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Wang Y, Gao F. Research Progress of CXCR4-Targeting Radioligands for Oncologic Imaging. Korean J Radiol 2023; 24:871-889. [PMID: 37634642 PMCID: PMC10462898 DOI: 10.3348/kjr.2023.0091] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/24/2023] [Accepted: 07/07/2023] [Indexed: 08/29/2023] Open
Abstract
C-X-C motif chemokine receptor 4 (CXCR4) plays a key role in various physiological functions, such as immune processes and disease development, and can influence angiogenesis, proliferation, and distant metastasis in tumors. Recently, several radioligands, including peptides, small molecules, and nanoclusters, have been developed to target CXCR4 for diagnostic purposes, thereby providing new diagnostic strategies based on CXCR4. Herein, we focus on the recent research progress of CXCR4-targeting radioligands for tumor diagnosis. We discuss their application in the diagnosis of hematological tumors, such as lymphomas, multiple myelomas, chronic lymphocytic leukemias, and myeloproliferative tumors, as well as nonhematological tumors, including tumors of the esophagus, breast, and central nervous system. Additionally, we explored the theranostic applications of CXCR4-targeting radioligands in tumors. Targeting CXCR4 using nuclear medicine shows promise as a method for tumor diagnosis, and further research is warranted to enhance its clinical applicability.
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Affiliation(s)
- Yanzhi Wang
- Key Laboratory for Experimental Teratology of the Ministry of Education and Research Center for Experimental Nuclear Medicine, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Feng Gao
- Key Laboratory for Experimental Teratology of the Ministry of Education and Research Center for Experimental Nuclear Medicine, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
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Yu J, Zhou X, Shen L. CXCR4-Targeted Radiopharmaceuticals for the Imaging and Therapy of Malignant Tumors. Molecules 2023; 28:4707. [PMID: 37375261 DOI: 10.3390/molecules28124707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/31/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
C-X-C chemokine receptor type 4 (CXCR4), also known as fusin or CD184, is a 7-transmembrane helix G-protein-coupled receptor that is encoded by the CXCR4 gene. Involved in various physiological processes, CXCR4 could form an interaction with its endogenous partner, chemokine ligand 12 (CXCL12), which is also named SDF-1. In the past several decades, the CXCR4/CXCL12 couple has attracted a large amount of research interest due to its critical functions in the occurrence and development of refractory diseases, such as HIV infection, inflammatory diseases, and metastatic cancer, including breast cancer, gastric cancer, and non-small cell lung cancer. Furthermore, overexpression of CXCR4 in tumor tissues was shown to have a high correlation with tumor aggressiveness and elevated risks of metastasis and recurrence. The pivotal roles of CXCR4 have encouraged an effort around the world to investigate CXCR4-targeted imaging and therapeutics. In this review, we would like to summarize the implementation of CXCR4-targeted radiopharmaceuticals in the field of various kinds of carcinomas. The nomenclature, structure, properties, and functions of chemokines and chemokine receptors are briefly introduced. Radiopharmaceuticals that could target CXCR4 will be described in detail according to their structure, such as pentapeptide-based structures, heptapeptide-based structures, nonapeptide-based structures, etc. To make this review a comprehensive and informative article, we would also like to provide the predictive prospects for the CXCR4-targeted species in future clinical development.
