vectors lack spatial selectivity for targeted gene delivery, a potentially critical limitation for delivering therapeutic doses in defined areas of the brain. The use of microbubbles, in conjunction with focused ultrasound (FUS), can enhance regional brain AAV transduction, but methods to assess transduction in vivo are needed. Methods: In a murine model, we combined positron emission tomography (PET) and optical imaging of reporter gene payloads to non-invasively assess the spatial distribution and transduction efficiency of systemically administered AAV9 after FUS and microbubble treatment. Capsid and reporter probe accumulation are reported as percent injected dose per cubic centimeter (%ID/cc) for in vivo PET quantification, whereas results for ex vivo assays are reported as percent injected dose per gram (%ID/g). Results: In a study spanning accumulation and transduction, mean AAV9 accumulation within the brain was 0.29 %ID/cc without FUS, whereas in the insonified region of interest of FUS-treated mice, the spatial mean and maximum reached ~2.3 %ID/cc and 4.3 %ID/cc, respectively. Transgene expression assessed in vivo by PET reporter gene imaging employing the pyruvate kinase M2 (PKM2)/[18F]DASA-10 reporter system increased up to 10-fold in the FUS-treated regions, as compared to mice receiving AAVs without FUS. Systemic injection of AAV9 packaging the EF1A-PKM2 transgene followed by FUS in one hemisphere resulted in 1) an average 102-fold increase in PKM2 mRNA concentration compared to mice treated with AAVs only and 2) a 12.5-fold increase in the insonified compared to the contralateral hemisphere of FUS-treated mice. Conclusion: Combining microbubbles with US-guided treatment facilitated a multi-hour BBB disruption and stable AAV transduction in targeted areas of the murine brain. This unique platform has the potential to provide insight and aid in the translation of AAV-based therapies for the treatment of neuropathologies.
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Affiliation(s)
- Javier Ajenjo
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Jai Woong Seo
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Josquin Foiret
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bo Wu
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Marina Nura Raie
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - James Wang
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Brett Zain Fite
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Nisi Zhang
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Rim Malek
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Corinne Beinat
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Noeen Malik
- Stanford Cyclotron & Radiochemistry Facility (CRF), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - David Alexander Anders
- Stanford Cyclotron & Radiochemistry Facility (CRF), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Katherine W. Ferrara
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
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Kendirli MT, Malek R, Silveira MB, Acosta C, Zhang S, Azevedo C, Nagy SC, Habte F, James ML, Recht LD, Beinat C. Development of [ 18F]DASA-10 for enhanced imaging of pyruvate kinase M2. Nucl Med Biol 2023; 124-125:108382. [PMID: 37634399 PMCID: PMC10843576 DOI: 10.1016/j.nucmedbio.2023.108382] [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: 07/18/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 08/29/2023]
Abstract
PURPOSE The aim of this study was to develop a positron emission tomography (PET) radiotracer for measuring pyruvate kinase M2 (PKM2) with improved physicochemical and pharmacokinetic properties compared to [18F]DASA-23. EXPERIMENTAL DESIGN First, we synthesized [18F]DASA-10 and tested its uptake and retention compared to [18F]DASA-23 in human and mouse glioma cell lines. We then confirmed the specificity of [18F]DASA-10 by transiently modulating the expression of PKM2 in DU145 and HeLa cells. Next, we determined [18F]DASA-10 pharmacokinetics in healthy nude mice using PET imaging and subsequently assessed the ability of [18F]DASA-10 versus [18F]DASA-23 to enable in vivo detection of intracranial gliomas in syngeneic C6 rat models of glioma. RESULTS [18F]DASA-10 demonstrated excellent cellular uptake and retention with values significantly higher than [18F]DASA-23 in all cell lines and timepoints investigated. [18F]DASA-10 showed a 73 % and 65 % reduced uptake respectively in DU145 and HeLa cells treated with PKM2 siRNA as compared to control siRNA treated cells. [18F]DASA-10 showed favorable biodistribution and pharmacokinetic properties and a significantly improved tumor-to-brain ratio in rat C6 glioma models relative to [18F]DASA-23 (3.2 ± 0.8 versus 1.6 ± 0.3, p = 0.01). CONCLUSION [18F]DASA-10 is a new PET radiotracer for molecular imaging of PKM2 with potential to overcome the prior limitations observed with [18F]DASA-23. [18F]DASA-10 shows promise for clinical translation to enable imaging of brain malignancies owing to its low background signal in the healthy brain.
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Affiliation(s)
- Mustafa T Kendirli
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 943065, USA
| | - Rim Malek
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Marina B Silveira
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA; Nuclear Technology Development Centre, National Nuclear Energy Commission, Belo Horizonte, MG 31270-901, Brazil
| | - Christopher Acosta
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Shuwen Zhang
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Carmen Azevedo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 943065, USA; Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Sydney C Nagy
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 943065, USA; Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Frezghi Habte
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Michelle L James
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 943065, USA; Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA
| | - Lawrence D Recht
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 943065, USA
| | - Corinne Beinat
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 943065, USA.
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8
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Combining CRISPR-Cas9 and brain imaging to study the link from genes to molecules to networks. Proc Natl Acad Sci U S A 2022; 119:e2122552119. [PMID: 36161926 DOI: 10.1073/pnas.2122552119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Receptors, transporters, and ion channels are important targets for therapy development in neurological diseases, but their mechanistic role in pathogenesis is often poorly understood. Gene editing and in vivo imaging approaches will help to identify the molecular and functional role of these targets and the consequence of their regional dysfunction on the whole-brain level. We combine CRISPR-Cas9 gene editing with in vivo positron emission tomography (PET) and functional MRI (fMRI) to investigate the direct link between genes, molecules, and the brain connectome. The extensive knowledge of the Slc18a2 gene encoding the vesicular monoamine transporter (VMAT2), involved in the storage and release of dopamine, makes it an excellent target for studying the gene network relationships while structurally preserving neuronal integrity and function. We edited the Slc18a2 in the substantia nigra pars compacta of adult rats and used in vivo molecular imaging besides behavioral, histological, and biochemical assessments to characterize the CRISPR-Cas9-mediated VMAT2 knockdown. Simultaneous PET/fMRI was performed to investigate molecular and functional brain alterations. We found that stage-specific adaptations of brain functional connectivity follow the selective impairment of presynaptic dopamine storage and release. Our study reveals that recruiting different brain networks is an early response to the dopaminergic dysfunction preceding neuronal cell loss. Our combinatorial approach is a tool to investigate the impact of specific genes on brain molecular and functional dynamics, which will help to develop tailored therapies for normalizing brain function.
