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Wongso H, Ono M, Yamasaki T, Kumata K, Higuchi M, Zhang MR, Fulham MJ, Katsifis A, Keller PA. Synthesis and structure-activity relationship (SAR) studies of 1,2,3-triazole, amide, and ester-based benzothiazole derivatives as potential molecular probes for tau protein. RSC Med Chem 2023; 14:858-868. [PMID: 37252097 PMCID: PMC10211319 DOI: 10.1039/d2md00358a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 01/24/2023] [Indexed: 01/04/2024] Open
Abstract
The pyridinyl-butadienyl-benzothiazole (PBB3 15) scaffold was used to develop tau ligands with improved in vitro and in vivo properties for imaging applications to provide insights into the etiology and characteristics of Alzheimer's disease. The photoisomerisable trans-butadiene bridge of PBB3 was replaced with 1,2,3-triazole, amide, and ester moieties and in vitro fluorescence staining studies revealed that triazole derivatives showed good visualisation of Aβ plaques, but failed to detect the neurofibrillary tangles (NFTs) in human brain sections. However, NFTs could be observed using the amide 110 and ester 129. Furthermore, the ligands showed low to high affinities (Ki = >1.5 mM-0.46 nM) at the shared binding site(s) with PBB3.
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Affiliation(s)
- Hendris Wongso
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong Wollongong NSW 2522 Australia
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency Puspiptek Banten 15314 Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency Sumedang 45363 Indonesia
| | - Maiko Ono
- Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology Chiba 263-8555 Japan
| | - Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum Science and Technology Chiba 263-8555 Japan
| | - Katsushi Kumata
- Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum Science and Technology Chiba 263-8555 Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology Chiba 263-8555 Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum Science and Technology Chiba 263-8555 Japan
| | - Michael J Fulham
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Paul A Keller
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong Wollongong NSW 2522 Australia
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2
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Rodnick ME, Sollert C, Stark D, Clark M, Katsifis A, Hockley BG, Parr DC, Frigell J, Henderson BD, Bruton L, Preshlock S, Abghari-Gerst M, Piert MR, Fulham MJ, Eberl S, Gagnon K, Scott PJH. Synthesis of 68Ga-radiopharmaceuticals using both generator-derived and cyclotron-produced 68Ga as exemplified by [ 68Ga]Ga-PSMA-11 for prostate cancer PET imaging. Nat Protoc 2022; 17:980-1003. [PMID: 35246649 DOI: 10.1038/s41596-021-00662-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 10/25/2021] [Indexed: 11/09/2022]
Abstract
[68Ga]Ga-PSMA-11, a urea-based peptidomimetic, is a diagnostic radiopharmaceutical for positron emission tomography (PET) imaging that targets the prostate-specific membrane antigen (PSMA). The recent Food and Drug Administration approval of [68Ga]Ga-PSMA-11 for PET imaging of patients with prostate cancer, expected follow-up approval of companion radiotherapeutics (e.g., [177Lu]Lu-PSMA-617, [225Ac]Ac-PSMA-617) and large prostate cancer patient volumes requiring access are poised to create an unprecedented demand for [68Ga]Ga-PSMA-11 in nuclear medicine clinics around the world. Meeting this global demand is going to require a variety of synthesis methods compatible with 68Ga eluted from a generator or produced on a cyclotron. To address this urgent need in the PET radiochemistry community, herein we report detailed protocols for the synthesis of [68Ga]Ga-PSMA-11, (also known as HBED-CC, Glu-urea-Lys(Ahx)-HBED-CC and PSMA-HBED-CC) using both generator-eluted and cyclotron-produced 68Ga and contrast the pros and cons of each method. The radiosyntheses are automated and have been validated for human use at two sites (University of Michigan (UM), United States; Royal Prince Alfred Hospital (RPA), Australia) and used to produce [68Ga]Ga-PSMA-11 for patient use in good activity yields (single generator, 0.52 GBq (14 mCi); dual generators, 1.04-1.57 GBq (28-42 mCi); cyclotron method (single target), 1.47-1.89 GBq (40-51 mCi); cyclotron method (dual target), 3.63 GBq (98 mCi)) and high radiochemical purity (99%) (UM, n = 645; RPA, n > 600). Both methods are appropriate for clinical production but, in the long term, the method employing cyclotron-produced 68Ga is the most promising for meeting high patient volumes. Quality control testing (visual inspection, pH, radiochemical purity and identity, radionuclidic purity and identity, sterile filter integrity, bacterial endotoxin content, sterility, stability) confirmed doses are suitable for clinical use, and there is no difference in clinical prostate cancer PET imaging using [68Ga]Ga-PSMA-11 prepared using the two production methods.
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Affiliation(s)
- Melissa E Rodnick
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | | | - Daniela Stark
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Mara Clark
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Brian G Hockley
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | | | - Jens Frigell
- GE Healthcare, GEMS PET Systems, Uppsala, Sweden
| | - Bradford D Henderson
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Laura Bruton
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Sean Preshlock
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Monica Abghari-Gerst
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Morand R Piert
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA
| | - Michael J Fulham
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.,Faculty of Engineering School of Computer Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Stefan Eberl
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia. .,Faculty of Engineering School of Computer Science, The University of Sydney, Sydney, New South Wales, Australia.
| | | | - Peter J H Scott
- University of Michigan, Department of Radiology, Division of Nuclear Medicine, Ann Arbor, MI, USA.
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Mattner F, Katsifis A, Bourdier T, Loc'h C, Berghofer P, Fookes C, Hung TT, Jackson T, Henderson D, Pham T, Lee BJ, Shepherd R, Greguric I, Wyatt N, Le T, Poon J, Power C, Fulham M. Synthesis and pharmacological evaluation of [ 18F]PBR316: a novel PET ligand targeting the translocator protein 18 kDa (TSPO) with low binding sensitivity to human single nucleotide polymorphism rs6971. RSC Med Chem 2021; 12:1207-1221. [PMID: 34355185 PMCID: PMC8292990 DOI: 10.1039/d1md00035g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/15/2021] [Indexed: 02/04/2023] Open
Abstract
Radiopharmaceuticals that target the translocator protein 18 kDa (TSPO) have been investigated with positron emission tomography (PET) to study neuroinflammation, neurodegeneration and cancer. We have developed the novel, achiral, 2-phenylimidazo[1,2-a]pyridine, PBR316 that targets the translocator protein 18 kDa (TSPO) that addresses some of the limitations inherent in current TSPO ligands; namely specificity in binding, blood brain barrier permeability, metabolism and insensitivity to TSPO binding in subjects as a result of rs6971 polymorphism. PBR316 has high nanomolar affinity (4.7-6.0 nM) for the TSPO, >5000 nM for the central benzodiazepine receptor (CBR) and low sensitivity to rs6971 polymorphism with a low affinity binders (LABs) to high affinity binders (HABs) ratio of 1.5. [18F]PBR316 was prepared in 20 ± 5% radiochemical yield, >99% radiochemical purity and a molar activity of 160-400 GBq μmol-1. Biodistribution in rats showed high uptake of [18F]PBR316 in organs known to express TSPO such as heart (3.9%) and adrenal glands (7.5% ID per g) at 1 h. [18F]PBR316 entered the brain and accumulated in TSPO-expressing regions with an olfactory bulb to brain ratio of 3 at 15 min and 7 at 4 h. Radioactivity was blocked by PK11195 and Ro 5-4864 but not Flumazenil. Metabolite analysis showed that radioactivity in adrenal glands and the brain was predominantly due to the intact radiotracer. PET-CT studies in mouse-bearing prostate tumour xenografts indicated biodistribution similar to rats with radioactivity in the tumour increasing with time. [18F]PBR316 shows in vitro binding that is insensitive to human polymorphism and has specific and selective in vivo binding to the TSPO. [18F]PBR316 is suitable for further biological and clinical studies.
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Affiliation(s)
- Filomena Mattner
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
- School of Pharmacy, University of Sydney Sydney NSW 2006 Australia
| | - Thomas Bourdier
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Christian Loc'h
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Paula Berghofer
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Christopher Fookes
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Tzong-Tyng Hung
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Timothy Jackson
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - David Henderson
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Tien Pham
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Brendan J Lee
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Rachael Shepherd
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Ivan Greguric
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Naomi Wyatt
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Thanh Le
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Jackson Poon
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Carl Power
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Michael Fulham
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
- Faculty of Engineering and Information Technologies, University of Sydney Sydney NSW 2006 Australia
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Wongso H, Yamasaki T, Kumata K, Ono M, Higuchi M, Zhang M, Fulham MJ, Katsifis A, Keller PA. Front Cover: Design, Synthesis, and Biological Evaluation of Novel Fluorescent Probes Targeting the 18‐kDa Translocator Protein (12/2021). ChemMedChem 2021. [DOI: 10.1002/cmdc.202100379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hendris Wongso
- School of Chemistry and Molecular Bioscience, and Molecular Horizons University of Wollongong Wollongong NSW 2522 Australia
- Center for Applied Nuclear Science and Technology National Nuclear Energy Agency Bandung 40132 Indonesia
| | - Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences National Institute of Radiological Sciences Chiba 263-8555 Japan
| | - Katsushi Kumata
- Department of Advanced Nuclear Medicine Sciences National Institute of Radiological Sciences Chiba 263-8555 Japan
| | - Maiko Ono
- Department of Functional Brain Imaging Research National Institutes for Quantum and Radiological Science and Technology Chiba 263-8555 Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research National Institutes for Quantum and Radiological Science and Technology Chiba 263-8555 Japan
| | - Ming‐Rong Zhang
- Department of Advanced Nuclear Medicine Sciences National Institute of Radiological Sciences Chiba 263-8555 Japan
| | - Michael J. Fulham
- Department of PET and Nuclear Medicine Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Paul A. Keller
- School of Chemistry and Molecular Bioscience, and Molecular Horizons University of Wollongong Wollongong NSW 2522 Australia
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Wongso H, Yamasaki T, Kumata K, Ono M, Higuchi M, Zhang MR, Fulham MJ, Katsifis A, Keller PA. Design, Synthesis, and Biological Evaluation of Novel Fluorescent Probes Targeting the 18-kDa Translocator Protein. ChemMedChem 2021; 16:1902-1916. [PMID: 33631047 DOI: 10.1002/cmdc.202000984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/22/2021] [Indexed: 12/20/2022]
Abstract
A series of fluorescent probes from the 6-chloro-2-phenylimidazo[1,2-a]pyridine-3-yl acetamides ligands featuring the 7-nitro-2-oxa-1,3-diazol-4-yl (NBD) moiety has been synthesized and biologically evaluated for their fluorescence properties and for their binding affinity to the 18-kDa translocator protein (TSPO). Spectroscopic studies including UV/Vis absorption and fluorescence measurements showed that the synthesized fluorescent probes exhibit favorable spectroscopic properties, especially in nonpolar environments. In vitro fluorescence staining in brain sections from lipopolysaccharide (LPS)-injected mice revealed partial colocalization of the probes with the TSPO. The TSPO binding affinity of the probes was measured on crude mitochondrial fractions separated from rat brain homogenates in a [11 C]PK11195 radioligand binding assay. All the new fluorescent probes demonstrated moderate to high binding affinity to the TSPO, with affinity (Ki ) values ranging from 0.58 nM to 3.28 μM. Taking these data together, we propose that the new fluorescent probes could be used to visualize the TSPO.
