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Feng Y, Meshaw RL, Finch SW, Zheng Y, Minn I, Vaidyanathan G, Pomper MG, Zalutsky MR. A third generation PSMA-targeted agent [ 211At]YF2: Synthesis and in vivo evaluation. Nucl Med Biol 2024; 134-135:108916. [PMID: 38703587 PMCID: PMC11180594 DOI: 10.1016/j.nucmedbio.2024.108916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/22/2024] [Accepted: 04/29/2024] [Indexed: 05/06/2024]
Abstract
INTRODUCTION Targeted α-particle therapy agents have shown promising responses in patients who have developed resistance to β--particle emitting radionuclides, albeit off-target toxicity remains a concern. Astatine-211 emits only one α-particle per decay and may alleviate the toxicity from α-emitting daughter radionuclides. Previously, we developed the low-molecular-weight PSMA-targeted agent [211At]L3-Lu that showed suitable therapeutic efficacy and was well tolerated in mice. Although [211At]L3-Lu had good characteristics, we now have evaluated a closely related analogue, [211At]YF2, to determine the better molecule for clinical translation. METHODS The tin precursors and unlabeled iodo standards for [211At]YF2 and [211At]L3-Lu each were synthesized and a new one-step labeling method was developed to produce [211At]YF2 and [211At]L3-Lu from the respective tin precursor. RCY and RCP were determined using RP-HPLC. Cell uptake, internalization and in vitro cell-killing (MTT) assays were performed on PSMA+ PC-3 PIP cells in parallel experiments to compare [211At]YF2 and [211At]L3-Lu directly. A paired-label biodistribution study was performed in athymic mice with subcutaneous PSMA-positive PC-3 PIP xenografts as a head-to-head comparison of [131I]YF2 and [125I]L3-Lu. The tissue distribution of [211At]YF2 and [211At]L3-Lu were determined individually in the same animal model. RESULTS The syntheses of tin precursors and unlabeled iodo standards were accomplished in reasonable yields. A streamlined and scalable radiolabeling method (1 h total synthesis time) was developed for the radiosynthesis of both [211At]YF2 and [211At]L3-Lu with 86 ± 7 % (n = 10) and 87 ± 5 % (n = 7) RCY, respectively, and > 95 % RCP for both. The maximum activity of [211At]YF2 produced to date was 666 MBq. An alternative method that did not involve HPLC purification was developed that provided similar RCY and RCP. Significantly higher cell uptake, internalization and cytotoxicity was seen for [211At]YF2 compared with [211At]L3-Lu. Significantly higher uptake and longer retention in tumor was seen for [131I]YF2 than for co-administered [125I]L3-Lu, while considerably higher renal uptake was seen for [131I]YF2. The biodistribution of [211At]YF2 was consistent with that of [131I]YF2. CONCLUSION [211At]YF2 exhibited higher cellular uptake, internalization and cytotoxicity than [211At]L3-Lu on PSMA-positive PC3 PIP cells. Likewise, higher uptake and longer retention in tumor was seen for [211At]YF2. Experiments to evaluate the dosimetry and therapeutic efficacy of [211At]YF2 are under way.
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Affiliation(s)
- Yutian Feng
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Rebecca L Meshaw
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Sean W Finch
- Department of Physics and Triangle Universities Nuclear Laboratory, Duke University, Durham, NC 27710, USA
| | - Yongxiang Zheng
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | | | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Michael R Zalutsky
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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Santos JF, Braz MT, Raposinho P, Cleeren F, Cassells I, Leekens S, Cawthorne C, Mendes F, Fernandes C, Paulo A. Synthesis and Preclinical Evaluation of PSMA-Targeted 111In-Radioconjugates Containing a Mitochondria-Tropic Triphenylphosphonium Carrier. Mol Pharm 2024; 21:216-233. [PMID: 37992229 DOI: 10.1021/acs.molpharmaceut.3c00787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Nuclear DNA is the canonical target for biological damage induced by Auger electrons (AE) in the context of targeted radionuclide therapy (TRT) of cancer, but other subcellular components might also be relevant for this purpose, such as the energized mitochondria of tumor cells. Having this in mind, we have synthesized novel DOTA-based chelators carrying a prostate-specific membrane antigen (PSMA) inhibitor and a triphenyl phosphonium (TPP) group that were used to obtain dual-targeted 111In-radioconjugates ([111In]In-TPP-DOTAGA-PSMA and [111In]In-TPP-DOTAGA-G3-PSMA), aiming to promote a selective uptake of an AE-emitter radiometal (111In) by PSMA+ prostate cancer (PCa) cells and an enhanced accumulation in the mitochondria. These dual-targeted 111In-radiocomplexes are highly stable under physiological conditions and in cell culture media. The complexes showed relatively similar binding affinities toward the PSMA compared to the reference tracer [111In]In-PSMA-617, in line with their high cellular uptake and internalization in PSMA+ PCa cells. The complexes compromised cell survival in a dose-dependent manner and in the case of [111In]In-TPP-DOTAGA-G3-PSMA to a higher extent than observed for the single-targeted congener [111In]In-PSMA-617. μSPECT imaging studies in PSMA+ PCa xenografts showed that the TPP pharmacophore did not interfere with the excellent in vivo tumor uptake of the "golden standard" [111In]In-PSMA-617, although it led to a higher kidney retention. Such kidney retention does not necessarily compromise their usefulness as radiotherapeutics due to the short tissue range of the Auger/conversion electrons emitted by 111In. Overall, our results provide valuable insights into the potential use of mitochondrial targeting by PSMA-based radiocomplexes for efficient use of AE-emitting radionuclides in TRT, giving impetus to extend the studies to other AE-emitting trivalent radiometals (e.g., 161Tb or 165Er) and to further optimize the designed dual-targeting constructs.
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Affiliation(s)
- Joana F Santos
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Maria T Braz
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Paula Raposinho
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Frederik Cleeren
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
| | - Irwin Cassells
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), 2400 Mol, Belgium
| | - Simon Leekens
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
| | - Christopher Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University of Leuven, 3000 Leuven, Belgium
| | - Filipa Mendes
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Célia Fernandes
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - António Paulo
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
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Yang X, Nao SC, Lin C, Kong L, Wang J, Ko CN, Liu J, Ma DL, Leung CH, Wang W. A cell-impermeable luminogenic probe for near-infrared imaging of prostate-specific membrane antigen in prostate cancer microenvironments. Eur J Med Chem 2023; 259:115659. [PMID: 37499288 DOI: 10.1016/j.ejmech.2023.115659] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 07/29/2023]
Abstract
Prostate-specific membrane antigen (PSMA) imaging probes are a promising tool for the diagnosis and image-guided surgery of prostate cancer (PCa). However, PSMA-specific luminescence probes for PCa detection and heterogeneity studies with high imaging contrast are lacking. Here, we report the first near-infrared (NIR) iridium(III) complex for the wash-free and specific imaging of PSMA in PCa cells and spheroids. The conjugation of a PSMA inhibitor, Lys-urea-Glu, to an iridium(III) complex synergizes the PSMA-specific affinity and biocompatibility of the inhibitor with the desirable photophysical properties of the iridium(III) complex, including NIR emission (670 nm), high photostability and a large Stokes shift. The cellular impermeability of the probe along with its strong binding affinity to PSMA enhances its specificity for PSMA, enabling the washing-free luminescent imaging of membrane PSMA with lower cytotoxicity. The probe was successfully applied for selectively visualizing PSMA-expressing cells and for the imaging of PSMA in a multicellular PCa model with good imaging penetration, indicating its potential use in complicated and heterogeneous tumor microenvironments. Furthermore, the probe showed good imaging performance in the PCa-bearing tumor mice via targeting PSMA in vivo. This work provides a novel strategy for the development of highly sensitive and specific NIR probes for PSMA in biological systems in vitro, which is of great significance for the precise diagnosis of PCa and for elucidating PCa heterogeneity.
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Affiliation(s)
- Xifang Yang
- Xi'an Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Medical Research, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi, 710072, China; Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, 400000, China
| | - Sang-Cuo Nao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau
| | - Chuankai Lin
- Xi'an Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Medical Research, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi, 710072, China; School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, 86 Hongqi Road, Ganzhou, China; Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, 400000, China
| | - Lingtan Kong
- Xi'an Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Medical Research, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi, 710072, China; Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, 400000, China
| | - Jing Wang
- Xi'an Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Medical Research, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi, 710072, China; Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, 400000, China
| | - Chung-Nga Ko
- Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Jinbiao Liu
- School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, 86 Hongqi Road, Ganzhou, China.
| | - Dik-Lung Ma
- Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Chung-Hang Leung
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau; Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau; Macao Centre for Research and Development in Chinese Medicine, University of Macau, Taipa, Macau; MoE Frontiers Science Centre for Precision Oncology, University of Macau, Taipa, Macau.
| | - Wanhe Wang
- Xi'an Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Medical Research, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi, 710072, China; Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, 400000, China.
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Ritawidya R, Wongso H, Effendi N, Pujiyanto A, Lestari W, Setiawan H, Humani TS. Lutetium-177-Labeled Prostate-Specific Membrane Antigen-617 for Molecular Imaging and Targeted Radioligand Therapy of Prostate Cancer. Adv Pharm Bull 2023; 13:701-711. [PMID: 38022814 PMCID: PMC10676551 DOI: 10.34172/apb.2023.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 02/04/2023] [Accepted: 04/24/2023] [Indexed: 12/01/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) represents a promising target for PSMA-overexpressing diseases, especially prostate cancer-a common type of cancer among men worldwide. In response to the challenges in tackling prostate cancers, several promising PSMA inhibitors from a variety of molecular scaffolds (e.g., phosphorous-, thiol-, and urea-based molecules) have been developed. In addition, PSMA inhibitors bearing macrocyclic chelators have attracted interest due to their favorable pharmacokinetic properties. Recently, conjugating a small PSMA molecule inhibitor-bearing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator, as exemplified by [177Lu]Lu-PSMA-617 could serve as a molecular imaging probe and targeted radioligand therapy (TRT) of metastatic castration resistant prostate cancer (mCRPC). Hence, studies related to mCRPC have drawn global attention. In this review, the recent development of PSMA ligand-617-labeled with 177Lu for the management of mCRPC is presented. Its molecular mechanism of action, safety, efficacy, and future direction are also described.
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Affiliation(s)
- Rien Ritawidya
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Raya Bandung-Sumedang KM 21, Sumedang, 45363, Indonesia
| | - Hendris Wongso
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Raya Bandung-Sumedang KM 21, Sumedang, 45363, Indonesia
| | - Nurmaya Effendi
- Faculty of Pharmacy, University of Muslim Indonesia, Kampus II UMI, Jl. Urip Sumoharjo No.225, Panaikang, Panakkukang, Kota, Makassar, Sulawesi Selatan 90231
| | - Anung Pujiyanto
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Wening Lestari
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Herlan Setiawan
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Titis Sekar Humani
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
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Baun C, Dam JH, Hildebrandt MG, Ewald JD, Kristensen BW, Gammelsrød VS, Olsen BB, Thisgaard H. Preclinical evaluation of [ 58mCo]Co-DOTA-PSMA-617 for Auger electron therapy of prostate cancer. Sci Rep 2023; 13:18837. [PMID: 37914790 PMCID: PMC10620164 DOI: 10.1038/s41598-023-43429-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 09/23/2023] [Indexed: 11/03/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA), highly expressed in prostate cancer, is a promising target for radionuclide therapy. Auger electron-emitting radionuclides are well suited for targeted radionuclide therapy if they can be delivered close to the DNA of the targeted cells. This preclinical study evaluated the theranostic pair [55/58mCo]Co-DOTA-PSMA-617 for PET imaging and Auger electron therapy of prostate cancer. [58mCo]Co-DOTA-PSMA-617 was successfully prepared with > 99% radiochemical yield and purity. In vitro, uptake and subcellular distribution assays in PSMA-positive prostate cancer cells showed PSMA-specific uptake with high cell-associated activity in the nucleus. Incubation with [58mCo]Co-DOTA-PSMA-617 reduced cell viability and clonogenic survival in a significant dose-dependent manner (p < 0.05). Biodistribution of xenografted mice showed high specific tumor uptake of the cobalt-labeled PSMA ligand for all time points with rapid clearance from normal tissues, which PET imaging confirmed. In vivo, therapy with [58mCo]Co-DOTA-PSMA-617 in tumor-bearing mice demonstrated significantly increased median survival for treated mice compared to control animals (p = 0.0014). In conclusion, [55/58mCo]Co-DOTA-PSMA-617 displayed excellent in vitro and in vivo properties, offering significant survival benefits in mice with no observed toxicities.
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Affiliation(s)
- Christina Baun
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Center for Personalized Response Monitoring in Oncology (PREMIO), Odense University Hospital, Odense, Denmark
| | - Johan Hygum Dam
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Malene Grubbe Hildebrandt
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Center for Personalized Response Monitoring in Oncology (PREMIO), Odense University Hospital, Odense, Denmark
- Centre for Innovative Medical Technology, Odense University Hospital, Odense, Denmark
| | - Jesper Dupont Ewald
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - Bjarne Winther Kristensen
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - Vigga Sand Gammelsrød
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Birgitte Brinkmann Olsen
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Department of Surgical Pathology, Zealand University Hospital, Roskilde, Denmark
| | - Helge Thisgaard
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000, Odense C, Denmark.