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9
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Xie P, Ling H, Pang M, He L, Zhuang Z, Zhang G, Chen Z, Weng C, Cheng S, Jiao J, Zhao Z, Tang BZ, Rong L. Umbilical Cord Mesenchymal Stem Cells Promoting Spinal Cord Injury Repair Visually Monitored by AIE‐Tat Nanoparticles. ADVANCED THERAPEUTICS 2022. [DOI: 10.1002/adtp.202200076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Peigen Xie
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Haiqian Ling
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Mao Pang
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Lei He
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Zeyan Zhuang
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Guiling Zhang
- Department of Nuclear Medicine The Third Affiliated Hospital of Sun Yat‐sen University 600 Tianhe Road Guangzhou Guangdong 510630 China
| | - Zihao Chen
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Chuanggui Weng
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Sijin Cheng
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
| | - Ju Jiao
- Department of Nuclear Medicine The Third Affiliated Hospital of Sun Yat‐sen University 600 Tianhe Road Guangzhou Guangdong 510630 China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong Kong Shenzhen Guangdong 518172 China
| | - Limin Rong
- Department of Spine Surgery The Third Affiliated Hospital of Sun Yat‐sen University Guangzhou 510600 China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery Guangzhou 510600 China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery Guangzhou 510600 China
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10
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Seo JW, Ajenjo J, Wu B, Robinson E, Raie MN, Wang J, Tumbale SK, Buccino P, Anders DA, Shen B, Habte FG, Beinat C, James ML, Reyes ST, Ravindra Kumar S, Miles TF, Lee JT, Gradinaru V, Ferrara KW. Multimodal imaging of capsid and cargo reveals differential brain targeting and liver detargeting of systemically-administered AAVs. Biomaterials 2022; 288:121701. [PMID: 35985893 PMCID: PMC9621732 DOI: 10.1016/j.biomaterials.2022.121701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 07/23/2022] [Indexed: 11/27/2022]
Abstract
The development of gene delivery vehicles with high organ specificity when administered systemically is a critical goal for gene therapy. We combine optical and positron emission tomography (PET) imaging of 1) reporter genes and 2) capsid tags to assess the temporal and spatial distribution and transduction of adeno-associated viruses (AAVs). AAV9 and two engineered AAV vectors (PHP.eB and CAP-B10) that are noteworthy for maximizing blood-brain barrier transport were compared. CAP-B10 shares a modification in the 588 loop with PHP.eB, but also has a modification in the 455 loop, added with the goal of reducing off-target transduction. PET and optical imaging revealed that the additional modifications retained brain receptor affinity. In the liver, the accumulation of AAV9 and the engineered AAV capsids was similar (∼15% of the injected dose per cc and not significantly different between capsids at 21 h). However, the engineered capsids were primarily internalized by Kupffer cells rather than hepatocytes, and liver transduction was greatly reduced. PET reporter gene imaging after engineered AAV systemic injection provided a non-invasive method to monitor AAV-mediated protein expression over time. Through comparison with capsid tagging, differences between brain localization and transduction were revealed. In summary, AAV capsids bearing imaging tags and reporter gene payloads create a unique and powerful platform to assay the pharmacokinetics, cellular specificity and protein expression kinetics of AAV vectors in vivo, a key enabler for the field of gene therapy.
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Affiliation(s)
- Jai Woong Seo
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Javier Ajenjo
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bo Wu
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Elise Robinson
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Marina Nura Raie
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - James Wang
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Spencer K Tumbale
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Pablo Buccino
- Stanford Cyclotron & Radiochemistry Facility (CRF), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - David Alexander Anders
- Stanford Cyclotron & Radiochemistry Facility (CRF), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bin Shen
- Stanford Cyclotron & Radiochemistry Facility (CRF), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Frezghi G Habte
- Stanford Center for Innovation in In vivo Imaging (SCi3), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Corinne Beinat
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Michelle L James
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Samantha Taylor Reyes
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Sripriya Ravindra Kumar
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Timothy F Miles
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jason T Lee
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Katherine W Ferrara
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA.
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11
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Reporter Genes for Brain Imaging Using MRI, SPECT and PET. Int J Mol Sci 2022; 23:ijms23158443. [PMID: 35955578 PMCID: PMC9368793 DOI: 10.3390/ijms23158443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 01/14/2023] Open
Abstract
The use of molecular imaging technologies for brain imaging can not only play an important supporting role in disease diagnosis and treatment but can also be used to deeply study brain functions. Recently, with the support of reporter gene technology, optical imaging has achieved a breakthrough in brain function studies at the molecular level. Reporter gene technology based on traditional clinical imaging modalities is also expanding. By benefiting from the deeper imaging depths and wider imaging ranges now possible, these methods have led to breakthroughs in preclinical and clinical research. This article focuses on the applications of magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) reporter gene technologies for use in brain imaging. The tracking of cell therapies and gene therapies is the most successful and widely used application of these techniques. Meanwhile, breakthroughs have been achieved in the research and development of reporter genes and their imaging probe pairs with respect to brain function research. This paper introduces the imaging principles and classifications of the reporter gene technologies of these imaging modalities, lists the relevant brain imaging applications, reviews their characteristics, and discusses the opportunities and challenges faced by clinical imaging modalities based on reporter gene technology. The conclusion is provided in the last section.
