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Jinda H, Nakashima K, Watanabe H, Ono M. Synthesis and Evaluation of a Cathepsin B-Recognizing Trifunctional Chelating Agent to Improve Tumor Retention of Radioimmunoconjugates. J Labelled Comp Radiopharm 2024; 67:295-304. [PMID: 38837480 DOI: 10.1002/jlcr.4112] [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: 01/23/2024] [Revised: 04/12/2024] [Accepted: 05/15/2024] [Indexed: 06/07/2024]
Abstract
Cathepsin B (CTSB) is a lysosomal protease that is overexpressed in tumor cells. Radioimmunoconjugates (RICs) composed of CTSB-recognizing chelating agents are expected to increase the molecular weights of their radiometabolites by forming conjugates with CTSB in cells, resulting in their improved retention in tumor cells. We designed a novel CTSB-recognizing trifunctional chelating agent, azide-[111In]In-DOTA-CTSB-substrate ([111In]In-ADCS), to synthesize a RIC, trastuzumab-[111In]In-ADCS ([111In]In-TADCS), and evaluated its utility to improve tumor retention of the RIC. [111In]In-ADCS and [111In]In-TADCS were synthesized with satisfactory yield and purity. [111In]In-ADCS was markedly stable in murine plasma until 96 h postincubation. [111In]In-ADCS showed binding to CTSB in vitro, and the conjugation was blocked by the addition of CTSB inhibitor. In the internalization assay, [111In]In-TADCS exhibited high-level retention in SK-OV-3 cells, indicating the in vitro utility of the CTSB-recognizing unit. In the biodistribution assay, [111In]In-TADCS showed high-level tumor accumulation, but the retention was hardly improved. In the first attempt to combine a CTSB-recognizing unit and RIC, these findings show the fundamental properties of the CTSB-recognizing trifunctional chelating agent to improve tumor retention of RICs.
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Affiliation(s)
- Hiroki Jinda
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Kazuma Nakashima
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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Hojorat M, Pineau J, Driver CHS, Esteban-Gómez D, Cordier M, Zeevaart JR, Platas-Iglesias C, Lima LMP, Le Bris N, Tripier R. Relevance of Oxocyclam from Palladium(II) Coordination to Radiopharmaceutical Development. Inorg Chem 2024; 63:11884-11896. [PMID: 38861670 DOI: 10.1021/acs.inorgchem.4c01780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
We provide a comprehensive study of the coordination of oxocyclam with palladium(II), including presentation of a novel bifunctional analogue, p-H2N-Bn-oxocyclam, bearing an aniline pendant. The complexation of palladium(II) with oxocyclam was examined by various techniques, including NMR analysis and potentiometric titrations which revealed that the Pd(II) complex can adopt different configurations such as trans-I and trans-III. In addition, oxocyclam forms a thermodynamically stable palladium(II) complex, the stabilization being attributed to the deprotonation of the amide function. The crystal structures of [Pd(H-1oxocyclam)]+ and [Pd(oxocyclam)]2+ were obtained, revealing the structural details previously anticipated, including, in the second case, the presence of the proton on the carbonyl oxygen atom. Additionally, the study explored the redox behavior of the Pd(II)-oxocyclam complex through reduction and oxidation voltammograms at different pH values. Successful 109Pd-labeling of oxocyclam and p-H2N-Bn-oxocyclam at pH 3.5 demonstrated high labeling efficiencies, whatever the species formed. The stability of the radiocomplexes was assessed and moderate transchelation toward EDTA was observed. Overall, oxocyclam displayed favorable properties for Pd(II) coordination and radiolabeling, suggesting its potential as a chelating agent for this metal in palladium-based applications.
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Affiliation(s)
- Maher Hojorat
- UMR CNRS 6521 CEMCA, Université de Brest, 6 Avenue Victor le Gorgeu, 29238 Brest, France
| | - Julie Pineau
- UMR CNRS 6521 CEMCA, Université de Brest, 6 Avenue Victor le Gorgeu, 29238 Brest, France
| | - Cathryn H S Driver
- South African Nuclear Energy Corporation, Radiochemistry and PreClinical Imaging Facility, Elias Motsoaledi Street, R104 Pelindaba, Pretoria 0240, North West, South Africa
| | - David Esteban-Gómez
- Departamento de Química, Facultade de Ciencias & Centro Interdisciplinar de Química e Bioloxía (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - Marie Cordier
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, Univ Rennes, 35000 Rennes, France
| | - Jan Rijn Zeevaart
- South African Nuclear Energy Corporation, Radiochemistry and PreClinical Imaging Facility, Elias Motsoaledi Street, R104 Pelindaba, Pretoria 0240, North West, South Africa
| | - Carlos Platas-Iglesias
- Departamento de Química, Facultade de Ciencias & Centro Interdisciplinar de Química e Bioloxía (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - Luís M P Lima
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Nathalie Le Bris
- UMR CNRS 6521 CEMCA, Université de Brest, 6 Avenue Victor le Gorgeu, 29238 Brest, France
| | - Raphaël Tripier
- UMR CNRS 6521 CEMCA, Université de Brest, 6 Avenue Victor le Gorgeu, 29238 Brest, France
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Tassano M, Camacho X, Freire T, Perroni C, da Costa V, Cabrera M, García MF, Fernandez M, Gambini JP, Cabral P, Osinaga E. Enhanced Tumor Targeting of Radiolabeled Mouse/Human Chimeric Anti-Tn Antibody in Losartan-Treated Mice Bearing Tn-Expressing Lung Tumors. Cancer Biother Radiopharm 2024; 39:337-348. [PMID: 38215243 DOI: 10.1089/cbr.2023.0138] [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: 01/14/2024] Open
Abstract
Aim: ChiTn, a mouse/human chimeric anti-Tn monoclonal antibody, was radiolabeled with iodine-131 (131I) and technetium-99m (99mTc) to assess its biodistribution and internalization in Tn-expressing (Tn+) and wild-type (Tn-) LL/2 lung cancer cells. Results: Selective accumulation and gradual internalization of ChiTn were observed in Tn+ cells. Biodistribution in mice with both Tn+ or Tn- lung tumors indicated that the uptake of radiolabeled ChiTn within tumors increased over time. Dual-labeling experiments with 99mTc and 131I showed different biodistribution patterns, with 99mTc exhibiting higher values in the liver, spleen, and kidneys, while 131I showed higher uptake in the thyroid and stomach. However, tumor uptake did not significantly differ between Tn+ and Tn- tumors. To improve tumor targeting, Losartan, an antihypertensive drug known to enhance tumor perfusion and drug delivery, was investigated. Biodistribution studies in Losartan-treated mice revealed significantly higher radiolabeled ChiTn uptake in Tn+ tumors. No significant changes were observed in the uptake of the control molecule IgG-HYNIC™99mTc. Conclusions: These findings demonstrate the enhanced tumor targeting of radiolabeled ChiTn in Losartan-treated mice with Tn-expressing lung tumors. They highlight the potential of ChiTn as a theranostic agent for cancer treatment and emphasize the importance of Losartan as an adjunctive treatment to improve tumor perfusion and drug delivery.