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Affiliation(s)
- Jingjing Yu
- HTA Co., Ltd., Beijing 102413, China
- Department of Nuclear Technology Application, China Institute of Atomic Energy, Beijing 102413, China
| | - Xu Zhou
- HTA Co., Ltd., Beijing 102413, China
| | - Langtao Shen
- HTA Co., Ltd., Beijing 102413, China
- National Isotope Center of Engineering and Technology, China Institute of Atomic Energy, Beijing 102413, China
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Alluri SR, Higashi Y, Kil KE. PET Imaging Radiotracers of Chemokine Receptors. Molecules 2021; 26:molecules26175174. [PMID: 34500609 PMCID: PMC8434599 DOI: 10.3390/molecules26175174] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 12/12/2022] Open
Abstract
Chemokines and chemokine receptors have been recognized as critical signal components that maintain the physiological functions of various cells, particularly the immune cells. The signals of chemokines/chemokine receptors guide various leukocytes to respond to inflammatory reactions and infectious agents. Many chemokine receptors play supportive roles in the differentiation, proliferation, angiogenesis, and metastasis of diverse tumor cells. In addition, the signaling functions of a few chemokine receptors are associated with cardiac, pulmonary, and brain disorders. Over the years, numerous promising molecules ranging from small molecules to short peptides and antibodies have been developed to study the role of chemokine receptors in healthy states and diseased states. These drug-like candidates are in turn exploited as radiolabeled probes for the imaging of chemokine receptors using noninvasive in vivo imaging, such as positron emission tomography (PET). Recent advances in the development of radiotracers for various chemokine receptors, particularly of CXCR4, CCR2, and CCR5, shed new light on chemokine-related cancer and cardiovascular research and the subsequent drug development. Here, we present the recent progress in PET radiotracer development for imaging of various chemokine receptors.
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Affiliation(s)
- Santosh R. Alluri
- University of Missouri Research Reactor, University of Missouri, Columbia, MO 65211, USA;
| | - Yusuke Higashi
- Department of Medicine, Tulane University, New Orleans, LA 70112, USA;
| | - Kun-Eek Kil
- University of Missouri Research Reactor, University of Missouri, Columbia, MO 65211, USA;
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211, USA
- Correspondence: ; Tel.: +1-(573)-884-7885
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Kwon D, Lozada J, Zhang Z, Zeisler J, Poon R, Zhang C, Roxin Á, Lin KS, Perrin D, Benard F. High-Contrast CXCR4-Targeted 18F-PET Imaging Using a Potent and Selective Antagonist. Mol Pharm 2020; 18:187-197. [PMID: 33253591 DOI: 10.1021/acs.molpharmaceut.0c00785] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
C-X-C chemokine receptor 4 (CXCR4) is highly expressed in cancers, contributing to proliferation, metastasis, and a poor prognosis. The noninvasive imaging of CXCR4 can enable the detection and characterization of aggressive cancers with poor outcomes. Currently, no 18F-labeled CXCR4 positron emission tomography (PET) radiotracer has demonstrated imaging contrast comparable to [68Ga]Ga-Pentixafor, a CXCR4-targeting radioligand. We, therefore, aimed to develop a high-contrast CXCR4-targeting radiotracer by incorporating a hydrophilic linker and trifluoroborate radioprosthesis to LY2510924, a known CXCR4 antagonist. A carboxy-ammoniomethyl-trifluoroborate (PepBF3) moiety was conjugated to the LY2510924-derived peptide possessing a triglutamate linker via amide bond formation to obtain BL08, whereas an alkyne ammoniomethyl-trifluoroborate (AMBF3) moiety was conjugated using the copper-catalyzed [3+2] cycloaddition click reaction to obtain BL09. BL08 and BL09 were radiolabeled with [18F]fluoride ion using 18F-19F isotope exchange. Pentixafor was radiolabeled with [68Ga]GaCl3. Side-by-side PET imaging and biodistribution studies were performed on immunocompromised mice bearing Daudi Burkitt lymphoma xenografts. The biodistribution of [18F]BL08 and [18F]BL09 showed tumor uptake at 2 h postinjection (p.i.) (5.67 ± 1.25%ID/g and 5.83 ± 0.92%ID/g, respectively), which were concordant with the results of PET imaging. [18F]BL08 had low background activity, providing tumor-to-blood, -muscle, and -liver ratios of 72 ± 20, 339 ± 81, and 14 ± 3 (2 h p.i.), respectively. [18F]BL09 behaved similarly, with ratios of 64 ± 20, 239 ± 72, and 17 ± 3 (2 h p.i.), respectively. This resulted in high-contrast visualization of tumors on PET imaging for both radiotracers. [18F]BL08 exhibited lower kidney uptake (2.2 ± 0.5%ID/g) compared to [18F]BL09 (7.6 ± 1.0%ID/g) at 2 h p.i. [18F]BL08 and [18F]BL09 demonstrated higher tumor-to-blood, -muscle, and -liver ratios compared to [68Ga]Ga-Pentixafor (18.9 ± 2.7, 95.4 ± 36.7, and 5.9 ± 0.7 at 2 h p.i., respectively). In conclusion, [18F]BL08 and [18F]BL09 enable high-contrast visualization of CXCR4 expression in Daudi xenografts. Based on high tumor-to-organ ratios, [18F]BL08 may prove a valuable new tool for CXCR4-targeted PET imaging with potential for translation. The use of a PepBF3 moiety is a new approach for the orthogonal conjugation of organotrifluoroborates for 18F-labeling of peptides.
