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Humpert S, Schneider D, Bier D, Schulze A, Neumaier F, Neumaier B, Holschbach M. 8-Bicycloalkyl-CPFPX derivatives as potent and selective tools for in vivo imaging of the A 1 adenosine receptor. Eur J Med Chem 2024; 271:116380. [PMID: 38615410 DOI: 10.1016/j.ejmech.2024.116380] [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] [Received: 01/18/2024] [Revised: 03/19/2024] [Accepted: 04/01/2024] [Indexed: 04/16/2024]
Abstract
Imaging of the A1 adenosine receptor (A1R) by positron emission tomography (PET) with 8-cyclopentyl-3-(3-[18F]fluoropropyl)-1-propyl-xanthine ([18F]CPFPX) has been widely used in preclinical and clinical studies. However, this radioligand suffers from rapid peripheral metabolism and subsequent accumulation of radiometabolites in the vascular compartment. In the present work, we prepared four derivatives of CPFPX by replacement of the cyclopentyl group with norbornane moieties. These derivatives were evaluated by competition binding studies, microsomal stability assays and LC-MS analysis of microsomal metabolites. In addition, the 18F-labeled isotopologue of 8-(1-norbornyl)-3-(3-fluoropropyl)-1-propylxanthine (1-NBX) as the most promising candidate was prepared by radiofluorination of the corresponding tosylate precursor and the resulting radioligand ([18F]1-NBX) was evaluated by permeability assays with Caco-2 cells and in vitro autoradiography in rat brain slices. Our results demonstrate that 1-NBX exhibits significantly improved A1R affinity and selectivity when compared to CPFPX and that it does not give rise to lipophilic metabolites expected to cross the blood-brain-barrier in microsomal assays. Furthermore, [18F]1-NBX showed a high passive permeability (Pc = 6.9 ± 2.9 × 10-5 cm/s) and in vitro autoradiography with this radioligand resulted in a distribution pattern matching A1R expression in the brain. Moreover, a low degree of non-specific binding (5%) was observed. Taken together, these findings identify [18F]1-NBX as a promising candidate for further preclinical evaluation as potential PET tracer for A1R imaging.
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Affiliation(s)
- Swen Humpert
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany
| | - Daniela Schneider
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany
| | - Dirk Bier
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany
| | - Annette Schulze
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany
| | - Felix Neumaier
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany; Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany
| | - Bernd Neumaier
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany; Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany; Max Planck Institute for Metabolism Research, Gleueler Straße 50, 50931, Cologne, Germany.
| | - Marcus Holschbach
- Forschungszentrum Jülich GmbH, Institute of Neurosciences and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428, Jülich, Germany
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Wodtke R, Laube M, Hauser S, Meister S, Ludwig FA, Fischer S, Kopka K, Pietzsch J, Löser R. Preclinical evaluation of an 18F-labeled N ε-acryloyllysine piperazide for covalent targeting of transglutaminase 2. EJNMMI Radiopharm Chem 2024; 9:1. [PMID: 38165538 PMCID: PMC10761660 DOI: 10.1186/s41181-023-00231-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/15/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Transglutaminase 2 (TGase 2) is a multifunctional protein and has a prominent role in various (patho)physiological processes. In particular, its transamidase activity, which is rather latent under physiological conditions, gains importance in malignant cells. Thus, there is a great need of theranostic probes for targeting tumor-associated TGase 2, and targeted covalent inhibitors appear to be particularly attractive as vector molecules. Such an inhibitor, equipped with a radionuclide suitable for noninvasive imaging, would be supportive for answering the general question on the possibility for functional characterization of tumor-associated TGase 2. For this purpose, the recently developed 18F-labeled Nε-acryloyllysine piperazide [18F]7b, which is a potent and selective irreversible inhibitor of TGase 2, was subject to a detailed radiopharmacological characterization herein. RESULTS An alternative radiosynthesis of [18F]7b is presented, which demands less than 300 µg of the respective trimethylammonio precursor per synthesis and provides [18F]7b in good