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Affiliation(s)
- Marcos Tassano
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ximena Camacho
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Teresa Freire
- Laboratorio de Inmunomodulacion y Desarrollo de Vacunas, Departamento de Inmunobiología, Facultad de Medicina, Universidad de La República, Montevideo, Uruguay
| | - Carolina Perroni
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Valeria da Costa
- Laboratorio de Inmunomodulacion y Desarrollo de Vacunas, Departamento de Inmunobiología, Facultad de Medicina, Universidad de La República, Montevideo, Uruguay
| | - Mirel Cabrera
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Maria Fernanda García
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Marcelo Fernandez
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Juan Pablo Gambini
- Centro de Medicina Nuclear e Imagenología Molecular, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Pablo Cabral
- Area de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Eduardo Osinaga
- Laboratorio de Inmunomodulacion y Desarrollo de Vacunas, Departamento de Inmunobiología, Facultad de Medicina, Universidad de La República, Montevideo, Uruguay
- Laboratorio de Glicobiología e Inmunología Tumoral, Institut Pasteur de Montevideo, Montevideo, Uruguay
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Tsuchihashi S, Nakashima K, Watanabe H, Ono M. Synthesis and evaluation of novel trifunctional chelating agents for pretargeting approach using albumin binder to improve tumor accumulation. Nucl Med Biol 2024; 132-133:108911. [PMID: 38614036 DOI: 10.1016/j.nucmedbio.2024.108911] [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: 01/19/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/15/2024]
Abstract
INTRODUCTION The pretargeting approach consists of in vivo ligation between pre-injected antibodies and low-molecular-weight radiolabeled effectors. The advantage of the pretargeting approach is to improve a tumor-to-background ratio, but the disadvantage is to compromise tumor accumulation. In this study, we applied albumin binder (ALB) to the pretargeting approach to overcome low tumor accumulation. METHODS We synthesized two novel trifunctional effectors containing an ALB moiety, a chelator, and a different tetrazine and two corresponding effectors without an ALB moiety. Albumin-binding assays and stability assays were performed using 111In-labeled effectors. Measurements of reaction rate constant were conducted using 111In-labeled effectors and anti-HER2 antibody trastuzumab modified by trans-cyclooctene, which drives the click reaction with tetrazine. Biodistribution studies using HER2-expressing tumor-bearing mice were performed with or without the pretargeting approach. RESULTS In albumin-binding assays, ALB-containing effectors exhibited a marked binding to albumin. Two ALB-containing effectors showed the difference in the reactivity and the slight difference in the stability. In biodistribution studies without the pretargeting approach, two ALB-containing effectors showed different pharmacokinetics in blood retention. With the pretargeting approach, the tumor accumulation was improved by the introduction of ALB and the highest tumor accumulation was observed in using the ALB-containing effector with higher blood retention. CONCLUSION These results suggest that the application of ALB to the pretargeting approach is effective to improve tumor accumulation, and the structure of tetrazine influences the utility of ALB-containing effectors.
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Affiliation(s)
- Shohei Tsuchihashi
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuma Nakashima
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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Suzuki H, Matsukawa M, Madokoro R, Terasaka Y, Kannaka K, Uehara T. Reduction of the hepatic radioactivity levels of [ 111In]In-DOTA-labeled antibodies via cleavage of a linkage metabolized in lysosomes. Nucl Med Biol 2024; 132-133:108910. [PMID: 38636351 DOI: 10.1016/j.nucmedbio.2024.108910] [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: 01/22/2024] [Revised: 03/15/2024] [Accepted: 04/04/2024] [Indexed: 04/20/2024]
Abstract
INTRODUCTION Radiolabeled antibodies are promising tools for cancer diagnosis using nuclear medicine. A DOTA-chelating system is useful for preparing immuno-positron emission tomography and immuno-single-photon emission computed tomography probes with various radiometals. Radiolabeled antibodies are generally metabolized in the reticuloendothelial system, producing radiometabolites after proteolysis in hepatic lysosomes. Because of the bulkiness and extremely high hydrophilicity of DOTA, radiometabolites containing a radiometal-DOTA complex typically exhibit high and persistent localization in hepatic lysosomes. Radioactivity in the liver impairs the accurate diagnosis of cancer surrounding the liver and liver metastasis, and a high tumor/liver ratio is desirable. In this study, we reduced the hepatic radioactivity of radiometal-labeled antibodies containing a DOTA-chelating system. A cleavable linkage was inserted to liberate the radiometabolite, which exhibited a short residence time in hepatocytes. METHODS Using indium-111 (111In)-labeled antibodies, we prepared 111In-labeled galactosyl-neoglycoalbumins (NGAs) because they are useful for evaluating the residence time of radiometabolites in the liver. An 111In-labeled NGA with a cleavable linkage ([111In]In-DO3AiBu-Bn-FGK-NGA) was administered to normal mice, and biodistribution studies and metabolic analyses of urinary and fecal samples were performed with comparison to an 111In-labeled NGA prepared by a conventional method ([111In]In-DOTA-Bn-SCN-NGA). Then, 111In-labeled antibodies ([111In]In-DO3AiBu-Bn-FGK-IgG and [111In]In-DOTA-Bn-SCN-IgG) were prepared using a procedure similar to that for 111In-labeled NGAs. In vitro plasma stability and biodistribution were investigated for both 111In-labeled antibodies in U87MG tumor-bearing mice. RESULTS Through the liberation of radiometabolites including [111In]In-DO3AiBu-Bn-F, [111In]In-DO3AiBu-Bn-FGK-NGA was cleared more rapidly from the liver than [111In]In-DOTA-Bn-SCN-NGA (4.07 ± 1.54%ID VS 71.68 ± 3.03%ID at 6 h postinjection). [111In]In-DO3AiBu-Bn-FGK-IgG exhibited lower tumor accumulation (8.83 ± 1.48%ID/g) but a significantly higher tumor/liver ratio (2.21 ± 0.53) than [111In]In-DOTA-Bn-SCN-IgG (11.65 ± 2.17%ID/g in the tumor and a tumor/liver ratio of 0.85 ± 0.18) at 72 h after injection. CONCLUSION A molecular design that reduces the high and persistent hepatic radioactivity of radiolabeled antibodies by liberating radiometabolites with a short hepatic residence time in lysosomes would be applicable for radiometal-labeled antibodies using a DOTA-chelating system.