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
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Alati S, Singh R, Pomper MG, Rowe SP, Banerjee SR. Preclinical Development in Radiopharmaceutical Therapy for Prostate Cancer. Semin Nucl Med 2023; 53:663-686. [PMID: 37468417 DOI: 10.1053/j.semnuclmed.2023.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
Prostate cancer is a leading cause of cancer death in men worldwide. Among the various treatment options, radiopharmaceutical therapy has shown notable success in metastatic, castration-resistant disease. Radiopharmaceutical therapy is a systemic approach that delivers cytotoxic radiation doses precisely to the malignant tumors and/or tumor microenvironment. Therapeutic radiopharmaceuticals are composed of a therapeutic radionuclide and a high-affinity, tumor-targeting carrier molecule. Therapeutic radionuclides used in preclinical prostate cancer studies are primarily α-, β--, or Auger-electron-emitting radiometals or radiohalogens. Monoclonal antibodies, antibody-derived fragments, peptides, and small molecules are frequently used as tumor-targeting molecules. Over the years, several important membrane-associated proteases and receptors have been identified, validated, and subsequently used for preclinical radiotherapeutic development for prostate cancer. Prostate-specific membrane antigen (PSMA) is the most well-studied prostate cancer-associated protease in preclinical literature. PSMA-targeting radiotherapeutic agents are being investigated using high-affinity antibody- and small-molecule-based agents for safety and efficacy. Early generations of such agents were developed simply by replacing radionuclides of the imaging agents with therapeutic ones. Later, extensive structure-activity relationship studies were conducted to address the safety and efficacy issues obtained from initial patient data. Recent regulatory approval of the 177Lu-labeled low-molecular-weight agent, 177Lu-PSMA-617, is a significant accomplishment. Current preclinical experiments are focused on the structural modification of 177Lu-PSMA-617 and relevant investigational agents to increase tumor targeting and reduce off-target binding and toxicity in healthy organs. While lutetium-177 (177Lu) remains the most widely used radionuclide, radiolabeled analogs with iodine-131 (128I), yttrium-90 (89Y), copper-67 (67Cu), and terbium-161 (161Tb) have been evaluated as potential alternatives in recent years. In addition, agents carrying the α-particle-emitting radiohalogen, astatine-211 (211At), or radiometals, actinium-225 (225Ac), lead-212 (212Pb), radium-223 (223Ra), and thorium-227 (227Th), have been increasingly investigated in preclinical research. Besides PSMA-based radiotherapeutics, other prominent prostate cancer-related proteases, for example, human kallikrein peptidases (HK2 and HK3), have been explored using monoclonal-antibody-(mAb)-based targeting platforms. Several promising mAbs targeting receptors overexpressed on the different stages of prostate cancer have also been developed for radiopharmaceutical therapy, for example, Delta-like ligand 3 (DLL-3), CD46, and CUB domain-containing protein 1 (CDCP1). Progress is also being made using peptide-based targeting platforms for the gastrin-releasing peptide receptor (GRPR), a well-established membrane-associated receptor expressed in localized and metastatic prostate cancers. Furthermore, mechanism-driven combination therapies appear to be a burgeoning area in the context of preclinical prostate cancer radiotherapeutics. Here, we review the current developments related to the preclinical radiopharmaceutical therapy of prostate cancer. These are summarized in two major topics: (1) therapeutic radionuclides and (2) tumor-targeting approaches using monoclonal antibodies, small molecules, and peptides.
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Affiliation(s)
- Suresh Alati
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Rajan Singh
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD.
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Rosenkranz AA, Slastnikova TA, Durymanov MO, Georgiev GP, Sobolev AS. Exploiting active nuclear import for efficient delivery of Auger electron emitters into the cell nucleus. Int J Radiat Biol 2023; 99:28-38. [PMID: 32856963 DOI: 10.1080/09553002.2020.1815889] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The most attractive features of Auger electrons (AEs) in cancer therapy are their extremely short range and sufficiently high linear energy transfer (LET) for a majority of them. The cytotoxic effects of AE emitters can be realized only in close vicinity to sensitive cellular targets and they are negligible if the emitters are located outside the cell. The nucleus is considered the compartment most sensitive to high LET particles. Therefore, the use of AE emitters could be most useful in specific recognition of a cancer cell and delivery of AE emitters into its nucleus. PURPOSE This review describes the studies aimed at developing effective anticancer agents for the delivery of AE emitters to the nuclei of target cancer cells. The use of peptide-based conjugates, nanoparticles, recombinant proteins, and other constructs for AE emitter targeted intranuclear delivery as well as their advantages and limitations are discussed. CONCLUSION Transport from the cytoplasm to the nucleus along with binding to the cancer cell is one of the key stages in the delivery of AE emitters; therefore, several constructs for exploitation of this transport have been developed. The transport is carried out through a nuclear pore complex (NPC) with the use of specific amino acid nuclear localization sequences (NLS) and carrier proteins named importins, which are located in the cytosol. Therefore, the effectiveness of NLS-containing delivery constructs designed to provide energy-dependent transport of AE emitter into the nuclei of cancer cells also depends on their efficient entry into the cytosol of the target cell.
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Affiliation(s)
- Andrey A Rosenkranz
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | | | | | - Alexander S Sobolev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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Perera M, Morris MJ. From Concept to Regulatory Drug Approval: Lessons for Theranostics. J Nucl Med 2022; 63:1793-1801. [PMID: 36456108 PMCID: PMC9730919 DOI: 10.2967/jnumed.121.263301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/03/2022] [Indexed: 12/13/2022] Open
Abstract
Radiopharmaceutical therapy is an emerging treatment modality that has demonstrated increasing importance as a significant component in the treatment of cancer. Prostate cancer (PCa) remains one of the commonest solid-organ tumors and is associated with significant societal burdens. Despite significant disease heterogeneity, PCa remains an ideal candidate for radiopharmaceutical therapy because of the prolonged disease course, metastatic disease tropism, and sensitivity to radiation therapy. To date, advanced PCa remains one of the most successful arenas for the development and approval of radiopharmaceutical agents. In this review, we aim to summarize the complex processes required to obtain regulatory approval for a novel agent and highlight the limitations and hurdles specific to the approval of radiopharmaceutical agents. In advanced PCa, we outline the importance of a framework for trial design with respect to defining disease state and acceptable outcome measures-as recommended by the Prostate Cancer Clinical Trials Working Group (PCWG). Finally, using the principles mandated by the Food and Drug Administration approval process and the framework provided by the PCWG, we outline experience with the successful approval of the radiopharmaceutical agents 223Ra and 177Lu-PSMA-617.
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Affiliation(s)
- Marlon Perera
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Michael J. Morris
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
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Future Prospective of Radiopharmaceuticals from Natural Compounds Using Iodine Radioisotopes as Theranostic Agents. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27228009. [PMID: 36432107 PMCID: PMC9694974 DOI: 10.3390/molecules27228009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 11/19/2022]
Abstract
Natural compounds provide precursors with various pharmacological activities and play an important role in discovering new chemical entities, including radiopharmaceuticals. In the development of new radiopharmaceuticals, iodine radioisotopes are widely used and interact with complex compounds including natural products. However, the development of radiopharmaceuticals from natural compounds with iodine radioisotopes has not been widely explored. This review summarizes the development of radiopharmaceuticals from natural compounds using iodine radioisotopes in the last 10 years, as well as discusses the challenges and strategies to improve future discovery of radiopharmaceuticals from natural resources. Literature research was conducted via PubMed, from which 32 research articles related to the development of natural compounds labeled with iodine radioisotopes were reported. From the literature, the challenges in developing radiopharmaceuticals from natural compounds were the purity and biodistribution. Despite the challenges, the development of radiopharmaceuticals from natural compounds is a golden opportunity for nuclear medicine advancement.
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10
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A Novel PSMA-Targeted Probe for NIRF-Guided Surgery and Photodynamic Therapy: Synthesis and Preclinical Validation. Int J Mol Sci 2022; 23:ijms232112878. [PMID: 36361667 PMCID: PMC9657290 DOI: 10.3390/ijms232112878] [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: 09/16/2022] [Revised: 10/10/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022] Open
Abstract
A total of 20% to 50% of prostate cancer (PCa) patients leave the surgery room with positive tumour margins. The intraoperative combination of fluorescence guided surgery (FGS) and photodynamic therapy (PDT) may be very helpful for improving tumour margin delineation and cancer therapy. PSMA is a transmembrane protein overexpressed in 90−100% of PCa cells. The goal of this work is the development of a PSMA-targeted Near InfraRed Fluorescent probe to offer the surgeon a valuable intraoperative tool for allowing a complete tumour removal, implemented with the possibility of using PDT to kill the eventual not resected cancer cells. PSMA-617 binding motif was conjugated to IRDye700DX-NHS and the conjugation did not affect the photophysical characteristics of the fluorophore. The affinity of IRDye700DX-PSMA-617 towards PCa cells followed the order of their PSMA expression, i.e., PC3-PIP > LNCaP > PC3, PC3-FLU. NIRF imaging showed a significant PC3-PIP tumour uptake after the injection of 1 or 5 nmol with a maximum tumour-to-muscle ratio (ca. 60) observed for both doses 24 h post-injection. Importantly, urine, healthy prostate, and the bladder were not fluorescent at 24 h post-injection. Flow cytometry and confocal images highlighted a co-localization of PSMA+ cells with IRDye700DX-PSMA uptake. Very interestingly, ex vivo analysis on a tumour specimen highlighted a significant PSMA expression by tumour-associated macrophages, likely attributable to extracellular vesicles secreted by the PSMA(+) tumour cells. FGS proved that IRDye700DX-PSMA was able to easily delineate tumour margins. PDT experiments showed a concentration-dependent decrease in cell viability (from 75% at 10 nM to 12% at 500 nM), whereas controls did not show any cytotoxicity. PC3-PIP tumour-bearing mice subjected to photodynamic therapy showed a delayed tumour growth. In conclusion, a novel PSMA-targeted NIRF dye with dual imaging-PDT capabilities was synthesized and displayed superior specificity compared to other small PSMA targeted molecules.
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11
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Rigby A, Firth G, Rivas C, Pham T, Kim J, Phanopoulos A, Wharton L, Ingham A, Li L, Ma MT, Orvig C, Blower PJ, Terry SY, Abbate V. Toward Bifunctional Chelators for Thallium-201 for Use in Nuclear Medicine. Bioconjug Chem 2022; 33:1422-1436. [PMID: 35801668 PMCID: PMC9305974 DOI: 10.1021/acs.bioconjchem.2c00284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Auger electron therapy exploits the cytotoxicity of low-energy electrons emitted during radioactive decay that travel very short distances (typically <1 μm). 201Tl, with a half-life of 73 h, emits ∼37 Auger and other secondary electrons per decay and can be tracked in vivo as its gamma emissions enable SPECT imaging. Despite the useful nuclear properties of 201Tl, satisfactory bifunctional chelators to incorporate it into bioconjugates for molecular targeting have not been developed. H4pypa, H5decapa, H4neunpa-NH2, and H4noneunpa are multidentate N- and O-donor chelators that have previously been shown to have high affinity for 111In, 177Lu, and 89Zr. Herein, we report the synthesis and serum stability of [nat/201Tl]Tl3+ complexes with H4pypa, H5decapa, H4neunpa-NH2, and H4noneunpa. All ligands quickly and efficiently formed complexes with [201Tl]Tl3+ that gave simple single-peak radiochromatograms and showed greatly improved serum stability compared to DOTA and DTPA. [natTl]Tl-pypa was further characterized using nuclear magnetic resonance spectroscopy (NMR), mass spectroscopy (MS), and X-ray crystallography, showing evidence of the proton-dependent presence of a nine-coordinate complex and an eight-coordinate complex with a pendant carboxylic acid group. A prostate-specific membrane antigen (PSMA)-targeting bioconjugate of H4pypa was synthesized and radiolabeled. The uptake of [201Tl]Tl-pypa-PSMA in DU145 PSMA-positive and PSMA-negative prostate cancer cells was evaluated in vitro and showed evidence of bioreductive release of 201Tl and cellular uptake characteristic of unchelated [201Tl]TlCl. SPECT/CT imaging was used to probe the in vivo biodistribution and stability of [201Tl]Tl-pypa-PSMA. In healthy animals, [201Tl]Tl-pypa-PSMA did not show the myocardial uptake that is characteristic of unchelated 201Tl. In mice bearing DU145 PSMA-positive and PSMA-negative prostate cancer xenografts, the uptake of [201Tl]Tl-pypa-PSMA in DU145 PSMA-positive tumors was higher than that in DU145 PSMA-negative tumors but insufficient for useful tumor targeting. We conclude that H4pypa and related ligands represent an advance compared to conventional radiometal chelators such as DOTA and DTPA for Tl3+ chelation but do not resist dissociation for long periods in the biological environment due to vulnerability to reduction of Tl3+ and subsequent release of Tl+. However, this is the first report describing the incorporation of [201Tl]Tl3+ into a chelator-peptide bioconjugate and represents a significant advance in the field of 201Tl-based radiopharmaceuticals. The design of the next generation of chelators must include features to mitigate this susceptibility to bioreduction, which does not arise for other trivalent heavy radiometals.