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Affiliation(s)
- Daniel Kwon
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada
| | - Jerome Lozada
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Zhengxing Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada
| | - Jutta Zeisler
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada
| | - Richel Poon
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada
| | - Áron Roxin
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada.,Department of Radiology, University of British Columbia, Vancouver V5Z 1M9, Canada
| | - David Perrin
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Francois Benard
- Department of Molecular Oncology, BC Cancer, Vancouver V5Z 1L3, Canada.,Department of Radiology, University of British Columbia, Vancouver V5Z 1M9, Canada
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Zhang H, Maeda M, Shindo M, Ko M, Mane M, Grommes C, Weber W, Blasberg R. Imaging CXCR4 Expression with Iodinated and Brominated Cyclam Derivatives. Mol Imaging Biol 2020; 22:1184-1196. [PMID: 32239371 PMCID: PMC7497443 DOI: 10.1007/s11307-020-01480-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE CXCR4 is one of several "chemokine" receptors expressed on malignant tumors (including GBM and PCNSL) and hematopoietic stem cells. Although 68Ga-pentixafor and 68Ga-NOTA-NFB have been shown to effectively image CXCR4 expression in myeloma and other systemic malignancies, imaging CXCR4 expression in brain tumors has been more limited due to the blood-brain barrier (BBB) and a considerable fraction of CXCR4 staining is intracellular. METHODS We synthesized 6 iodinated and brominated cyclam derivatives with high affinity (low nM range) for CXCR4, since structure-based estimates of lipophilicity suggested rapid transfer across the BBB and tumor cell membranes. RESULTS We tested 3 iodinated and 3 brominated cyclam derivatives in several CXCR4(+) and CXCR4(-) cell lines, with and without cold ligand blocking. To validate these novel radiolabeled cyclam derivatives for diagnostic CXCR4 imaging efficacy in brain tumors, we established appropriated murine models of intracranial GBM and PCNSL. Based on initial studies, 131I-HZ262 and 76Br-HZ270-1 were shown to be the most avidly accumulated radioligands. 76Br-HZ270-1 was selected for further study in the U87-CXCR4 and PCNSL #15 intracranial tumor models, because of its high uptake (9.5 ± 1.3 %ID/g, SD) and low non-specific uptake (1.6 ± 0.7 %ID/g, SD) in the s.c. U87-CXCR4 tumor models. However, imaging CXCR4 expression in intracranial U87-CXCR4 and PCNSL #15 tumors with 76Br-HZ270-1 was unsuccessful, following either i.v. or spinal-CSF injection. CONCLUSIONS Imaging CXCR4 expression with halogenated cyclam derivatives was successful in s.c. located tumors, but not in CNS located tumors. This was largely due to the following: (i) the hydrophilicity of the radiolabeled analogues-as reflected in the "measured" radiotracer distribution (LogD) in octanol/PBS-which stands in contrast to the structure-based estimate of LogP, which was the rationale for initiating the study and (ii) the presence of a modest BTB in intracranial U87-CXCR4 gliomas and an intact BBB/BTB in the intracranial PCNSL animal model.