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Affiliation(s)
- Hiroyuki Suzuki
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
| | - Masato Matsukawa
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Rikako Madokoro
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Yui Terasaka
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Kento Kannaka
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Tomoya Uehara
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
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Suzuki H, Kannaka K, Uehara T. Approaches to Reducing Normal Tissue Radiation from Radiolabeled Antibodies. Pharmaceuticals (Basel) 2024; 17:508. [PMID: 38675468 PMCID: PMC11053530 DOI: 10.3390/ph17040508] [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: 03/19/2024] [Revised: 04/02/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Radiolabeled antibodies are powerful tools for both imaging and therapy in the field of nuclear medicine. Radiolabeling methods that do not release radionuclides from parent antibodies are essential for radiolabeling antibodies, and practical radiolabeling protocols that provide high in vivo stability have been established for many radionuclides, with a few exceptions. However, several limitations remain, including undesirable side effects on the biodistribution profiles of antibodies. This review summarizes the numerous efforts made to tackle this problem and the recent advances, mainly in preclinical studies. These include pretargeting approaches, engineered antibody fragments and constructs, the secondary injection of clearing agents, and the insertion of metabolizable linkages. Finally, we discuss the potential of these approaches and their prospects for further clinical application.
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Affiliation(s)
- Hiroyuki Suzuki
- Laboratory of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan; (K.K.); (T.U.)
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Delaney S, Nagy Á, Karlström AE, Zeglis BM. Site-Specific Photoaffinity Bioconjugation for the Creation of 89Zr-Labeled Radioimmunoconjugates. Mol Imaging Biol 2023; 25:1104-1114. [PMID: 37052759 PMCID: PMC10570397 DOI: 10.1007/s11307-023-01818-5] [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: 02/06/2023] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 04/14/2023]
Abstract
PURPOSE Site-specific approaches to bioconjugation produce well-defined and homogeneous immunoconjugates with potential for superior in vivo behavior compared to analogs synthesized using traditional, stochastic methods. The possibility of incorporating photoaffinity chemistry into a site-specific bioconjugation strategy is particularly enticing, as it could simplify and accelerate the preparation of homogeneous immunoconjugates for the clinic. In this investigation, we report the synthesis, in vitro characterization, and in vivo evaluation of a site-specifically modified, 89Zr-labeled radioimmunoconjugate created via the reaction between an mAb and an Fc-binding protein bearing a photoactivatable 4-benzoylphenylalanine residue. PROCEDURES A variant of the Fc-binding Z domain of protein A containing a photoactivatable, 4-benzoylphenylalanine residue - Z(35BPA) - was modified with desferrioxamine (DFO), combined with the A33 antigen-targeting mAb huA33, and irradiated with UV light. The resulting immunoconjugate - DFOZ(35BPA)-huA33 - was purified and characterized via SDS-PAGE, MALDI-ToF mass spectrometry, surface plasmon resonance, and flow cytometry. The radiolabeling of DFOZ(35BPA)-huA33 was optimized to produce [89Zr]Zr-DFOZ(35BPA)-huA33, and the immunoreactivity of the radioimmunoconjugate was determined with SW1222 human colorectal cancer cells. Finally, the in vivo performance of [89Zr]Zr-DFOZ(35BPA)-huA33 in mice bearing subcutaneous SW1222 xenografts was interrogated via PET imaging and biodistribution experiments and compared to that of a stochastically labeled control radioimmunoconjugate, [89Zr]Zr-DFO-huA33. RESULTS HuA33 was site-specifically modified with Z(35BPA)-DFO, producing an immunoconjugate with on average 1 DFO/mAb, high in vitro stability, and high affinity for its target. [89Zr]Zr-DFOZ(35BPA)-huA33 was synthesized in 95% radiochemical yield and exhibited a specific activity of 2 mCi/mg and an immunoreactive fraction of ~ 0.85. PET imaging and biodistribution experiments revealed that high concentrations of the radioimmunoconjugate accumulated in tumor tissue (i.e., ~ 40%ID/g at 120 h p.i.) but also that the Z(35BPA)-bearing immunoPET probe produced higher uptake in the liver, spleen, and kidneys than its stochastically modified cousin, [89Zr]Zr-DFO-huA33. CONCLUSIONS Photoaffinity chemistry and an Fc-binding variant of the Z domain were successfully leveraged to create a novel site-specific strategy for the synthesis of radioimmunoconjugates. The probe synthesized using this method - DFOZ(35BPA)-huA33 - was well-defined and homogeneous, and the resulting radioimmunoconjugate ([89Zr]Zr-DFOZ(35BPA)-huA33) boasted high specific activity, stability, and immunoreactivity. While the site-specifically modified radioimmunoconjugate produced high activity concentrations in tumor tissue, it also yielded higher uptake in healthy organs than a stochastically modified analog, suggesting that optimization of this system is necessary prior to clinical translation.
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Affiliation(s)
- Samantha Delaney
- Department of Chemistry, Hunter College, City University of New York, New York, NY, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ábel Nagy
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Amelie Eriksson Karlström
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
| | - Brian M Zeglis
- Department of Chemistry, Hunter College, City University of New York, New York, NY, USA.
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA.
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA.
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA.
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Nakashima K, Watanabe H, Ono M. Development of Novel Trifunctional Chelating Agents That Enhance Tumor Retention of Radioimmunoconjugates. J Med Chem 2023; 66:12812-12827. [PMID: 37721492 DOI: 10.1021/acs.jmedchem.3c00472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Chelator-containing radioimmunoconjugates (RICs) composed of monoclonal antibodies, chelators, and radiometals exhibit broad potential for cancer diagnosis or therapy. In this study, we developed novel trifunctional chelating agents that enhance the tumor retention of RICs, MDPEI2, and MDPEI4, which contain the metal chelator DOTA, a maleimide moiety, and diethylenetriamine (PEI2) or tetraethylenepentamine (PEI4), respectively, as a poly(ethylenimine) (PEI) scaffold for the addition of positive charges to the radiometabolites of RICs to reduce their release from tumor cells. Trastuzumab radiolabeled by [111In]In-MDPEI2 ([111In]In-TMDPEI2) or [111In]In-MDPEI4 ([111In]In-TMDPEI4) showed high immunoreactivity and lower rates of exportations of their radiometabolites from tumor cells than RICs without PEI scaffolds. The tumor uptake of [111In]In-TMDPEI2 and [111In]In-TMDPEI4 was enhanced compared with RICs without PEI scaffolds, and [111In]In-TMDPEI2 exhibited the highest tumor/blood ratio. These results indicate the utility of MDPEI2 to synthesize RICs with favorable tumor-targeting properties in vivo by controlling the radioactivity distribution in tumor cells.