radiochemical yields (17 ± 7%) and high (radio)chemical purities (≥ 99%). Ex vivo biodistribution studies in healthy mice at 5 and 60 min p.i. revealed no permanent enrichment of 18F-activity in tissues with the exception of the bone tissue. In vivo pretreatment with ketoconazole and in vitro murine liver microsome studies complemented by mass spectrometric analysis demonstrated that bone uptake originates from metabolically released [18F]fluoride. Further metabolic transformations of [18F]7b include mono-hydroxylation and glucuronidation. Based on blood sampling data and liver microsome experiments, pharmacokinetic parameters such as plasma and intrinsic clearance were derived, which substantiated the apparently rapid distribution of [18F]7b in and elimination from the organisms. A TGase 2-mediated uptake of [18F]7b in different tumor cell lines could not be proven. Moreover, evaluation of [18F]7b in melanoma tumor xenograft models based on A375-hS100A4 (TGase 2 +) and MeWo (TGase 2 -) cells by ex vivo biodistribution and PET imaging studies were not indicative for a specific targeting. CONCLUSION [18F]7b is a valuable radiometric tool to study TGase 2 in vitro under various conditions. However, its suitability for targeting tumor-associated TGase 2 is strongly limited due its unfavorable pharmacokinetic properties as demonstrated in rodents. Consequently, from a radiochemical perspective [18F]7b requires appropriate structural modifications to overcome these limitations.
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Affiliation(s)
- Robert Wodtke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany.
| | - Markus Laube
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Sandra Hauser
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Sebastian Meister
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Friedrich-Alexander Ludwig
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, 04318, Leipzig, Germany
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, 04318, Leipzig, Germany
| | - Klaus Kopka
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, 04318, Leipzig, Germany
- School of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
- School of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany
| | - Reik Löser
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany.
- School of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany.
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3
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Lemm S, Köhler S, Wodtke R, Jung F, Küpper JH, Pietzsch J, Laube M. Investigation of Radiotracer Metabolic Stability In Vitro with CYP-Overexpressing Hepatoma Cell Lines. Cells 2022; 11:cells11152447. [PMID: 35954291 PMCID: PMC9368227 DOI: 10.3390/cells11152447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/22/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
The characterization of novel radiotracers toward their metabolic stability is an essential part of their development. While in vitro methods such as liver microsome assays or ex vivo blood or tissue samples provide information on overall stability, little or no information is obtained on cytochrome P450 (CYP) enzyme and isoform-specific contribution to the metabolic fate of individual radiotracers. Herein, we investigated recently established CYP-overexpressing hepatoblastoma cell lines (HepG2) for their suitability to study the metabolic stability of radiotracers in general and to gain insight into CYP isoform specificity. Wildtype HepG2 and CYP1A2-, CYP2C19-, and CYP3A4-overexpressing HepG2 cells were incubated with radiotracers, and metabolic turnover was analyzed. The optimized protocol, covering cell seeding in 96-well plates and analysis of supernatant by radio thin-layer-chromatography for higher throughput, was transferred to the evaluation of three 18F-labeled celecoxib-derived cyclooxygenase-2 inhibitors (coxibs). These investigations revealed time-dependent degradation of the intact radiotracers, as well as CYP isoform- and substrate-specific differences in their metabolic profiles. HepG2 CYP2C19 proved to be the cell line showing the highest metabolic turnover for each radiotracer studied here. Comparison with human and murine liver microsome assays showed good agreement with the human metabolite profile obtained by the HepG2 cell lines. Therefore, CYP-overexpressing HepG2 cells provide a good complement for assessing the metabolic stability of radiotracers and allow the analysis of the CYP isoform-specific contribution to the overall radiotracer metabolism.