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Affiliation(s)
- Hanwen Zhang
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Masatomo Maeda
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Neurosurgery, Nozaki Tokushukai Hospital, Osaka, Japan
| | - Masahiro Shindo
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Neurosurgery, Nozaki Tokushukai Hospital, Osaka, Japan
| | - Myat Ko
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mayuresh Mane
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Christian Grommes
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Wolfgang Weber
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Nuclear Medicine, Technical University Munich, Munich, Germany
| | - Ronald Blasberg
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Molecular Pharmacology & Chemistry Program, Memorial Sloan Kettering Cancer Center, Zuckerman Research Center (ZRC), Z-2060, 1275 York Avenue, New York, NY, 10065, USA.
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Adlere I, Caspar B, Arimont M, Dekkers S, Visser K, Stuijt J, de Graaf C, Stocks M, Kellam B, Briddon S, Wijtmans M, de Esch I, Hill S, Leurs R. Modulators of CXCR4 and CXCR7/ACKR3 Function. Mol Pharmacol 2019; 96:737-752. [DOI: 10.1124/mol.119.117663] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/14/2019] [Indexed: 02/06/2023] Open
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Brickute D, Braga M, Kaliszczak MA, Barnes C, Lau D, Carroll L, Stevens E, Trousil S, Alam IS, Nguyen QD, Aboagye EO. Development and Evaluation of an 18F-Radiolabeled Monocyclam Derivative for Imaging CXCR4 Expression. Mol Pharm 2019; 16:2106-2117. [PMID: 30883140 PMCID: PMC6522096 DOI: 10.1021/acs.molpharmaceut.9b00069] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 01/02/2023]
Abstract
In humans, C-X-C chemokine receptor type 4 (CXCR4) is a protein that is encoded by the CXCR4 gene and binds the ligand CXCL12 (also known as SDF-1). The CXCR4-CXCL12 interaction in cancer elicits biological activities that result in tumor progression and has accordingly been the subject of significant investigation for detection and treatment of the disease. Peptidic antagonists have been labeled with a variety of radioisotopes for the detection of CXCR4, but the methodology utilizing small molecules has predominantly used radiometals. We report here the development of a 18F-radiolabeled cyclam-based small molecule radioprobe, [18F]MCFB, for imaging CXCR4 expression. The IC50 value of [19F]MCFB for CXCR4 was similar to that of AMD3465 (111.3 and 89.8 nM, respectively). In vitro binding assays show that the tracer depicted a differential CXCR4 expression, which was blocked in the presence of AMD3465, demonstrating the specificity of [18F]MCFB. Positron emission tomography (PET) imaging studies showed a distinct uptake of the radioprobe in lymphoma and breast cancer xenografts. High liver and kidney uptakes were seen with [18F]MCFB, leading us to further examine the basis of its pharmacokinetics in relation to the tracer's cationic nature and thus the role of organic cation transporters (OCTs). Substrate competition following the intravenous injection of metformin led to a marked decrease in the urinary excretion of [18F]MCFB, with moderate changes observed in other organs, including the liver. Our results suggest involvement of OCTs in the renal elimination of the tracer. In conclusion, the 18F-radiolabeled monocyclam, [18F]MCFB, has potential to detect tumor CXCR4 in nonhepatic tissues.
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Affiliation(s)
| | | | - Maciej A. Kaliszczak
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Chris Barnes
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Doreen Lau
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Laurence Carroll
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Elizabeth Stevens
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Sebastian Trousil
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Israt S. Alam
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Quang-Dé Nguyen
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
| | - Eric O. Aboagye
- Cancer Imaging Centre, Department
of
Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K.