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Affiliation(s)
- Kazuma Nakashima
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
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Umeda IO, Koike Y, Ogata M, Kaneko E, Hamamichi S, Uehara T, Moribe K, Arano Y, Takahashi T, Fujii H. New liposome-radionuclide-chelate combination for tumor targeting and rapid healthy tissue clearance. J Control Release 2023; 361:847-855. [PMID: 37543291 DOI: 10.1016/j.jconrel.2023.07.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/19/2023] [Accepted: 07/31/2023] [Indexed: 08/07/2023]
Abstract
Radionuclide imaging and therapy are promising methods for controlling systemic cancers; however, their clinical application has been limited by excessive radionuclide accumulation in healthy tissues. To minimize radionuclide accumulation in non-cancerous tissues while ensuring sufficient build up in tumors, we aimed to develop a method that controlled the in vivo dynamics of radionuclides post-administration. To this end, we describe a novel strategy that combines liposomes, a potent carrier system for drug delivery, with unique radionuclide-ligand complexes based on 111In-ethylenedicysteine. Conventional 111In-ligand-complexes-carrying liposomes delivered substantial amounts of radionuclides to tumors; however, they also accumulated in the liver and spleen. In contrast, 111In-ethylenedicysteine-carrying liposomes greatly reduced non-specific accumulation, while being retained selectively at high doses within tumors. Liposomes were rapidly broken down in the liver, releasing encapsulated 111In-ligand complexes. Among the chelates used, only 111In-ethylenedicysteine could escape from the liver and be excreted in the urine. Instead, most liposomes remained intact in tumors, retaining the radionuclide-ligand complexes within them. Therefore, high tumor accumulation was obtained regardless of the type of 111In-ligand complexes in the liposomes. In vivo single photon emission computed tomography/computed tomography imaging with 111In-ethylenedicysteine-carrying liposomes accurately revealed tumor-selective radionuclide retention with little background. Hence, our new strategy could greatly enhance tumor-to-healthy tissue ratios, improve diagnostic imaging, boost therapeutic efficacy, reduce toxicity to healthy tissues, and facilitate radionuclide imaging and therapy.
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Affiliation(s)
- Izumi O Umeda
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1, Kashiwanoha, Kashiwa, Chiba 277-8577, Japan; Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8583, Japan; Kyoto College of Medical Science, 1-3, Imakita, Oyama-higashi, Sonobe, Nantan, Kyoto 622-0041, Japan.
| | - Yusuke Koike
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1, Kashiwanoha, Kashiwa, Chiba 277-8577, Japan; Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Mayumi Ogata
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1, Kashiwanoha, Kashiwa, Chiba 277-8577, Japan; Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Emi Kaneko
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Shusei Hamamichi
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1, Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
| | - Tomoya Uehara
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Kunikazu Moribe
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Yasushi Arano
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Cyuo-ku, Chiba, Chiba 260-8675, Japan
| | - Tadayuki Takahashi
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8583, Japan
| | - Hirofumi Fujii
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1, Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
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10
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Vilhelmsson Timmermand O, Safi M, Holmqvist B, Strand J. Evaluation of enhanced permeability effect and different linear energy transfer of radionuclides in a prostate cancer xenograft model. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2023; 13:147-155. [PMID: 37736493 PMCID: PMC10509292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/30/2023] [Indexed: 09/23/2023]
Abstract
We have previously investigated the biodistribution and therapy effect of a humanized monoclonal antibody targeting free prostate-specific antigen (fPSA) intended for theranostics of hormone-refractory prostate cancer. In the present study, we evaluated the off-target effect and different linear energy transfer (LET) radionuclides without the effect of PSA targeting by using an antibody with the same scaffold as previously used immunoconjugates but with random, non-specific, antigen binding region. This allows us to identify alterations generated by specific targeting and those related to passive bystander effects, such as enhanced permeability and retention (EPR). A control humanized IgG monoclonal antibody (hIgG1) and an isotype control IgG monoclonal antibody were conjugated with the chelator CHX-A"-DTPA. The immunoconjugate was radiolabeled with either Lutetium-177 ([177Lu]Lu) or Indium-111 ([111In]In). A biodistribution study in mice carrying LNCaP xenografts, was performed to evaluate the non-specific uptake of [177Lu]Lu-hIgG1 in tumors and normal organs. Further, therapy studies of [177Lu]Lu and [111In]In labeled IgG were performed in BALB/c mice carrying LNCaP xenografts. Tumor tissues of treated xenografts and control were sectioned and immunohistochemically stained for Ki67 and PSA. The highest tumor uptake for the [177Lu]Lu-hIgG1 was seen at 72 hours (7.2±2 %IA/g), when comparing the tumor uptake of the fPSA targeting antibody to the non-specific antibody, the non-specific antibody contributes to half of the tumor uptake at 72 h. The liver uptake was 3.1±0.5 %IA/g at 24 h, 2.8±0.5 %IA/g at 72 h and 1.3±0.6 %IA/g at 120 h in LNCaP xenografts, which was approximately three times lower at 24 h and two times lower at 72 h than for the antibody with preserved targeting. Immunohistochemical labeling showed a reduction of PSA expression and a reduction of Ki67 labeled cells in the [111In]In treated LNCaP tumors, compared to vehicle and [177Lu]Lu treated mice. In conclusion, we found that specific targeting might negatively influence normal organ uptake when targeting secreted antigens. Furthermore, different energy deposition i.e. linear energy transfer of a radionuclide might have diverse effects on receptor expression and cell proliferation in tumors.