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Affiliation(s)
- Alex Rigby
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - George Firth
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Charlotte Rivas
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Truc Pham
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Jana Kim
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Andreas Phanopoulos
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, United Kingdom
| | - Luke Wharton
- Medicinal
Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Life
Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Aidan Ingham
- Medicinal
Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Life
Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Lily Li
- Medicinal
Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Life
Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Michelle T Ma
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Chris Orvig
- Medicinal
Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Philip J. Blower
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Samantha Y.A. Terry
- School
of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Vincenzo Abbate
- School
of Cancer & Pharmaceutical Sciences, King’s College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, United Kingdom
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12
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psma-targeted NIR probes for image-guided detection of prostate cancer. Colloids Surf B Biointerfaces 2022; 218:112734. [DOI: 10.1016/j.colsurfb.2022.112734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/14/2022] [Accepted: 07/27/2022] [Indexed: 11/23/2022]
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13
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Searching for a Paradigm Shift in Auger-Electron Cancer Therapy with Tumor-Specific Radiopeptides Targeting the Mitochondria and/or the Cell Nucleus. Int J Mol Sci 2022; 23:ijms23137238. [PMID: 35806239 PMCID: PMC9266350 DOI: 10.3390/ijms23137238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 11/17/2022] Open
Abstract
Although 99mTc is not an ideal Auger electron (AE) emitter for Targeted Radionuclide Therapy (TRT) due to its relatively low Auger electron yield, it can be considered a readily available “model” radionuclide useful to validate the design of new classes of AE-emitting radioconjugates. With this in mind, we performed a detailed study of the radiobiological effects and mechanisms of cell death induced by the dual-targeted radioconjugates 99mTc-TPP-BBN and 99mTc-AO-BBN (TPP = triphenylphosphonium; AO = acridine orange; BBN = bombesin derivative) in human prostate cancer PC3 cells. 99mTc-TPP-BBN and 99mTc-AO-BBN caused a remarkably high reduction of the survival of PC3 cells when compared with the single-targeted congener 99mTc-BBN, leading to an augmented formation of γH2AX foci and micronuclei. 99mTc-TPP-BBN also caused a reduction of the mtDNA copy number, although it enhanced the ATP production by PC3 cells. These differences can be attributed to the augmented uptake of 99mTc-TPP-BBN in the mitochondria and enhanced uptake of 99mTc-AO-BBN in the nucleus, allowing the irradiation of these radiosensitive organelles with the short path-length AEs emitted by 99mTc. In particular, the results obtained for 99mTc-TPP-BBN reinforce the relevance of targeting the mitochondria to promote stronger radiobiological effects by AE-emitting radioconjugates.
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14
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Frei A, Rigby A, Yue TTC, Firth G, Ma MT, Long NJ. To chelate thallium(I) - synthesis and evaluation of Kryptofix-based chelators for 201Tl. Dalton Trans 2022; 51:9039-9048. [PMID: 35640142 DOI: 10.1039/d2dt01074g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
While best known for its toxic properties, thallium has also been explored for applications in nuclear diagnostics and medicine. Indeed, [201Tl]TlCl has been used extensively for nuclear imaging in the past before it was superceded by other radionuclides such as 99mTc. One reason for this loss of interest is the severe lack of suitable organic chelators able to effectively coordinate ionic forms of Tl and deliver it to specific diseased tissue by means of attached biological vectors. Herein, we describe the synthesis and characterisation of a series of Kryptofix 222-based chelators that can be radiolabelled with 201Tl(I) in high radiochemical yields at ambient temperature. We demonstrate that from these simple chelators, targeted derivatives are readily accessible and describe the synthesis and preliminary biological evaluation of a PSMA-targeted 201Tl-labelled Kryptofix 222-peptide conjugate. While the Kryptofix system is demonstrably capable of binding the thallium cation, no PSMA-mediated cell-uptake could be detected with the PSMA conjugate, suggesting that this targeting moiety may not be ideal for use in conjunction with 201Tl.
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Affiliation(s)
- Angelo Frei
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Alex Rigby
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Thomas T C Yue
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - George Firth
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Nicholas J Long
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
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15
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Stenberg VY, Tornes AJK, Nilsen HR, Revheim ME, Bruland ØS, Larsen RH, Juzeniene A. Factors Influencing the Therapeutic Efficacy of the PSMA Targeting Radioligand 212Pb-NG001. Cancers (Basel) 2022; 14:cancers14112784. [PMID: 35681766 PMCID: PMC9179904 DOI: 10.3390/cancers14112784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Prostate-specific membrane antigen (PSMA) is a protein overexpressed in metastatic castration-resistant prostate cancer and a promising target for targeted radionuclide therapy. PSMA-targeted alpha therapy is of growing interest due to the high-emission energy and short range of alpha particles, resulting in a prominent cytotoxic potency. This study assesses the influence of various factors on the in vitro and in vivo therapeutic efficacy of the alpha particle generating PSMA-targeting radioligand 212Pb-NG001. Abstract This study aimed to determine the influence of cellular PSMA expression, radioligand binding and internalization, and repeated administrations on the therapeutic effects of the PSMA-targeting radioligand 212Pb-NG001. Cellular binding and internalization, cytotoxicity, biodistribution, and the therapeutic efficacy of 212Pb-NG001 were investigated in two human prostate cancer cell lines with different PSMA levels: C4-2 (PSMA+) and PC-3 PIP (PSMA+++). Despite 10-fold higher PSMA expression on PC-3 PIP cells, cytotoxicity and therapeutic efficacy of the radioligand was only 1.8-fold better than for the C4-2 model, possibly explained by lower cellular internalization and less blood-rich stroma in PC-3 PIP xenografts. Mice bearing subcutaneous PC-3 PIP xenografts were treated with 0.2, 0.4, and 0.8 MBq of 212Pb-NG001 that resulted in therapeutic indexes of 2.7, 3.0, and 3.5, respectively. A significant increase in treatment response was observed in mice that received repeated injections compared to the corresponding single dose (therapeutic indexes of 3.6 for 2 × 0.2 MBq and 4.4 for 2 × 0.4 MBq). The results indicate that 212Pb-NG001 can induce therapeutic effects at clinically transferrable doses, both in the C4-2 model that resembles solid tumors and micrometastases with natural PSMA expression and in the PC-3 PIP model that mimics poorly vascularized metastases.
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Affiliation(s)
- Vilde Yuli Stenberg
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (A.J.K.T.); (A.J.)
- Nucligen AS, 0379 Oslo, Norway;
- Institute of Clinical Medicine, University of Oslo, 0318 Oslo, Norway; (M.-E.R.); (Ø.S.B.)
- Correspondence: ; Tel.: +47-9012-8434
| | - Anna Julie Kjøl Tornes
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (A.J.K.T.); (A.J.)
- Nucligen AS, 0379 Oslo, Norway;
- Institute of Clinical Medicine, University of Oslo, 0318 Oslo, Norway; (M.-E.R.); (Ø.S.B.)
| | - Hogne Røed Nilsen
- Department of Pathology, Rikshospitalet, Oslo University Hospital, 0372 Oslo, Norway;
| | - Mona-Elisabeth Revheim
- Institute of Clinical Medicine, University of Oslo, 0318 Oslo, Norway; (M.-E.R.); (Ø.S.B.)
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, 0379 Oslo, Norway
| | - Øyvind Sverre Bruland
- Institute of Clinical Medicine, University of Oslo, 0318 Oslo, Norway; (M.-E.R.); (Ø.S.B.)
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
| | | | - Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (A.J.K.T.); (A.J.)
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16
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Jeitner TM, Babich JW, Kelly JM. Advances in PSMA theranostics. Transl Oncol 2022; 22:101450. [PMID: 35597190 PMCID: PMC9123266 DOI: 10.1016/j.tranon.2022.101450] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/04/2022] [Accepted: 05/08/2022] [Indexed: 12/15/2022] Open
Abstract
PSMA is an appealing target for theranostic because it is a transmembrane protein with a known substrate that is overexpessed on prostate cancer cells and internalizes upon ligand binding. There are a number of PSMA theranostic ligands in clinical evaluation, clinical trial, or clinically approved. PSMA theranostic ligands increase progression-free survival, overall survival, and pain in patients with metastatic castration resistant prostate cancer. A major obstacle to PSMA-targeted radioligand therapy is off-target toxicity in salivary glands.
The validation of prostate specific membrane antigen (PSMA) as a molecular target in metastatic castration-resistant prostate cancer has stimulated the development of multiple classes of theranostic ligands that specifically target PSMA. Theranostic ligands are used to image disease or selectively deliver cytotoxic radioactivity to cells expressing PSMA according to the radioisotope conjugated to the ligand. PSMA theranostics is a rapidly advancing field that is now integrating into clinical management of prostate cancer patients. In this review we summarize published research describing the biological role(s) and activity of PSMA, highlight the most clinically advanced PSMA targeting molecules and biomacromolecules, and identify next generation PSMA ligands that aim to further improve treatment efficacy. The goal of this review is to provide a comprehensive assessment of the current state-of-play and a roadmap to achieving further advances in PSMA theranostics.
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Affiliation(s)
- Thomas M Jeitner
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA
| | - John W Babich
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA; Weill Cornell Medicine, Sandra and Edward Meyer Cancer Center, New York, NY 10021, USA; Weill Cornell Medicine, Citigroup Biomedical Imaging Center, New York, NY 10021, USA
| | - James M Kelly
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA; Weill Cornell Medicine, Citigroup Biomedical Imaging Center, New York, NY 10021, USA.
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17
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Sergeeva O, Zhang Y, Julian W, Sasikumar A, Awadallah A, Kenyon J, Shi W, Sergeev M, Huang S, Sexton S, Iyer R, Xin W, Avril N, Chan ER, Lee Z. Imaging of Tumor-Associated Vascular Prostate-Specific Membrane Antigen in Woodchuck Model of Hepatocellular Carcinoma. GASTRO HEP ADVANCES 2022; 1:631-639. [PMID: 35844243 PMCID: PMC9280909 DOI: 10.1016/j.gastha.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND AIMS Radiolabeled short peptide ligands targeting prostate-specific membrane antigen (PSMA) were developed initially for imaging and treatment of prostate cancers. While many nonprostate solid tumors including hepatocellular carcinoma (HCC) express little PSMA, their neovasculature expresses a high level of PSMA, which is avid for Gallium-68-labeled PSMA-targeting radio-ligand (68Ga-PSMA-11) for positron emission tomography (PET). However, the lack of a spontaneous animal model of tumor-associated vascular PSMA overexpression has hindered the development and assessment of PSMA-targeting radioligands for imaging and therapy of the nonprostatic cancers. We identified detectable indigenous PSMA expression on tumor neovascular endothelia in a naturally occurring woodchuck model of HCC. METHODS Molecular docking was performed with 3 bait PSMA ligands and compared between human and woodchuck PSMA. Initially, PET images were acquired dynamically after intravenously injecting 37 MBq (1.0 mCi) of 68Ga-PSMA-11 into woodchuck models of HCC. Subsequently, 10-minute static PET scans were conducted for other animals 1-hour after injection due to HCC and liver background uptake stabilization at 30-45 minutes after injection. Liver tissue samples were harvested after imaging, fresh-frozen for quantitative reverse transcription polymerase chain reaction and western blot for validation, or fixed for histology for correlation. RESULTS Our preclinical studies confirmed the initial clinical findings of 68Ga-PSMA-11 uptake in HCC. The agents (ligands and antibodies) developed against human PSMA were found to be reactive against the woodchuck PSMA. CONCLUSION This animal model offers a unique opportunity for investigating the biogenesis of tumor-associated vascular PSMA, its functional role(s), and potentials for future treatment strategies targeting tumor vascular PSMA using already developed PSMA-targeting agents.
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Affiliation(s)
- Olga Sergeeva
- Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Yifan Zhang
- Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Willian Julian
- Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Arun Sasikumar
- Nuclear Medicine, St. Gregorios International Cancer Care Centre, Parumala, Kerala, India
| | - Amad Awadallah
- Pathology, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | | | - Wuxian Shi
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio
| | - Maxim Sergeev
- Radiology, University Hospitals Clevel and Medical Center, Cleveland, Ohio
| | - Steve Huang
- Nuclear Medicine, Cleveland Clinic, Cleveland, Ohio
| | - Sandra Sexton
- Medical Oncology, Roswell Park Cancer Institute, Buffalo, New York
| | - Renuka Iyer
- Medical Oncology, Roswell Park Cancer Institute, Buffalo, New York
| | - Wei Xin
- Pathology, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Norbert Avril
- Radiology, University Hospitals Clevel and Medical Center, Cleveland, Ohio
| | - Ernest Ricky Chan
- Institute for Computational Biology, Case Western Reserve University, Cleveland, Ohio
| | - Zhenghong Lee
- Radiology, Case Western Reserve University, Cleveland, Ohio
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18
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Gafita A, Marcus C, Kostos L, Schuster DM, Calais J, Hofman MS. Predictors and Real-World Use of Prostate-Specific Radioligand Therapy: PSMA and Beyond. Am Soc Clin Oncol Educ Book 2022; 42:1-17. [PMID: 35609224 DOI: 10.1200/edbk_350946] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
PSMA is a transmembrane protein that is markedly overexpressed in prostate cancer, making it an excellent target for imaging and treating patients with prostate cancer. Several small molecule inhibitors and antibodies of PSMA have been radiolabeled for use as therapeutic agents and are currently under clinical investigation. PSMA-based radionuclide therapy is a promising therapeutic option for men with metastatic prostate cancer. The phase II TheraP study demonstrated superior efficacy, lower side effects, and improved patient-reported outcomes compared with cabazitaxel. The phase III VISION study demonstrated that radionuclide therapy with β-emitter 177Lu-PSMA-617 can prolong survival and improve quality of life when offered in addition to standard-of-care therapy in men with PSMA-positive metastatic castration-resistant prostate cancer whose disease had progressed with conventional treatments. Nevertheless, up to 30% of patients have inherent resistance to PSMA-based radionuclide therapy, and acquired resistance is inevitable. Hence, strategies to increase the efficacy of PSMA-based radionuclide therapy have been under clinical investigation. These include better patient selection; increased radiation damage delivery via dosimetry-based administered dose or use of α-emitters instead of β-emitters; or using combinatorial approaches to overcome radioresistance mechanisms (innate or acquired), such as with novel hormonal agents, PARP inhibitors, or immunotherapy.