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Affiliation(s)
- Hendris Wongso
- School of Chemistry and Molecular Bioscience, and Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia.,Center for Applied Nuclear Science and Technology, National Nuclear Energy Agency, Bandung, 40132, Indonesia
| | - Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Chiba, 263-8555, Japan
| | - Katsushi Kumata
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Chiba, 263-8555, Japan
| | - Maiko Ono
- Department of Functional Brain Imaging Research, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Chiba, 263-8555, Japan
| | - Michael J Fulham
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, 2050, Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, 2050, Australia
| | - Paul A Keller
- School of Chemistry and Molecular Bioscience, and Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia
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6
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Rodnick ME, Sollert C, Stark D, Clark M, Katsifis A, Hockley BG, Parr DC, Frigell J, Henderson BD, Abghari-Gerst M, Piert MR, Fulham MJ, Eberl S, Gagnon K, Scott PJH. Cyclotron-based production of 68Ga, [ 68Ga]GaCl 3, and [ 68Ga]Ga-PSMA-11 from a liquid target. EJNMMI Radiopharm Chem 2020; 5:25. [PMID: 33180205 PMCID: PMC7661618 DOI: 10.1186/s41181-020-00106-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 10/19/2020] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To optimize the direct production of 68Ga on a cyclotron, via the 68Zn(p,n)68Ga reaction using a liquid cyclotron target. We Investigated the yield of cyclotron-produced 68Ga, extraction of [68Ga]GaCl3 and subsequent [68Ga]Ga-PSMA-11 labeling using an automated synthesis module. METHODS Irradiations of a 1.0 M solution of [68Zn]Zn(NO3)2 in dilute (0.2-0.3 M) HNO3 were conducted using GE PETtrace cyclotrons and GE 68Ga liquid targets. The proton beam energy was degraded to a nominal 14.3 MeV to minimize the co-production of 67Ga through the 68Zn(p,2n)67Ga reaction without unduly compromising 68Ga yields. We also evaluated the effects of varying beam times (50-75 min) and beam currents (27-40 μA). Crude 68Ga production was measured. The extraction of [68Ga]GaCl3 was performed using a 2 column solid phase method on the GE FASTlab Developer platform. Extracted [68Ga]GaCl3 was used to label [68Ga]Ga-PSMA-11 that was intended for clinical use. RESULTS The decay corrected yield of 68Ga at EOB was typically > 3.7 GBq (100 mCi) for a 60 min beam, with irradiations of [68Zn]Zn(NO3)2 at 0.3 M HNO3. Target/chemistry performance was more consistent when compared with 0.2 M HNO3. Radionuclidic purity of 68Ga was typically > 99.8% at EOB and met the requirements specified in the European Pharmacopoeia (< 2% combined 66/67Ga) for a practical clinical product shelf-life. The activity yield of [68Ga]GaCl3 was typically > 50% (~ 1.85 GBq, 50 mCi); yields improved as processes were optimized. Labeling yields for [68Ga]Ga-PSMA-11 were near quantitative (~ 1.67 GBq, 45 mCi) at EOS. Cyclotron produced [68Ga]Ga-PSMA-11 underwent full quality control, stability and sterility testing, and was implemented for human use at the University of Michigan as an Investigational New Drug through the US FDA and also at the Royal Prince Alfred Hospital (RPA). CONCLUSION Direct cyclotron irradiation of a liquid target provides clinically relevant quantities of [68Ga]Ga-PSMA-11 and is a viable alternative to traditional 68Ge/68Ga generators.
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Affiliation(s)
- Melissa E Rodnick
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | | | - Daniela Stark
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, Australia
| | - Mara Clark
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Sydney, Australia
| | - Brian G Hockley
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | | | - Jens Frigell
- GE Healthcare, GEMS PET Systems, Uppsala, Sweden
| | - Bradford D Henderson
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Monica Abghari-Gerst
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Morand R Piert
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Michael J Fulham
- Department of Molecular Imaging, Royal Prince Alfred Hospital and Sydney Medical School, University of Sydney, Sydney, Australia
| | - Stefan Eberl
- Department of Molecular Imaging, Royal Prince Alfred Hospital and School of Computer Science, The University of Sydney, Sydney, Australia.
| | | | - Peter J H Scott
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
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Evans BJ, King AT, Katsifis A, Matesic L, Jamie JF. Methods to Enhance the Metabolic Stability of Peptide-Based PET Radiopharmaceuticals. Molecules 2020; 25:molecules25102314. [PMID: 32423178 PMCID: PMC7287708 DOI: 10.3390/molecules25102314] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/28/2022] Open
Abstract
The high affinity and specificity of peptides towards biological targets, in addition to their favorable pharmacological properties, has encouraged the development of many peptide-based pharmaceuticals, including peptide-based positron emission tomography (PET) radiopharmaceuticals. However, the poor in vivo stability of unmodified peptides against proteolysis is a major challenge that must be overcome, as it can result in an impractically short in vivo biological half-life and a subsequently poor bioavailability when used in imaging and therapeutic applications. Consequently, many biologically and pharmacologically interesting peptide-based drugs may never see application. A potential way to overcome this is using peptide analogues designed to mimic the pharmacophore of a native peptide while also containing unnatural modifications that act to maintain or improve the pharmacological properties. This review explores strategies that have been developed to increase the metabolic stability of peptide-based pharmaceuticals. It includes modifications of the C- and/or N-termini, introduction of d- or other unnatural amino acids, backbone modification, PEGylation and alkyl chain incorporation, cyclization and peptide bond substitution, and where those strategies have been, or could be, applied to PET peptide-based radiopharmaceuticals.
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Affiliation(s)
- Brendan J. Evans
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
| | - Andrew T. King
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia;
| | - Lidia Matesic
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia;
| | - Joanne F. Jamie
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
- Correspondence: ; Tel.: +61-2-9850-8283
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Lum JS, du Bois TM, Mattner F, Katsifis A, Brown SJ, Huang XF, Newell KA. Increased translocator protein (TSPO) binding throughout neurodevelopment in the perinatal phencyclidine rodent model of schizophrenia. Schizophr Res 2019; 212:243-245. [PMID: 31420201 DOI: 10.1016/j.schres.2019.07.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/24/2019] [Accepted: 07/27/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Jeremy S Lum
- Illawarra Health and Medical Research Institute, Wollongong, Australia; Molecular Horizons and School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia.
| | - Teresa M du Bois
- Illawarra Health and Medical Research Institute, Wollongong, Australia; Molecular Horizons and School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Filomena Mattner
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Missenden Road, Camperdown, 2050, Australia
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Missenden Road, Camperdown, 2050, Australia
| | - Samara J Brown
- Illawarra Health and Medical Research Institute, Wollongong, Australia; Molecular Horizons and School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Xu-Feng Huang
- Illawarra Health and Medical Research Institute, Wollongong, Australia; Molecular Horizons and School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Kelly A Newell
- Illawarra Health and Medical Research Institute, Wollongong, Australia; Molecular Horizons and School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
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9
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Wallin M, Turner P, Katsifis A, Yang M, Chan HK. Crystal structure of aqua-(2-{[2-({2-[bis-(carboxyl-ato-κ O-meth-yl)amino-κ N]eth-yl}(carboxyl-ato-κ O-meth-yl)amino-κ N)eth-yl](carb-oxy-meth-yl)aza-niumyl}acetato)-gallium(III) trihydrate. Acta Crystallogr E Crystallogr Commun 2018; 74:1054-1057. [PMID: 30116560 PMCID: PMC6073008 DOI: 10.1107/s2056989018009428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 06/30/2018] [Indexed: 11/30/2022]
Abstract
In the title GaIII complex compound with pentetic acid, [Ga(C14H20N3O10)(H2O)]·3H2O, the GaIII centre is bound in a slightly distorted octa-hedral coordination sphere by two amine N atoms, three carboxyl-ate O atoms and one water O atom. The complex mol-ecule exists as a zwitterion. In the crystal, the complexes are linked to each other via O-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (001). Three uncoordinating water mol-ecules link the complex layers via O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network.