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12
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Hegi-Johnson F, Rudd S, Hicks RJ, De Ruysscher D, Trapani JA, John T, Donnelly P, Blyth B, Hanna G, Everitt S, Roselt P, MacManus MP. Imaging immunity in patients with cancer using positron emission tomography. NPJ Precis Oncol 2022; 6:24. [PMID: 35393508 PMCID: PMC8989882 DOI: 10.1038/s41698-022-00263-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 02/24/2022] [Indexed: 12/26/2022] Open
Abstract
Immune checkpoint inhibitors and related molecules can achieve tumour regression, and even prolonged survival, for a subset of cancer patients with an otherwise dire prognosis. However, it remains unclear why some patients respond to immunotherapy and others do not. PET imaging has the potential to characterise the spatial and temporal heterogeneity of both immunotherapy target molecules and the tumor immune microenvironment, suggesting a tantalising vision of personally-adapted immunomodulatory treatment regimens. Personalised combinations of immunotherapy with local therapies and other systemic therapies, would be informed by immune imaging and subsequently modified in accordance with therapeutically induced immune environmental changes. An ideal PET imaging biomarker would facilitate the choice of initial therapy and would permit sequential imaging in time-frames that could provide actionable information to guide subsequent therapy. Such imaging should provide either prognostic or predictive measures of responsiveness relevant to key immunotherapy types but, most importantly, guide key decisions on initiation, continuation, change or cessation of treatment to reduce the cost and morbidity of treatment while enhancing survival outcomes. We survey the current literature, focusing on clinically relevant immune checkpoint immunotherapies, for which novel PET tracers are being developed, and discuss what steps are needed to make this vision a reality.
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Affiliation(s)
- Fiona Hegi-Johnson
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
| | - Stacey Rudd
- Department of Chemistry, University of Melbourne, Melbourne, VIC, Australia
| | - Rodney J Hicks
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
- Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Dirk De Ruysscher
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joseph A Trapani
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Thomas John
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
- Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Paul Donnelly
- Department of Chemistry, University of Melbourne, Melbourne, VIC, Australia
| | - Benjamin Blyth
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
| | - Gerard Hanna
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
| | - Sarah Everitt
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
| | - Peter Roselt
- Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Michael P MacManus
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.
- The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia.
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13
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NRM 2021 Abstract Booklet. J Cereb Blood Flow Metab 2021; 41:11-309. [PMID: 34905986 PMCID: PMC8851538 DOI: 10.1177/0271678x211061050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Beinat C, Patel CB, Haywood T, Murty S, Naya L, Castillo JB, Reyes ST, Phillips M, Buccino P, Shen B, Park JH, Koran MEI, Alam IS, James ML, Holley D, Halbert K, Gandhi H, He JQ, Granucci M, Johnson E, Liu DD, Uchida N, Sinha R, Chu P, Born DE, Warnock GI, Weissman I, Hayden-Gephart M, Khalighi M, Massoud TF, Iagaru A, Davidzon G, Thomas R, Nagpal S, Recht LD, Gambhir SS. A Clinical PET Imaging Tracer ([ 18F]DASA-23) to Monitor Pyruvate Kinase M2-Induced Glycolytic Reprogramming in Glioblastoma. Clin Cancer Res 2021; 27:6467-6478. [PMID: 34475101 PMCID: PMC8639752 DOI: 10.1158/1078-0432.ccr-21-0544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 07/15/2021] [Accepted: 08/30/2021] [Indexed: 01/10/2023]
Abstract
PURPOSE Pyruvate kinase M2 (PKM2) catalyzes the final step in glycolysis, a key process of cancer metabolism. PKM2 is preferentially expressed by glioblastoma (GBM) cells with minimal expression in healthy brain. We describe the development, validation, and translation of a novel PET tracer to study PKM2 in GBM. We evaluated 1-((2-fluoro-6-[18F]fluorophenyl)sulfonyl)-4-((4-methoxyphenyl)sulfonyl)piperazine ([18F]DASA-23) in cell culture, mouse models of GBM, healthy human volunteers, and patients with GBM. EXPERIMENTAL DESIGN [18F]DASA-23 was synthesized with a molar activity of 100.47 ± 29.58 GBq/μmol and radiochemical purity >95%. We performed initial testing of [18F]DASA-23 in GBM cell culture and human GBM xenografts implanted orthotopically into mice. Next, we produced [18F]DASA-23 under FDA oversight, and evaluated it in healthy volunteers and a pilot cohort of patients with glioma. RESULTS In mouse imaging studies, [18F]DASA-23 clearly delineated the U87 GBM from surrounding healthy brain tissue and had a tumor-to-brain ratio of 3.6 ± 0.5. In human volunteers, [18F]DASA-23 crossed the intact blood-brain barrier and was rapidly cleared. In patients with GBM, [18F]DASA-23 successfully outlined tumors visible on contrast-enhanced MRI. The uptake of [18F]DASA-23 was markedly elevated in GBMs compared with normal brain, and it identified a metabolic nonresponder within 1 week of treatment initiation. CONCLUSIONS We developed and translated [18F]DASA-23 as a new tracer that demonstrated the visualization of aberrantly expressed PKM2 for the first time in human subjects. These results warrant further clinical evaluation of [18F]DASA-23 to assess its utility for imaging therapy-induced normalization of aberrant cancer metabolism.
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Affiliation(s)
- Corinne Beinat
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California.