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Affiliation(s)
- Andrei Gafita
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Charles Marcus
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Louise Kostos
- Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - David M Schuster
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Jeremie Calais
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Michael S Hofman
- Molecular Imaging and Therapeutic Nuclear Medicine, Cancer Imaging; Prostate Cancer Theranostics and Imaging Centre of Excellence, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
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19
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Xu H, Wang Y, Zhang J, Duan X, Zhang T, Cai X, Ha H, Byun Y, Fan Y, Yang Z, Wang Y, Liu Z, Yang X. A self-triggered radioligand therapy agent for fluorescence imaging of the treatment response in prostate cancer. Eur J Nucl Med Mol Imaging 2022; 49:2693-2704. [PMID: 35235005 DOI: 10.1007/s00259-022-05743-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/20/2022] [Indexed: 12/18/2022]
Abstract
PURPOSE Radioligand therapy (RLT) targeting prostate-specific membrane antigen (PSMA) is emerging as an effective treatment option for metastatic castration-resistant prostate cancer (mCRPC). An imaging-based method to quantify early treatment responses can help to understand and optimize RLT. METHODS We developed a self-triggered probe 2 targeting the colocalization of PSMA and caspase-3 for fluorescence imaging of RLT-induced apoptosis. RESULTS The probe binds to PSMA potently with a Ki of 4.12 nM, and its fluorescence can be effectively switched on by caspase-3 with a Km of 67.62 μM. Cellular and in vivo studies demonstrated its specificity for imaging radiation-induced caspase-3 upregulation in prostate cancer. To identify the detection limit of our method, we showed that probe 2 could achieve 1.79 times fluorescence enhancement in response to 177Lu-RLT in a medium PSMA-expressing 22Rv1 xenograft model. CONCLUSION Probe 2 can potently bind to PSMA, and the fluorescence signal can be sensitively switched on by caspase-3 both in vitro and in vivo. This method may provide an effective tool to investigate and optimize PSMA-RLT.
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Affiliation(s)
- Hongchuang Xu
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China
| | - Yanpu Wang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Jingming Zhang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China
| | - Xiaojiang Duan
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China
| | - Ting Zhang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Xuekang Cai
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China
| | - Hyunsoo Ha
- College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong, 30019, South Korea
| | - Youngjoo Byun
- College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong, 30019, South Korea
| | - Yan Fan
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China.,NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals, Beijing, 100142, China
| | - Yiguang Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100191, China
| | - Zhaofei Liu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China. .,NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals, Beijing, 100142, China.
| | - Xing Yang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, China. .,NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals, Beijing, 100142, China. .,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.
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20
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Principles and Applications of Auger-Electron Radionuclide Therapy. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00040-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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21
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Olson AP, Ma L, Feng Y, Najafi Khosroshahi F, Kelley SP, Aluicio-Sarduy E, Barnhart TE, Hennkens HM, Ellison PA, Jurisson SS, Engle JW. A Third Generation Potentially Bifunctional Trithiol Chelate, Its nat,1XXSb(III) Complex, and Selective Chelation of Radioantimony ( 119Sb) from Its Sn Target. Inorg Chem 2021; 60:15223-15232. [PMID: 34606252 DOI: 10.1021/acs.inorgchem.1c01690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The therapeutic potential of the Meitner-Auger- and conversion-electron emitting radionuclide 119Sb remains unexplored because of the difficulty of incorporating it into biologically targeted compounds. To address this challenge, we report the development of 119Sb production from electroplated tin cyclotron targets and its complexation by a novel trithiol chelate. The chelation reaction occurs in harsh solvent conditions even in the presence of large quantities of tin, which are necessary for production on small, low energy (16 MeV) cyclotrons. The 119Sb-trithiol complex has high stability and can be purified by HPLC. The third generation trithiol chelate and the analogous stable natSb-trithiol compound were synthesized and characterized, including by single-crystal X-ray diffraction analyses.
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Affiliation(s)
- Aeli P Olson
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Li Ma
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Yutian Feng
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | | | - Steven P Kelley
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Heather M Hennkens
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States.,University of Missouri Research Reactor (MURR), Columbia, Missouri 65203, United States
| | - Paul A Ellison
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Silvia S Jurisson
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States.,Department of Radiology, University of Wisconsin, Madison, Wisconsin 53705, United States
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22
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Zhang J, Rakhimbekova A, Duan X, Yin Q, Foss CA, Fan Y, Xu Y, Li X, Cai X, Kutil Z, Wang P, Yang Z, Zhang N, Pomper MG, Wang Y, Bařinka C, Yang X. A prostate-specific membrane antigen activated molecular rotor for real-time fluorescence imaging. Nat Commun 2021; 12:5460. [PMID: 34526506 PMCID: PMC8443597 DOI: 10.1038/s41467-021-25746-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 08/25/2021] [Indexed: 12/03/2022] Open
Abstract
Surgery is an efficient way to treat localized prostate cancer (PCa), however, it is challenging to demarcate rapidly and accurately the tumor boundary intraoperatively, as existing tumor detection methods are seldom performed in real-time. To overcome those limitations, we develop a fluorescent molecular rotor that specifically targets the prostate-specific membrane antigen (PSMA), an established marker for PCa. The probes have picomolar affinity (IC50 = 63-118 pM) for PSMA and generate virtually instantaneous onset of robust fluorescent signal proportional to the concentration of the PSMA-probe complex. In vitro and ex vivo experiments using PCa cell lines and clinical samples, respectively, indicate the utility of the probe for biomedical applications, including real-time monitoring of endocytosis and tumor staging. Experiments performed in a PCa xenograft model reveal suitability of the probe for imaging applications in vivo.
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Affiliation(s)
- Jingming Zhang
- Department of Nuclear Medicine, Peking University First Hospital, 100034, Beijing, China
| | - Anastasia Rakhimbekova
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 25250, Vestec, Czech Republic
| | - Xiaojiang Duan
- Department of Nuclear Medicine, Peking University First Hospital, 100034, Beijing, China
| | - Qingqing Yin
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, 100191, Beijing, China
| | - Catherine A Foss
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Yan Fan
- Department of Nuclear Medicine, Peking University First Hospital, 100034, Beijing, China
| | - Yangyang Xu
- Department of Urology, Peking University First Hospital, 100034, Beijing, China
- The Institute of Urology, Peking University, 100034, Beijing, China
- National Urological Cancer Center, 100034, Beijing, China
- Beijing Key Laboratory of Urogenital Diseases (Male) Molecular Diagnosis and Treatment Center, 10034, Beijing, China
| | - Xuesong Li
- Department of Urology, Peking University First Hospital, 100034, Beijing, China
- The Institute of Urology, Peking University, 100034, Beijing, China
- National Urological Cancer Center, 100034, Beijing, China
- Beijing Key Laboratory of Urogenital Diseases (Male) Molecular Diagnosis and Treatment Center, 10034, Beijing, China
| | - Xuekang Cai
- Department of Nuclear Medicine, Peking University First Hospital, 100034, Beijing, China
| | - Zsofia Kutil
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 25250, Vestec, Czech Republic
| | - Pengyuan Wang
- Department of General Surgery, Peking University First Hospital, 100034, Beijing, China
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/ Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, 100142, Beijing, China
| | - Ning Zhang
- Translational Cancer Research Center, Peking University First Hospital, 100034, Beijing, China
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Yiguang Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, 100191, Beijing, China.
| | - Cyril Bařinka
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 25250, Vestec, Czech Republic.
| | - Xing Yang
- Department of Nuclear Medicine, Peking University First Hospital, 100034, Beijing, China.
- Institute of Medical Technology, Peking University Health Science Center, 100191, Beijing, China.
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23
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Verger E, Cheng J, de Santis V, Iafrate M, Jackson JA, Imberti C, Fruhwirth GO, Blower PJ, Ma MT, Burnham DR, Terry SYA. Validation of the plasmid study to relate DNA damaging effects of radionuclides to those from external beam radiotherapy. Nucl Med Biol 2021; 100-101:36-43. [PMID: 34153932 PMCID: PMC7611685 DOI: 10.1016/j.nucmedbio.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/31/2021] [Accepted: 06/10/2021] [Indexed: 12/29/2022]
Abstract
INTRODUCTION The biological consequences of absorbed radiation doses are ill-defined for radiopharmaceuticals, unlike for external beam radiotherapy (EBRT). A reliable assay that assesses the biological consequences of any radionuclide is much needed. Here, we evaluated the cell-free plasmid DNA assay to determine the relative biological effects of radionuclides such as Auger electron-emitting [67Ga]GaCl3 or [111In]InCl3 compared to EBRT. METHODS Supercoiled pBR322 plasmid DNA (1.25 or 5 ng/μL) was incubated with 0.5 or 1 MBq [67Ga]GaCl3 or [111In]InCl3 for up to 73 h or was exposed to EBRT (137Cs; 5 Gy/min; 0-40 Gy). The induction of relaxed and linear plasmid DNA, representing single and double strand breaks, respectively, was assessed by gel electrophoresis. Chelated forms of 67Ga were also investigated using DOTA and THP. Topological conversion rates for supercoiled-to-relaxed (ksrx) or relaxed-to-linear (krlx) DNA were obtained by fitting a kinetic model. RESULTS DNA damage increased both with EBRT dose and incubation time for [67Ga]GaCl3 and [111In]InCl3. Damage caused by [67Ga]GaCl3 decreased when chelated. [67Ga]GaCl3 proved more damaging than [111In]InCl3; 1.25 ng/μL DNA incubated with 0.5 MBq [67Ga]GaCl3 for 2 h led to a 70% decrease of intact plasmid DNA as opposed to only a 19% decrease for [111In]InCl3. For both EBRT and radionuclides, conversion rates were slower for 5 ng/μL than 1.25 ng/μL plasmid DNA. DNA damage caused by 1 Gy EBRT was the equivalent to damage caused by 0.5 MBq unchelated [67Ga]GaCl3 and [111In]InCl3 after 2.05 ± 0.36 and 9.3 ± 0.77 h of incubation, respectively. CONCLUSIONS This work has highlighted the power of the plasmid DNA assay for a rapid determination of the relative biological effects of radionuclides compared to external beam radiotherapy. It is envisaged this approach will enable the systematic assessment of imaging and therapeutic radionuclides, including Auger electron-emitters, to further inform radiopharmaceutical design and application.
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Affiliation(s)
- Elise Verger
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jordan Cheng
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Vittorio de Santis
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Madeleine Iafrate
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jessica A Jackson
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Cinzia Imberti
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Gilbert O Fruhwirth
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom; Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, Guy's Hospital Campus, London SE1 1UL, United Kingdom
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Daniel R Burnham
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
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24
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Impact of the mouse model and molar amount of injected ligand on the tissue distribution profile of PSMA radioligands. Eur J Nucl Med Mol Imaging 2021; 49:470-480. [PMID: 34402925 PMCID: PMC8803738 DOI: 10.1007/s00259-021-05446-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/02/2021] [Indexed: 12/26/2022]
Abstract
Purpose Various preclinical study designs are described in the literature for the evaluation of PSMA radioligands. In this study, [177Lu]Lu-Ibu-DAB-PSMA, an albumin-binding radioligand, and [177Lu]Lu-PSMA-617 were investigated and compared under variable experimental conditions. Methods In vitro cell uptake studies were performed with PC-3 PIP and LNCaP tumor cells using a range of molar concentrations (0.75–500 nM) of both radioligands. Biodistribution and SPECT/CT imaging studies were carried out with the respective tumor mouse models using 0.05 nmol and 1.0 nmol injected ligand per mouse. Results In both tumor cell lines, the uptake of the radioligands was increased when using low molar concentrations of the respective ligand. The observed saturation effect at high ligand concentrations was more pronounced for LNCaP cells that express PSMA at lower levels than for PC-3 PIP cells. At all investigated timepoints, the in vivo uptake of both radioligands was higher in PC-3 PIP tumors than in LNCaP tumors. A low molar amount of injected ligand increased the PC-3 PIP tumor uptake mainly for [177Lu]Lu-Ibu-DAB-PSMA; however, the molar amount of ligand was relevant for both radioligands when using LNCaP tumors. Renal retention of both radioligands was, however, up to fourfold higher during the first hours after application of a low ligand amount compared to the high ligand amount. Conclusion The results of this preclinical study underline the relevance of the tumor model and applied ligand amount for the characterization of PSMA radioligands. The application of equal preclinical study designs is crucial to allow the comparison of novel radioligands with existing ones and, thus, predict potential advantages of new radioligands in view of a clinical application. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05446-5.