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Affiliation(s)
- Sandy Lemm
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
| | - Susanne Köhler
- Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Universitätsplatz 1, 01968 Senftenberg, Germany
| | - Robert Wodtke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Friedrich Jung
- Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Universitätsplatz 1, 01968 Senftenberg, Germany
| | - Jan-Heiner Küpper
- Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Universitätsplatz 1, 01968 Senftenberg, Germany
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
| | - Markus Laube
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Correspondence:
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4
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Aigbogun OP, Nwabufo CK, Owens MN, Allen KJH, Lee JS, Phenix CP, Krol ES. An HPLC-UV validated bioanalytical method for measurement of in vitro phase 1 kinetics of α-synuclein binding bifunctional compounds. Xenobiotica 2022; 52:916-927. [PMID: 36282181 DOI: 10.1080/00498254.2022.2140315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aggregates of the protein α-synuclein are associated with pathophysiology of Parkinson's disease and are present in Lewy Bodies found in the brains of Parkinson's patients. We previously demonstrated that bifunctional compounds composed of caffeine linked via a six carbon chain to either 1-aminoindan (C8-6-I) or nicotine (C8-6-N) bind α-synuclein and protect yeast cells from α-synuclein mediated toxicity.A critical step in development of positron emission tomography (PET) probes for neurodegenerative diseases is evaluation of their metabolic stability. We determined that C8-6-I, and C8-6-N both undergo phase 1 P450 metabolism in mouse, rat, and human liver microsomes. We utilised this metabolic information to guide the design of fluorinated analogues for use as PET probes and determined that the fluorine in 19F-C8-6-I and 19F-C8-6-N is stable to P450 enzymes.We have developed and validated an analytical HPLC-UV method following FDA and EMA guidelines to measure in vitro phase 1 kinetics of these compounds and determine their Vmax, KM and CLint,u in mouse liver microsomes. We found that C8-6-I and 19F-C8-6-I have a two- to fourfold lower CLint,u than C8-6-N, and 19F-C8-6-N. Our approach shows a simple, specific, and effective system to design and develop compounds as PET probes.
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Affiliation(s)
- Omozojie P Aigbogun
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Madeline N Owens
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Kevin J H Allen
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jeremy S Lee
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Christopher P Phenix
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ed S Krol
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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5
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Liu L, Johnson PD, Prime ME, Khetarpal V, Lee MR, Brown CJ, Chen X, Clark-Frew D, Coe S, Conlon M, Davis R, Ensor S, Esposito S, Moren AF, Gai X, Green S, Greenaway C, Haber J, Halldin C, Hayes S, Herbst T, Herrmann F, Heßmann M, Hsai MM, Kotey A, Mangette JE, Mills MR, Monteagudo E, Nag S, Nibbio M, Orsatti L, Schaertl S, Scheich C, Sproston J, Stepanov V, Varnäs K, Varrone A, Wityak J, Mrzljak L, Munoz-Sanjuan I, Bard JA, Dominguez C. [ 11C]CHDI-626, a PET Tracer Candidate for Imaging Mutant Huntingtin Aggregates with Reduced Binding to AD Pathological Proteins. J Med Chem 2021; 64:12003-12021. [PMID: 34351166 DOI: 10.1021/acs.jmedchem.1c00667] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The expanded polyglutamine-containing mutant huntingtin (mHTT) protein is implicated in neuronal degeneration of medium spiny neurons in Huntington's disease (HD) for which multiple therapeutic approaches are currently being evaluated to eliminate or reduce mHTT. Development of effective and orthogonal biomarkers will ensure accurate assessment of the safety and efficacy of pharmacologic interventions. We have identified and optimized a class of ligands that bind to oligomerized/aggregated mHTT, which is a hallmark in the HD postmortem brain. These ligands are potentially useful imaging biomarkers for HD therapeutic development in both preclinical and clinical settings. We describe here the optimization of the benzo[4,5]imidazo[1,2-a]pyrimidine series that show selective binding to mHTT aggregates over Aβ- and/or tau-aggregates associated with Alzheimer's disease pathology. Compound [11C]-2 was selected as a clinical candidate based on its high free fraction in the brain, specific binding in the HD mouse model, and rapid brain uptake/washout in nonhuman primate positron emission tomography imaging studies.