| | - Chirag B Patel
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Tom Haywood
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Surya Murty
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Lewis Naya
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Jessa B Castillo
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Samantha T Reyes
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Megan Phillips
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Pablo Buccino
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Bin Shen
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Jun Hyung Park
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Mary Ellen I Koran
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Stanford University, Stanford, California
| | - Israt S Alam
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Michelle L James
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Dawn Holley
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Kim Halbert
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Harsh Gandhi
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Joy Q He
- Stanford Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Monica Granucci
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California
| | - Eli Johnson
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California
| | - Daniel Dan Liu
- Stanford Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Nobuko Uchida
- Stanford Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Rahul Sinha
- Stanford Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Pauline Chu
- Stanford Human Research Histology Core, Stanford University School of Medicine, Stanford, California
| | - Donald E Born
- Department of Pathology, Neuropathology, Stanford University School of Medicine, Stanford, California
| | | | - Irving Weissman
- Stanford Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Melanie Hayden-Gephart
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California
| | - Mehdi Khalighi
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
| | - Tarik F Massoud
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
- Division of Neuroimaging and Neurointervention, Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Andrei Iagaru
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Stanford University, Stanford, California
| | - Guido Davidzon
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Stanford University, Stanford, California
| | - Reena Thomas
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Seema Nagpal
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Lawrence D Recht
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
| | - Sanjiv Sam Gambhir
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California
- Departments of Bioengineering and Materials Science & Engineering, Stanford University, Stanford, California
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15
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Shimojo M, Ono M, Takuwa H, Mimura K, Nagai Y, Fujinaga M, Kikuchi T, Okada M, Seki C, Tokunaga M, Maeda J, Takado Y, Takahashi M, Minamihisamatsu T, Zhang M, Tomita Y, Suzuki N, Maximov A, Suhara T, Minamimoto T, Sahara N, Higuchi M. A genetically targeted reporter for PET imaging of deep neuronal circuits in mammalian brains. EMBO J 2021; 40:e107757. [PMID: 34636430 PMCID: PMC8591537 DOI: 10.15252/embj.2021107757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 01/27/2023] Open
Abstract
Positron emission tomography (PET) allows biomolecular tracking but PET monitoring of brain networks has been hampered by a lack of suitable reporters. Here, we take advantage of bacterial dihydrofolate reductase, ecDHFR, and its unique antagonist, TMP, to facilitate in vivo imaging in the brain. Peripheral administration of radiofluorinated and fluorescent TMP analogs enabled PET and intravital microscopy, respectively, of neuronal ecDHFR expression in mice. This technique can be used to the visualize neuronal circuit activity elicited by chemogenetic manipulation in the mouse hippocampus. Notably, ecDHFR-PET allows mapping of neuronal projections in non-human primate brains, demonstrating the applicability of ecDHFR-based tracking technologies for network monitoring. Finally, we demonstrate the utility of TMP analogs for PET studies of turnover and self-assembly of proteins tagged with ecDHFR mutants. These results establish opportunities for a broad spectrum of previously unattainable PET analyses of mammalian brain circuits at the molecular level.
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Affiliation(s)
- Masafumi Shimojo
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Maiko Ono
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Hiroyuki Takuwa
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Koki Mimura
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yuji Nagai
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Masayuki Fujinaga
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Tatsuya Kikuchi
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Maki Okada
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Chie Seki
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Masaki Tokunaga
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Jun Maeda
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yuhei Takado
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Manami Takahashi
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Takeharu Minamihisamatsu
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Ming‐Rong Zhang
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yutaka Tomita
- Department of NeurologyKeio University School of MedicineTokyoJapan
| | - Norihiro Suzuki
- Department of NeurologyKeio University School of MedicineTokyoJapan
| | - Anton Maximov
- Department of NeuroscienceThe Scripps Research InstituteLa JollaCAUSA
| | - Tetsuya Suhara
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Takafumi Minamimoto
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Naruhiko Sahara
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Makoto Higuchi
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
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16
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Helfer BM, Ponomarev V, Patrick PS, Blower PJ, Feitel A, Fruhwirth GO, Jackman S, Pereira Mouriès L, Park MVDZ, Srinivas M, Stuckey DJ, Thu MS, van den Hoorn T, Herberts CA, Shingleton WD. Options for imaging cellular therapeutics in vivo: a multi-stakeholder perspective. Cytotherapy 2021; 23:757-773. [PMID: 33832818 PMCID: PMC9344904 DOI: 10.1016/j.jcyt.2021.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/01/2021] [Accepted: 02/13/2021] [Indexed: 12/13/2022]
Abstract
Cell-based therapies have been making great advances toward clinical reality. Despite the increase in trial activity, few therapies have successfully navigated late-phase clinical trials and received market authorization. One possible explanation for this is that additional tools and technologies to enable their development have only recently become available. To support the safety evaluation of cell therapies, the Health and Environmental Sciences Institute Cell Therapy-Tracking, Circulation and Safety Committee, a multisector collaborative committee, polled the attendees of the 2017 International Society for Cell & Gene Therapy conference in London, UK, to understand the gaps and needs that cell therapy developers have encountered regarding safety evaluations in vivo. The goal of the survey was to collect information to inform stakeholders of areas of interest that can help ensure the safe use of cellular therapeutics in the clinic. This review is a response to the cellular imaging interests of those respondents. The authors offer a brief overview of available technologies and then highlight the areas of interest from the survey by describing how imaging technologies can meet those needs. The areas of interest include imaging of cells over time, sensitivity of imaging modalities, ability to quantify cells, imaging cellular survival and differentiation and safety concerns around adding imaging agents to cellular therapy protocols. The Health and Environmental Sciences Institute Cell Therapy-Tracking, Circulation and Safety Committee believes that the ability to understand therapeutic cell fate is vital for determining and understanding cell therapy efficacy and safety and offers this review to aid in those needs. An aim of this article is to share the available imaging technologies with the cell therapy community to demonstrate how these technologies can accomplish unmet needs throughout the translational process and strengthen the understanding of cellular therapeutics.
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Affiliation(s)
| | - Vladimir Ponomarev
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - P Stephen Patrick
- Department of Medicine, Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Alexandra Feitel
- Formerly, Health and Environmental Sciences Institute, US Environmental Protection Agency, Washington, DC, USA
| | - Gilbert O Fruhwirth
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Shawna Jackman
- Charles River Laboratories, Shrewsbury, Massachusetts, USA
| | | | - Margriet V D Z Park
- Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - Mangala Srinivas
- Department of Tumor Immunology, Radboud University Medical Center, Nijmegen, the Netherlands; Cenya Imaging BV, Amsterdam, the Netherlands
| | - Daniel J Stuckey
- Department of Medicine, Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - Mya S Thu
- Visicell Medical Inc, La Jolla, California, USA
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17
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Sellmyer MA, Lee IK, Mankoff DA. Building the Bridge: Molecular Imaging Biomarkers for 21 st Century Cancer Therapies. J Nucl Med 2021; 62:jnumed.121.262484. [PMID: 34446450 PMCID: PMC8612205 DOI: 10.2967/jnumed.121.262484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/05/2021] [Accepted: 08/05/2021] [Indexed: 01/17/2023] Open
Abstract
Precision medicine, where the molecular underpinnings of the disease are assessed for tailored therapies, has greatly impacted cancer care. In parallel, a new pillar of therapeutics has emerged with profound success, including immunotherapies such as checkpoint inhibitors and cell-based therapies. Nonetheless, it remains essential to develop paradigms to predict and monitor for therapeutic response. Molecular imaging has the potential to add substantially to all phases of cancer patient care: predicative, companion diagnostics can illuminate therapeutic target density within a tumor, and pharmacodynamic imaging biomarkers can complement traditional modalities to judge a favorable treatment response. This "Focus on Molecular Imaging" article discusses the current role of molecular imaging in oncology and highlights an additional step in clinical paradigm termed a "therapeutic biomarker," which serves to assess whether next generation drugs reach their target to elicit a favorable clinical response.