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Affiliation(s)
- Martin Wallin
- Advanced Drug Delivery Group, School of Pharmacy, University of Sydney, NSW, 2006, Australia
| | - Peter Turner
- School of Chemistry, University of Sydney, NSW 2006, Australia
| | - Andrew Katsifis
- Department of PET & Nuclear Medicine, Royal Prince Alfred Hospital, NSW 2050, Australia
| | - Mingshi Yang
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Hak-Kim Chan
- Advanced Drug Delivery Group, School of Pharmacy, University of Sydney, NSW, 2006, Australia
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10
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Affiliation(s)
- Jackson Poon
- Department of PET and Nuclear Medicine Royal Prince Alfred Hospital, Sydney, Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine Royal Prince Alfred Hospital, Sydney, Australia
| | - Michael Fulham
- Department of PET and Nuclear Medicine Royal Prince Alfred Hospital, Sydney, Australia
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11
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Tieu W, Lifa T, Katsifis A, Codd R. Octadentate Zirconium(IV)-Loaded Macrocycles with Varied Stoichiometry Assembled From Hydroxamic Acid Monomers using Metal-Templated Synthesis. Inorg Chem 2017; 56:3719-3728. [DOI: 10.1021/acs.inorgchem.7b00362] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- William Tieu
- School of Medical
Sciences (Pharmacology) and Bosch Institute, The University of Sydney, New
South Wales 2006, Australia
| | - Tulip Lifa
- School of Medical
Sciences (Pharmacology) and Bosch Institute, The University of Sydney, New
South Wales 2006, Australia
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Camperdown, New South Wales 2050, Australia
| | - Rachel Codd
- School of Medical
Sciences (Pharmacology) and Bosch Institute, The University of Sydney, New
South Wales 2006, Australia
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12
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Yang MY, Verschuer J, Shi Y, Song Y, Katsifis A, Eberl S, Wong K, Brannan JD, Cai W, Finlay WH, Chan HK. The effect of device resistance and inhalation flow rate on the lung deposition of orally inhaled mannitol dry powder. Int J Pharm 2016; 513:294-301. [DOI: 10.1016/j.ijpharm.2016.09.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 10/21/2022]
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13
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Eberl S, Katsifis A, Peyronneau MA, Wen L, Henderson D, Loc'h C, Greguric I, Verschuer J, Pham T, Lam P, Mattner F, Mohamed A, Fulham MJ. Preclinical in vivo and in vitro comparison of the translocator protein PET ligands [ 18F]PBR102 and [ 18F]PBR111. Eur J Nucl Med Mol Imaging 2016; 44:296-307. [PMID: 27699720 DOI: 10.1007/s00259-016-3517-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/05/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE To determine the metabolic profiles of the translocator protein ligands PBR102 and PBR111 in rat and human microsomes and compare their in vivo binding and metabolite uptake in the brain of non-human primates (Papio hamadryas) using PET-CT. METHODS In vitro metabolic profiles of PBR102 and PBR111 in rat and human liver microsomes were assessed by liquid chromatography-tandem mass spectrometry. [18F]PBR102 and [18F]PBR111 were prepared by nucleophilic substitution of their corresponding p-toluenesulfonyl precursors with [18F]fluoride. List mode PET-CT brain imaging with arterial blood sampling was performed in non-human primates. Blood plasma measurements and metabolite analysis, using solid-phase extraction, provided the metabolite profile and metabolite-corrected input functions for kinetic model fitting. Blocking and displacement PET-CT scans, using PK11195, were performed. RESULTS Microsomal analyses identified the O-de-alkylated, hydroxylated and N-de-ethyl derivatives of PBR102 and PBR111 as the main metabolites. The O-de-alkylated compounds were the major metabolites in both species; human liver microsomes were less active than those from rat. Metabolic profiles in vivo in non-human primates and previously published rat experiments were consistent with the microsomal results. PET-CT studies showed that K1 was similar for baseline and blocking studies for both radiotracers; VT was reduced during the blocking study, suggesting low non-specific binding and lack of appreciable metabolite uptake in the brain. CONCLUSIONS [18F]PBR102 and [18F]PBR111 have distinct metabolic profiles in rat and non-human primates. Radiometabolites contributed to non-specific binding and confounded in vivo brain analysis of [18F]PBR102 in rodents; the impact in primates was less pronounced. Both [18F]PBR102 and [18F]PBR111 are suitable for PET imaging of TSPO in vivo. In vitro metabolite studies can be used to predict in vivo radioligand metabolism and can assist in the design and development of better radioligands.
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Affiliation(s)
- S Eberl
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia. .,Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, 2006, Australia.
| | - A Katsifis
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia.,Faculty of Pharmacy, University of Sydney, Sydney, NSW, 2006, Australia
| | - M A Peyronneau
- IMIV, CEA, Inserm, Univ. Paris-Sud, CNRS, Université Paris-Saclay, CEA-SHFJ, Orsay, France
| | - L Wen
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia.,Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, 2006, Australia
| | - D Henderson
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia
| | - C Loc'h
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia
| | - I Greguric
- Radiochemistry and Radiotracers Platform, ANSTO, New Illawarra Road, Lucas Heights, NSW, 2234, Australia
| | - J Verschuer
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia
| | - T Pham
- Radiochemistry and Radiotracers Platform, ANSTO, New Illawarra Road, Lucas Heights, NSW, 2234, Australia
| | - P Lam
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia
| | - F Mattner
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia
| | - A Mohamed
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia.,Sydney Medical School, University of Sydney, Sydney, NSW, 2006, Australia
| | - M J Fulham
- Department of Molecular Imaging (PET and Nuclear Medicine), Royal Prince Alfred Hospital, Building 63, Level A7, Missenden Road, Camperdown, NSW, 2050, Australia.,Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, 2006, Australia.,Sydney Medical School, University of Sydney, Sydney, NSW, 2006, Australia
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14
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Lengkeek NA, Roberts MP, Zhang L, Lee ICJ, Fookes CJR, Dikic B, Herzog H, Katsifis A, Greguric I. Synthesis and Binding Affinity of Fluorine Containing NG-acyl and -sulfonyl BIBP3226 Derivatives: Ligands for the NPY Y1 Receptor. Aust J Chem 2016. [DOI: 10.1071/ch15569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The neuropeptide Y (NPY) receptors are abundant in a range of tumours hence are a molecular target for tumour imaging and therapy, particularly by the use of radiolabelled molecules. NG-Substituted derivatives of the NPY receptor antagonist, BIBP3226, were prepared aiming to improve its current usability and to incorporate a positron-emitting radioisotope for development in positron emission tomography (PET) radiopharmaceuticals. The BIBP3226 derivatives were prepared in seven steps while retaining the critically important amino acid chirality. The acyl derivative retained acceptable ligand binding, however the sulfonyl derivatives lost almost all binding affinity.
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15
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Amhaoul H, Hamaide J, Bertoglio D, Reichel SN, Verhaeghe J, Geerts E, Van Dam D, De Deyn PP, Kumar-Singh S, Katsifis A, Van Der Linden A, Staelens S, Dedeurwaerdere S. Brain inflammation in a chronic epilepsy model: Evolving pattern of the translocator protein during epileptogenesis. Neurobiol Dis 2015; 82:526-539. [PMID: 26388398 DOI: 10.1016/j.nbd.2015.09.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/24/2015] [Accepted: 09/16/2015] [Indexed: 11/27/2022] Open
Abstract
AIMS A hallmark in the neuropathology of temporal lobe epilepsy is brain inflammation which has been suggested as both a biomarker and a new mechanistic target for treatments. The translocator protein (TSPO), due to its high upregulation under neuroinflammatory conditions and the availability of selective PET tracers, is a candidate target. An important step to exploit this target is a thorough characterisation of the spatiotemporal profile of TSPO during epileptogenesis. METHODS TSPO expression, microglial activation, astrocyte reactivity and cell loss in several brain regions were evaluated at five time points during epileptogenesis, including the chronic epilepsy phase in the kainic acid-induced status epilepticus (KASE) model (n = 52) and control Wistar Han rats (n = 33). Seizure burden was also determined in the chronic phase. Furthermore, ¹⁸F-PBR111 PET/MRI scans were acquired longitudinally in an additional four KASE animals. RESULTS TSPO expression measured with in vitro and in vivo techniques was significantly increased at each time point and peaked two weeks post-SE in the limbic system. A prominent association between TSPO expression and activated microglia (p < 0.001; r = 0.7), as well as cell loss (p < 0.001; r = -0.8) could be demonstrated. There was a significant positive correlation between spontaneous seizures and TSPO upregulation in several brain regions with increased TSPO expression. CONCLUSIONS TSPO expression was dynamically upregulated during epileptogenesis, persisted in the chronic phase and correlated with microglia activation rather than reactive astrocytes. TSPO expression was correlating with spontaneous seizures and its high expression during the latent phase might possibly suggest being an important switching point in disease ontogenesis which could be further investigated by PET imaging.
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Affiliation(s)
- Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Julie Hamaide
- Department of Translational Neurosciences, University of Antwerp, Belgium; Bio-Imaging Lab, University of Antwerp, Belgium
| | - Daniele Bertoglio
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | | | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | - Elly Geerts
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium; Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Belgium; Department of Neurology and Alzheimer Research Center, University of Groningen and University Medical Center Groningen (UMCG), The Netherlands
| | - Samir Kumar-Singh
- Laboratory of Cell Biology & Histology, University of Antwerp, Belgium
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Australia
| | | | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
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16
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Roberts MP, Nguyen V, Ashford ME, Berghofer P, Wyatt NA, Krause-Heuer AM, Pham TQ, Taylor SR, Hogan L, Jiang CD, Fraser BH, Lengkeek NA, Matesic L, Gregoire MC, Denoyer D, Hicks RJ, Katsifis A, Greguric I. Synthesis and in Vivo Evaluation of [123I]Melanin-Targeted Agents. J Med Chem 2015; 58:6214-24. [PMID: 26177000 DOI: 10.1021/acs.jmedchem.5b00777] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
This study reports the synthesis, [(123)I]radiolabeling, and biological profile of a new series of iodinated compounds for potential translation to the corresponding [(131)I]radiolabeled compounds for radionuclide therapy of melanoma. Radiolabeling was achieved via standard electrophilic iododestannylation in 60-90% radiochemical yield. Preliminary SPECT imaging demonstrated high and distinct tumor uptake of all compounds, as well as high tumor-to-background ratios compared to the literature compound [(123)I]4 (ICF01012). The most favorable compounds ([(123)I]20, [(123)I]23, [(123)I]41, and [(123)I]53) were selected for further biological investigation. Biodistribution studies indicated that all four compounds bound to melanin containing tissue with low in vivo deiodination; [(123)I]20 and [(123)I]53 in particular displayed high and prolonged tumor uptake (13% ID/g at 48 h). [(123)I]53 had the most favorable overall profile of the cumulative uptake over time of radiosensitive organs. Metabolite analysis of the four radiotracers found [(123)I]41 and [(123)I]53 to be the most favorable, displaying high and prolonged amounts of intact tracer in melanin containing tissues, suggesting melanin specific binding. Results herein suggest that compound [(123)I]53 displays favorable in vivo pharmacokinetics and stability and hence is an ideal candidate to proceed with further preclinical [(131)I] therapeutic evaluation.