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Affiliation(s)
| | | | | | - Joanna Strand
- Department of Oncology, Lund UniversityLund, Sweden
- Department of Hematology, Oncology, Radiation Physics, Skåne University Hospital, Lund UniversityLund, Sweden
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11
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Brown AM, Butman JL, Lengacher R, Vargo NP, Martin KE, Koller A, Śmiłowicz D, Boros E, Robinson JR. N, N-Alkylation Clarifies the Role of N- and O-Protonated Intermediates in Cyclen-Based 64Cu Radiopharmaceuticals. Inorg Chem 2023; 62:1362-1376. [PMID: 36490364 DOI: 10.1021/acs.inorgchem.2c02907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Radioisotopes of Cu, such as 64Cu and 67Cu, are alluring targets for imaging (e.g., positron emission tomography, PET) and radiotherapeutic applications. Cyclen-based macrocyclic polyaminocarboxylates are one of the most frequently examined bifunctional chelators in vitro and in vivo, including the FDA-approved 64Cu radiopharmaceutical, Cu(DOTATATE) (Detectnet); however, connections between the structure of plausible reactive intermediates and their stability under physiologically relevant conditions remain to be established. In this study, we share the synthesis of a cyclen-based, N,N-alkylated spirocyclic chelate, H2DO3AC4H8, which serves as a model for N-protonation. Our combined experimental (in vitro and in vivo) and computational studies unravel complex pH-dependent speciation and enable side-by-side comparison of N- and O-protonated species of relevant 64Cu radiopharmaceuticals. Our studies suggest that N-protonated species are not inherently unstable species under physiological conditions and demonstrate the potential of N,N-alkylation as a tool for the rational design of future radiopharmaceuticals.
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Affiliation(s)
- Alexander M Brown
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Jana L Butman
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Raphael Lengacher
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Natasha P Vargo
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Kirsten E Martin
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Angus Koller
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Dariusz Śmiłowicz
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Jerome R Robinson
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
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12
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Lee JH, Jung KH, Kim M, Lee KH. Cysteine-specific 89Zr-labeled anti-CD25 IgG allows immuno-PET imaging of interleukin-2 receptor-α on T cell lymphomas. Front Immunol 2022; 13:1017132. [PMID: 36591250 PMCID: PMC9797992 DOI: 10.3389/fimmu.2022.1017132] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction Positron emission tomography (PET) using radiolabeled Abs as imaging tracer is called immuno-PET. Immuno-PET can verify therapeutic Ab delivery and can noninvasively quantify global levels of target expression in tumors of living subjects. The interleukin-2 receptor α chain (IL-2Rα; CD25) is a promising target for immune therapy and radioimmunotherapy of lymphomas. Immuno-PET could facilitate this approach by visualizing CD25 expression in vivo. Methods We prepared 89Zr-anti-CD25 IgG specifically labeled to sulfhydryl moieties by maleimide-deferoxamine conjugation. Results and Discussion CD25(+) SUDHL1 human T-cell lymphoma cells showed high anti-human 89Zr-CD25 IgG binding that reached 32-fold of that of CD25(-) human lymphoma cells and was completely blocked by excess unlabeled Ab. In SUDHL1 tumor-bearing nude mice, pharmacokinetic studies demonstrated exponential reductions of whole blood and plasma activity following intravenous 89Zr-anti-CD25 IgG injection, with half-lives of 26.0 and 23.3 h, respectively. SUDHL1 tumor uptake of 89Zr-CD25 IgG was lower per weight in larger tumors, but blood activity did not correlate with tumor size or blood level of human CD25, indicating minimal influence by circulating soluble CD25 protein secreted from the lymphoma cells. 89Zr-CD25 IgG PET allowed high-contrast SUDHL1 lymphoma visualization at five days. Biodistribution studies confirmed high tumor 89Zr-CD25 IgG uptake (8.7 ± 0.9%ID/g) that was greater than blood (5.2 ± 1.6%ID/g) and organ uptakes (0.7 to 3.5%ID/g). Tumor CD25-specific targeting was confirmed by suppression of tumor uptake to 4.3 ± 0.2%ID by excess unlabeled CD25 IgG, as well as by low tumor uptake of 89Zr-labeled IgG2a isotype control Ab (3.6 ± 0.9%ID). Unlike CD25(+) lymphocytes from mouse thymus that showed specific uptake of anti-mouse 89Zr-CD25 IgG, EL4 mouse lymphoma cells had low CD25 expression and showed low uptake. In immunocompetent mice bearing EL4 tumors, anti-mouse 89Zr-CD25 IgG displayed low uptakes in normal organs as well as in the tumor. Furthermore, the biodistribution was not influenced by Ab blocking, indicating that specific uptake in nontumor tissues was minimal. 89Zr-CD25 IgG immuno-PET may thus be useful for imaging of T-cell lymphomas and noninvasive assessment of CD25 expression on target cells in vivo.
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Affiliation(s)
- Jin Hee Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyung-Ho Jung
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Mina Kim
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea,*Correspondence: Kyung-Han Lee,
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13
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Rodriguez C, Delaney S, Sarrett SM, Keinänen OM, Zeglis BM. Antibody Engineering for Nuclear Imaging and Radioimmunotherapy. J Nucl Med 2022; 63:1316-1322. [PMID: 35863894 PMCID: PMC9454464 DOI: 10.2967/jnumed.122.263861] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/07/2022] [Indexed: 01/26/2023] Open
Abstract
Radiolabeled antibodies have become indispensable tools in nuclear medicine. However, the natural roles of antibodies within the immune system mean that they have several intrinsic limitations as a platform for radiopharmaceuticals. In recent years, the field has increasingly turned to antibody engineering to circumvent these issues while retaining the manifold benefits of the immunoglobulin framework. In this "Focus on Molecular Imaging" review, we cover recent advances in the application of antibody engineering to immunoPET, immunoSPECT, and radioimmunotherapy. Specifically, we address how antibody engineering has been used to improve radioimmunoconjugates on four fronts: optimizing pharmacokinetics, facilitating site-specific bioconjugation, modulating Fc interactions, and creating bispecific constructs.