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Affiliation(s)
- Mark A. Sellmyer
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Iris K. Lee
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David A. Mankoff
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
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18
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Fuchigami T, Haywood T, Gowrishankar G, Anders D, Namavari M, Wardak M, Gambhir SS. Synthesis and Characterization of 9-(4-[ 18F]Fluoro-3-(hydroxymethyl)butyl)-2-(phenylthio)-6-oxopurine as a Novel PET Agent for Mutant Herpes Simplex Virus Type 1 Thymidine Kinase Reporter Gene Imaging. Mol Imaging Biol 2021; 22:1151-1160. [PMID: 32691392 DOI: 10.1007/s11307-020-01517-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE [18F]FHBG has been used as a positron emission tomography (PET) imaging tracer for the monitoring of herpes simplex virus type 1 thymidine kinase (HSV1-tk), a reporter gene for cell and gene therapy in humans. However, this tracer shows inadequate blood-brain barrier (BBB) penetration and, therefore, would be limited for accurate quantification of reporter gene expression in the brain. Here, we report the synthesis and evaluation of 9-(4-[18F]fluoro-3-(hydroxymethyl)butyl)-2(phenylthio)-6-oxopurine ([18F]FHBT) as a new PET tracer for imaging reporter gene expression of HSV1-tk and its mutant HSV1-sr39tk, with the aim of improved BBB penetration. PROCEDURES [18F]FHBT was prepared by using a tosylate precursor and [18F]KF. The cellular uptake of [18F]FHBT was performed in HSV1-sr39tk-positive (+) or HSV1-sr39tk-negative (-) MDA-MB-231 breast cancer cells. The specificity of [18F]FHBT to assess HSV1-sr39tk expression was evaluated by in vitro blocking studies using 1 mM of ganciclovir (GCV). Penetration of [18F]FHBT and [18F]FHBG across the BBB was assessed by dynamic PET imaging studies in normal mice. RESULTS The tosylate precursor reacted with [18F]KF using Kryptofix2.2.2 followed by deprotection to give [18F]FHBT in 10 % radiochemical yield (decay-corrected). The uptake of [18F]FHBT in HSV1-sr39tk (+) cells was significantly higher than that of HSV1-sr39tk (-) cells. In the presence of GCV (1 mM), the uptake of [18F]FHBT was significantly decreased, indicating that [18F]FHBT serves as a selective substrate of HSV1-sr39TK. PET images and time-activity curves of [18F]FHBT in the brain regions showed similar initial brain uptakes (~ 12.75 min) as [18F]FHBG (P > 0.855). Slower washout of [18F]FHBT was observed at the later time points (17.75 - 57.75 min, P > 0.207). CONCLUSIONS Although [18F]FHBT showed no statistically significant improvement of BBB permeability compared with [18F]FHBG, we have demonstrated that the 2-(phenylthio)-6-oxopurine backbone can serve as a novel scaffold for developing HSV1-tk/HSV1-sr39tk reporter gene imaging agents for additional research in the future.
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Affiliation(s)
- Takeshi Fuchigami
- Department of Hygienic Chemistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.,Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - Tom Haywood
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - Gayatri Gowrishankar
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - David Anders
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - Mohammad Namavari
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - Mirwais Wardak
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA
| | - Sanjiv Sam Gambhir
- Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, 318 Campus Drive, Room E150A, Stanford, CA, 94305, USA. .,Department of Bioengineering and Materials Science & Engineering, Bio-X Program, Stanford University, 318 Campus Dr., Room E150 Stanford, Stanford, CA, 94305, USA.
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19
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Tian M, He X, Jin C, He X, Wu S, Zhou R, Zhang X, Zhang K, Gu W, Wang J, Zhang H. Transpathology: molecular imaging-based pathology. Eur J Nucl Med Mol Imaging 2021; 48:2338-2350. [PMID: 33585964 PMCID: PMC8241651 DOI: 10.1007/s00259-021-05234-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 02/01/2021] [Indexed: 12/27/2022]
Abstract
Pathology is the medical specialty concerned with the study of the disease nature and causes, playing a key role in bridging basic researches and clinical medicine. In the course of development, pathology has significantly expanded our understanding of disease, and exerted enormous impact on the management of patients. However, challenges facing pathology, the inherent invasiveness of pathological practice and the persistent concerns on the sample representativeness, constitute its limitations. Molecular imaging is a noninvasive technique to visualize, characterize, and measure biological processes at the molecular level in living subjects. With the continuous development of equipment and probes, molecular imaging has enabled an increasingly precise evaluation of pathophysiological changes. A new pathophysiology visualization system based on molecular imaging is forming and shows the great potential to reform the pathological practice. Several improvements in "trans-," including trans-scale, transparency, and translation, would be driven by this new kind of pathological practice. Pathological changes could be evaluated in a trans-scale imaging mode; tissues could be transparentized to better present the underlying pathophysiological information; and the translational processes of basic research to the clinical practice would be better facilitated. Thus, transpathology would greatly facilitate in deciphering the pathophysiological events in a multiscale perspective, and supporting the precision medicine in the future.
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Affiliation(s)
- Mei Tian
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China.
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China.
| | - Xuexin He
- Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Chentao Jin
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Xiao He
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Shuang Wu
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Rui Zhou
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Xiaohui Zhang
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Kai Zhang
- Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Weizhong Gu
- Department of Pathology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jing Wang
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Hong Zhang
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
- Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China.