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Affiliation(s)
- Maxine P Roberts
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Vu Nguyen
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Mark E Ashford
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Paula Berghofer
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Naomi A Wyatt
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Anwen M Krause-Heuer
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Tien Q Pham
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Stephen R Taylor
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Leena Hogan
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Cathy D Jiang
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Benjamin H Fraser
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Nigel A Lengkeek
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Lidia Matesic
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Marie-Claude Gregoire
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Delphine Denoyer
- ‡Centre for Molecular Imaging, Peter MacCallum Cancer Centre, 12 St. Andrew's Place, East Melbourne, Victoria 3002, Australia
| | - Rodney J Hicks
- ‡Centre for Molecular Imaging, Peter MacCallum Cancer Centre, 12 St. Andrew's Place, East Melbourne, Victoria 3002, Australia
| | - Andrew Katsifis
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Ivan Greguric
- †LifeSciences Division, Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
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17
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Mattner F, Quinlivan M, Greguric I, Pham T, Liu X, Jackson T, Berghofer P, Fookes CJR, Dikic B, Gregoire MC, Dolle F, Katsifis A. Radiosynthesis, In Vivo Biological Evaluation, and Imaging of Brain Lesions with [123I]-CLINME, a New SPECT Tracer for the Translocator Protein. Dis Markers 2015; 2015:729698. [PMID: 26199457 PMCID: PMC4496498 DOI: 10.1155/2015/729698] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 06/10/2015] [Indexed: 11/17/2022]
Abstract
The high affinity translocator protein (TSPO) ligand 6-chloro-2-(4'-iodophenyl)-3-(N,N-methylethyl)imidazo[1,2-a]pyridine-3-acetamide (CLINME) was radiolabelled with iodine-123 and assessed for its sensitivity for the TSPO in rodents. Moreover neuroinflammatory changes on a unilateral excitotoxic lesion rat model were detected using SPECT imaging. [(123)I]-CLINME was prepared in 70-80% radiochemical yield. The uptake of [(123)I]-CLINME was evaluated in rats by biodistribution, competition, and metabolite studies. The unilateral excitotoxic lesion was performed by injection of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid unilaterally into the striatum. The striatum lesion was confirmed and correlated with TSPO expression in astrocytes and activated microglia by immunohistochemistry and autoradiography. In vivo studies with [(123)I]-CLINME indicated a biodistribution pattern consistent with TPSO distribution and the competition studies with PK11195 and Ro 5-4864 showed that [(123)I]-CLINME is selective for this site. The metabolite study showed that the extractable radioactivity was unchanged [(123)I]-CLINME in organs which expresses TSPO. SPECT/CT imaging on the unilateral excitotoxic lesion indicated that the mean ratio uptake in striatum (lesion:nonlesion) was 2.2. Moreover, TSPO changes observed by SPECT imaging were confirmed by immunofluorescence, immunochemistry, and autoradiography. These results indicated that [(123)I]-CLINME is a promising candidate for the quantification and visualization of TPSO expression in activated astroglia using SPECT.
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Affiliation(s)
- F. Mattner
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
| | - M. Quinlivan
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - I. Greguric
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - T. Pham
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - X. Liu
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - T. Jackson
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - P. Berghofer
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - C. J. R. Fookes
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - B. Dikic
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - M.-C. Gregoire
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - F. Dolle
- CEA, DSV/I2BM, Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, 91401 Orsay, France
| | - A. Katsifis
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
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18
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Callaghan PD, Wimberley CA, Rahardjo GL, Berghofer PJ, Pham TQ, Jackson T, Zahra D, Bourdier T, Wyatt N, Greguric I, Howell NR, Siegele R, Pastuovic Z, Mattner F, Loc’h C, Gregoire MC, Katsifis A. Comparison of in vivo binding properties of the 18-kDa translocator protein (TSPO) ligands [18F]PBR102 and [18F]PBR111 in a model of excitotoxin-induced neuroinflammation. Eur J Nucl Med Mol Imaging 2014; 42:138-51. [DOI: 10.1007/s00259-014-2895-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 08/13/2014] [Indexed: 12/22/2022]
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19
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Bourdier T, Henderson D, Fookes CJ, Lam P, Mattner F, Fulham M, Katsifis A. Synthesis of [11C]PBR170, a novel imidazopyridine, for imaging the translocator protein with PET. Appl Radiat Isot 2014; 90:46-52. [DOI: 10.1016/j.apradiso.2014.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/26/2014] [Accepted: 03/08/2014] [Indexed: 10/25/2022]
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20
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Asih PR, Barron AM, Ji B, Katsifis A, Mattner F, Verdile G, Gupta VB, Trengove R, Martins RN. P4‐198: NOVEL TRANSLOCATOR PROTEIN (TSPO) LIGANDS FOR THE POTENTIAL TREATMENT OF ALZHEIMER'S DISEASE: A NEXT GENERATION ALTERNATIVE TO CONVENTIONAL HORMONE THERAPY. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.05.1715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Bin Ji
- National Institute of Radiological SciencesChibaJapan
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21
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Vivash L, Gregoire MC, Bouilleret V, Berard A, Wimberley C, Binns D, Roselt P, Katsifis A, Myers DE, Hicks RJ, O'Brien TJ, Dedeurwaerdere S. In vivo measurement of hippocampal GABAA/cBZR density with [18F]-flumazenil PET for the study of disease progression in an animal model of temporal lobe epilepsy. PLoS One 2014; 9:e86722. [PMID: 24466212 PMCID: PMC3897736 DOI: 10.1371/journal.pone.0086722] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 12/15/2013] [Indexed: 11/18/2022] Open
Abstract
Purpose Imbalance of inhibitory GABAergic neurotransmission has been proposed to play a role in the pathogenesis of temporal lobe epilepsy (TLE). This study aimed to investigate whether [18F]-flumazenil ([18F]-FMZ) PET could be used to non-invasively characterise GABAA/central benzodiazepine receptor (GABAA/cBZR) density and affinity in vivo in the post-kainic acid status epilepticus (SE) model of TLE. Methods Dynamic [18F]-FMZ -PET scans using a multi-injection protocol were acquired in four male wistar rats for validation of the partial saturation model (PSM). SE was induced in eight male Wistar rats (10 weeks of age) by i.p. injection of kainic acid (7.5–25 mg/kg), while control rats (n = 7) received saline injections. Five weeks post-SE, an anatomic MRI scan was acquired and the following week an [18F]-FMZ PET scan (3.6–4.6 nmol). The PET data was co-registered to the MRI and regions of interest drawn on the MRI for selected structures. A PSM was used to derive receptor density and apparent affinity from the [18F]-FMZ PET data. Key Findings The PSM was found to adequately model [18F]-FMZ binding in vivo. There was a significant decrease in hippocampal receptor density in the SE group (p<0.01), accompanied by an increase in apparent affinity (p<0.05) compared to controls. No change in cortical receptor binding was observed. Hippocampal volume reduction and cell loss was only seen in a subset of animals. Histological assessment of hippocampal cell loss was significantly correlated with hippocampal volume measured by MRI (p<0.05), but did not correlate with [18F]-FMZ binding. Significance Alterations to hippocampal GABAA/cBZR density and affinity in the post-kainic acid SE model of TLE are detectable in vivo with [18F]-FMZ PET and a PSM. These changes are independent from hippocampal cell and volume loss. [18F]-FMZ PET is useful for investigating the role that changes GABAA/cBZR density and binding affinity play in the pathogenesis of TLE.
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Affiliation(s)
- Lucy Vivash
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Marie-Claude Gregoire
- Department of LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, New South Wales, Australia
| | - Viviane Bouilleret
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Alexis Berard
- Department of LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, New South Wales, Australia
| | - Catriona Wimberley
- Department of LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, New South Wales, Australia
| | - David Binns
- The Centre for Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Peter Roselt
- The Centre for Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Andrew Katsifis
- Department of LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, New South Wales, Australia
| | - Damian E. Myers
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Rodney J. Hicks
- The Centre for Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Terence J. O'Brien
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
| | - Stefanie Dedeurwaerdere
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
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Ashford ME, Nguyen VH, Greguric I, Pham TQ, Keller PA, Katsifis A. Synthesis and in vitro evaluation of tetrahydroisoquinolines with pendent aromatics as sigma-2 (σ2) selective ligands. Org Biomol Chem 2014; 12:783-94. [DOI: 10.1039/c3ob42254b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sigma-2 selective ligands – a SAR study showing increased potency and selectivity with derivatives showing the potential to be converted into radiolabelled ligands.
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Affiliation(s)
- Mark E. Ashford
- ANSTO Life Sciences Division
- ANSTO
- Kirrawee DC, Australia
- Centre for Medicinal Chemistry
- School of Chemistry
| | - Vu H. Nguyen
- ANSTO Life Sciences Division
- ANSTO
- Kirrawee DC, Australia
| | - Ivan Greguric
- ANSTO Life Sciences Division
- ANSTO
- Kirrawee DC, Australia
| | - Tien Q. Pham
- ANSTO Life Sciences Division
- ANSTO
- Kirrawee DC, Australia
| | - Paul A. Keller
- Centre for Medicinal Chemistry
- School of Chemistry
- University of Wollongong
- , Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine
- Royal Prince Alfred Hospital
- Sydney, Australia
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Nguyen VH, Pham T, Fookes C, Berghofer P, Greguric I, Arthur A, Mattner F, Rahardjo G, Davis E, Howell N, Gregoire MC, Katsifis A, Shepherd R. Synthesis and biological characterisation of 18F-SIG343 and 18F-SIG353, novel and high selectivity σ2 radiotracers, for tumour imaging properties. EJNMMI Res 2013; 3:80. [PMID: 24330526 PMCID: PMC3878827 DOI: 10.1186/2191-219x-3-80] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 11/21/2013] [Indexed: 12/13/2022] Open
Abstract
Background Sigma2 (σ2) receptors are highly expressed in cancer cell lines and in tumours. Two novel selective 18F-phthalimido σ2 ligands, 18F-SIG343 and 18F-SIG353, were prepared and characterised for their potential tumour imaging properties. Methods Preparation of 18F-SIG343 and 18F-SIG353 was achieved via nucleophilic substitution of their respective nitro precursors. In vitro studies including radioreceptor binding assays in the rat brain membrane and cell uptake studies in the A375 cell line were performed. In vivo studies were carried out in mice bearing A375 tumours including positron emission tomography (PET) imaging, biodistribution, blocking and metabolite studies. Results In vitro studies showed that SIG343 and SIG353 displayed excellent affinity and selectivity for σ2 receptors (Ki(σ2) = 8 and 3 nM, σ2:σ1 = 200- and 110-fold, respectively). The σ2 selectivity of 18F-SIG343 was further confirmed by blocking studies in A375 cells, however, not noted for 18F-SIG353. Biodistribution studies showed that both radiotracers had similar characteristics including moderately high tumour uptake (4%ID/g to 5%ID/g); low bone uptake (3%ID/g to 4%ID/g); and high tumour-to-muscle uptake ratios (four- to sevenfold) up to 120 min. Although radiotracer uptake in organs known to express σ receptors was significantly blocked by pre-injection of competing σ ligands, the blocking effect was not observed in the tumour. PET imaging studies indicated major radioactive localisation in the chest cavity for both ligands, with approximately 1%ID/g uptake in the tumour at 120 min. Metabolite studies showed that the original radiotracers remained unchanged 65% to 80% in the tumour up to 120 min. Conclusions The lead ligands showed promising in vitro and in vivo characteristics. However, PET imaging indicated low tumour-to-background ratios. Furthermore, we were unable to demonstrate that uptake in the A375 tumour was σ2-specific. 18F-SIG343 and 18F-SIG343 do not display ideal properties for imaging the σ2 receptor in the A375 tumour model. However, since the radiotracers show promising in vitro and in vivo characteristics, longer scans using appropriate half-life isotopes and alternative tumour models will be carried out in future studies to fully validate the imaging characteristics of these radiotracers.