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[ 18F]Fluoroethyltriazolyl Monocyclam Derivatives as Imaging Probes for the Chemokine Receptor CXCR4. Molecules 2019; 24:molecules24081612. [PMID: 31022852 PMCID: PMC6514812 DOI: 10.3390/molecules24081612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/15/2019] [Accepted: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
Determining chemokine receptor CXCR4 expression is significant in multiple diseases due to its role in promoting inflammation, cell migration and tumorigenesis. [68Ga]Pentixafor is a promising ligand for imaging CXCR4 expression in multiple tumor types, but its utility is limited by the physical properties of 68Ga. We screened a library of >200 fluorine-containing structural derivatives of AMD-3465 to identify promising candidates for in vivo imaging of CXCR4 expression by positron emission tomography (PET). Compounds containing fluoroethyltriazoles consistently achieved higher docking scores. Six of these higher scoring compounds were radiolabeled by click chemistry and evaluated in PC3-CXCR4 cells and BALB/c mice bearing bilateral PC3-WT and PC3-CXCR4 xenograft tumors. The apparent CXCR4 affinity of the ligands was relatively low, but tumor uptake was CXCR4-specific. The tumor uptake of [18F]RPS-534 (7.2 ± 0.3 %ID/g) and [18F]RPS-547 (3.1 ± 0.5 %ID/g) at 1 h p.i. was highest, leading to high tumor-to-blood, tumor-to-muscle, and tumor-to-lung ratios. Total cell-associated activity better predicted in vivo tumor uptake than did the docking score or apparent CXCR4 affinity. By this metric, and on the basis of their high yielding radiosynthesis, high tumor uptake, and good contrast to background, [18F]RPS-547, and especially [18F]RPS-534, are promising 18F-labeled candidates for imaging CXCR4 expression.
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Amor-Coarasa A, Kelly J, Ponnala S, Vedvyas Y, Nikolopoulou A, Williams C, Jin MM, David Warren J, Babich JW. [ 18F]RPS-544: A PET tracer for imaging the chemokine receptor CXCR4. Nucl Med Biol 2018; 60:37-44. [PMID: 29544122 DOI: 10.1016/j.nucmedbio.2018.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/29/2017] [Accepted: 01/22/2018] [Indexed: 12/18/2022]
Abstract
INTRODUCTION CXCR4 specific [18F]-labeled positron emission tomography (PET) imaging agents are needed which would enable general distribution of the radiotracer for clinical investigation. We sought to synthesize, radiolabel and evaluate [18F]RPS-544, a novel non-peptide CXCR4 antagonist as a CXCR4 specific probe. We compared [18F]RPS-544 with the previously published [18F]-3 ([18F]RPS-510 in this paper) in a bi-lateral tumor model of differential CXCR4 expression for its ability to selectively target CXCR4 expression. METHODS Radiolabeling of [18F]RPS-544 and [18F]RPS-510 was performed by aromatic substitution on a 6-nitropyridyl group using no-carrier-added [18F]fluoride under basic conditions. 18F incorporation was determined by radioHPLC. Semi-preparative HPLC was used to purify the final product prior to reformulation. Imaging and biodistribution was performed in nude mice with bilateral PC3 (CXCR4+ and WT) xenograft tumors at 1, 2 and 4 h post injection. RESULTS RPS-544 bound CXCR4 with an IC50 of 4.9 ± 0.3 nM. [18F]RPS-544 showed preferential uptake in CXCR4+ tumors, with a CXCR4/WT ratio of 3.3 ± 1.3 at 1 h p.i. and 2.3 ± 0.5 at 2 h p.i. Maximum uptake in the CXCR4+ tumors was 3.4 ± 1.2%ID/g at 1 h p.i., significantly greater (p = 0.003) than the uptake in the WT tumor. Tumor/blood ratios were 2.5 ± 0.4 and 3.6 ± 0.3 at 1 and 2 h p.i. Tumor/muscle ratios were >4 at all time-points. Tumor/lung ratios were >2 at 1 h and 2 h p.i. Substantial uptake was observed in the liver (15-25%ID/g), kidneys (25-35%ID/g), the small intestine (1-7%ID/g) and the large intestine (1-12%ID/g). Blood concentrations varied over time (0.5-2%ID/g). All other organs showed uptake of <1%ID/g at all time points studied with clearance profiles similar to blood clearance. CONCLUSIONS Here we present, to the best of our knowledge, the first high affinity [18F]-labeled tracer, suitable for in vivo PET imaging of CXCR4. [18F]RPS-544 displayed high affinity for CXCR4 and good tumor uptake with a maximum uptake at 1 h p.i.. CXCR4 dependent uptake was demonstrated using bilateral tumors with differential CXCR4 expression as well as pharmacological blockade using the known CXCR4 antagonist, AMD-3100. Tissue contrast as judged by tumor to normal tissue ratios was positive in several key tissues. The structural and pharmacological similarities between [18F]RPS-544 and the approved drug AMD-3465, combined with the ease of synthesis and high molar activity (>185 GBq/μmol) achieved during radiosynthesis could lead to accelerated translation into the clinic.