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China.
- College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China.
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China.
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20
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Boehm MA, Bonaventura J, Gomez JL, Solís O, Stein EA, Bradberry CW, Michaelides M. Translational PET applications for brain circuit mapping with transgenic neuromodulation tools. Pharmacol Biochem Behav 2021; 204:173147. [PMID: 33549570 PMCID: PMC8297666 DOI: 10.1016/j.pbb.2021.173147] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 02/08/2023]
Abstract
Transgenic neuromodulation tools have transformed the field of neuroscience over the past two decades by enabling targeted manipulation of neuronal populations and circuits with unprecedented specificity. Chemogenetic and optogenetic neuromodulation systems are among the most widely used and allow targeted control of neuronal activity through the administration of a selective compound or light, respectively. Innovative genetic targeting strategies are utilized to transduce specific cells to express transgenic receptors and opsins capable of manipulating neuronal activity. These allow mapping of neuroanatomical projection sites and link cellular manipulations with brain circuit functions and behavior. As these tools continue to expand knowledge of the nervous system in preclinical models, developing translational applications for human therapies is becoming increasingly possible. However, new strategies for implementing and monitoring transgenic tools are needed for safe and effective use in translational research and potential clinical applications. A major challenge for such applications is the need to track the location and function of chemogenetic receptors and opsins in vivo, and new developments in positron emission tomography (PET) imaging techniques offer promising solutions. The goal of this review is to summarize current research combining transgenic tools with PET for in vivo mapping and manipulation of brain circuits and to propose future directions for translational applications.
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Affiliation(s)
- Matthew A Boehm
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States; Department of Neuroscience, Brown University, Providence, RI 02906, United States.
| | - Jordi Bonaventura
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Juan L Gomez
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Oscar Solís
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Elliot A Stein
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Charles W Bradberry
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Michael Michaelides
- National Institute on Drug Abuse Intramural Research Program, 251 Bayview Blvd, Baltimore, MD 21224, United States; Department of Psychiatry & Behavioral Sciences, Johns Hopkins Medicine, Baltimore, MD, 21205, United States.
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21
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Jacobs AH, Schelhaas S, Viel T, Waerzeggers Y, Winkeler A, Zinnhardt B, Gelovani J. Imaging of Gene and Cell-Based Therapies: Basis and Clinical Trials. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00060-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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22
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Tarantal AF. In Vivo Imaging and Gene Therapy: Monitoring Safety, Biodistribution, and Long-Term Expression with Positron Emission Tomography. Hum Gene Ther 2020; 31:1224-1225. [PMID: 33337271 DOI: 10.1089/hum.2020.29145.ata] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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23
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Ballon DJ, Rosenberg JB, Fung EK, Nikolopoulou A, Kothari P, De BP, He B, Chen A, Heier LA, Sondhi D, Kaminsky SM, Mozley PD, Babich JW, Crystal RG. Quantitative Whole-Body Imaging of I-124-Labeled Adeno-Associated Viral Vector Biodistribution in Nonhuman Primates. Hum Gene Ther 2020; 31:1237-1259. [PMID: 33233962 PMCID: PMC7769048 DOI: 10.1089/hum.2020.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/03/2020] [Indexed: 12/19/2022] Open
Abstract
A method is presented for quantitative analysis of the biodistribution of adeno-associated virus (AAV) gene transfer vectors following in vivo administration. We used iodine-124 (I-124) radiolabeling of the AAV capsid and positron emission tomography combined with compartmental modeling to quantify whole-body and organ-specific biodistribution of AAV capsids from 1 to 72 h following administration. Using intravenous (IV) and intracisternal (IC) routes of administration of AAVrh.10 and AAV9 vectors to nonhuman primates in the absence or presence of anticapsid immunity, we have identified novel insights into initial capsid biodistribution and organ-specific capsid half-life. Neither I-124-labeled AAVrh.10 nor AAV9 administered intravenously was detected at significant levels in the brain relative to the administered vector dose. Approximately 50% of the intravenously administered labeled capsids were dispersed throughout the body, independent of the liver, heart, and spleen. When administered by the IC route, the labeled capsid had a half-life of ∼10 h in the cerebral spinal fluid (CSF), suggesting that by this route, the CSF serves as a source with slow diffusion into the brain. For both IV and IC administration, there was significant influence of pre-existing anticapsid immunity on I-124-capsid biodistribution. The methodology facilitates quantitative in vivo viral vector dosimetry, which can serve as a technique for evaluation of both on- and off-target organ biodistribution, and potentially accelerate gene therapy development through rapid prototyping of novel vector designs.
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Affiliation(s)
- Douglas J. Ballon
- Department of Radiology, Citigroup Biomedical Imaging Center
- Department of Genetic Medicine
| | | | - Edward K. Fung
- Department of Radiology, Citigroup Biomedical Imaging Center
| | | | - Paresh Kothari
- Department of Radiology, Citigroup Biomedical Imaging Center
| | | | - Bin He
- Department of Radiology, Citigroup Biomedical Imaging Center
| | | | - Linda A. Heier
- Department of Radiology; Weill Cornell Medical College, New York, New York, USA
| | | | | | | | - John W. Babich
- Department of Radiology, Citigroup Biomedical Imaging Center
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24
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Serganova I, Blasberg RG. Molecular Imaging with Reporter Genes: Has Its Promise Been Delivered? J Nucl Med 2020; 60:1665-1681. [PMID: 31792128 DOI: 10.2967/jnumed.118.220004] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/18/2019] [Indexed: 12/20/2022] Open
Abstract
The first reporter systems were developed in the early 1980s and were based on measuring the activity of an enzyme-as a surrogate measure of promoter-driven transcriptional activity-which is now known as a reporter gene system. The initial objective and application of reporter techniques was to analyze the activity of a specific promoter (namely, the expression of a gene that is under the regulation of the specific promoter that is linked to the reporter gene). This system allows visualization of specific promoter activity with great sensitivity. In general, there are 2 classes of reporter systems: constitutively expressed (always-on) reporter constructs used for cell tracking, and inducible reporter systems sensitive to endogenous signaling molecules and transcription factors that characterize specific tissues, tumors, or signaling pathways.This review traces the development of different reporter systems, using fluorescent and bioluminescent proteins as well as radionuclide-based reporter systems. The development and application of radionuclide-based reporter systems is the focus of this review. The question at the end of the review is whether the "promise" of reporter gene imaging has been realized. What is required for moving forward with radionuclide-based reporter systems, and what is required for successful translation to clinical applications?