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Affiliation(s)
- Cindy Rodriguez
- Department of Chemistry, Hunter College, City University of New York, New York, New York
- Ph.D. Program in Chemistry, Graduate Center of City University of New York, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Samantha Delaney
- Department of Chemistry, Hunter College, City University of New York, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Ph.D. Program in Biochemistry, Graduate Center of City University of New York, New York, New York
| | - Samantha M Sarrett
- Department of Chemistry, Hunter College, City University of New York, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Ph.D. Program in Biochemistry, Graduate Center of City University of New York, New York, New York
| | - Outi M Keinänen
- Department of Chemistry, Hunter College, City University of New York, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Chemistry, University of Helsinki, Helsinki, Finland; and
| | - Brian M Zeglis
- Department of Chemistry, Hunter College, City University of New York, New York, New York;
- Ph.D. Program in Chemistry, Graduate Center of City University of New York, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Ph.D. Program in Biochemistry, Graduate Center of City University of New York, New York, New York
- Department of Radiology, Weill Cornell Medical College, New York, New York
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14
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Lee KH, Jung KH, Lee JH. Immuno-PET Imaging and Radioimmunotherapy of Lymphomas. Mol Pharm 2022; 19:3484-3491. [PMID: 36046954 DOI: 10.1021/acs.molpharmaceut.2c00563] [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: 11/30/2022]
Abstract
Monoclonal antibodies (Ab) have revolutionized the management of lymphomas, the most common hematologic malignancy in adults. Indeed, incorporation of rituximab into the regimen for indolent non-Hodgkin's lymphomas (NHLs) has dramatically improved treatment response and disease outcome. Yet, newer Ab therapeutics against promising antigen targets need to be developed to treat refractory or relapsed patients. Treatment efficacy can be further enhanced by conjugating toxic molecules to the Abs. Radioimmunotherapy (RIT) harnesses Abs as vehicles for targeted delivery of therapeutic radionuclide payloads for direct killing of targeted tumor cells. Positron emission tomography (PET) with radiolabeled Abs (called immuno-PET) can facilitate the development of new Ab therapeutics and RIT by providing pharmacokinetic and pharmacodynamic information and by quantifying tumor antigen level relevant for treatment decision. Immuno-PET has recently gravitated toward labeling Abs with 89Zr, a radiometal with a 3.3 day half-life that is trapped following Ab internalization and thus provides high-resolution PET images with excellent contrast. Immuno-PET methods against major lymphoma antigens including CD20 and other promising targets are currently under development. With continued improvements, immuno-PET has the potential to be used in lymphoma management as an imaging biomarker for patient selection and assessment of treatment response.
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Affiliation(s)
- Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, 50 Ilwon-dong, Gangnam-gu, Seoul 06351, Korea.,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul 06355, Korea
| | - Kyung-Ho Jung
- Department of Nuclear Medicine, Samsung Medical Center, 50 Ilwon-dong, Gangnam-gu, Seoul 06351, Korea.,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul 06355, Korea
| | - Jin Hee Lee
- Department of Nuclear Medicine, Samsung Medical Center, 50 Ilwon-dong, Gangnam-gu, Seoul 06351, Korea.,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul 06355, Korea
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15
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Sarrett SM, Rodriguez C, Rymarczyk G, Hosny MM, Keinänen O, Delaney S, Thau S, Krantz BA, Zeglis BM. Lysine-Directed Site-Selective Bioconjugation for the Creation of Radioimmunoconjugates. Bioconjug Chem 2022; 33:1750-1760. [PMID: 35946495 DOI: 10.1021/acs.bioconjchem.2c00354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of radioimmunoconjugates via the stochastic attachment of bifunctional chelators to lysines can yield heterogeneous products with suboptimal in vitro and in vivo behavior. In response to this, several site-selective approaches to bioconjugation have been developed, yet each has intrinsic drawbacks, such as the need for expensive reagents or the complexity of incorporating unnatural amino acids into IgGs. Herein, we describe the use of a simple and facile approach to lysine-directed site-selective bioconjugation for the generation of radioimmunoconjugates. This strategy relies upon on the selective modification of single lysine residues within each light chain of the monoclonal antibody (mAb) with a branched azide-bearing perfluorophenyl ester (PFP-bisN3) followed by the ligation of dibenzocyclooctyne (DBCO)-bearing payloads to these bioorthogonal handles via the strain-promoted azide-alkyne cycloaddition. This methodology was used to create [89Zr]Zr-SSKDFO-pertuzumab, a radioimmunoconjugate of the HER2-targeting mAb pertuzumab labeled with desferrioxamine (DFO) and the positron-emitting radiometal zirconium-89 (89Zr). [89Zr]Zr-SSKDFO-pertuzumab was compared to a pair of analogous probes: one synthesized via random lysine modification ([89Zr]Zr-DFO-pertuzumab) and another via thiol-maleimide chemistry ([89Zr]Zr-malDFO-pertuzumab). The bioconjugation strategy was assessed using ESI mass spectrometry, SDS-PAGE, and autoradiography. All three immunoconjugates demonstrated comparable binding to HER2 via flow cytometry and surface plasmon resonance (SPR), and 89Zr-labeled variants of each were synthesized in >99% radiochemical yield and molar activities of up to ∼55.5 GBq/μmol (10 mCi/mg). Subsequently, the in vivo behavior of this trio of 89Zr-immunoPET probes was interrogated in athymic nude mice bearing subcutaneous HER2-expressing BT-474 human breast cancer xenografts. [89Zr]Zr-SSKDFO-pertuzumab, [89Zr]Zr-malDFO-pertuzumab, and [89Zr]Zr-DFO-pertuzumab produced positron emission tomography (PET) images with high tumoral uptake and high tumor-to-healthy organ activity concentration ratios. A terminal biodistribution study complemented the PET results, revealing tumoral activity concentrations of 126.9 ± 50.3%ID/g, 86.9 ± 53.2%ID/g, and 92.5 ± 27.2%ID/g at 144 h post-injection for [89Zr]Zr-SSKDFO-pertuzumab, [89Zr]Zr-malDFO-pertuzumab, and [89Zr]Zr-DFO-pertuzumab, respectively. Taken together, the data clearly illustrate that this highly modular and facile approach to site-selective bioconjugation produces radioimmunoconjugates that are better-defined and more homogeneous than stochastically modified constructs and also exhibit excellent in vitro and in vivo performance. Furthermore, we contend that this lysine-directed strategy holds several key advantages over extant approaches to site-selective bioconjugation, especially in the context of production for the clinic.