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Affiliation(s)
- Vu H Nguyen
- LifeSciences, ANSTO, Locked Bag 2001, Kirrawee, New South Wales 2232, Australia.
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Haskali MB, Roselt PD, Karas JA, Noonan W, Wichmann CW, Katsifis A, Hicks RJ, Hutton CA. One-step radiosynthesis of 4-nitrophenyl 2-[(18) F]fluoropropionate ([(18) F]NFP); improved preparation of radiolabeled peptides for PET imaging. J Labelled Comp Radiopharm 2013; 56:726-30. [PMID: 24339012 DOI: 10.1002/jlcr.3111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 08/06/2013] [Accepted: 08/12/2013] [Indexed: 01/30/2023]
Abstract
The versatile (18) F-labeled prosthetic group, 4-nitrophenyl 2-[(18) F]fluoropropionate ([(18) F]NFP), was synthesized in a single step in 45 min from 4-nitrophenyl 2-bromopropionate, with a decay corrected radiochemical yield of 26.2% ± 2.2%. Employing this improved synthesis of [(18) F]NFP, [(18) F]GalactoRGD - the current 'gold standard' tracer for imaging the expression of αV β3 integrin - was prepared with high specific activity in 90 min and 20% decay corrected radiochemical yield from [(18) F]fluoride.
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Affiliation(s)
- Mohammad B Haskali
- School of Chemistry, The University of Melbourne, Vic., 3010, Australia; Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Vic., 3010, Australia; The Centre for Molecular Imaging and Translational Research Laboratory, The Peter MacCallum Cancer Centre, Melbourne, Vic., Australia
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25
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Mattner F, Staykova M, Berghofer P, Wong HJ, Fordham S, Callaghan P, Jackson T, Pham T, Gregoire MC, Zahra D, Rahardjo G, Linares D, Katsifis A. Central nervous system expression and PET imaging of the translocator protein in relapsing-remitting experimental autoimmune encephalomyelitis. J Nucl Med 2013; 54:291-8. [PMID: 23321458 DOI: 10.2967/jnumed.112.108894] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Glial neuroinflammation is associated with the development and progression of multiple sclerosis. PET imaging offers a unique opportunity to evaluate neuroinflammatory processes longitudinally in a noninvasive and clinically translational manner. (18)F-PBR111 is a newly developed PET radiopharmaceutical with high affinity and selectivity for the translocator protein (TSPO), expressed on activated glia. This study aimed to investigate neuroinflammation at different phases of relapsing-remitting (RR) experimental autoimmune encephalomyelitis (EAE) in the brains of SJL/J mice by postmortem histologic analysis and in vivo by PET imaging with (18)F-PBR111. METHODS RR EAE was induced by immunization with PLP(139-151) peptide in complete Freund's adjuvant. Naive female SJL/J mice and mice immunized with saline-complete Freund's adjuvant were used as controls. The biodistribution of (18)F-PBR111 was measured in 13 areas of the central nervous system and compared with PET imaging results during different phases of RR EAE. The extents of TSPO expression and glial activation were assessed with immunohistochemistry, immunofluorescence, and a real-time polymerase chain reaction. RESULTS There was significant TSPO expression in all of the central nervous system areas studied at the peak of the first clinical episode and, importantly, at the preclinical stage. In contrast, only a few TSPO-positive cells were observed at the second episode. At the third episode, there was again an increase in TSPO expression. TSPO expression was associated with microglial cells or macrophages without obvious astrocyte labeling. The dynamics of (18)F-PBR111 uptake in the brain, as measured by in vivo PET imaging and biodistribution, followed the pattern of TSPO expression during RR EAE. CONCLUSION PET imaging with the TSPO ligand (18)F-PBR111 clearly reflected the dynamics of microglial activation in the SJL/J mouse model of RR EAE. The results are the first to highlight the discrepancy between the clinical symptoms of EAE and TSPO expression in the brain, as measured by PET imaging at the peaks of various EAE episodes. The results suggest a significant role for PET imaging investigations of neuroinflammation in multiple sclerosis and allow for in vivo follow-up of antiinflammatory treatment strategies.
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Affiliation(s)
- Filomena Mattner
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales, Australia.
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Taylor SR, Roberts MP, Wyatt NA, Pham TQ, Stark D, Bourdier T, Roselt P, Katsifis A, Greguric I. Synthesis and Radiosynthesis of a Novel PET Fluorobenzyl Piperazine for Melanoma Tumour Imaging; [18F]MEL054. Aust J Chem 2013. [DOI: 10.1071/ch12489] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
2-{2-[4-(4-[18F]-Fluorobenzyl)piperazin-1-yl]-2-oxoethyl}isoindolin-1-one ([18F]MEL054), is a new potent indolinone-based melanin binder designed to target melanotic tumours. [18F]MEL054 was prepared by an automated two-step radiosynthesis, comprising of the preparation of 4-[18F]fluorobenzaldehyde from 4-formyl-N,N,N-trimethylanilinium triflate, followed by reductive alkylation with 2-(2-oxo-2-piperazin-1-ylethyl)isoindolin-1-one. 4-[18F]Fluorobenzaldehyde was prepared on a GE TRACERlab FXFN module in 68 ± 8 % radiochemical yield (RCY, non-decay corrected), purified by a Sep-Pak Plus C18 cartridge and eluted into the reactor of an in-house modified Nuclear Interface [18F]FDG synthesis module for the subsequent reductive alkylation reaction. HPLC purification produced [18F]MEL054 in a collected RCY of 34 ± 9 % (non-decay corrected), the total preparation time (including Sep-Pak Plus C18 and HPLC purification) did not exceed 105 min. The radiochemical purity of [18F]MEL054 was greater than 99 % with a specific radioactivity of 71–119 GBq μmol–1 and [18F]MEL054 remained stable in saline solution (>98 %) after 3 h.
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27
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Dedeurwaerdere S, Callaghan PD, Pham T, Rahardjo GL, Amhaoul H, Berghofer P, Quinlivan M, Mattner F, Loc'h C, Katsifis A, Grégoire MC. PET imaging of brain inflammation during early epileptogenesis in a rat model of temporal lobe epilepsy. EJNMMI Res 2012; 2:60. [PMID: 23136853 PMCID: PMC3570346 DOI: 10.1186/2191-219x-2-60] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 10/01/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recently, inflammatory cascades have been suggested as a target for epilepsy therapy. Positron emission tomography (PET) imaging offers the unique possibility to evaluate brain inflammation longitudinally in a non-invasive translational manner. This study investigated brain inflammation during early epileptogenesis in the post-kainic acid-induced status epilepticus (KASE) model with post-mortem histology and in vivo with [18F]-PBR111 PET. METHODS Status epilepticus (SE) was induced (N = 13) by low-dose injections of KA, while controls (N = 9) received saline. Translocator protein (TSPO) expression and microglia activation were assessed with [125I]-CLINDE autoradiography and OX-42 immunohistochemistry, respectively, 7 days post-SE. In a subgroup of rats, [18F]-PBR111 PET imaging with metabolite-corrected input function was performed before post-mortem evaluation. [18F]-PBR111 volume of distribution (Vt) in volume of interests (VOIs) was quantified by means of kinetic modelling and a VOI/metabolite-corrected plasma activity ratio. RESULTS Animals with substantial SE showed huge overexpression of TSPO in vitro in relevant brain regions such as the hippocampus and amygdala (P < 0.001), while animals with mild symptoms displayed a smaller increase in TSPO in amygdala only (P < 0.001). TSPO expression was associated with OX-42 signal but without obvious cell loss. Similar in vivo [18F]-PBR111 increases in Vt and the simplified ratio were found in key regions such as the hippocampus (P < 0.05) and amygdala (P < 0.01). CONCLUSION Both post-mortem and in vivo methods substantiate that the brain regions important in seizure generation display significant brain inflammation during epileptogenesis in the KASE model. This work enables future longitudinal investigation of the role of brain inflammation during epileptogenesis and evaluation of anti-inflammatory treatments.
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Affiliation(s)
- Stefanie Dedeurwaerdere
- Department of Translational Neuroscience, University of Antwerp, FGEN CDE T4.20, Universiteitsplein 1, Wilrijk, Antwerp, 2610, Belgium
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Paul D Callaghan
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Tien Pham
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Gita L Rahardjo
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Halima Amhaoul
- Department of Translational Neuroscience, University of Antwerp, FGEN CDE T4.20, Universiteitsplein 1, Wilrijk, Antwerp, 2610, Belgium
| | - Paula Berghofer
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | | | - Filomena Mattner
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Christian Loc'h
- LifeSciences, ANSTO, Locked Bag, Kirrawee DC, NSW, 2232, Australia
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia
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Chen J, Huang XF, Qiao L, Katsifis A. Insulin caused drug resistance to oxaliplatin in colon cancer cell line HT29. J Gastrointest Oncol 2012; 2:27-33. [PMID: 22811824 DOI: 10.3978/j.issn.2078-6891.2010.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 12/20/2010] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Obesity is associated with poor prognosis of colon cancer and the mechanism for this is unknown. This study tested insulin-caused resistance to oxaliplatin via activation of PI3K/Akt pathway in HT29 cells. METHODS The effect of insulin on oxaliplatin cytotoxicity was tested by pre-incubation with 1µM insulin followed by addition of oxaliplatin. Phosphorylated Akt was determined by Western blotting. RESULTS Addition of 1µM insulin decreased the cytotoxicity of oxaliplatin. PI3K specific inhibitor Ly294002 abolished such an effect of insulin. pAkt were highly activated by insulin plus oxaliplatin and inhibited by addition of Ly294002. CONCLUSION Insulin decreased drug efficacy of oxaliplatin in HT29 cells, which could be mediated by the activation of the PI3K/Akt pathway.