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25
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Osytek KM, Blower PJ, Costa IM, Smith GE, Abbate V, Terry SYA. In vitro proof of concept studies of radiotoxicity from Auger electron-emitter thallium-201. EJNMMI Res 2021; 11:63. [PMID: 34224019 PMCID: PMC8257813 DOI: 10.1186/s13550-021-00802-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/03/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Auger electron-emitting radionuclides have potential in targeted treatment of small tumors. Thallium-201 (201Tl), a gamma-emitting radionuclide used in myocardial perfusion scintigraphy, decays by electron capture, releasing around 37 Auger and Coster-Kronig electrons per decay. However, its therapeutic and toxic effects in cancer cells remain largely unexplored. Here, we assess 201Tl in vitro kinetics, radiotoxicity and potential for targeted molecular radionuclide therapy, and aim to test the hypothesis that 201Tl is radiotoxic only when internalized. METHODS Breast cancer MDA-MB-231 and prostate cancer DU145 cells were incubated with 200-8000 kBq/mL [201Tl]TlCl. Potassium concentration varied between 0 and 25 mM to modulate cellular uptake of 201Tl. Cell uptake and efflux rates of 201Tl were measured by gamma counting. Clonogenic assays were used to assess cell survival after 90 min incubation with 201Tl. Nuclear DNA damage was measured with γH2AX fluorescence imaging. Controls included untreated cells and cells treated with decayed [201Tl]TlCl. RESULTS 201Tl uptake in both cell lines reached equilibrium within 90 min and washed out exponentially (t1/2 15 min) after the radioactive medium was exchanged for fresh medium. Cellular uptake of 201Tl in DU145 cells ranged between 1.6 (25 mM potassium) and 25.9% (0 mM potassium). Colony formation by both cell lines decreased significantly as 201Tl activity in cells increased, whereas 201Tl excluded from cells by use of high potassium buffer caused no significant toxicity. Non-radioactive TlCl at comparable concentrations caused no toxicity. An estimated average 201Tl intracellular activity of 0.29 Bq/cell (DU145 cells) and 0.18 Bq/cell (MDA-MB-231 cells) during 90 min exposure time caused 90% reduction in clonogenicity. 201Tl at these levels caused on average 3.5-4.6 times more DNA damage per nucleus than control treatments. CONCLUSIONS 201Tl reduces clonogenic survival and increases nuclear DNA damage only when internalized. These findings justify further development and evaluation of 201Tl therapeutic radiopharmaceuticals.
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Affiliation(s)
- Katarzyna M Osytek
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Ines M Costa
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Gareth E Smith
- Theragnostics Limited, 2 Arlington Square, Bracknell, RG12 1WA, UK
| | - Vincenzo Abbate
- Department of Analytical, Environmental and Forensic Sciences, King's College London, London, UK.
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
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26
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Costa IM, Cheng J, Osytek KM, Imberti C, Terry SYA. Methods and techniques for in vitro subcellular localization of radiopharmaceuticals and radionuclides. Nucl Med Biol 2021; 98-99:18-29. [PMID: 33964707 PMCID: PMC7610823 DOI: 10.1016/j.nucmedbio.2021.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/18/2021] [Accepted: 03/30/2021] [Indexed: 12/28/2022]
Abstract
In oncology, the holy grail of radiotherapy is specific radiation dose deposition in tumours with minimal healthy tissue toxicity. If used appropriately, injectable, systemic radionuclide therapies could meet these criteria, even for treatment of micrometastases and single circulating tumour cells. The clinical use of α and β- particle-emitting molecular radionuclide therapies is rising, however clinical translation of Auger electron-emitting radionuclides is hampered by uncertainty around their exact subcellular localisation, which in turn affects the accuracy of dosimetry. This review aims to discuss and compare the advantages and disadvantages of various subcellular localisation methods available to localise radiopharmaceuticals and radionuclides for in vitro investigations.
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Affiliation(s)
- Ines M Costa
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Jordan Cheng
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Katarzyna M Osytek
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Cinzia Imberti
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Samantha Y A Terry
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom.
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27
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Mease RC, Kang C, Kumar V, Ray S, Minn IL, Brummet M, Gabrielson K, Feng Y, Park A, Kiess A, Sgouros G, Vaidyanathan G, Zalutsky M, Pomper MG. An improved 211At-labeled agent for PSMA-targeted alpha therapy. J Nucl Med 2021; 63:259-267. [PMID: 34088772 DOI: 10.2967/jnumed.121.262098] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/05/2021] [Indexed: 11/16/2022] Open
Abstract
α-Particle emitters targeting the prostate-specific membrane antigen (PSMA) proved effective in treating patients with prostate cancer who were unresponsive to the corresponding β-particle therapy. Astatine-211 is an α-emitter that may engender less toxicity than other α-emitting agents. We synthesized a new 211At-labeled radiotracer targeting PSMA that resulted from the search for a pharmacokinetically optimized agent. Methods: A small series of 125I-labeled compounds were synthesized from their tin precursors to evaluate the effect of location of radiohalogen within the molecule and the presence of lutetium in the chelate on biodistribution. On that basis, 211At-VK-02-90-Lu was selected and evaluated in cell uptake and internalization studies, biodistribution and PSMA+ PC3 PIP tumor growth control in experimental flank and metastatic (PC3-ML-Luc) models. A long-term (13-month) toxicity study was performed for 211At-VK-02-90-Lu, including tissue chemistries and histopathology. Results: The radiochemical yield of 211At-VK-02-90-Lu was 17.8 ± 8.2%. Lead compound 211At-VK-02-90-Lu demonstrated total uptake within PSMA+ PC3 PIP cells of 13.4 ± 0.5% of the input dose after 4 h of incubation with little uptake in control cells. In SCID mice, 211At-VK-02-90-Lu provided 30.6 ± 4.8 percentage of injected dose per gram (%ID/g) of uptake in PSMA+ PC3 PIP tumor at 1 h post-injection that decreased to 9.46 ± 0.96 %ID/g by 24 h. Tumor-to-salivary gland and tumor-to-kidney ratios were 129 ± 99 at 4 h and 130 ± 113 at 24 h, respectively. De-astatination was not significant (stomach 0.34 ± 0.20%ID/g at 4 h). Dose-dependent survival was demonstrated at higher doses (>1.48 MBq) in both flank and metastatic models. There was little off-target toxicity as demonstrated by hematopoietic stability, unchanged tissue chemistries, weight gain rather than loss throughout treatment, and favorable histopathology. Conclusion: Compound 211At-VK-02-90-Lu or close analogs may provide limited and acceptable toxicity while retaining efficacy in management of prostate cancer.
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Affiliation(s)
| | | | - Vivek Kumar
- Johns Hopkins Medical Institutions, United States
| | | | | | - Mary Brummet
- Johns Hopkins Medical Institutions, United States
| | | | | | - Andrew Park
- Johns Hopkins Medical Institutions, United States
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28
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Pirovano G, Wilson TC, Reiner T. Auger: The future of precision medicine. Nucl Med Biol 2021; 96-97:50-53. [PMID: 33831745 PMCID: PMC8164972 DOI: 10.1016/j.nucmedbio.2021.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022]
Abstract
First reported by Lise Meitner in 1922 and independently by Pierre Auger in 1923, the Auger effect has been explored as a potential source for targeted radiotherapy. The Auger effect is based on the emission of a low energy electron (typically <25 keV) from an atom post electron capture (EC), internal conversion (IC), or incident X-rays excitation. This phenomenon can cause the emission of a primary electron and multiple electron tracks typically in the nearest proximity of the emission site (2-500 nm). The short range of the emitted Auger cascade results in medium/high levels of linear energy transfer (4-26 keV/μm) exerted on the surrounding tissue. This property makes Auger emitters the ideal candidates for delivering high levels of targeted radiation to a specific target with dimensions comparable to, for example, the DNA. By using a targeting vector such as a small molecule, peptide or antibody, one has the potential of delivering high levels of radiation to tumor specific biomarkers while circumventing off-site toxicity in healthy cells; a challenge which is harder to overcome when using other, longer range sources of radiation such as beta and alpha emitting radionuclides. Several reviews on Auger emitters have been published over the years with two recent examples. For these reviews and others, we support their analysis and therefore to avoid simple repetition, this commentary will seek to address additional aspects and viewpoints. Specifically, we will focus on those most promising preclinical and clinical studies using small molecules, peptides, antibodies and how these studies may serve as a template for future studies.
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Affiliation(s)
- Giacomo Pirovano
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Thomas C Wilson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Department of Radiology, Weill Cornell Medical College, New York, NY 10065, USA; Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York City, NY 10065, USA.
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29
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Pei P, Liu T, Shen W, Liu Z, Yang K. Biomaterial-mediated internal radioisotope therapy. MATERIALS HORIZONS 2021; 8:1348-1366. [PMID: 34846446 DOI: 10.1039/d0mh01761b] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Radiation therapy (RT), including external beam radiotherapy (EBRT) and internal radioisotope therapy (RIT), has been an indispensable strategy for cancer therapy in clinical practice in recent years. Ionized atoms and free radicals emitted from the nucleus of radioisotopes can cleave a single strand of DNA, inducing the apoptosis of cancer cells. Thus far, nuclides used for RIT could be classified into three main types containing alpha (α), beta (β), and Auger particle emitters. In order to enhance the bioavailability and reduce the physiological toxicity of radioisotopes, various biomaterials have been utilized as multifunctional nanocarriers, including targeting molecules, macromolecular monoclonal antibodies, peptides, inorganic nanomaterials, and organic and polymeric nanomaterials. Therapeutic radioisotopes have been labeled onto these nanocarriers via different methods (chelating, chemical doping, encapsulating, displacement) to inhibit or kill cancer cells. With the continuous development of research in this respect, more promising biomaterials as well as novel therapeutic strategies have emerged to achieve the high-performance RIT of cancer. In this review article, we summarize recent advances in biomaterial-mediated RIT of cancer and provide guidance for non-experts to understand nuclear medicine and to conduct cancer radiotherapy.
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Affiliation(s)
- Pei Pei
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, Jiangsu 215123, China.
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30
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Ha H, Kwon H, Lim T, Jang J, Park SK, Byun Y. Inhibitors of prostate-specific membrane antigen in the diagnosis and therapy of metastatic prostate cancer - a review of patent literature. Expert Opin Ther Pat 2021; 31:525-547. [PMID: 33459068 DOI: 10.1080/13543776.2021.1878145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II, is a potential target protein for imaging and treatment of patients with prostate cancer because of its overexpression during metastasis. Various PSMA-targeted imaging and therapeutic probes have been designed and synthesized based on the Lys-urea-Glu motif. Structural modifications have been made exclusively in the linker region, while maintaining the Lys-urea-Glu structure that interacts with S1 and S1' pockets. AREA COVERED This review includes WIPO-listed patents (from January 2017 to June 2020) reporting PSMA-targeted probes based on the Lys-urea-Glu or Glu-urea-Glu structure. EXPERT OPINION : PSMA-targeted imaging agents labeled with radionuclides such as fluorine-18, copper-64, gallium-68, and technetium-99m have been successfully translated into clinical phase for the early diagnosis of metastatic prostate cancer. Recently, PSMA-targeted therapeutic agents labeled with iodine-131, lutetium-177, astatine-211, and lead-212 have also been developed with notable progress. Most PSMA-targeted agents are based on the Lys-urea-Glu or Glu-urea-Glu structure, demonstrate strong PSMA-binding affinity in nanomolar range, and achieve diverse structural modifications in the non-pharmacophore pocket. By exploiting the S1 accessory pocket or the tunnel region of the PSMA active site, the in vivo efficacy and pharmacokinetic profiles of the PMSA-targeted agents can be effectively modulated.
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Affiliation(s)
- Hyunsoo Ha
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
| | - Hongmok Kwon
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
| | - Taehyeong Lim
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
| | - Jaebong Jang
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
| | - Song-Kyu Park
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
| | - Youngjoo Byun
- Department of Pharmacy, College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, South Korea
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Boinapally S, Ahn HH, Cheng B, Brummet M, Nam H, Gabrielson KL, Banerjee SR, Minn I, Pomper MG. A prostate-specific membrane antigen (PSMA)-targeted prodrug with a favorable in vivo toxicity profile. Sci Rep 2021; 11:7114. [PMID: 33782486 PMCID: PMC8007718 DOI: 10.1038/s41598-021-86551-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/09/2021] [Indexed: 11/09/2022] Open
Abstract
Prostate-specific membrane antigen (PSMA) is a promising target for the treatment of advanced prostate cancer (PC) and various solid tumors. Although PSMA-targeted radiopharmaceutical therapy (RPT) has enabled significant imaging and prostate-specific antigen (PSA) responses, accumulating clinical data are beginning to reveal certain limitations, including a subgroup of non-responders, relapse, radiation-induced toxicity, and the need for specialized facilities for its administration. To date non-radioactive attempts to leverage PSMA to treat PC with antibodies, nanomedicines or cell-based therapies have met with modest success. We developed a non-radioactive prodrug, SBPD-1, composed of a small-molecule PSMA-targeting moiety, a cancer-selective cleavable linker, and the microtubule inhibitor monomethyl auristatin E (MMAE). SBPD-1 demonstrated high binding affinity to PSMA (Ki = 8.84 nM) and selective cytotoxicity to PSMA-expressing PC cell lines (IC50 = 3.90 nM). SBPD-1 demonstrated a significant survival benefit in two murine models of human PC relative to controls. The highest dose tested did not induce toxicity in immunocompetent mice. The high specific targeting ability of SBPD-1 to PSMA-expressing tumors and its favorable toxicity profile warrant its further development.
