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Radiolabeled Compounds for Diagnosis and Treatment of Cancer

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Medicinal Chemistry".

Deadline for manuscript submissions: closed (30 June 2021) | Viewed by 46657

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Guest Editor
Vaccine Translational Research Branch/VRP/DAIDS, National Institute of Allergy and Infectious Diseases (NIH), 5601 Fishers Lane, Room 9B56, Rockville, MD 20892, USA
Interests: radiotracers; drug discovery; drug development; biomarkers; end point; therapeutic effect; drug efficacy
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Significant advances in the design and evaluation of novel radiopharmaceuticals in preclinical and clinical environments have allowed for wider adoption of imaging technologies, such as SPECT and PET, and treatment of various cancers. Numerous radiopharmaceuticals have become available commercially for various applications, and more are going through development and the regulatory approval process. These radiopharmaceuticals are critical to the diagnosis and staging of diseases as well as the selection of patients for various therapies and the monitoring of their outcomes.

The editorial team of Molecules is developing a Special Issue titled “Radiolabeled Compounds for Diagnosis and Treatment of Cancer”. This Special Issue will focus on all aspects of design, characterization, evaluation, and development of novel radiolabeled compounds for the diagnosis and treatment of cancer and the application of new radiochemistry and methodologies for the development of novel radiolabeled compounds.

Submissions—both original research papers and reviews—related to the areas mentioned above are cordially invited.

Prof. Dr. Krishan Kumar
Guest Editor

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Keywords

  • Radiopharmaceuticals
  • Imaging pharmaceuticals
  • Diagnosis of cancer
  • Treatment of cancer
  • Radiolabeled compounds
  • Preclinical
  • Radiochemistry
  • Radiolabeling
  • Methodologies

Published Papers (12 papers)

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Editorial

Jump to: Research, Review

4 pages, 154 KiB  
Editorial
Radiolabeled Compounds for Diagnosis and Treatment of Cancer
by Krishan Kumar
Molecules 2021, 26(20), 6227; https://doi.org/10.3390/molecules26206227 - 15 Oct 2021
Viewed by 1205
Abstract
Nuclear medicine was recognized as a potential medical field a long time ago when 131I was used in thyroid cancer patients [...] Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)