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Affiliation(s)
- Longbin Liu
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Peter D Johnson
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Michael E Prime
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Vinod Khetarpal
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Matthew R Lee
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Christopher J Brown
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Xuemei Chen
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Daniel Clark-Frew
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Samuel Coe
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Mike Conlon
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Randall Davis
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Samantha Ensor
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Simone Esposito
- IRBM, IRBM Science Park S.p.A., Via Pontina Km 30,600, Pomezia, Rome 00071, Italy
| | - Anton Forsberg Moren
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - Xinjie Gai
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Samantha Green
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Catherine Greenaway
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - James Haber
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Christer Halldin
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - Sarah Hayes
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Todd Herbst
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Frank Herrmann
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, Hamburg 22419, Germany
| | - Manuela Heßmann
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, Hamburg 22419, Germany
| | - Ming Min Hsai
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Adrian Kotey
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - John E Mangette
- Albany Molecular Research, Inc., 1001 Main Street, Buffalo, New York 14203, United States
| | - Matthew R Mills
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Edith Monteagudo
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Sangram Nag
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - Martina Nibbio
- IRBM, IRBM Science Park S.p.A., Via Pontina Km 30,600, Pomezia, Rome 00071, Italy
| | - Laura Orsatti
- IRBM, IRBM Science Park S.p.A., Via Pontina Km 30,600, Pomezia, Rome 00071, Italy
| | - Sabine Schaertl
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, Hamburg 22419, Germany
| | - Christoph Scheich
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, Hamburg 22419, Germany
| | - Joanne Sproston
- Evotec (U.K.) Ltd, 114 Innovation Drive, Milton Park, Abingdon OX14 4RZ, U.K
| | - Vladimir Stepanov
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - Katarina Varnäs
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - Andrea Varrone
- Department of Clinical Neuroscience, Centre for Psychiatric Research, Karolinska Hospital, Karolinska Institutet, Stockholm S-17176, Sweden
| | - John Wityak
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Ladislav Mrzljak
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Ignacio Munoz-Sanjuan
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Jonathan A Bard
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
| | - Celia Dominguez
- CHDI Management/CHDI Foundation, 6080 Center Drive, Suite 700, Los Angeles, California 90045, United States
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Drug-Like Small Molecule HSP27 Functional Inhibitor Sensitizes Lung Cancer Cells to Gefitinib or Cisplatin by Inducing Altered Cross-Linked Hsp27 Dimers. Pharmaceutics 2021; 13:pharmaceutics13050630. [PMID: 33925114 PMCID: PMC8145107 DOI: 10.3390/pharmaceutics13050630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/18/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Relationships between heat shock protein 27 (HSP27) and cancer aggressiveness, metastasis, drug resistance, and poor patient outcomes in various cancer types including non-small cell lung cancer (NSCLC) were reported, and inhibition of HSP27 expression is suggested to be a possible strategy for cancer therapy. Unlike HSP90 or HSP70, HSP27 does not have an ATP-binding pocket, and no effective HSP27 inhibitors have been identified. Previously, NSCLC cancer cells were sensitized to radiation and chemotherapy when co-treated with small molecule HSP27 functional inhibitors such as zerumbone (ZER), SW15, and J2 that can induce abnormal cross-linked HSP27 dimer. In this study, cancer inhibition effects of NA49, a chromenone compound with better solubility, longer circulation time, and less toxicity than J2, were examined in combination with anticancer drugs such as cisplatin and gefitinib in NSCLC cell lines. When the cytotoxic drug cisplatin was treated in combination with NA49 in epidermal growth factor receptors (EGFRs) WT cell lines, sensitization was induced in an HSP27 expression-dependent manner. With gefitinib treatment, NA49 showed increased combination effects in both EGFR WT and Mut cell lines, also with HSP27 expression-dependent patterns. Moreover, NA49 induced sensitization in EGFR Mut cells with a secondary mutation of T790M when combined with gefitinib. Augmented tumor growth inhibition was shown with the combination of cisplatin or gefitinib and NA49 in nude mouse xenograft models. These results suggest the combination of HSP27 inhibitor NA49 and anticancer agents as a candidate for overcoming HSP27-mediated drug resistance in NSCLC patients.