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Affiliation(s)
- Srikanth Boinapally
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Hye-Hyun Ahn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Bei Cheng
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Mary Brummet
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Hwanhee Nam
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Kathleen L Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Sangeeta R Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
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Divgi C, Carrasquillo JA, Meredith R, Seo Y, Frey EC, Bolch WE, Zimmerman BE, Akabani G, Jacobson DA, Brown B, Davern SM, Hobbs RF, Humm J, Moros EG, Morse D, Papineni R, Zanzonico P, Benedict SH, Sgouros G. Overcoming Barriers to Radiopharmaceutical Therapy (RPT): An Overview From the NRG-NCI Working Group on Dosimetry of Radiopharmaceutical Therapy. Int J Radiat Oncol Biol Phys 2021; 109:905-912. [PMID: 33309909 PMCID: PMC8399328 DOI: 10.1016/j.ijrobp.2020.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/23/2020] [Accepted: 12/04/2020] [Indexed: 12/16/2022]
Abstract
Radiopharmaceutical therapy (RPT) continues to demonstrate tremendous potential in improving the therapeutic gains in radiation therapy by specifically delivering radiation to tumors that can be well assessed in terms of dosimetry and imaging. Dosimetry in external beam radiation therapy is standard practice. This is not the case, however, in RPT. This NRG (acronym formed from the first letter of the 3 original groups: National Surgical Adjuvant Breast and Bowel Project, the Radiation Therapy Oncology Group, and the Gynecologic Oncology Group)-National Cancer Institute Working Group review describes some of the challenges to improving RPT. The main priorities for advancing the field include (1) developing and adopting best practice guidelines for incorporating patient-specific dosimetry for RPT that can be used at both large clinics with substantial resources and more modest clinics that have limited resources, (2) establishing and improving strategies for introducing new radiopharmaceuticals for clinical investigation, (3) developing approaches to address the radiophobia that is associated with the administration of radioactivity for cancer therapy, and (4) solving the financial and logistical issues of expertise and training in the developing field of RPT.
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Affiliation(s)
| | - Jorge A Carrasquillo
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ruby Meredith
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California
| | - Eric C Frey
- Russell H. Morgan Department of Radiology and Radiologic Science, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Wesley E Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Brian E Zimmerman
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland
| | - Gamal Akabani
- Department of Nuclear Engineering, Texas A&M University, College Station, Texas
| | - Daniel A Jacobson
- Isotope and Fuel Cycle Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Ben Brown
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Sandra M Davern
- Isotope and Fuel Cycle Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Robert F Hobbs
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John Humm
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Eduardo G Moros
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - David Morse
- Department of Cancer Physiology and Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida; Departments of Oncologic Sciences and Physics, University of South Florida, Tampa, Florida
| | - Rao Papineni
- Departments of Molecular and Integrative Physiology and Family Medicine Research Division, University of Kansas Medical Center, Kansas City, Kansas; PACT and Health, Branford, Connecticut; Precision X-Ray Inc, North Branford, Connecticut
| | - Pat Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California Davis Comprehensive Cancer Center, Sacramento, California
| | - George Sgouros
- Russell H. Morgan Department of Radiology and Radiologic Science, Johns Hopkins University, School of Medicine, Baltimore, Maryland.
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Vaidyanathan G, Mease RC, Minn I, Choi J, Chen Y, Shallal H, Kang CM, McDougald D, Kumar V, Pomper MG, Zalutsky MR. Synthesis and preliminary evaluation of 211At-labeled inhibitors of prostate-specific membrane antigen for targeted alpha particle therapy of prostate cancer. Nucl Med Biol 2021; 94-95:67-80. [PMID: 33601187 PMCID: PMC7987787 DOI: 10.1016/j.nucmedbio.2021.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/01/2021] [Accepted: 01/02/2021] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The high potency and short tissue range of α-particles are attractive features for targeted radionuclide therapy, particularly for cancers with micro-metastases. In the current study, we describe the synthesis of a series of 211At-labeled prostate-specific membrane antigen (PSMA) inhibitors and their preliminary evaluation as potential agents for metastatic prostate cancer treatment. METHODS Four novel Glu-urea based PSMA ligands containing a trialkyl stannyl group were synthesized and labeled with 211At, and for comparative purposes, 131I, via halodestannylation reactions with N-chlorosuccinimide as the oxidant. A PSMA inhibitory assay was performed to evaluate PSMA binding of the unlabeled, iodinated compounds. A series of paired-label biodistribution experiments were performed to compare each 211At-labeled PSMA ligand to its 131I-labeled counterpart in mice bearing subcutaneous PC3 PSMA+ PIP xenografts. RESULTS Radiochemical yields ranged from 32% to 65% for the 211At-labeled PSMA inhibitors and were consistently lower than those obtained with the corresponding 131I-labeled analogue. Good localization in PC3 PSMA+ PIP but not control xenografts was observed for all labeled molecules studied, which exhibited a variable degree of in vivo dehalogenation as reflected by thyroid and stomach activity levels. Normal tissue uptake and in vivo stability for several of the compounds was markedly improved compared with the previously evaluated compounds, [211At]DCABzL and [*I]DCIBzL. CONCLUSIONS AND IMPLICATIONS FOR PATIENT CARE Compared with the first generation compound [211At]DCABzL, several of the novel 211At-labeled PSMA ligands exhibited markedly improved stability in vivo and higher tumor-to-normal tissue ratios. [211At]GV-620 has the most promising characteristics and warrants further evaluation as a targeted radiotherapeutic for prostate cancer.
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Affiliation(s)
| | - Ronnie C Mease
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jaeyeon Choi
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Ying Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hassan Shallal
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Choong Mo Kang
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Darryl McDougald
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Vivek Kumar
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael R Zalutsky
- Department of Radiology, Duke University Medical Center, Durham, NC, USA.
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Bandari RP, Carmack TL, Malhotra A, Watkinson L, Fergason Cantrell EA, Lewis MR, Smith CJ. Development of Heterobivalent Theranostic Probes Having High Affinity/Selectivity for the GRPR/PSMA. J Med Chem 2021; 64:2151-2166. [PMID: 33534560 DOI: 10.1021/acs.jmedchem.0c01785] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this study, we describe the development of heterobivalent [DUPA-6-Ahx-([111In]In-DO3A)-8-Aoc-BBN ANT] and [DUPA-6-Ahx-([177Lu]Lu-DO3A)-8-Aoc-BBN ANT] radiotracers that display very high selectivity/specificity for gastrin-releasing peptide receptor (GRPR)-/prostate-specific membrane antigen (PSMA)-expressing cells. These studies include metallation, purification, characterization, and in vitro and in vivo evaluation of the new small-molecule-/peptide-based radiopharmaceuticals having utility for imaging and potentially therapy. Competitive displacement binding assays using PC-3 cells and LNCaP cell membranes showed high binding affinity for the GRPR or the PSMA. Biodistribution studies showed favorable excretion pharmacokinetics with high tumor uptake in PC-3 or PC-3 prostatic inhibin peptide (PIP) tumor-bearing mice. For example, tumor accumulation at the 1 h time point ranged from (4.74 ± 0.90) to (7.51 ± 2.61)%ID/g. Micro-single-photon emission computed tomography (microSPECT) molecular imaging investigations showed very high uptake in tumors with minimal accumulation of tracers in the surrounding collateral tissues in xenografted mice at 4 h postintravenous injection. In conclusion, [DUPA-6-Ahx-([111In]In-DO3A)-8-Aoc-BBN ANT] and [DUPA-6-Ahx-([177Lu]Lu-DO3A)-8-Aoc-BBN ANT] tracers displayed favorable pharmacokinetic and excretion profiles with high uptake and retention in tumors.
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Affiliation(s)
- Rajendra P Bandari
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States.,Department of Radiology, University of Missouri School of Medicine, Columbia, Missouri 65211, United States
| | - Terry L Carmack
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States.,University of Missouri Research Reactor Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Anil Malhotra
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States
| | - Lisa Watkinson
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States.,University of Missouri Research Reactor Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Emily A Fergason Cantrell
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States.,University of Missouri Research Reactor Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Michael R Lewis
- Department of Veterinary Medicine and Surgery, University of Missouri College of Veterinary Medicine, Columbia, Missouri 65211, United States
| | - Charles J Smith
- Research Division, Harry S. Truman Memorial Veterans' Hospital, Research Service Room A005, 800 Hospital Drive, Columbia, Missouri 65201, United States.,Department of Radiology, University of Missouri School of Medicine, Columbia, Missouri 65211, United States.,University of Missouri Research Reactor Center, University of Missouri, Columbia, Missouri 65211, United States
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Ghiani S, Hawala I, Szikra D, Trencsényi G, Baranyai Z, Nagy G, Vágner A, Stefania R, Pandey S, Maiocchi A. Synthesis, radiolabeling, and pre-clinical evaluation of [ 44Sc]Sc-AAZTA conjugate PSMA inhibitor, a new tracer for high-efficiency imaging of prostate cancer. Eur J Nucl Med Mol Imaging 2021; 48:2351-2362. [PMID: 33420915 DOI: 10.1007/s00259-020-05130-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/18/2020] [Indexed: 01/04/2023]
Abstract
PURPOSE The aim of this work was to demonstrate the suitability of AAZTA conjugated to PSMA inhibitor (B28110) labeled with scandium-44 as a new PET tracer for diagnostic imaging of prostate cancer. BACKGROUND Nowadays, scandium-44 has received significant attention as a potential radionuclide with favorable characteristics for PET applications. A polyaminopolycarboxylate heptadentate ligand based on a 1,4-diazepine scaffold (AAZTA) has been thoroughly studied as chelator for Gd3+ ions for MRI applications. The excellent results of the equilibrium, kinetic, and labeling studies led to a preliminary assessment of the in vitro and in vivo behavior of [44Sc][Sc-(AAZTA)]- and two derivatives, i.e., [44Sc][Sc (CNAAZTA-BSA)] and [44Sc][Sc (CNAAZTA-cRGDfK)]. RESULTS B28110 was synthesized by hybrid approach, combining solid-phase peptide synthesis (SPPS) and solution chemistry to obtain high purity (97%) product with an overall yield of 9%. Subsequently, the radioactive labeling was performed with scandium-44 produced from natural calcium target in cyclotron, in good radiochemical yields (RCY) under mild condition (pH 4, 298 K). Stability study in human plasma showed good RCP% of [44Sc]Sc-B28110 up to 24 h (94.32%). In vivo PET/MRI imaging on LNCaP tumor-bearing mice showed high tracer accumulation in the tumor regions as early as 20 min post-injection. Ex vivo biodistribution studies confirmed that the accumulation of 44Sc-PSMA-617 was two-fold lower than that of the radiolabeled B28110 probes. CONCLUSIONS This work demonstrated the suitability of B28110 for the complexation with scandium-44 at room temperature and the high performance of the resulting new tracer based on AAZTA chelator for the diagnosis of prostate cancer using PET.
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Affiliation(s)
- S Ghiani
- Bracco Research Centre, Bracco Imaging SpA, Via Ribes 5, 10010, Colleretto Giacosa (TO), Italy.
| | - I Hawala
- Dipartimento di Biotecnologie Molecolari e Scienze per la salute, Centro di Imaging Molecolare, Università degli Studi di Torino, Via Nizza 52, 10126, Torino, Italy
| | - D Szikra
- Scanomed Ltd., Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - G Trencsényi
- Scanomed Ltd., Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Z Baranyai
- Bracco Research Centre, Bracco Imaging SpA, Via Ribes 5, 10010, Colleretto Giacosa (TO), Italy
| | - G Nagy
- Scanomed Ltd., Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - A Vágner
- Scanomed Ltd., Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - R Stefania
- Dipartimento di Biotecnologie Molecolari e Scienze per la salute, Centro di Imaging Molecolare, Università degli Studi di Torino, Via Nizza 52, 10126, Torino, Italy
| | - S Pandey
- Bracco Research USA Inc., 259 Prospect Plains Rd., Bldg. H, Monroe Township, NJ, 08831, USA
| | - A Maiocchi
- Bracco SpA, Via Caduti di Marcinelle, 13, 20134, Milan, Italy
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Li Y, Chyan MK, Hamlin DK, Nguyen H, Vessella R, Wilbur DS. Evaluation of radioiodinated protein conjugates and their potential metabolites containing lysine-urea-glutamate (LuG), PEG and closo-decaborate(2-) as models for targeting astatine-211 to metastatic prostate cancer. Nucl Med Biol 2021; 92:217-227. [PMID: 32409263 PMCID: PMC7606587 DOI: 10.1016/j.nucmedbio.2020.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 04/29/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The use of lysine-urea-glutamate (LuG) for targeting the PSMA antigen on prostate cancer (PCa) is a promising method for delivering the alpha particle-emitting radionuclide astatine-211 (211At) to metastatic PCa. High kidney localization has been a problem with radiolabeled LuG derivatives, but has been adequately addressed in radiometal-labeled DOTA-LuG derivatives by linker optimization. Herein, we report an investigation of an alternate approach to diminishing the kidney concentrations of radiolabeled LuG-containing compounds. METHODS Our approach involves PEGylated LuG moieties and closo-decaborate (2-) moieties conjugated to streptavidin (SAv) or human serum albumin (HSA). After preparing the LuG conjugates, SAv and HSA conjugates were succinylated to decrease their kidney localization and radioiodinated for evaluation in athymic mice bearing C4-2B osseous PCa tumor xenografts. RESULTS Covalently attaching LuG to succinylated SAv and HSA significantly reduced kidney localization, but unfortunately succinylation resulted in decreased tumor concentrations. In contrast, a potential metabolite [131I]16b, an unconjugated LuG derivative containing a dPEG4® linker, provided tumor concentrations of ~15% ID/g at 4 h pi. A second unconjugated LuG derivative with a similar structure, but containing a dPEG12® linker, [131I]16a had tumor concentrations of ~4%ID/g at 4 h pi. Those results suggest that long PEG linkers also affect tumor localization in a negative manner. CONCLUSION Conjugation of PEGylated LuG derivatives to proteins can be an effective approach to diminishing kidney localization of radiolabeled LuG reagents, but the protein, linker and the method of linkage need to be further studied. Additionally, modification of the unconjugated 16b to decrease kidney localization may provide PCa targeting agents for use with radiohalogens, including 211At. Advances in knowledge and implications for patient care: This study is the first to evaluate PEGylated LuG and closo-decaborate (2-) moieties conjugated to proteins as potential methods for diminishing the kidney concentrations of radiolabeled LuG-containing compounds.