Research

Jump to: Editorial, Review

12 pages, 1729 KiB  
Communication
A Novel Reagent for Radioiodine Labeling of New Chemical Entities (NCEs) and Biomolecules
by Krishan Kumar and Karen Woolum
Molecules 2021, 26(14), 4344; https://doi.org/10.3390/molecules26144344 - 18 Jul 2021
Cited by 12 | Viewed by 3430
Abstract
Radioiodine labeling of peptides and proteins is routinely performed by using various oxidizing agents such as Chloramine T, Iodobeads, and Iodogen reagent and radioactive iodide (I), although some other oxidizing agents were also investigated. The main objective of the present study [...] Read more.
Radioiodine labeling of peptides and proteins is routinely performed by using various oxidizing agents such as Chloramine T, Iodobeads, and Iodogen reagent and radioactive iodide (I), although some other oxidizing agents were also investigated. The main objective of the present study was to develop and test a novel reagent, inorganic monochloramine (NH2Cl), for radioiodine labeling of new chemical entities and biomolecules which is cost-effective, easy to make and handle, and is selective to label amino acids, peptides, and proteins. The data presented in this report demonstrate that the yields of the non-radioactive iodine labeling reactions using monochloramine are >70% for an amino acid (tyrosine) and a cyclic peptide (cyclo Arg-Gly-Asp-d-Tyr-Lys, cRGDyK). No evidence of the formation of N-chloro derivatives in cRGDyK was observed, suggesting that the reagent is selective in iodinating the tyrosine residue in the biomolecules. The method was successfully translated into radioiodine labeling of amino acid, a peptide, and a protein, Bovine Serum Albumin (BSA). Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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13 pages, 2028 KiB  
Article
In Vitro Evaluation of the Squaramide-Conjugated Fibroblast Activation Protein Inhibitor-Based Agents AAZTA5.SA.FAPi and DOTA.SA.FAPi
by Euy Sung Moon, Yentl Van Rymenant, Sandeep Battan, Joni De Loose, An Bracke, Pieter Van der Veken, Ingrid De Meester and Frank Rösch
Molecules 2021, 26(12), 3482; https://doi.org/10.3390/molecules26123482 - 08 Jun 2021
Cited by 10 | Viewed by 3170
Abstract
Recently, the first squaramide-(SA) containing FAP inhibitor-derived radiotracers were introduced. DATA5m.SA.FAPi and DOTA.SA.FAPi with their non-radioactive complexes showed high affinity and selectivity for FAP. After a successful preclinical study with [68Ga]Ga-DOTA.SA.FAPi, the first patient studies were realized for both [...] Read more.
Recently, the first squaramide-(SA) containing FAP inhibitor-derived radiotracers were introduced. DATA5m.SA.FAPi and DOTA.SA.FAPi with their non-radioactive complexes showed high affinity and selectivity for FAP. After a successful preclinical study with [68Ga]Ga-DOTA.SA.FAPi, the first patient studies were realized for both compounds. Here, we present a new squaramide-containing compound targeting FAP, based on the AAZTA5 chelator 1,4-bis-(carboxylmethyl)-6-[bis-(carboxymethyl)-amino-6-pentanoic-acid]-perhydro-1,4-diazepine. For this molecule (AAZTA5.SA.FAPi), complexation with radionuclides such as gallium-68, scandium-44, and lutetium-177 was investigated, and the in vitro properties of the complexes were characterized and compared with those of DOTA.SA.FAPi. AAZTA5.SA.FAPi and its derivatives labelled with non-radioactive isotopes demonstrated similar excellent inhibitory potencies compared to the previously published SA.FAPi ligands, i.e., sub-nanomolar IC50 values for FAP and high selectivity indices over the serine proteases PREP and DPPs. Labeling with all three radiometals was easier and faster with AAZTA5.SA.FAPi compared to the corresponding DOTA analogue at ambient temperature. Especially, scandium-44 labeling with the AAZTA derivative resulted in higher specific activities. Both DOTA.SA.FAPi and AAZTA5.SA.FAPi showed sufficiently high stability in different media. Therefore, these FAP inhibitor agents could be promising for theranostic approaches targeting FAP. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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20 pages, 2113 KiB  
Article
Radionuclide Molecular Imaging of EpCAM Expression in Triple-Negative Breast Cancer Using the Scaffold Protein DARPin Ec1
by Anzhelika Vorobyeva, Ekaterina Bezverkhniaia, Elena Konovalova, Alexey Schulga, Javad Garousi, Olga Vorontsova, Ayman Abouzayed, Anna Orlova, Sergey Deyev and Vladimir Tolmachev
Molecules 2020, 25(20), 4719; https://doi.org/10.3390/molecules25204719 - 14 Oct 2020
Cited by 11 | Viewed by 3082
Abstract
Efficient treatment of disseminated triple-negative breast cancer (TNBC) remains an unmet clinical need. The epithelial cell adhesion molecule (EpCAM) is often overexpressed on the surface of TNBC cells, which makes EpCAM a potential therapeutic target. Radionuclide molecular imaging of EpCAM expression might permit [...] Read more.