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Affiliation(s)
- Inna Serganova
- Department of Neurology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ronald G Blasberg
- Department of Neurology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York .,Department of Radiology, Memorial Hospital, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York; and.,Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York
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25
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Computationally Guided Intracerebral Drug Delivery via Chronically Implanted Microdevices. Cell Rep 2020; 31:107734. [PMID: 32521259 DOI: 10.1016/j.celrep.2020.107734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/24/2020] [Accepted: 05/13/2020] [Indexed: 11/21/2022] Open
Abstract
Treatments for neurologic diseases are often limited in efficacy due to poor spatial and temporal control over their delivery. Intracerebral delivery partially overcomes this by directly infusing therapeutics to the brain. Brain structures, however, are nonuniform and irregularly shaped, precluding complete target coverage by a single bolus without significant off-target effects and possible toxicity. Nearly complete coverage is crucial for effective modulation of these structures. We present a framework with computational mapping algorithms for neural drug delivery (COMMAND) to guide multi-bolus targeting of brain structures that maximizes coverage and minimizes off-target leakage. Custom-fabricated chronic neural implants leverage rational fluidic design to achieve multi-bolus delivery in rodents through a single infusion of radioactive tracer (Cu-64). The resulting spatial distributions replicate computed spatial coverage with 5% error in vivo, as detected by positron emission tomography. COMMAND potentially enables accurate, efficacious targeting of discrete brain regions.
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26
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Ashmore-Harris C, Iafrate M, Saleem A, Fruhwirth GO. Non-invasive Reporter Gene Imaging of Cell Therapies, including T Cells and Stem Cells. Mol Ther 2020; 28:1392-1416. [PMID: 32243834 PMCID: PMC7264441 DOI: 10.1016/j.ymthe.2020.03.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/15/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cell therapies represent a rapidly emerging class of new therapeutics. They are intended and developed for the treatment of some of the most prevalent human diseases, including cancer, diabetes, and for regenerative medicine. Currently, they are largely developed without precise assessment of their in vivo distribution, efficacy, or survival either clinically or preclinically. However, it would be highly beneficial for both preclinical cell therapy development and subsequent clinical use to assess these parameters in situ to enable enhancements in efficacy, applicability, and safety. Molecular imaging can be exploited to track cells non-invasively on the whole-body level and can enable monitoring for prolonged periods in a manner compatible with rapidly expanding cell types. In this review, we explain how in vivo imaging can aid the development and clinical translation of cell-based therapeutics. We describe the underlying principles governing non-invasive in vivo long-term cell tracking in the preclinical and clinical settings, including available imaging technologies, reporter genes, and imaging agents as well as pitfalls related to experimental design. Our emphasis is on adoptively transferred T cell and stem cell therapies.
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Affiliation(s)
- Candice Ashmore-Harris
- Imaging Therapy and Cancer Group, Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK; Centre for Stem Cells and Regenerative Medicine, School of Basic and Medical Biosciences, King's College London, London SE1 9RT, UK
| | - Madeleine Iafrate
- Imaging Therapy and Cancer Group, Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK
| | - Adeel Saleem
- Imaging Therapy and Cancer Group, Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, London SE1 9RT, UK; Department of Haematological Medicine, King's College Hospital, London SE5 9RS, UK
| | - Gilbert O Fruhwirth
- Imaging Therapy and Cancer Group, Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK.
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27
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Seo JW, Ingham ES, Mahakian L, Tumbale S, Wu B, Aghevlian S, Shams S, Baikoghli M, Jain P, Ding X, Goeden N, Dobreva T, Flytzanis NC, Chavez M, Singhal K, Leib R, James ML, Segal DJ, Cheng RH, Silva EA, Gradinaru V, Ferrara KW. Positron emission tomography imaging of novel AAV capsids maps rapid brain accumulation. Nat Commun 2020; 11:2102. [PMID: 32355221 PMCID: PMC7193641 DOI: 10.1038/s41467-020-15818-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 03/31/2020] [Indexed: 01/07/2023] Open
Abstract
Adeno-associated viruses (AAVs) are typically single-stranded deoxyribonucleic acid (ssDNA) encapsulated within 25-nm protein capsids. Recently, tissue-specific AAV capsids (e.g. PHP.eB) have been shown to enhance brain delivery in rodents via the LY6A receptor on brain endothelial cells. Here, we create a non-invasive positron emission tomography (PET) methodology to track viruses. To provide the sensitivity required to track AAVs injected at picomolar levels, a unique multichelator construct labeled with a positron emitter (Cu-64, t1/2 = 12.7 h) is coupled to the viral capsid. We find that brain accumulation of the PHP.eB capsid 1) exceeds that reported in any previous PET study of brain uptake of targeted therapies and 2) is correlated with optical reporter gene transduction of the brain. The PHP.eB capsid brain endothelial receptor affinity is nearly 20-fold greater than that of AAV9. The results suggest that novel PET imaging techniques can be applied to inform and optimize capsid design. Adeno-associated viruses (AAVs) can be targeted in a tissue-specific manner, but their tissue accumulation cannot be assessed in a non-invasive manner. Here the authors conjugate a multivalent chelator labelled with Cu-64 to the surface of AAVs and image the brain accumulation of the PHB.eB capsid by PET.
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Affiliation(s)
- Jai Woong Seo
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA.,Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Elizabeth S Ingham
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Lisa Mahakian
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Spencer Tumbale
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bo Wu
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Sadaf Aghevlian
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Shahin Shams
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Mo Baikoghli
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Poorva Jain
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Xiaozhe Ding
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nick Goeden
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tatyana Dobreva
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nicholas C Flytzanis
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Michael Chavez
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | - Ryan Leib
- Stanford University Mass Spectrometry, Stanford, CA, USA
| | - Michelle L James
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA
| | - David J Segal
- Genome Center and Department of Biochemistry and Molecular Medicine, University of California, Davis, CA, USA
| | - R Holland Cheng
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Eduardo A Silva
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Katherine W Ferrara
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA.