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Affiliation(s)
- Yawen Li
- Radiochemistry Division, Department of Radiation Oncology, University of Washington, Seattle, WA 98105, United States of America
| | - Ming-Kuan Chyan
- Radiochemistry Division, Department of Radiation Oncology, University of Washington, Seattle, WA 98105, United States of America
| | - Donald K Hamlin
- Radiochemistry Division, Department of Radiation Oncology, University of Washington, Seattle, WA 98105, United States of America
| | - Holly Nguyen
- GU Cancer Research Lab, Department of Urology, University of Washington, Seattle, WA 98195, United States of America
| | - Robert Vessella
- GU Cancer Research Lab, Department of Urology, University of Washington, Seattle, WA 98195, United States of America
| | - D Scott Wilbur
- Radiochemistry Division, Department of Radiation Oncology, University of Washington, Seattle, WA 98105, United States of America.
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Rowe SP, Sadaghiani MS, Werner RA, Higuchi T, Derlin T, Solnes LB, Pomper MG. Prostate Cancer Theranostics. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00087-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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PARP Theranostic Auger Emitters Are Cytotoxic in BRCA Mutant Ovarian Cancer and Viable Tumors from Ovarian Cancer Patients Enable Ex-Vivo Screening of Tumor Response. Molecules 2020; 25:molecules25246029. [PMID: 33352773 PMCID: PMC7766161 DOI: 10.3390/molecules25246029] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/14/2020] [Accepted: 12/18/2020] [Indexed: 12/23/2022] Open
Abstract
Theranostics are emerging as a pillar of cancer therapy that enable the use of single molecule constructs for diagnostic and therapeutic application. As poly adenosine diphosphate (ADP)-ribose polymerase 1 (PARP-1) is overexpressed in various cancer types, and is localized to the nucleus, PARP-1 can be safely targeted with Auger emitters to induce DNA damage in tumors. Here, we investigated a radioiodinated PARP inhibitor, [125I]KX1, and show drug target specific DNA damage and subsequent killing of BRCA1 and non-BRCA mutant ovarian cancer cells at sub-pharmacological concentrations several orders of magnitude lower than traditional PARP inhibitors. Furthermore, we demonstrated that viable tumor tissue from ovarian cancer patients can be used to screen tumor radiosensitivity ex-vivo, enabling the direct assessment of therapeutic efficacy. Finally, we showed tumors can be imaged by single-photon computed tomography (SPECT) with PARP theranostic, [123I]KX1, in a human ovarian cancer xenograft mouse model. These data support the utility of PARP-1 targeted radiopharmaceutical therapy as a theranostic option for PARP-1 overexpressing ovarian cancers.
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Lee BS, Chu SY, Jung WJ, Jeong HJ, Lee K, Kim MH, Kim MH, Chi DY, Ahn H, Lee YJ, Lee KC, Lim SM. 18 F-labeled 1,2,3-triazole-linked Glu-urea-Lys-based PSMA ligands have good pharmacokinetic properties for positron emission tomography imaging of prostate cancer. Prostate 2020; 80:1383-1393. [PMID: 32960990 DOI: 10.1002/pros.24062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 07/23/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Prostate-specific membrane antigen (PSMA) is increasingly recognized as an excellent target for prostate cancer imaging and therapy. Finding compounds with a high target-to-nontarget ratio are an important challenge in the development of positron emission tomography (PET) imaging agents. In this study, we attempted to find a suitable compound from a simply-synthesized compound library. METHOD 18 F-labeling was achieved in a two-step synthesis consisting of [18 F]fluorination of azido sulfonates followed by copper(I)-catalyzed click ligation. In vitro binding experiment and in vivo studies were carried out using isogenic PSMA+ PC3-PIP and PSMA- PC3-flu cells and 22RV1 cells. [125 I]MIP-1095 was used to measure the binding affinities of compounds through a competitive binding assay, and [18 F]DCFPyL was used for a comparative assessment of compounds. Radiation dosimetry data were obtained using OLINDA/EXM software. RESULTS Nine novel PSMA ligands were synthesized by the combination of three azido compounds and three terminal acetylene-containing Glu-urea-Lys compounds. Among them, compound 6f having a pyridine moiety showed a high binding affinity of 6.51 ± 0.19 nM (Ki ). 18 F-labeled compounds were obtained at moderate yields within 70 to 75 minutes (including high-performance liquid chromatography purification). Compound [18 F]6c had the lowest log P of -2.693. MicroPET/computed tomography (CT) images were acquired from 22RV1 cell xenograft mice after injecting [18 F]6c, [18 F]6f, and [18 F]6i. Additional microPET/CT experiments of [18 F]6c and [18 F]6f were performed using PSMA+ PC3-PIP and PSMA- PC3-flu cell-bearing mice. [18 F]6c was selected for further studies because it was found to have high uptake in tumors and rapid renal clearance, resulting in great tumor-to-nontumor ratios and distinct tumor images with very low background activity. Human dosimetry estimation of [18 F]6c using OLINDA/EXM software was calculated, resulting in an effective dose of 4.35 × 10-3 mSv/MBq. CONCLUSIONS [18 F]6c showed significant tumor uptake, a high tumor-to-nontumor ratio, and good radiation dosimetry results, suggesting further development as a potential diagnostic PET agent for prostate cancer.
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Affiliation(s)
- Byoung Se Lee
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - So Young Chu
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Woon Jung Jung
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Hyeon Jin Jeong
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Kyongkyu Lee
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Min Hwan Kim
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Mi Hyun Kim
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Dae Yoon Chi
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
- Department of Chemistry, Sogang University, Seoul, Republic of Korea
| | - Heesu Ahn
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Yong Jin Lee
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Kyo Chul Lee
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Sang Moo Lim
- Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
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Howell RW. Advancements in the use of Auger electrons in science and medicine during the period 2015-2019. Int J Radiat Biol 2020; 99:2-27. [PMID: 33021416 PMCID: PMC8062591 DOI: 10.1080/09553002.2020.1831706] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/01/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023]
Abstract
Auger electrons can be highly radiotoxic when they are used to irradiate specific molecular sites. This has spurred basic science investigations of their radiobiological effects and clinical investigations of their potential for therapy. Focused symposia on the biophysical aspects of Auger processes have been held quadrennially. This 9th International Symposium on Physical, Molecular, Cellular, and Medical Aspects of Auger Processes at Oxford University brought together scientists from many different fields to review past findings, discuss the latest studies, and plot the future work to be done. This review article examines the research in this field that was published during the years 2015-2019 which corresponds to the period since the last meeting in Japan. In addition, this article points to future work yet to be done. There have been a plethora of advancements in our understanding of Auger processes. These advancements range from basic atomic and molecular physics to new ways to implement Auger electron emitters in radiopharmaceutical therapy. The highly localized doses of radiation that are deposited within a 10 nm of the decay site make them precision tools for discovery across the physical, chemical, biological, and medical sciences.
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Affiliation(s)
- Roger W Howell
- Division of Radiation Research, Department of Radiology, New Jersey Medical School, Rutgers University, Newark, NJ, USA
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Abstract
Radiopharmaceutical therapy (RPT) is emerging as a safe and effective targeted approach to treating many types of cancer. In RPT, radiation is systemically or locally delivered using pharmaceuticals that either bind preferentially to cancer cells or accumulate by physiological mechanisms. Almost all radionuclides used in RPT emit photons that can be imaged, enabling non-invasive visualization of the biodistribution of the therapeutic agent. Compared with almost all other systemic cancer treatment options, RPT has shown efficacy with minimal toxicity. With the recent FDA approval of several RPT agents, the remarkable potential of this treatment is now being recognized. This Review covers the fundamental properties, clinical development and associated challenges of RPT. Radiopharmaceutical therapy is emerging as a safe and effective approach for the treatment of cancer, offering several advantages over existing therapeutic strategies. Here, Sgouros and colleagues provide an overview of the fundamental properties of radiopharmaceutical therapy, discuss agents in use and in clinical development and highlight the associated translational challenges.
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Belchior A, Di Maria S, Fernandes C, Vaz P, Paulo A, Raposinho P. Radiobiological and dosimetric assessment of DNA-intercalated 99mTc-complexes bearing acridine orange derivatives. EJNMMI Res 2020; 10:79. [PMID: 32661612 PMCID: PMC7359215 DOI: 10.1186/s13550-020-00663-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/25/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Recently, a new family of 99mTc(I)-tricarbonyl complexes bearing an acridine orange (AO) DNA targeting unit and different linkers between the Auger emitter (99mTc) and the AO moiety was evaluated for Auger therapy. Among them, 99mTc-C3 places the corresponding radionuclide at a shortest distance to DNA and produces important double strand breaks (DSB) yields in plasmid DNA providing the first evidence that 99mTc can efficiently induce DNA damage when well positioned to the double helix. Here in, we have extended the studies to human prostate cancer PC3 cells using the 99mTc-C3 and 99mTc-C5 complexes, aiming to assess how the distance to DNA influences the radiation-induced biological effects in this tumoral cell line, namely, in which concerns early and late damage effects. RESULTS Our results highlight the limited biological effectiveness of Auger electrons, as short path length radiation, with increasing distances to DNA. The evaluation of the radiation-induced biological effects was complemented with a comparative microdosimetric study based on intracellular dose values. The comparative study, between MIRD and Monte Carlo (MC) methods used to assess the cellular doses, revealed that efforts should be made in order to standardize the bioeffects modeling for DNA-incorporated Auger electron emitters. CONCLUSIONS 99mTc might not be the ideal radionuclide for Auger therapy but can be useful to validate the design of new classes of Auger-electron emitting radioconjugates. In this context, our results highlight the crucial importance of the distance of Auger electron emitters to the target DNA and encourage the development of strategies for the fine tuning of the distance to DNA for other medical radionuclides (e.g., 111In or 161Tb) in order to enhance their radiotherapeutic effects within the Auger therapy of cancer.
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Affiliation(s)
- Ana Belchior
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Célia Fernandes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - António Paulo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Paula Raposinho
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
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Wilson TC, Jannetti SA, Guru N, Pillarsetty N, Reiner T, Pirovano G. Improved radiosynthesis of 123I-MAPi, an auger theranostic agent. Int J Radiat Biol 2020; 99:70-76. [PMID: 32552309 PMCID: PMC7775866 DOI: 10.1080/09553002.2020.1781283] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/15/2020] [Accepted: 05/20/2020] [Indexed: 01/17/2023]
Abstract
PURPOSE 123I-MAPi, a novel PARP1-targeted Auger radiotherapeutic has shown promising results in pre-clinical glioma model. Currently, 123I-MAPi is synthesized using multistep synthesis that results in modest yields and low molar activities (MA) that limits the ability to translate this technology for human studies where high doses are administered. Therefore, new methods are needed to synthesize 123I-MAPi in high activity yields (AY) and improved MA to facilitate clinical translation and multicenter trials. MATERIALS AND METHODS 123I-MAPi was prepared in a single step via 123I-iododetannylation of the corresponding tributylstannane precursor. In vitro internalization assay, subcellular fractionation and confocal microscopy where used to evaluate the performance of 123I-MAPi in a small cell lung cancer model. RESULTS 123I-MAPi was synthesized in a single step from the corresponding stannane precursor in AY of 45 ± 2% and MA of 11.8 ± 4.8 GBq µmol-1. In vitro in LX22 cells showed rapid internalization (5 min) with accumulation found predominantly in the membrane, nucleus and chromatin of the cell as determined by subcellular fractionation. CONCLUSIONS Here, we have developed an improved radiosynthesis of 123I-MAPi, an Auger theranostic agent. This process was achieved using a single step, 123I-iododestannylation reaction from the corresponding stannane precursor in good AY and MA. 123I-MAPi was evaluated in vitro in a small cell lung cancer model with high PARP expression, rapid internalization and high nuclear uptake shown.