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Affiliation(s)
- Jiezhong Chen
- Illawarra Health and Medical Research Institute and School of Health Sciences, University of Wollongong, Wollongong, Australia
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29
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Ranson M, Berghofer P, Vine KL, Greguric I, Shepherd R, Katsifis A. Different radiolabelling methods alter the pharmacokinetic and biodistribution properties of Plasminogen Activator Inhibitor Type 2 (PAI-2) forms. Nucl Med Biol 2012; 39:833-9. [DOI: 10.1016/j.nucmedbio.2012.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/22/2011] [Accepted: 01/17/2012] [Indexed: 11/28/2022]
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Bourdier T, Pham TQ, Henderson D, Jackson T, Lam P, Izard M, Katsifis A. Automated radiosynthesis of [18F]PBR111 and [18F]PBR102 using the Tracerlab FXFN and Tracerlab MXFDG module for imaging the peripheral benzodiazepine receptor with PET. Appl Radiat Isot 2012; 70:176-83. [DOI: 10.1016/j.apradiso.2011.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 10/17/2022]
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Chen J, Katsifis A, Hu C, Huang XF. Insulin decreases therapeutic efficacy in colon cancer cell line HT29 via the activation of the PI3K/Akt pathway. Curr Drug Discov Technol 2011; 8:119-25. [PMID: 21513489 DOI: 10.2174/157016311795563820] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 02/03/2011] [Indexed: 11/22/2022]
Abstract
Obesity has been associated with both the carcinogenesis and poor prognosis of colon cancer, one of the leading causes of cancer-related death. Increased blood levels of insulin in obese subjects have been demonstrated to play a key role in carcinogenesis. It is also possible that insulin affects treatment efficacy, leading to poor prognosis. In this study, we demonstrated that insulin can increase HT29 colon cancer cell line resistance to cycloheximide and 5-fluorouracil induced cytotoxicity. This effect can be inhibited by the PI3K/Akt inhibitor Ly294002, indicating the important role of this pathway in the insulin-induced inefficacy of chemotherapy. The insulin-induced resistance to cycloheximide and 5-fluorouracil can be used in drug screening to overcome the inefficacy of chemotherapy in obesity-associated colon cancer.
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Affiliation(s)
- Jiezhong Chen
- Illawarra Health and Medical Research Institute, University of Wollongong, NSW, Australia.
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Lin HQ, Meriaty H, Katsifis A. Prediction of synergistic antitumour effect of gefitinib and radiation in vitro. Anticancer Res 2011; 31:2883-2888. [PMID: 21868533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AIM This study investigated the potential of a series of biomarkers in predicting the interaction of gefitinib and radiation in tumour treatment. MATERIALS AND METHODS In vitro assays were performed on human skin cancer and melanoma cell lines. The antitumour effect was measured by using the MTT assay. Total and phosphorylated epidermal growth factor receptor (EGFR and pEGFR) levels were determined by cell-based ELISA. RESULTS Gefitinib and radiation interacted to inhibit tumour cell proliferation in a cell line-dependent manner. Synergism dominated the interaction (76%), followed by additive effect (20%) and a few instances of antagonism (4%). Correlation analyses revealed a significant correlation between the median combination index (CI) and gefitinib IC₅₀, radiation ID₅₀, gefitinib- or EGF-modulated EGFR and/or pEGFR expression (all p ≤ 0.05). CONCLUSION A potential role of gefitinib efficacy, radiation efficacy and gefitinib- or EGF-modulated EGFR and/or pEGFR expression in the prediction of interaction between gefitinib and radiation is supported.
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Affiliation(s)
- Hui Qiang Lin
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232, Australia.
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Kee D, Liu W, Devitt BA, Wolfe R, Ware R, Salemi R, Dobrovic A, Brglevska S, Kelly J, Callahan J, Katsifis A, Roselt P, Neels OC, Bourdier T, Hicks RJ, McArthur GA. Melanoma pigmentation affects melanoma-specific survival and provides a potential target for radiopharmaceutical-based imaging and therapy. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.8563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Katsifis A, Loc'h C, Henderson D, Bourdier T, Pham T, Greguric I, Lam P, Callaghan P, Mattner F, Eberl S, Fulham M. A rapid solid-phase extraction method for measurement of non-metabolised peripheral benzodiazepine receptor ligands, [(18)F]PBR102 and [(18)F]PBR111, in rat and primate plasma. Nucl Med Biol 2011; 38:137-48. [PMID: 21220137 DOI: 10.1016/j.nucmedbio.2010.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 07/21/2010] [Accepted: 07/25/2010] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To develop a rapid and reliable method for estimating non-metabolised PBR ligands fluoroethoxy ([(18)F]PBR102)- and fluoropropoxy ([(18)F]PBR111)-substituted 2-(6-chloro-2-phenyl)imidazo[1,2-a]pyridine-3-yl)-N,N-diethylacetamides in plasma. METHODS Rats and baboons were imaged with PET up to 2 h postinjection of [(18)F]PBR102 and [(18)F]PBR111 under baseline conditions, after pre-blocking or displacement with PK11195. Arterial plasma samples were directly analysed by reverse-phase solid-phase extraction (RP-SPE) and RP-HPLC and by normal-phase TLC. SPE cartridges were successively washed with acetonitrile/water mixtures. SPE eluant radioactivity was measured in a γ-counter to determine the parent compound fraction and then analysed by HPLC and TLC for validation. RESULTS In SPE, hydrophilic and lipophilic radiolabelled metabolites were eluted in water and 20% acetonitrile/water. All non-metabolised [(18)F]PBR102 and [(18)F]PBR111 were in SPE acetonitrile fraction as confirmed by HPLC and TLC analysis. Unchanged (%) [(18)F]PBR102 and [(18)F]PBR111 from SPE analysis in rat and baboon plasma agreed with those from HPLC and TLC analysis. In rats and baboons, the fraction of unchanged tracer followed a bi-exponential decrease, with half-lives of 7 to 10 min for the fast component and >80 min for the slow component for both tracers. CONCLUSIONS Direct plasma SPE analysis of [(18)F]PBR102 and [(18)F]PBR111 can reliably estimate parent compound fraction. SPE was superior to HPLC for samples with low activity; it allows rapid and accurate metabolite analysis of a large number of plasma samples for improved estimation of metabolite-corrected input function during quantitative PET imaging studies.
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Mattner F, Bandin DL, Staykova M, Berghofer P, Gregoire MC, Ballantyne P, Quinlivan M, Fordham S, Pham T, Willenborg DO, Katsifis A. Evaluation of [¹²³I]-CLINDE as a potent SPECT radiotracer to assess the degree of astroglia activation in cuprizone-induced neuroinflammation. Eur J Nucl Med Mol Imaging 2011; 38:1516-28. [PMID: 21484375 DOI: 10.1007/s00259-011-1784-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/01/2011] [Indexed: 10/18/2022]
Abstract
PURPOSE The purpose of this study was to assess the feasibility and sensitivity of the high-affinity translocator protein (TSPO) ligand [(123)I]-CLINDE in imaging TSPO changes in vivo and characterise and compare astroglial and TSPO changes in the cuprizone model of demyelination and remyelination in C57BL/6 mice. METHODS C57BL/6 mice were fed with cuprizone for 4 weeks to induce demyelination followed by 2-4 weeks of standard diet (remyelination). Groups of mice were followed by in vivo single photon emission computed tomography (SPECT)/CT imaging using [(123)I]-CLINDE and uptake correlated with biodistribution, autoradiography, immunohistochemistry, immunofluorescence and real-time polymerase chain reaction (RT-PCR). RESULTS The uptake of [(123)I]-CLINDE in the brain as measured by SPECT imaging over the course of treatment reflects the extent of the physiological response, with significant increases observed during demyelination followed by a decrease in uptake during remyelination. This was confirmed by autoradiography and biodistribution studies. A positive correlation between TSPO expression and astrogliosis was found and both activated astrocytes and microglial cells expressed TSPO. [(123)I]-CLINDE uptake reflects astrogliosis in brain structures such as corpus callosum, caudate putamen, medium septum and olfactory tubercle as confirmed by both in vitro and in vivo results. CONCLUSION The dynamics in the cuprizone-induced astroglial and TSPO changes, observed by SPECT imaging, were confirmed by immunofluorescence, RT-PCR and autoradiography. The highly specific TSPO radioiodinated ligand CLINDE can be used as an in vivo marker for early detection and monitoring of a variety of neuropathological conditions using noninvasive brain imaging techniques.
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Affiliation(s)
- Filomena Mattner
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, Sydney, NSW 2234, Australia.
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Abstract
Colorectal cancer is the third most common cancer with a 5-year survival rate of less than 10%. It is caused by alterations of multiple signal pathways which are affected by both genetic and environmental factors. In some cases, EGFR is important in the carcinogenesis of colorectal cancer suggesting anti-EGFR therapy may be a potential treatment option. However, in other cases it is not effective, which may be related to its down-stream targeted gene mutations. KRAS is highly emphasized in the literature but other mutations like Src, PIK3CA, and BRAF may also be important. Furthermore, obesity may decrease the effectiveness of anti-EGFR treatment as it increases the risk factors for colorectal cancer. Using next-generation sequencing technology, it may be possible to identify all gene mutations in an individual with colorectal cancer. Therefore, gene mutations affecting anti-EGFR therapy in colorectal cancer patients can be identified.
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Affiliation(s)
- Jiezhong Chen
- Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, NSW 2522, Australia.
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Bourdier T, Greguric I, Roselt P, Jackson T, Faragalla J, Katsifis A. Fully automated one-pot radiosynthesis of O-(2-[18F]fluoroethyl)-L-tyrosine on the TracerLab FX(FN) module. Nucl Med Biol 2011; 38:645-51. [PMID: 21718939 DOI: 10.1016/j.nucmedbio.2011.01.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 12/06/2010] [Accepted: 01/03/2011] [Indexed: 11/28/2022]
Abstract
INTRODUCTION An efficient fully automated method for the radiosynthesis of enantiomerically pure O-(2-[(18)F]fluoroethyl)-L-tyrosine ([(18)F]FET) using the GE TracerLab FX(FN) synthesis module via the O-(2-tosyloxyethyl)-N-trityl-L-tyrosine tert-butylester precursor has been developed. METHODS The radiolabelling of [(18)F]FET involved a classical [(18)F]fluoride nucleophilic substitution performed in acetonitrile using potassium carbonate and Kryptofix 222, followed by acid hydrolysis using 2N hydrochloric acid. RESULTS [(18)F]FET was produced in 35±5% (n=22) yield non-decay-corrected (55±5% decay-corrected) and with radiochemical and enantiomeric purity of >99% with a specific activity of >90 GBq/μmol after 63 min of radiosynthesis including HPLC purification and formulation. CONCLUSION The automated radiosynthesis provides high and reproducible yields suitable for routine clinical use.
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Affiliation(s)
- Thomas Bourdier
- LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC NSW 2232, Sydney, Australia.