Efficient treatment of disseminated triple-negative breast cancer (TNBC) remains an unmet clinical need. The epithelial cell adhesion molecule (EpCAM) is often overexpressed on the surface of TNBC cells, which makes EpCAM a potential therapeutic target. Radionuclide molecular imaging of EpCAM expression might permit selection of patients for EpCAM-targeting therapies. In this study, we evaluated a scaffold protein, designed ankyrin repeat protein (DARPin) Ec1, for imaging of EpCAM in TNBC. DARPin Ec1 was labeled with a non-residualizing [125I]I-para-iodobenzoate (PIB) label and a residualizing [99mTc]Tc(CO)3 label. Both imaging probes retained high binding specificity and affinity to EpCAM-expressing MDA-MB-468 TNBC cells after labeling. Internalization studies showed that Ec1 was retained on the surface of MDA-MB-468 cells to a high degree up to 24 h. Biodistribution in Balb/c nu/nu mice bearing MDA-MB-468 xenografts demonstrated specific uptake of both [125I]I-PIB-Ec1 and [99mTc]Tc(CO)3-Ec1 in TNBC tumors. [125I]I-PIB-Ec1 had appreciably lower uptake in normal organs compared with [99mTc]Tc(CO)3-Ec1, which resulted in significantly (p < 0.05) higher tumor-to-organ ratios. The biodistribution data were confirmed by micro-Single-Photon Emission Computed Tomography/Computed Tomography (microSPECT/CT) imaging. In conclusion, an indirectly radioiodinated Ec1 is the preferable probe for imaging of EpCAM in TNBC. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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19 pages, 1961 KiB  
Article
Initial In Vitro and In Vivo Evaluation of a Novel CCK2R Targeting Peptide Analog Labeled with Lutetium-177
by Anton Amadeus Hörmann, Maximilian Klingler, Maliheh Rezaeianpour, Nikolas Hörmann, Ronald Gust, Soraya Shahhosseini and Elisabeth von Guggenberg
Molecules 2020, 25(19), 4585; https://doi.org/10.3390/molecules25194585 - 08 Oct 2020
Cited by 10 | Viewed by 2621
Abstract
Targeting of cholecystokinin-2 receptor (CCK2R) expressing tumors using radiolabeled minigastrin (MG) analogs is hampered by rapid digestion of the linear peptide in vivo. In this study, a new MG analog stabilized against enzymatic degradation was investigated in preclinical studies to characterize the metabolites [...] Read more.
Targeting of cholecystokinin-2 receptor (CCK2R) expressing tumors using radiolabeled minigastrin (MG) analogs is hampered by rapid digestion of the linear peptide in vivo. In this study, a new MG analog stabilized against enzymatic degradation was investigated in preclinical studies to characterize the metabolites formed in vivo. The new MG analog DOTA-DGlu-Pro-Tyr-Gly-Trp-(N-Me)Nle-Asp-1Nal-NH2 comprising site-specific amino acid substitutions in position 2, 6 and 8 and different possible metabolites thereof were synthesized. The receptor interaction of the peptide and selected metabolites was evaluated in a CCK2R-expressing cell line. The enzymatic stability of the 177Lu-labeled peptide analog was evaluated in vitro in different media as well as in BALB/c mice up to 1 h after injection and the metabolites were identified based on radio-HPLC analysis. The new radiopeptide showed a highly increased stability in vivo with >56% intact radiopeptide in the blood of BALB/c mice 1 h after injection. High CCK2R affinity and cell uptake was confirmed only for the intact peptide, whereas enzymatic cleavage within the receptor specific C-terminal amino acid sequence resulted in complete loss of affinity and cell uptake. A favorable biodistribution profile was observed in BALB/c mice with low background activity, preferential renal excretion and prolonged uptake in CCK2R-expressing tissues. The novel stabilized MG analog shows high potential for diagnostic and therapeutic use. The radiometabolites characterized give new insights into the enzymatic degradation in vivo. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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21 pages, 3580 KiB  
Article
Evaluation of Met-Val-Lys as a Renal Brush Border Enzyme-Cleavable Linker to Reduce Kidney Uptake of 68Ga-Labeled DOTA-Conjugated Peptides and Peptidomimetics
by Shreya Bendre, Zhengxing Zhang, Hsiou-Ting Kuo, Julie Rousseau, Chengcheng Zhang, Helen Merkens, Áron Roxin, François Bénard and Kuo-Shyan Lin
Molecules 2020, 25(17), 3854; https://doi.org/10.3390/molecules25173854 - 25 Aug 2020
Cited by 18 | Viewed by 3895
Abstract
High kidney uptake is a common feature of peptide-based radiopharmaceuticals, leading to reduced detection sensitivity for lesions adjacent to kidneys and lower maximum tolerated therapeutic dose. In this study, we evaluated if the Met-Val-Lys (MVK) linker could be used to lower kidney uptake [...] Read more.
High kidney uptake is a common feature of peptide-based radiopharmaceuticals, leading to reduced detection sensitivity for lesions adjacent to kidneys and lower maximum tolerated therapeutic dose. In this study, we evaluated if the Met-Val-Lys (MVK) linker could be used to lower kidney uptake of 68Ga-labeled DOTA-conjugated peptides and peptidomimetics. A model compound, [68Ga]Ga-DOTA-AmBz-MVK(Ac)-OH (AmBz: aminomethylbenzoyl), and its derivative, [68Ga]Ga-DOTA-AmBz-MVK(HTK01166)-OH, coupled with the PSMA (prostate-specific membrane antigen)-targeting motif of the previously reported HTK01166 were synthesized and evaluated to determine if they could be recognized and cleaved by the renal brush border enzymes. Additionally, positron emission tomography (PET) imaging, ex vivo biodistribution and in vivo stability studies were conducted in mice to evaluate their pharmacokinetics. [68Ga]Ga-DOTA-AmBz-MVK(Ac)-OH was effectively cleaved specifically by neutral endopeptidase (NEP) of renal brush border enzymes at the Met-Val amide bond, and the radio-metabolite [68Ga]Ga-DOTA-AmBz-Met-OH was rapidly excreted via the renal pathway with minimal kidney retention. [68Ga]Ga-DOTA-AmBz-MVK(HTK01166)-OH retained its PSMA-targeting capability and was also cleaved by NEP, although less effectively when compared to [68Ga]Ga-DOTA-AmBz-MVK(Ac)-OH. The kidney uptake of [68Ga]Ga-DOTA-AmBz-MVK(HTK01166)-OH was 30% less compared to that of [68Ga]Ga-HTK01166. Our data demonstrated that derivatives of [68Ga]Ga-DOTA-AmBz-MVK-OH can be cleaved specifically by NEP, and therefore, MVK can be a promising cleavable linker for use to reduce kidney uptake of radiolabeled DOTA-conjugated peptides and peptidomimetics. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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18 pages, 2716 KiB  
Article
Radiochemical Synthesis and Evaluation of Novel Radioconjugates of Neurokinin 1 Receptor Antagonist Aprepitant Dedicated for NK1R-Positive Tumors
by Paweł K. Halik, Piotr F. J. Lipiński, Joanna Matalińska, Przemysław Koźmiński, Aleksandra Misicka and Ewa Gniazdowska
Molecules 2020, 25(16), 3756; https://doi.org/10.3390/molecules25163756 - 18 Aug 2020
Cited by 17 | Viewed by 3385
Abstract
Aprepitant, a lipophilic and small molecular representative of neurokinin 1 receptor antagonists, is known for its anti-proliferative activity on numerous cancer cell lines that are sensitive to Substance P mitogen action. In the presented research, we developed two novel structural modifications of aprepitant [...] Read more.
Aprepitant, a lipophilic and small molecular representative of neurokinin 1 receptor antagonists, is known for its anti-proliferative activity on numerous cancer cell lines that are sensitive to Substance P mitogen action. In the presented research, we developed two novel structural modifications of aprepitant to create aprepitant conjugates with different radionuclide chelators. All of them were radiolabeled with 68Ga and 177Lu radionuclides and evaluated in terms of their lipophilicity and stability in human serum. Furthermore, fully stable conjugates were examined in molecular modelling with a human neurokinin 1 receptor structure and in a competitive radioligand binding assay using rat brain homogenates in comparison to the aprepitant molecule. This initial research is in the conceptual stage to give potential theranostic-like radiopharmaceutical pairs for the imaging and therapy of neurokinin 1 receptor-overexpressing cancers. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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24 pages, 3815 KiB  
Article
Involvement of Differentially Expressed microRNAs in the PEGylated Liposome Encapsulated 188Rhenium-Mediated Suppression of Orthotopic Hypopharyngeal Tumor
by Bing-Ze Lin, Shen-Ying Wan, Min-Ying Lin, Chih-Hsien Chang, Ting-Wen Chen, Muh-Hwa Yang and Yi-Jang Lee
Molecules 2020, 25(16), 3609; https://doi.org/10.3390/molecules25163609 - 08 Aug 2020
Cited by 6 | Viewed by 3306
Abstract
Hypopharyngeal cancer (HPC) accounts for the lowest survival rate among all types of head and neck cancers (HNSCC). However, the therapeutic approach for HPC still needs to be investigated. In this study, a theranostic 188Re-liposome was prepared to treat orthotopic HPC tumors [...] Read more.
Hypopharyngeal cancer (HPC) accounts for the lowest survival rate among all types of head and neck cancers (HNSCC). However, the therapeutic approach for HPC still needs to be investigated. In this study, a theranostic 188Re-liposome was prepared to treat orthotopic HPC tumors and analyze the deregulated microRNA expressive profiles. The therapeutic efficacy of 188Re-liposome on HPC tumors was evaluated using bioluminescent imaging followed by next generation sequencing (NGS) analysis, in order to address the deregulated microRNAs and associated signaling pathways. The differentially expressed microRNAs were also confirmed using clinical HNSCC samples and clinical information from The Cancer Genome Atlas (TCGA) database. Repeated doses of 188Re-liposome were administrated to tumor-bearing mice, and the tumor growth was apparently suppressed after treatment. For NGS analysis, 13 and 9 microRNAs were respectively up-regulated and down-regulated when the cutoffs of fold change were set to 5. Additionally, miR-206-3p and miR-142-5p represented the highest fold of up-regulation and down-regulation by 188Re-liposome, respectively. According to Differentially Expressed MiRNAs in human Cancers (dbDEMC) analysis, most of 188Re-liposome up-regulated microRNAs were categorized as tumor suppressors, while down-regulated microRNAs were oncogenic. The KEGG pathway analysis showed that cancer-related pathways and olfactory and taste transduction accounted for the top pathways affected by 188Re-liposome. 188Re-liposome down-regulated microRNAs, including miR-143, miR-6723, miR-944, and miR-136 were associated with lower survival rates at a high expressive level. 188Re-liposome could suppress the HPC tumors in vivo, and the therapeutic efficacy was associated with the deregulation of microRNAs that could be considered as a prognostic factor. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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Review