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Affiliation(s)
- Samantha M Sarrett
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States.,Ph.D. Program in Biochemistry, Graduate Center of the City University of New York, New York, New York 10016, United States.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, United States
| | - Cindy Rodriguez
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, United States.,Ph.D. Program in Chemistry, Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Grzegorz Rymarczyk
- Advanced Proteome Therapeutics Inc, Boston, Massachusetts 02118, United States
| | - Meena M Hosny
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States
| | - Outi Keinänen
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, United States.,Department of Chemistry, University of Helsinki, Helsinki, 00100, Finland
| | - Samantha Delaney
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States.,Ph.D. Program in Biochemistry, Graduate Center of the City University of New York, New York, New York 10016, United States.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, United States
| | - Sarah Thau
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States
| | - Benjamin A Krantz
- Advanced Proteome Therapeutics Inc, Boston, Massachusetts 02118, United States.,Department of Medicine, Division of Hematology and Medical Oncology, NYU Grossman School of Medicine, New York, New York 10016, United States
| | - Brian M Zeglis
- Department of Chemistry, Hunter College, City University of New York, New York, New York 10065, United States.,Ph.D. Program in Biochemistry, Graduate Center of the City University of New York, New York, New York 10016, United States.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, United States.,Ph.D. Program in Chemistry, Graduate Center of the City University of New York, New York, New York 10016, United States.,Department of Radiology, Weill Cornell Medical College, New York, New York 10021, United States
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16
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Pineau J, Lima LMP, Platas‐Iglesias C, Zeevaart JR, Driver CHS, Le Bris N, Tripier R. Relevance of Palladium to Radiopharmaceutical Development Considering Enhanced Coordination Properties of TE1PA. Chemistry 2022; 28:e202200942. [PMID: 35560962 PMCID: PMC9401000 DOI: 10.1002/chem.202200942] [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: 03/28/2022] [Indexed: 11/09/2022]
Abstract
The limited use of palladium‐103 and ‐109 radionuclides for molecular radiotherapy is surely due to the lack of appropriate ligands capable of fulfilling all criteria required for application in nuclear medicine. Furthermore, the thermodynamic properties of these complexes in solution remain difficult to establish. The challenge is compounded when considering that radiolabeling of compounds for translation to clinical trials requires fast complexation. Thus, the coordination of Pd(II) and 103/109Pd‐nuclides is a huge challenge in terms of molecular design and physicochemical characterization. Herein, we report a comprehensive study highlighting TE1PA, a monopicolinate cyclam – already established in nuclear imaging with 64Cu‐PET (positron emission tomography) imaging tracers – as a highly relevant chelator for natural Pd and subsequently 109Pd‐nuclide. The structural, thermodynamic, kinetic and radiolabeling studies of Pd(II) with TE1PA, as well as the comparison of this complex with three structurally related derivatives, support palladium‐TE1PA radiopharmaceuticals as leading candidates for targeted nuclear medicine.
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Affiliation(s)
- Julie Pineau
- Univ Brest, UMR CNRS 6521 CEMCA 6 avenue Victor le Gorgeu 29238 Brest France) E-mail: s
| | - Luís M. P. Lima
- Instituto de Tecnologia Química e Biológica António Xavier Universidade Nova de Lisboa Av. da República 2780-157 Oeiras Portugal
| | - Carlos Platas‐Iglesias
- Departamento de Química Facultade de Ciencias & Centro de Investigaciones Científicas Avanzadas (CICA) Universidade da Coruña San Vicente de Elviña 15071 A Coruña Spain
| | - Jan Rijn Zeevaart
- South African Nuclear Energy Corporation Radiochemistry and PreClinical Imaging Facility Elias Motsoaledi Street, R104 Pelindaba North West 0240 South Africa
| | - Cathryn H. S. Driver
- South African Nuclear Energy Corporation Radiochemistry and PreClinical Imaging Facility Elias Motsoaledi Street, R104 Pelindaba North West 0240 South Africa
| | - Nathalie Le Bris
- Univ Brest, UMR CNRS 6521 CEMCA 6 avenue Victor le Gorgeu 29238 Brest France) E-mail: s
| | - Raphaël Tripier
- Univ Brest, UMR CNRS 6521 CEMCA 6 avenue Victor le Gorgeu 29238 Brest France) E-mail: s
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17
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Ebrahimi F, Hosseinimehr SJ. Homomultimer strategy for improvement of radiolabeled peptides and antibody fragments in tumor targeting. Curr Med Chem 2022; 29:4923-4957. [PMID: 35450521 DOI: 10.2174/0929867329666220420131836] [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: 11/23/2021] [Revised: 01/18/2022] [Accepted: 02/07/2022] [Indexed: 11/22/2022]
Abstract
A homomultimeric radioligand is composed of multiple identical ligands connected to the linker and radionuclide to detect a variety of overexpressed receptors on cancer cells. Multimer strategy holds great potential for introducing new radiotracers based on peptide and monoclonal antibody (mAb) derivatives in molecular imaging and therapy. It offers a reliable procedure for the preparation of biological-based targeting with diverse affinities and pharmacokinetics. In this context, we provide a useful summary and interpretation of the main results by a comprehensive look at multimeric radiopharmaceuticals in nuclear oncology. Therefore, there will be explanations for the strategy mechanisms and the main variables affecting the biodistribution results. The discussion is followed by highlights of recent work in the targeting of various types of receptors. The consequences are expressed based on comparing some parameters between monomer and multimer counterparts in each relevant section.
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Affiliation(s)
- Fatemeh Ebrahimi
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Jalal Hosseinimehr
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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18
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Zettlitz KA, Salazar FB, Yamada RE, Trinh KR, Vasuthasawat A, Timmerman JM, Morrison SL, Wu AM. 89Zr-ImmunoPET shows therapeutic efficacy of anti-CD20 interferon-α fusion protein in a murine B-cell lymphoma model. Mol Cancer Ther 2022; 21:607-615. [PMID: 35086952 DOI: 10.1158/1535-7163.mct-21-0732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/23/2021] [Accepted: 01/19/2022] [Indexed: 11/16/2022]
Abstract
Antibody-mediated tumor delivery of cytokines can overcome limitations of systemic administration (toxicity, short half-lives). Previous work showed improved anti-tumor potency of anti-CD20-interferon alpha (IFNα) fusion proteins in preclinical mouse models of B-cell lymphoma. Although tumor targeting is mediated by the antibody part of the fusion protein, the cytokine component might strongly influence biodistribution and pharmacokinetics, as a result of its affinity, size, valency and receptor distribution. Here, we used positron emission tomography (immunoPET) to study the in vivo biodistribution and tumor targeting of the anti-CD20 rituximab-murine IFNα1 fusion protein (Rit-mIFNα) and compared it to the parental mAb (rituximab, Rit). Rit-mIFNα and Rit were radiolabeled with zirconium-89 (89Zr, t1/2 78.4 h) and injected into C3H mice bearing syngeneic B-cell lymphomas (38C13-hCD20). Dynamic (2 h p.i.) and static (4, 24 and 72 h) PET scans were acquired. Ex vivo biodistribution was performed after the final scan. Both 89Zr-Rit-mIFNα and 89Zr-Rit specifically target hCD20-expressing B-cell lymphoma in vivo. 89Zr-Rit-mIFNα showed specific uptake in tumors (7.6 {plus minus} 1.0 %ID/g at 75 h p.i.), which was significantly lower than 89Zr-Rit (38.4 {plus minus} 9.9 %ID/g, p<0.0001). ImmunoPET studies also revealed differences in the biodistribution, 89Zr-Rit-mIFNα showed rapid blood clearance and high accumulation in the liver compared with 89Zr-Rit. Importantly, immunoPET clearly revealed a therapeutic effect of the single 89Zr-Rit-mIFNα dose, resulting in smaller tumors and fewer lymph node metastases compared to mice receiving 89Zr-Rit. Mice receiving 89Zr-Rit-mIFNα had enlarged spleens, suggesting that systemic immune activation contributes to therapeutic efficacy in addition to the direct antitumoral activity of IFNα. In conclusion, immunoPET allows the non-invasive tracking and quantification of the antibody-cytokine fusion protein and helps understand the in vivo behavior and therapeutic efficacy.