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Affiliation(s)
- Thomas C Wilson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Stephen A Jannetti
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Biochemistry, Hunter College, The City University of New York (CUNY), New York, NY, USA
- Program in Biochemistry, The Graduate Center, CUNY, New York, NY, USA
| | - Navjot Guru
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Giacomo Pirovano
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Pirovano G, Jannetti SA, Carter LM, Sadique A, Kossatz S, Guru N, Demétrio De Souza França P, Maeda M, Zeglis BM, Lewis JS, Humm JL, Reiner T. Targeted Brain Tumor Radiotherapy Using an Auger Emitter. Clin Cancer Res 2020; 26:2871-2881. [PMID: 32066626 PMCID: PMC7299758 DOI: 10.1158/1078-0432.ccr-19-2440] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/07/2019] [Accepted: 02/12/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE Glioblastoma multiforme is a highly aggressive form of brain cancer whose location, tendency to infiltrate healthy surrounding tissue, and heterogeneity significantly limit survival, with scant progress having been made in recent decades. EXPERIMENTAL DESIGN 123I-MAPi (Iodine-123 Meitner-Auger PARP1 inhibitor) is a precise therapeutic tool composed of a PARP1 inhibitor radiolabeled with an Auger- and gamma-emitting iodine isotope. Here, the PARP inhibitor, which binds to the DNA repair enzyme PARP1, specifically targets cancer cells, sparing healthy tissue, and carries a radioactive payload within reach of the cancer cells' DNA. RESULTS The high relative biological efficacy of Auger electrons within their short range of action is leveraged to inflict DNA damage and cell death with high precision. The gamma ray emission of 123I-MAPi allows for the imaging of tumor progression and therapy response, and for patient dosimetry calculation. Here we demonstrated the efficacy and specificity of this small-molecule radiotheranostic in a complex preclinical model. In vitro and in vivo studies demonstrate high tumor uptake and a prolonged survival in mice treated with 123I-MAPi when compared with vehicle controls. Different methods of drug delivery were investigated to develop this technology for clinical applications, including convection enhanced delivery and intrathecal injection. CONCLUSIONS Taken together, these results represent the first full characterization of an Auger-emitting PARP inhibitor which demonstrate a survival benefit in mouse models of GBM and confirm the high potential of 123I-MAPi for clinical translation.
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Affiliation(s)
- Giacomo Pirovano
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Stephen A Jannetti
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Biochemistry, Hunter College, The City University of New York (CUNY), New York, New York
- PhD Program in Biochemistry, The Graduate Center, The City University of New York (CUNY), New York, New York
| | - Lukas M Carter
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ahmad Sadique
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Susanne Kossatz
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Navjot Guru
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | | | - Masatomo Maeda
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Brian M Zeglis
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Chemistry, Hunter College, The City University of New York (CUNY), New York, New York
- Department of Radiology, Weill Cornell Medical College, New York, New York
- PhD Program in Chemistry, The Graduate Center, The City University of New York (CUNY), New York, New York
| | - Jason S Lewis
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medical College, New York, New York
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Pharmacology, Weill Cornell Medical College, New York, New York
| | - John L Humm
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York.
- Department of Radiology, Weill Cornell Medical College, New York, New York
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
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The five “W”s and “How” of Targeted Alpha Therapy: Why? Who? What? Where? When? and How? RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI 2020. [DOI: 10.1007/s12210-020-00900-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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46
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Czerwińska M, Bilewicz A, Kruszewski M, Wegierek-Ciuk A, Lankoff A. Targeted Radionuclide Therapy of Prostate Cancer-From Basic Research to Clinical Perspectives. Molecules 2020; 25:E1743. [PMID: 32290196 PMCID: PMC7181060 DOI: 10.3390/molecules25071743] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/23/2020] [Accepted: 04/07/2020] [Indexed: 12/18/2022] Open
Abstract
Prostate cancer is the most commonly diagnosed malignancy in men and the second leading cause of cancer-related deaths in Western civilization. Although localized prostate cancer can be treated effectively in different ways, almost all patients progress to the incurable metastatic castration-resistant prostate cancer. Due to the significant mortality and morbidity rate associated with the progression of this disease, there is an urgent need for new and targeted treatments. In this review, we summarize the recent advances in research on identification of prostate tissue-specific antigens for targeted therapy, generation of highly specific and selective molecules targeting these antigens, availability of therapeutic radionuclides for widespread medical applications, and recent achievements in the development of new-generation small-molecule inhibitors and antibody-based strategies for targeted prostate cancer therapy with alpha-, beta-, and Auger electron-emitting radionuclides.
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Affiliation(s)
- Malwina Czerwińska
- Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.C.); (M.K.)
| | - Aleksander Bilewicz
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland;
| | - Marcin Kruszewski
- Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.C.); (M.K.)
- Department of Molecular Biology and Translational Research, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland
| | - Aneta Wegierek-Ciuk
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Uniwersytecka 7, 24-406 Kielce, Poland;
| | - Anna Lankoff
- Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.C.); (M.K.)
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Uniwersytecka 7, 24-406 Kielce, Poland;
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Duan X, Liu F, Kwon H, Byun Y, Minn I, Cai X, Zhang J, Pomper MG, Yang Z, Xi Z, Yang X. (S)-3-(Carboxyformamido)-2-(3-(carboxymethyl)ureido)propanoic Acid as a Novel PSMA Targeting Scaffold for Prostate Cancer Imaging. J Med Chem 2020; 63:3563-3576. [PMID: 32207938 DOI: 10.1021/acs.jmedchem.9b02031] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Xiaojiang Duan
- Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China
| | - Futao Liu
- Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China
| | - Hongmok Kwon
- College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, Republic of Korea
| | - Youngjoo Byun
- College of Pharmacy, Korea University, 2511 Sejong-ro, Sejong 30019, Republic of Korea
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, United States
| | - Xuekang Cai
- Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China
| | - Jingming Zhang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, United States
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Zhen Xi
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, National Pesticide Engineering Research Center (Tianjin), Nankai University, Tianjin 300071, China
| | - Xing Yang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China
- Institute of Medical Technology, Peking University, Beijing 100191. China
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Shen CJ, Minn I, Hobbs RF, Chen Y, Josefsson A, Brummet M, Banerjee SR, Brayton CF, Mease RC, Pomper MG, Kiess AP. Auger radiopharmaceutical therapy targeting prostate-specific membrane antigen in a micrometastatic model of prostate cancer. Am J Cancer Res 2020; 10:2888-2896. [PMID: 32194842 PMCID: PMC7053212 DOI: 10.7150/thno.38882] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/26/2019] [Indexed: 12/19/2022] Open
Abstract
Auger radiopharmaceutical therapy is a promising strategy for micrometastatic disease given high linear energy transfer and short range in tissues, potentially limiting normal tissue toxicities. We previously demonstrated anti-tumor efficacy of a small-molecule Auger electron emitter targeting the prostate-specific membrane antigen (PSMA), 2-[3-[1-carboxy-5-(4-[125I]iodo-benzoylamino)-pentyl]-ureido]-pentanedioic acid), or 125I-DCIBzL, in a mouse xenograft model. Here, we investigated the therapeutic efficacy, long-term toxicity, and biodistribution of 125I-DCIBzL in a micrometastatic model of prostate cancer (PC). Methods: To test the therapeutic efficacy of 125I-DCIBzL in micrometastatic PC, we used a murine model of human metastatic PC in which PSMA+ PC3-ML cells expressing firefly luciferase were injected intravenously in NSG mice to form micrometastatic deposits. One week later, 0, 0.37, 1.85, 3.7, 18.5, 37, or 111 MBq of 125I-DCIBzL was administered (intravenously). Metastatic tumor burden was assessed using bioluminescence imaging (BLI). Long-term toxicity was evaluated via serial weights and urinalysis of non-tumor-bearing mice over a 12-month period, as well as final necropsy. Results: In the micrometastatic PC model, activities of 18.5 MBq 125I-DCIBzL and above significantly delayed development of detectable metastatic disease by BLI and prolonged survival in mice. Gross metastases were detectable in control mice and those treated with 0.37-3.7 MBq 125I-DCIBzL at a median of 2 weeks post-treatment, versus 4 weeks for those treated with 18.5-111 MBq 125I-DCIBzL (P<0.0001 by log-rank test). Similarly, treatment with ≥18.5 MBq 125I-DCIBzL yielded a median survival of 11 weeks, compared with 6 weeks for control mice (P<0.0001). At 12 months, there was no appreciable toxicity via weight, urinalysis, or necropsy evaluation in mice treated with any activity of 125I-DCIBzL, which represents markedly less toxicity than the analogous PSMA-targeted α-particle emitter. Macro-to-microscale dosimetry modeling demonstrated lower absorbed dose in renal cell nuclei versus tumor cell nuclei due to lower levels of drug uptake and cellular internalization in combination with the short range of Auger emissions. Conclusion: PSMA-targeted radiopharmaceutical therapy with the Auger emitter 125I-DCIBzL significantly delayed development of detectable metastatic disease and improved survival in a micrometastatic model of PC, with no long-term toxicities noted at 12 months, suggesting a favorable therapeutic ratio for treatment of micrometastatic PC.
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Umbricht CA, Köster U, Bernhardt P, Gracheva N, Johnston K, Schibli R, van der Meulen NP, Müller C. Alpha-PET for Prostate Cancer: Preclinical investigation using 149Tb-PSMA-617. Sci Rep 2019; 9:17800. [PMID: 31780798 PMCID: PMC6882876 DOI: 10.1038/s41598-019-54150-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/05/2019] [Indexed: 12/27/2022] Open
Abstract
In this study, it was aimed to investigate 149Tb-PSMA-617 for targeted α-therapy (TAT) using a mouse model of prostate-specific membrane antigen (PSMA)-expressing prostate cancer. 149Tb-PSMA-617 was prepared with >98% radiochemical purity (6 MBq/nmol) for the treatment of mice with PSMA-positive PC-3 PIP tumors. 149Tb-PSMA-617 was applied at 1 × 6 MBq (Day 0) or 2 × 3 MBq (Day 0 & Day 1 or Day 0 & Day 3) and the mice were monitored over time until they had reached a pre-defined endpoint which required euthanasia. The tumor growth was significantly delayed in mice of the treated groups as compared to untreated controls (p < 0.05). TAT was most effective in mice injected with 2 × 3 MBq (Day 0 & 1) resulting in a median lifetime of 36 days, whereas in untreated mice, the median lifetime was only 20 days. Due to the β+-emission of 149Tb, tumor localization was feasible using PET/CT after injection of 149Tb-PSMA-617 (5 MBq). The PET images confirmed the selective accumulation of 149Tb-PSMA-617 in PC-3 PIP tumor xenografts. The unique characteristics of 149Tb for TAT make this radionuclide of particular interest for future clinical translation, thereby, potentially enabling PET-based imaging to monitor the radioligand’s tissue distribution.
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Affiliation(s)
- Christoph A Umbricht
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Ulli Köster
- Institut Laue-Langevin, 38042, Grenoble, France
| | - Peter Bernhardt
- Department of Radiation Physics, Institution of Clinical Science, Sahlgrenska Academy, University of Gothenburg, 413 45, Gothenburg, Sweden.,Medical Bioengeneering, Sahlgrenska University Hospital, 413 45, Gothenburg, Sweden
| | - Nadezda Gracheva
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | | | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.,Laboratory of Radiochemistry, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland. .,Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
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50
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Delivery systems exploiting natural cell transport processes of macromolecules for intracellular targeting of Auger electron emitters. Nucl Med Biol 2019; 80-81:45-56. [PMID: 31810828 DOI: 10.1016/j.nucmedbio.2019.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/24/2019] [Accepted: 11/25/2019] [Indexed: 12/17/2022]
Abstract
The presence of Auger electrons (AE) among the decay products of a number of radionuclides makes these radionuclides an attractive means for treating cancer because these short-range electrons can cause significant damage in the immediate vicinity of the decomposition site. Moreover, the extreme locality of the effect provides a potential for selective eradication of cancer cells with minimal damage to adjacent normal cells provided that the delivery of the AE emitter to the most vulnerable parts of the cell can be achieved. Few cellular compartments have been regarded as the desired target site for AE emitters, with the cell nucleus generally recognized as the preferred site for AE decay due to the extreme sensitivity of nuclear DNA to direct damage by radiation of high linear energy transfer. Thus, the advantages of AE emitters for cancer therapy are most likely to be realized by their selective delivery into the nucleus of the malignant cells. To achieve this goal, delivery systems must combine a challenging complex of properties that not only provide cancer cell preferential recognition but also cell entry followed by transport into the cell nucleus. A promising strategy for achieving this is the recruitment of natural cell transport processes of macromolecules, involved in each of the aforementioned steps. To date, a number of constructs exploiting intracellular transport systems have been proposed for AE emitter delivery to the nucleus of a targeted cell. An example of such a multifunctional vehicle that provides smart step-by-step delivery is the so-called modular nanotransporter, which accomplishes selective recognition, binding, internalization, and endosomal escape followed by nuclear import of the delivered radionuclide. The current review will focus on delivery systems utilizing various intracellular transport pathways and their combinations in order to provide efficient targeting of AE to the cancer cell nucleus.
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