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40 pages, 2787 KiB  
Review
Radiochemistry, Production Processes, Labeling Methods, and ImmunoPET Imaging Pharmaceuticals of Iodine-124
by Krishan Kumar and Arijit Ghosh
Molecules 2021, 26(2), 414; https://doi.org/10.3390/molecules26020414 - 14 Jan 2021
Cited by 29 | Viewed by 4354
Abstract
Target-specific biomolecules, monoclonal antibodies (mAb), proteins, and protein fragments are known to have high specificity and affinity for receptors associated with tumors and other pathological conditions. However, the large biomolecules have relatively intermediate to long circulation half-lives (>day) and tumor localization times. Combining [...] Read more.
Target-specific biomolecules, monoclonal antibodies (mAb), proteins, and protein fragments are known to have high specificity and affinity for receptors associated with tumors and other pathological conditions. However, the large biomolecules have relatively intermediate to long circulation half-lives (>day) and tumor localization times. Combining superior target specificity of mAbs and high sensitivity and resolution of the PET (Positron Emission Tomography) imaging technique has created a paradigm-shifting imaging modality, ImmunoPET. In addition to metallic PET radionuclides, 124I is an attractive radionuclide for radiolabeling of mAbs as potential immunoPET imaging pharmaceuticals due to its physical properties (decay characteristics and half-life), easy and routine production by cyclotrons, and well-established methodologies for radioiodination. The objective of this report is to provide a comprehensive review of the physical properties of iodine and iodine radionuclides, production processes of 124I, various 124I-labeling methodologies for large biomolecules, mAbs, and the development of 124I-labeled immunoPET imaging pharmaceuticals for various cancer targets in preclinical and clinical environments. A summary of several production processes, including 123Te(d,n)124I, 124Te(d,2n)124I, 121Sb(α,n)124I, 123Sb(α,3n)124I, 123Sb(3He,2n)124I, natSb(α, xn)124I, natSb(3He,n)124I reactions, a detailed overview of the 124Te(p,n)124I reaction (including target selection, preparation, processing, and recovery of 124I), and a fully automated process that can be scaled up for GMP (Good Manufacturing Practices) production of large quantities of 124I is provided. Direct, using inorganic and organic oxidizing agents and enzyme catalysis, and indirect, using prosthetic groups, 124I-labeling techniques have been discussed. Significant research has been conducted, in more than the last two decades, in the development of 124I-labeled immunoPET imaging pharmaceuticals for target-specific cancer detection. Details of preclinical and clinical evaluations of the potential 124I-labeled immunoPET imaging pharmaceuticals are described here. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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19 pages, 3261 KiB  
Review
PET Radiotracers for CNS-Adrenergic Receptors: Developments and Perspectives
by Santosh Reddy Alluri, Sung Won Kim, Nora D. Volkow and Kun-Eek Kil
Molecules 2020, 25(17), 4017; https://doi.org/10.3390/molecules25174017 - 03 Sep 2020
Cited by 4 | Viewed by 3315
Abstract
Epinephrine (E) and norepinephrine (NE) play diverse roles in our body’s physiology. In addition to their role in the peripheral nervous system (PNS), E/NE systems including their receptors are critical to the central nervous system (CNS) and to mental health. Various antipsychotics, antidepressants, [...] Read more.
Epinephrine (E) and norepinephrine (NE) play diverse roles in our body’s physiology. In addition to their role in the peripheral nervous system (PNS), E/NE systems including their receptors are critical to the central nervous system (CNS) and to mental health. Various antipsychotics, antidepressants, and psychostimulants exert their influence partially through different subtypes of adrenergic receptors (ARs). Despite the potential of pharmacological applications and long history of research related to E/NE systems, research efforts to identify the roles of ARs in the human brain taking advantage of imaging have been limited by the lack of subtype specific ligands for ARs and brain penetrability issues. This review provides an overview of the development of positron emission tomography (PET) radiotracers for in vivo imaging of AR system in the brain. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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37 pages, 5184 KiB  