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Species Differences in Microsomal Metabolism of Xanthine-Derived A 1 Adenosine Receptor Ligands. Pharmaceuticals (Basel) 2021; 14:ph14030277. [PMID: 33803861 PMCID: PMC8003343 DOI: 10.3390/ph14030277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/10/2021] [Accepted: 03/15/2021] [Indexed: 11/17/2022] Open
Abstract
Tracer development for positron emission tomography (PET) requires thorough evaluation of pharmacokinetics, metabolism, and dosimetry of candidate radioligands in preclinical animal studies. Since variations in pharmacokinetics and metabolism of a compound occur in different species, careful selection of a suitable model species is mandatory to obtain valid data. This study focuses on species differences in the in vitro metabolism of three xanthine-derived ligands for the A1 adenosine receptor (A1AR), which, in their 18F-labeled form, can be used to image A1AR via PET. In vitro intrinsic clearance and metabolite profiles of 8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (CPFPX), an established A1AR-ligand, and two novel analogs, 8-cyclobutyl-3-(3-fluoropropyl)-1-propylxanthine (CBX) and 3-(3-fluoropropyl)-8-(1-methylcyclobutyl)-1-propylxanthine (MCBX), were determined in liver microsomes from humans and preclinical animal species. Molecular mechanisms leading to significant differences between human and animal metabolite profiles were also examined. The results revealed significant species differences regarding qualitative and quantitative aspects of microsomal metabolism. None of the tested animal species fully matched human microsomal metabolism of the three A1AR ligands. In conclusion, preclinical evaluation of xanthine-derived A1AR ligands should employ at least two animal species, preferably rodent and dog, to predict in vivo behavior in humans. Surprisingly, rhesus macaques appear unsuitable due to large differences in metabolic activity towards the test compounds.
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Gonsalves MD, Colizza K, Smith JL, Oxley JC. In vitro and in vivo studies of triacetone triperoxide (TATP) metabolism in humans. Forensic Toxicol 2020. [DOI: 10.1007/s11419-020-00540-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Abstract
Purpose
Triacetone triperoxide (TATP) is a volatile but powerful explosive that appeals to terrorists due to its ease of synthesis from household items. For this reason, bomb squad, canine (K9) units, and scientists must work with this material to mitigate this threat. However, no information on the metabolism of TATP is available.
Methods
In vitro experiments using human liver microsomes and recombinant enzymes were performed on TATP and TATP-OH for metabolite identification and enzyme phenotyping. Enzyme kinetics for TATP hydroxylation were also investigated. Urine from laboratory personnel collected before and after working with TATP was analyzed for TATP and its metabolites.
Results
While experiments with flavin monooxygenases were inconclusive, those with recombinant cytochrome P450s (CYPs) strongly suggested that CYP2B6 was the principle enzyme responsible for TATP hydroxylation. TATP-O-glucuronide was also identified and incubations with recombinant uridine diphosphoglucuronosyltransferases (UGTs) indicated that UGT2B7 catalyzes this reaction. Michaelis–Menten kinetics were determined for TATP hydroxylation, with Km = 1.4 µM and Vmax = 8.7 nmol/min/nmol CYP2B6. TATP-O-glucuronide was present in the urine of all three volunteers after being exposed to TATP vapors showing good in vivo correlation to in vitro data. TATP and TATP-OH were not observed.
Conclusions
Since scientists working to characterize and detect TATP to prevent terrorist attacks are constantly exposed to this volatile compound, attention should be paid to its metabolism. This paper is the first to elucidate some exposure, metabolism and excretion of TATP in humans and to identify a marker of TATP exposure, TATP-O-glucuronide in urine.
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Schneider D, Oskamp A, Holschbach M, Neumaier B, Bier D, Bauer A. Influence of binding affinity and blood plasma level on cerebral pharmacokinetics and PET imaging characteristics of two novel xanthine PET radioligands for the A1 adenosine receptor. Nucl Med Biol 2020; 82-83:1-8. [DOI: 10.1016/j.nucmedbio.2019.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/16/2019] [Accepted: 12/01/2019] [Indexed: 10/25/2022]
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