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Affiliation(s)
- Alejandro Amor-Coarasa
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - James Kelly
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Shashikanth Ponnala
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Yogindra Vedvyas
- Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Anastasia Nikolopoulou
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY, USA
| | - Clarence Williams
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Moonsoo M Jin
- Molecular Imaging Innovations Institute (MI(3)), Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - J David Warren
- Milstein Chemistry Core Facility, Weill Cornell Medicine, New York, NY, USA; Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - John W Babich
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA.
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Schwarzenböck SM, Stenzel J, Otto T, Helldorff HV, Bergner C, Kurth J, Polei S, Lindner T, Rauer R, Hohn A, Hakenberg OW, Wester HJ, Vollmar B, Krause BJ. [ 68Ga]pentixafor for CXCR4 imaging in a PC-3 prostate cancer xenograft model - comparison with [ 18F]FDG PET/CT, MRI and ex vivo receptor expression. Oncotarget 2017; 8:95606-95619. [PMID: 29221153 PMCID: PMC5707047 DOI: 10.18632/oncotarget.21024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 08/17/2017] [Indexed: 12/29/2022] Open
Abstract
Purpose The aim was to characterize the properties of [68Ga]Pentixafor as tracer for prostate cancer imaging in a PC-3 prostate cancer xenograft mouse model and to investigate its correlation with [18F]FDG PET/CT, magnetic resonance imaging (MRI) and ex vivo analyses. Methods Static [68Ga]Pentixafor and [18F]FDG PET as well as morphological/ diffusion weighted MRI and 1H MR spectroscopy was performed. Imaging data were correlated with ex vivo biodistribution and CXCR4 expression in PC-3 tumors (immunohistochemistry (IHC), mRNA analysis). Flow cytometry was performed for evaluation of localization of CXCR4 receptors (in vitro PC-3 cell experiments). Results Tumor uptake of [68Ga]Pentixafor was significantly lower compared to [18F]FDG. Ex vivo CXCR4 mRNA expression of tumors was shown by PCR. Only faint tumor CXCR4 expression was shown by IHC (immuno reactive score of 3). Accordingly, flow cytometry of PC-3 cells revealed only a faint signal, cell membrane permeabilisation showed a slight signal increase. There was no significant correlation of [68Ga]Pentixafor tumor uptake and ex vivo receptor expression. Spectroscopy showed typical spectra of prostate cancer. Conclusion PC-3 tumor uptake of [68Ga]Pentixafor was existent but lower compared to [18F]FDG. No significant correlation of ex vivo tumor CXCR4 receptor expression and [68Ga]Pentixafor tumor uptake was shown. CXCR4 receptor expression on the surface of PC-3 cells was existent but rather low possibly explaining the limited [68Ga]Pentixafor tumor uptake; receptor localization in the interior of PC-3 cells is presumable as shown by cell membrane permeabilisation. Further studies are necessary to define the role of [68Ga]Pentixafor in prostate cancer imaging.
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Affiliation(s)
- Sarah M Schwarzenböck
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Jan Stenzel
- Core Facility Small Animal Imaging, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Thomas Otto
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Heike V Helldorff
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Carina Bergner
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Jens Kurth
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Stefan Polei
- Core Facility Small Animal Imaging, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Tobias Lindner
- Core Facility Small Animal Imaging, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Romina Rauer
- Core Facility Small Animal Imaging, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Alexander Hohn
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Oliver W Hakenberg
- Department of Urology, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Hans J Wester
- Institute for Radiopharmaceutical Chemistry, Technische Universität München, 85748 Garching, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, Rostock University Medical Centre, 18057 Rostock, Germany
| | - Bernd J Krause
- Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany
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