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28
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Iafrate M, Fruhwirth GO. How Non-invasive in vivo Cell Tracking Supports the Development and Translation of Cancer Immunotherapies. Front Physiol 2020; 11:154. [PMID: 32327996 PMCID: PMC7152671 DOI: 10.3389/fphys.2020.00154] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/12/2020] [Indexed: 12/26/2022] Open
Abstract
Immunotherapy is a relatively new treatment regimen for cancer, and it is based on the modulation of the immune system to battle cancer. Immunotherapies can be classified as either molecular or cell-based immunotherapies, and both types have demonstrated promising results in a growing number of cancers. Indeed, several immunotherapies representing both classes are already approved for clinical use in oncology. While spectacular treatment successes have been reported, particularly for so-called immune checkpoint inhibitors and certain cell-based immunotherapies, they have also been accompanied by a variety of severe, sometimes life-threatening side effects. Furthermore, not all patients respond to immunotherapy. Hence, there is the need for more research to render these promising therapeutics more efficacious, more widely applicable, and safer to use. Whole-body in vivo imaging technologies that can interrogate cancers and/or immunotherapies are highly beneficial tools for immunotherapy development and translation to the clinic. In this review, we explain how in vivo imaging can aid the development of molecular and cell-based anti-cancer immunotherapies. We describe the principles of imaging host T-cells and adoptively transferred therapeutic T-cells as well as the value of traceable cancer cell models in immunotherapy development. Our emphasis is on in vivo cell tracking methodology, including important aspects and caveats specific to immunotherapies. We discuss a variety of associated experimental design aspects including parameters such as cell type, observation times/intervals, and detection sensitivity. The focus is on non-invasive 3D cell tracking on the whole-body level including aspects relevant for both preclinical experimentation and clinical translatability of the underlying methodologies.
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Affiliation(s)
| | - Gilbert O. Fruhwirth
- Imaging Therapy and Cancer Group, Department of Imaging Chemistry and Biology, School of Biomedical Engineering & Imaging Sciences, King’s College London, London, United Kingdom
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29
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Human biodistribution and radiation dosimetry of [ 18F]DASA-23, a PET probe targeting pyruvate kinase M2. Eur J Nucl Med Mol Imaging 2020; 47:2123-2130. [PMID: 31938892 DOI: 10.1007/s00259-020-04687-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/05/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE To assess the safety, biodistribution, and radiation dosimetry of the novel positron emission tomography (PET) radiopharmaceutical 1-((2-fluoro-6-[[18F]]fluorophenyl)sulfonyl)-4-((4-methoxyphenyl)sulfonyl)piperazine ([18F]DASA-23) in healthy volunteers. METHODS We recruited 5 healthy volunteers who provided a written informed consent. Volunteers were injected with 295.0 ± 8.2 MBq of [18F]DASA-23 intravenously. Immediately following injection, a dynamic scan of the brain was acquired for 15 min. This was followed by serial whole-body PET/MRI scans acquired up to 3 h post-injection. Blood samples were collected at regular intervals, and vital signs monitored pre- and post-radiotracer administration. Regions of interest were drawn around multiple organs, time-activity curves were calculated, and organ uptake and dosimetry were estimated with OLINDA/EXM (version 1.1) software. RESULTS All subjects tolerated the PET/MRI examination, without adverse reactions to [18F]DASA-23. [18F]DASA-23 passively crossed the blood-brain barrier, followed by rapid clearance from the brain. High accumulation of [18F]DASA-23 was noted in organs such as the gallbladder, liver, small intestine, and urinary bladder, suggesting hepatobiliary and urinary clearance. The effective dose of [18F]DASA-23 was 23.5 ± 5.8 μSv/MBq. CONCLUSION We successfully completed a pilot first-in-human study of [18F]DASA-23. Our results indicate that [18F]DASA-23 can be used safely in humans to evaluate pyruvate kinase M2 levels. Ongoing studies are evaluating the ability of [18F]DASA-23 to visualize intracranial malignancies, NCT03539731. TRIAL REGISTRATION ClinicalTrials.gov , NCT03539731 (registered 28 May 2018).
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Krekorian M, Fruhwirth GO, Srinivas M, Figdor CG, Heskamp S, Witney TH, Aarntzen EH. Imaging of T-cells and their responses during anti-cancer immunotherapy. Theranostics 2019; 9:7924-7947. [PMID: 31656546 PMCID: PMC6814447 DOI: 10.7150/thno.37924] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 09/30/2019] [Indexed: 12/23/2022] Open
Abstract
Immunotherapy has proven to be an effective approach in a growing number of cancers. Despite durable clinical responses achieved with antibodies targeting immune checkpoint molecules, many patients do not respond. The common denominator for immunotherapies that have successfully been introduced in the clinic is their potential to induce or enhance infiltration of cytotoxic T-cells into the tumour. However, in clinical research the molecules, cells and processes involved in effective responses during immunotherapy remain largely obscure. Therefore, in vivo imaging technologies that interrogate T-cell responses in patients represent a powerful tool to boost further development of immunotherapy. This review comprises a comprehensive analysis of the in vivo imaging technologies that allow the characterisation of T-cell responses induced by anti-cancer immunotherapy, with emphasis on technologies that are clinically available or have high translational potential. Throughout we discuss their respective strengths and weaknesses, providing arguments for selecting the optimal imaging options for future research and patient management.
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Affiliation(s)
- Massis Krekorian
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Gilbert O. Fruhwirth
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, Kings' College London, London, United Kingdom
| | - Mangala Srinivas
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Carl G. Figdor
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Sandra Heskamp
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Timothy H. Witney
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, Kings' College London, London, United Kingdom
| | - Erik H.J.G. Aarntzen
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
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Affiliation(s)
| | - Pablo Bascuñana
- Department of Nuclear Medicine, Hannover Medical School, Germany
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