Review
Overview of Radiolabeled Somatostatin Analogs for Cancer Imaging and Therapy
by Romain Eychenne, Christelle Bouvry, Mickael Bourgeois, Pascal Loyer, Eric Benoist and Nicolas Lepareur
Molecules 2020, 25(17), 4012; https://doi.org/10.3390/molecules25174012 - 02 Sep 2020
Cited by 68 | Viewed by 10102
Abstract
Identified in 1973, somatostatin (SST) is a cyclic hormone peptide with a short biological half-life. Somatostatin receptors (SSTRs) are widely expressed in the whole body, with five subtypes described. The interaction between SST and its receptors leads to the internalization of the ligand–receptor [...] Read more.
Identified in 1973, somatostatin (SST) is a cyclic hormone peptide with a short biological half-life. Somatostatin receptors (SSTRs) are widely expressed in the whole body, with five subtypes described. The interaction between SST and its receptors leads to the internalization of the ligand–receptor complex and triggers different cellular signaling pathways. Interestingly, the expression of SSTRs is significantly enhanced in many solid tumors, especially gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). Thus, somatostatin analogs (SSAs) have been developed to improve the stability of the endogenous ligand and so extend its half-life. Radiolabeled analogs have been developed with several radioelements such as indium-111, technetium-99 m, and recently gallium-68, fluorine-18, and copper-64, to visualize the distribution of receptor overexpression in tumors. Internal metabolic radiotherapy is also used as a therapeutic strategy (e.g., using yttrium-90, lutetium-177, and actinium-225). With some radiopharmaceuticals now used in clinical practice, somatostatin analogs developed for imaging and therapy are an example of the concept of personalized medicine with a theranostic approach. Here, we review the development of these analogs, from the well-established and authorized ones to the most recently developed radiotracers, which have better pharmacokinetic properties and demonstrate increased efficacy and safety, as well as the search for new clinical indications. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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20 pages, 3278 KiB  
Review
Pyrazoles as Key Scaffolds for the Development of Fluorine-18-Labeled Radiotracers for Positron Emission Tomography (PET)
by Pedro M. O. Gomes, Artur M. S. Silva and Vera L. M. Silva
Molecules 2020, 25(7), 1722; https://doi.org/10.3390/molecules25071722 - 09 Apr 2020
Cited by 10 | Viewed by 3344
Abstract
The need for increasingly personalized medicine solutions (precision medicine) and quality medical treatments, has led to a growing demand and research for image-guided therapeutic solutions. Positron emission tomography (PET) is a powerful imaging technique that can be established using complementary imaging systems and [...] Read more.
The need for increasingly personalized medicine solutions (precision medicine) and quality medical treatments, has led to a growing demand and research for image-guided therapeutic solutions. Positron emission tomography (PET) is a powerful imaging technique that can be established using complementary imaging systems and selective imaging agents—chemical probes or radiotracers—which are drugs labeled with a radionuclide, also called radiopharmaceuticals. PET has two complementary purposes: selective imaging for diagnosis and monitoring of disease progression and response to treatment. The development of selective imaging agents is a growing research area, with a high number of diverse drugs, labeled with different radionuclides, being reported nowadays. This review article is focused on the use of pyrazoles as suitable scaffolds for the development of 18F-labeled radiotracers for PET imaging. A brief introduction to PET and pyrazoles, as key scaffolds in medicinal chemistry, is presented, followed by a description of the most important [18F]pyrazole-derived radiotracers (PET tracers) that have been developed in the last 20 years for selective PET imaging, grouped according to their specific targets. Full article
(This article belongs to the Special Issue Radiolabeled Compounds for Diagnosis and Treatment of Cancer)
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