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Bourdier T, Shepherd R, Berghofer P, Jackson T, Fookes CJR, Denoyer D, Dorow DS, Greguric I, Gregoire MC, Hicks RJ, Katsifis A. Radiosynthesis and Biological Evaluation of l- and d-S-(3-[18F]Fluoropropyl)homocysteine for Tumor Imaging Using Positron Emission Tomography. J Med Chem 2011; 54:1860-70. [PMID: 21351733 DOI: 10.1021/jm101513q] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas Bourdier
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Rachael Shepherd
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Paula Berghofer
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Timothy Jackson
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Christopher J. R. Fookes
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Delphine Denoyer
- Centre for Molecular Imaging, The Peter MacCallum Cancer Centre, 12 St. Andrew's Place, East Melbourne, VIC, 3002, Australia
| | - Donna S. Dorow
- Centre for Molecular Imaging, The Peter MacCallum Cancer Centre, 12 St. Andrew's Place, East Melbourne, VIC, 3002, Australia
| | - Ivan Greguric
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Marie-Claude Gregoire
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
| | - Rodney J. Hicks
- Centre for Molecular Imaging, The Peter MacCallum Cancer Centre, 12 St. Andrew's Place, East Melbourne, VIC, 3002, Australia
| | - Andrew Katsifis
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Sydney, Australia
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Greguric I, Taylor S, Pham T, Wyatt N, Jiang CD, Bourdier T, Loc'h C, Roselt P, Neels OC, Katsifis A. Radiosynthesis of a Novel PET Fluoronicotinamide for Melanoma Tumour PET Imaging; [18F]MEL050. Aust J Chem 2011. [DOI: 10.1071/ch11048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
[18F]6-Fluoro-N-[2-(diethylamino)ethyl]nicotinamide [18F]MEL050 is a novel nicotinamide-based radiotracer, designed to target random metastatic dissemination of melanoma tumours by targeting melanin. Preclinical studies suggest that [18F]MEL050 has an excellent potential to improve diagnosis and staging of melanoma. Here we report the radiochemical optimization conditions of [18F]MEL050 and its large scale automated synthesis using a GE FXFN automated radiosynthesis module for clinical, phase-1 investigation. [18F]MEL050 was prepared via a one-step synthesis using no-carrier added K[18F]F-Krytpofix® 222 (DMSO, 170°C, 5 min) followed by HPLC purification. Using 6-chloro-N-[2-(diethylamino)ethyl]nicotinamide as precursor, [18F]MEL050 was obtained in 40–46% radiochemical yield (non-decay corrected), in greater than 99.9% radiochemical purity and specific activity ranging from 240 to 325 GBq μmol–1. Total synthesis time including formulation was 40 min and [18F]MEL050 was stable (99.8%) in PBS for 6 h.
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Denoyer D, Potdevin T, Roselt P, Neels OC, Kirby L, Greguric I, Katsifis A, Dorow DS, Hicks RJ. Improved detection of regional melanoma metastasis using 18F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide, a melanin-specific PET probe, by perilesional administration. J Nucl Med 2010; 52:115-22. [PMID: 21149487 DOI: 10.2967/jnumed.110.078154] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The efficacy of differing routes of administration of 18F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide (18F-MEL050), a new benzamide-based PET radiotracer for imaging regional lymph node metastasis in melanoma, was assessed. METHODS B16-Black/6 metastatic melanoma cells harboring an mCherry transgene were implanted into the left-upper-foot surface of 49 C57 Black/6 mice as a model of popliteal lymph node (PLN) metastasis. Ultrasound scanning of the left PLN was performed at baseline and in combination with 18F-MEL050 PET on days 5, 9, and 14. Mice were divided into 2 groups to compare the results of tracer administration either subcutaneously at the tumor site (local) or in the lateral tail vein (systemic). After PET on each imaging day, 5 mice per group-including any with evidence of metastasis-were sacrificed for ex vivo validation studies including assessment of retained radioactivity and presence of the mCherry transgene as a surrogate of nodal tumor burden. RESULTS Nine mice were judged as positive for PLN metastasis by ultrasound at day 5, and 8 PLNs were positive on 18F-MEL050 PET, 3 after systemic and 5 after local administration. Ex vivo analysis showed that ultrasound correctly identified 90% of positive PLNs, with 1 false-positive. 18F-MEL050 PET correctly identified 60% of positive PLNs after systemic administration and 100% after local administration with no false-positive results by either route. The average node-to-background ratio for positive PLNs was 6.8 in the systemic-administration group and correlated with disease burden. In the local-administration group, the mean uptake ratio was 48, without clear relation to metastatic burden. Additional sites of metastatic disease were also correctly identified by 18F-MEL050 PET. CONCLUSION In addition to its potential for systemic staging, perilesional administration of 18F-MEL050 may allow sensitive and specific, noninvasive identification of regional lymph node metastasis in pigmented malignant melanomas.
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Affiliation(s)
- Delphine Denoyer
- Centre for Cancer Imaging and Translational Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
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Lin HQ, Katsifis A, Meriaty H. Tumour response to gefitinib is associated with EGF- and gefitinib- but not radiation-modulated EGFR expression. Anticancer Res 2010; 30:4899-4905. [PMID: 21187468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
AIM This study was conducted to explore the relationship between different treatment-modulated EGFR expression and gefitinib sensitivity. MATERIALS AND METHODS Gefitinib-sensitive (A431) and -resistant (A375, MALME-3M, and SK-MEL 5) tumour cell lines were treated with epidermal growth factor (EGF), gefitinib or radiation in vitro, and EGFR expression levels were measured by using ELISA. RESULTS EGF, and gefitinib treatment resulted in significantly higher levels of total and/or phosphorylated EGFR in sensitive than in resistant tumours and this was associated with gefitinib IC(50). In contrast, radiation-modulated EGFR expression, both total and phosphorylated, did not correlate with the efficacy of gefitinib. Stimulation of proliferation by EGF was significantly stronger in A431 than in the other three lines, indicating sensitive tumours were more EGFR-dependent than resistant tumours for cell proliferation. CONCLUSION These findings imply a potential role of EGF- and gefitinib-modulated EGFR expression in predicting gefitinib sensitivity.
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Affiliation(s)
- Hui Qiang Lin
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
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Arlicot N, Petit E, Katsifis A, Toutain J, Divoux D, Bodard S, Roussel S, Guilloteau D, Bernaudin M, Chalon S. Detection and quantification of remote microglial activation in rodent models of focal ischaemia using the TSPO radioligand CLINDE. Eur J Nucl Med Mol Imaging 2010; 37:2371-80. [PMID: 20814674 DOI: 10.1007/s00259-010-1598-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 08/09/2010] [Indexed: 01/09/2023]
Abstract
PURPOSE Neuroinflammation is involved in stroke pathophysiology and might be imaged using radioligands targeting the 18 kDa translocator protein (TSPO). METHODS We studied microglial reaction in brain areas remote from the primary lesion site in two rodent models of focal cerebral ischaemia (permanent or transient) using [125I]-CLINDE, a promising TSPO single photon emission computed tomography radioligand. RESULTS In a mouse model of permanent middle cerebral artery occlusion (MCAO), ex vivo autoradiographic studies demonstrated, besides in the ischaemic territory, accumulation of [125I]-CLINDE in the ipsilateral thalamus with a binding that progressed up to 3 weeks after MCAO. [125I]-CLINDE binding markedly decreased in animals pre-injected with either unlabelled CLINDE or PK11195, while no change was observed with flumazenil pre-treatment, demonstrating TSPO specificity. In rats subjected to transient MCAO, [125I]-CLINDE binding in the ipsilateral thalamus and substantia nigra pars reticulata (SNr) was significantly higher than that in contralateral tissue. Moreover, [125I]-CLINDE binding in the thalamus and SNr was quantitatively correlated to the ischaemic volume assessed by MRI in the cortex and striatum, respectively. CONCLUSION Clinical consequences of secondary neuronal degeneration in stroke might be better treated thanks to the discrimination of neuronal processes using in vivo molecular imaging and potent TSPO radioligands like CLINDE to guide therapeutic interventions.
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Affiliation(s)
- Nicolas Arlicot
- UMR Inserm U 930, CNRS ERL 3106, Université François Rabelais de Tours, CHRU de Tours, Tours, France.
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Carson RE, Weinzimmer DP, Koren A, Alagille D, Fowles K, Ashworth S, Seibyl JP, Katsifis A, Gunn RN, Rabiner EA, Tang SP, Tamagnan G. PET evaluation of the TSPO ligands [F-18]FEPPA, [F-18]PRB06, and [F-18]PBR111 in nonhuman primate. Neuroimage 2010. [DOI: 10.1016/j.neuroimage.2010.04.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Denoyer D, Greguric I, Roselt P, Neels OC, Aide N, Taylor SR, Katsifis A, Dorow DS, Hicks RJ. High-contrast PET of melanoma using (18)F-MEL050, a selective probe for melanin with predominantly renal clearance. J Nucl Med 2010; 51:441-7. [PMID: 20150254 DOI: 10.2967/jnumed.109.070060] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The aim of this study was to evaluate the novel probe (18)F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide ((18)F-MEL050) for the imaging of primary and metastatic melanoma. METHODS PET using (18)F-MEL050 was performed in murine models of melanoma. The specificity of (18)F-MEL050 was studied by comparing its accumulation in pigmented B16-F0 allograft tumors with that of human amelanotic A375 xenografts using PET and high-resolution autoradiography. (18)F-MEL050 PET results were compared with (18)F-FDG PET, the current standard in melanoma molecular imaging. To test the ability of (18)F-MEL050 to assess the metastatic spread of melanoma, a murine model of lung metastasis was imaged by PET/CT, and results correlated with physical assessment of tumor burden in the lungs. RESULTS In pigmented B16-F0 grafts, (18)F-MEL050 PET yielded a tumor-to-background ratio of approximately 20:1 at 1 h and greater than 50:1 at 2 and 3 h. In the B16-F0 melanoma allograft model, tumor-to-background ratio was more than 9-fold higher for (18)F-MEL050 than for (18)F-FDG (50.9 +/- 6.9 vs. 5.8 +/- 0.5). No uptake was observed in the amelanotic melanoma xenografts. Intense uptake of (18)F-MEL050 was evident in metastatic lesions in the lungs of B16-BL6 tumor-bearing mice on PET at 2 h after tracer injection, with high concordance between (18)F-MEL050 accumulation on PET/CT and tumor burden determined at necroscopy. CONCLUSION (18)F-MEL050 has a rapid tumor uptake and high retention with specificity for melanin, suggesting great potential for noninvasive clinical evaluation of suspected metastatic melanoma.
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Affiliation(s)
- Delphine Denoyer
- Centre for Molecular Imaging and Translational Research Laboratory, Peter MacCallum Cancer Centre, Victoria, Australia
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Van Camp N, Boisgard R, Kuhnast B, Thézé B, Viel T, Grégoire MC, Chauveau F, Boutin H, Katsifis A, Dollé F, Tavitian B. In vivo imaging of neuroinflammation: a comparative study between [(18)F]PBR111, [ (11)C]CLINME and [ (11)C]PK11195 in an acute rodent model. Eur J Nucl Med Mol Imaging 2010; 37:962-72. [PMID: 20069292 DOI: 10.1007/s00259-009-1353-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 12/01/2009] [Indexed: 11/29/2022]
Abstract
PURPOSE The key role of neuroinflammation in acute and chronic neurological disorders has stimulated the search for specific radiotracers targeting the peripheral benzodiazepine receptor (PBR)/18 kDa translocator protein (TSPO), a hallmark of neuroinflammation. Here we evaluate the new radiotracer for positron emission tomography (PET) [(18)F]PBR111 in a rodent model of acute inflammation and compare it with [(11)C]CLINME, an (11)C-labelled tracer of the same chemical family, and with the isoquinolinic carboxamide [(11)C]PK11195. METHODS We studied radiometabolites by HPLC, in vitro binding by autoradiography and in vivo brain kinetics as well as in vivo specificity of binding using PET imaging. RESULTS We show that this radiotracer has a high in vitro specificity for PBR/TSPO versus central benzodiazepine receptors, as reflected by the drastic reduction of its binding to target tissue by addition of PK11195 or PBR111, while addition of flumazenil does not affect binding. Only intact [(18)F]PBR111 is detected in brain up to 60 min after i.v. injection, and PET imaging shows an increased uptake in the lesion as compared to the contralateral side as early as 6 min after injection. Administration of an excess of PK11195 and PBR111, 20 min after [(18)F]PBR111 administration, induces a rapid and complete displacement of [(18)F]PBR111 binding from the lesion. Modelling of the PET data using the simplified reference tissue model showed increased binding potential (BP) in comparison to [(11)C]PK11195. CONCLUSION [(18)F]PBR111 is a metabolically stable tracer with a high specific in vitro and in vivo binding to TSPO. In addition, considering the longer half-life of (18)F over (11)C, these results support [(18)F]PBR111 as a promising PET tracer of the PBR/TSPO for neuroinflammation imaging.
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Affiliation(s)
- Nadja Van Camp
- CEA, I2BM, SHFJ, Laboratoire d'Imagerie Moléculaire Expérimentale (LIME), 4 place Leclerc, 91400 Orsay, France
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Katsifis A, Barlin G, Mattner F, Dikic B. Synthesis of [123I]iodine labelled imidazo[1,2-b] pyridazines as potential probes for the study of peripheral benzodiazepine receptors using SPECT. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.92.4.305.35581] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The pyridazines 3-acetamidomethyl-6-chloro-2-(4´-iodophenyl)imidazo[1,2-b]pyridazine 1 (IC50=1.6 nM) and 3-benzamidomethyl-6-iodo-2-(4´-t-butylphenyl)imidazo[1,2-b] pyridazine 2 (IC50=4.2 nM), are high affinity and selective ligands for the Peripheral Benzodiazepine Receptors (PBR) compared to the Central Benzodiazepine counterparts. The [123I] 1 and [123I] 2 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination of [123I] 1 was achieved by iododestannylation of the corresponding tributyl tin precursor with Na[ 123I] in the presence of peracetic acid or chloramine-T and the product isolated by C-18 RP HPLC. Radioiodination of [123I] 2 was achieved by copper assisted bromine [123I]iodine exchange of the corresponding bromo precursor in the presence of acetic acid and sodium bisulfate as reducing agent at 200 °C. Purification of the crude products were achieved by semi-preparative C-18 RP HPLC to give the products in radiochemical yields >90%. The products were obtained in >97% chemical and radiochemical purity and with specific activities >180 GBq/μmol.
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Greguric I, Taylor SR, Denoyer D, Ballantyne P, Berghofer P, Roselt P, Pham TQ, Mattner F, Bourdier T, Neels OC, Dorow DS, Loc'h C, Hicks RJ, Katsifis A. Discovery of [18F]N-(2-(diethylamino)ethyl)-6-fluoronicotinamide: a melanoma positron emission tomography imaging radiotracer with high tumor to body contrast ratio and rapid renal clearance. J Med Chem 2009; 52:5299-302. [PMID: 19691348 DOI: 10.1021/jm9008423] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The high melanoma uptake and rapid body clearance displayed by our series of [(123)I]iodonicotinamides prompted the development of [(18)F]N-(2-(diethylamino)ethyl)-6-fluoronicotinamide ([(18)F]2), a novel radiotracer for PET melanoma imaging. Significantly, unlike fluorobenzoates, [(18)F]fluorine incorporation on the nicotinamide ring is one step, facile, and high yielding. [(18)F]2 displayed high tumor uptake, rapid body clearance via predominantly renal excretion, and is currently being evaluated in preclinical studies for progression into clinical trials to assess the responsiveness of therapeutic agents.
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Affiliation(s)
- Ivan Greguric
- Radiopharmaceuticals Research Institute, Australian Nuclear Science and Technology Organisation, Menai, NSW 2234, Sydney, Australia.
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Katsifis A, Mattner F, Dikic B, Papazian V. Synthesis of substituted [123I]imidazo[1,2-α]pyridines as potential probes for the study of the peripheral benzodiazepine receptors using SPECT. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2000.88.3-4.229] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The imidazo[1,2-α]pyridines [N,N´-dimethyl-6-chloro-(4´zf-iodophenyl)imidazo[1,2-α]pyridine-3-acetamide 1, [N,N´l-6-chloro-(4´-iodophenyl)imidazo[1,2-α]pyridine-3-acetamide 2, and [N-methyl-6-chloro-(4´-iodophenyl)imidazo[1,2-α]pyridine-3-acetamide 3, are high affinity and selective ligands for the Peripheral Benzodiazepine Receptors (PBR). The [123I]1-3 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination was achieved by iododestannylation reactions of the corresponding tributyl tin precursors with Na[123I] in the presence of peracetic acid, chloramine-T or Iodogen. Purification of the crude product was achieved by semipreparative C-18 RP HPLC to give the products in radiochemical yields of 40-85%. The products were obtained in >97% chemical and radiochemical purity and with specific activities >80 GBq/μmol.
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Lim SM, Katsifis A, Villemagne VL, Best R, Jones G, Saling M, Bradshaw J, Merory J, Woodward M, Hopwood M, Rowe CC. The 18F-FDG PET cingulate island sign and comparison to 123I-beta-CIT SPECT for diagnosis of dementia with Lewy bodies. J Nucl Med 2009; 50:1638-45. [PMID: 19759102 DOI: 10.2967/jnumed.109.065870] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Neuroimaging is increasingly used to supplement the clinical diagnosis of dementia with Lewy bodies (DLB) by showing reduced occipital metabolism and perfusion and reduced striatal dopaminergic innervation. We aimed to optimize the interpretation of (18)F-FDG PET images for differentiating DLB from Alzheimer disease (AD) and to compare the results with dopamine transporter imaging using (123)I-beta-carbomethoxy-3ss-(4-iodophenyl)tropane ((123)I-beta-CIT) SPECT. METHODS Fourteen subjects with a clinical diagnosis of DLB and 10 with AD underwent both (18)F-FDG PET and (123)I-beta-CIT SPECT. Four DLB and 1 AD diagnoses were subsequently confirmed at autopsy. Diagnostic accuracy was calculated for visual interpretation by 3 readers of standard 3-plane and stereotactic surface projection (18)F-FDG PET images, receiver-operating-characteristic analysis of regional (18)F-FDG uptake, and a cutoff value for the striatal-to-occipital binding ratio of beta-CIT defined by receiver-operating-characteristic analysis. RESULTS Visual interpretation of 3-plane (18)F-FDG PET images had a sensitivity of 83% and specificity of 93% for DLB, slightly higher than the results with the stereotactic surface projection images. Regionally, hypometabolism in the lateral occipital cortex had the highest sensitivity (88%), but relative preservation of the mid or posterior cingulate gyrus (cingulate island sign) had the highest specificity (100%). Region-of-interest analysis revealed that occipital hypometabolism and relative preservation of the posterior cingulate both had a sensitivity of 77% and specificity of 80%. beta-CIT achieved 100% accuracy and greater effect size than did (18)F-FDG PET (Cohen d = 4.1 vs. 1.9). CONCLUSION Both (18)F-FDG PET and (123)I-beta-CIT SPECT appear useful for the diagnosis of DLB, although the latter provides more robust results. The cingulate island sign may enhance the specificity of (18)F-FDG PET.
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Affiliation(s)
- Seok Ming Lim
- Department of Nuclear Medicine and Centre for PET, Austin Health, Victoria, Australia
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Abstract
The method for (64)Cu production based on a (64)Ni target using an 18MeV proton energy beam was developed. The studies on the optimisation of targetry for the 18MeV proton bombardments were performed in terms of the cost-effective target utilisation and purity of the (64)Cu product. The thickness-specific (64)Cu yield (microCi/(microA x microm)) was introduced into the optimisation calculation with respect to cost-effective target utilisation. A maximum target utilisation efficacy factor (TUE) was found for the proton energy range of 2.5-13MeV with corresponding target thickness of 36.2microm. With the optimised target thickness and proton energy range, the (64)Ni target thickness saving of 45.6% was achieved, while the overall (64)Cu yield loss is only 23.9%, compared to the use of the whole effective proton energy range of 0-18MeV with target thickness of 66.6microm. This optimisation has the advantage of reducing the target amount to a reasonable level, and therefore the cost of the expensive (64)Ni target material. The (64)Ni target electroplated on the Au-Tl multi layer coated Cu-substrate was a new and competent design for an economic production of high quality (64)Cu radioisotope using an 18MeV proton energy cyclotron or a 30MeV cyclotron with proton beam adjustable to 18MeV. In this design, the Au coating layer plays a role of protection of "cold" Cu leakage from the Cu substrate and Tl serves to depress the proton beam energy (from 18MeV to the energy optimised value 13MeV). The ion exchange chromatographic technique with a gradient elution was applied to improve the (64)Cu separation with respect to reducing the processing time and control of (64)Cu product quality.
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Affiliation(s)
- Van So Le
- Radiopharmaceutical Research Institute, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights , P.M.B. 1 Menai, NSW 2234, Australia.
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