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Affiliation(s)
- Kirstin A Zettlitz
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Felix B Salazar
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Reiko E Yamada
- Division of Hematology and Oncology, Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - K Ryan Trinh
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Alex Vasuthasawat
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - John M Timmerman
- Division of Hematology and Oncology, Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Sherie L Morrison
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Anna M Wu
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
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19
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Kip A, Heskamp S. Antibodies and antibody constructs as radiopharmaceuticals. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00009-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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20
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Sokolov AV, Dostdar SA, Attwood MM, Krasilnikova AA, Ilina AA, Nabieva AS, Lisitsyna AA, Chubarev VN, Tarasov VV, Schiöth HB. Brain Cancer Drug Discovery: Clinical Trials, Drug Classes, Targets, and Combinatorial Therapies. Pharmacol Rev 2021; 73:1-32. [PMID: 34663683 DOI: 10.1124/pharmrev.121.000317] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Brain cancer is a formidable challenge for drug development, and drugs derived from many cutting-edge technologies are being tested in clinical trials. We manually characterized 981 clinical trials on brain tumors that were registered in ClinicalTrials.gov from 2010 to 2020. We identified 582 unique therapeutic entities targeting 581 unique drug targets and 557 unique treatment combinations involving drugs. We performed the classification of both the drugs and drug targets based on pharmacological and structural classifications. Our analysis demonstrates a large diversity of agents and targets. Currently, we identified 32 different pharmacological directions for therapies that are based on 42 structural classes of agents. Our analysis shows that kinase inhibitors, chemotherapeutic agents, and cancer vaccines are the three most common classes of agents identified in trials. Agents in clinical trials demonstrated uneven distribution in combination approaches; chemotherapy agents, proteasome inhibitors, and immune modulators frequently appeared in combinations, whereas kinase inhibitors, modified immune effector cells did not as was shown by combination networks and descriptive statistics. This analysis provides an extensive overview of the drug discovery field in brain cancer, shifts that have been happening in recent years, and challenges that are likely to come. SIGNIFICANCE STATEMENT: This review provides comprehensive quantitative analysis and discussion of the brain cancer drug discovery field, including classification of drug, targets, and therapies.
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Affiliation(s)
- Aleksandr V Sokolov
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Samira A Dostdar
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Misty M Attwood
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Aleksandra A Krasilnikova
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Anastasia A Ilina
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Amina Sh Nabieva
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Anna A Lisitsyna
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Vladimir N Chubarev
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Vadim V Tarasov
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden (A.V.S., S.A.D., M.M.A., H.B.S.); and Department of Pharmacology, Institute of Pharmacy (A.V.S., S.A.D., A.A.K., A.A.I., A.S.N., A.A.L., V.N.C., V.V.T.) and Institute of Translational Medicine and Biotechnology (V.V.T., H.B.S.), I. M. Sechenov First Moscow State Medical University, Moscow, Russia
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21
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Bouleau A, Lebon V, Truillet C. PET imaging of immune checkpoint proteins in oncology. Pharmacol Ther 2021; 222:107786. [PMID: 33307142 DOI: 10.1016/j.pharmthera.2020.107786] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/30/2020] [Indexed: 02/07/2023]
Abstract
Despite the remarkable clinical successes of immune checkpoint inhibitors (ICIs) in various advanced cancers, response is still limited to a subset of patients that generally exhibit tumoral expression of immune checkpoint (IC) proteins. Development of biomarkers assessing the expression of such ICs is therefore a major challenge nowadays to refine patient selection and improve therapeutic benefits. Positron emission tomography (PET) imaging using IC-targeted radiolabeled monoclonal antibodies (immunoPET) provides a non-invasive and whole-body visualization of in vivo IC biodistribution. As such, PET imaging of ICs may serve as a robust biomarker to predict and monitor responses to ICIs, complementing the existing immunohistochemical techniques. Besides monoclonal antibodies, other PET radioligand formats, ranging from antibody-derived fragments to small proteins, have gained increasing interest owing to their faster pharmacokinetics and enhanced imaging characteristics. We provide an overview of the various strategies investigated so far for PET imaging of ICs in preclinical and clinical studies, emphasizing their benefits and limitations. Moreover, we discuss various parameters to consider for designing optimized and best-suited PET radioligands.
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Affiliation(s)
- Alizée Bouleau
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du Général Leclerc, 91401 ORSAY, France
| | - Vincent Lebon
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du Général Leclerc, 91401 ORSAY, France
| | - Charles Truillet
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du Général Leclerc, 91401 ORSAY, France.
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22
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Le PJ, Miersch S, Forbes MW, Jarvik N, Ku A, Sidhu SS, Reilly RM, Winnik MA. Site-Specific Conjugation of Metal-Chelating Polymers to Anti-Frizzled-2 Antibodies via Microbial Transglutaminase. Biomacromolecules 2021; 22:2491-2504. [PMID: 33961407 DOI: 10.1021/acs.biomac.1c00246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal-chelating polymer-based radioimmunoconjugates (RICs) are effective agents for radioimmunotherapy but are currently limited by nonspecific binding and off-target organ uptake. Nonspecific binding appears after conjugation of the polymer to the antibody and may be related to random lysine conjugation since the polymers themselves do not bind to cells. To investigate the role of conjugation sites on nonspecific binding of polymer RICs, we developed a microbial transglutaminase reaction to prepare site-specific antibody-polymer conjugates. The reaction was enabled by introducing a Q-tag (i.e., 7M48) into antibody (i.e., Fab) fragments and synthesizing a polyglutamide-based metal-chelating polymer with a PEG amine block to yield substrates. Mass spectrometric analyses confirmed that the microbial transglutaminase conjugation reaction was site-specific. For comparison, random lysine conjugation analogs with an average of one polymer per Fab were prepared by bis-aryl hydrazone conjugation. Conjugates were prepared from an anti-frizzled-2 Fab to target the Wnt pathway, along with a nonbinding specificity control, anti-Luciferase Fab. Fabs were engineered from a trastuzumab-based IgG1 framework and lack lysines in the antigen-binding site. Conjugates were analyzed for thermal conformational stability by differential scanning fluorimetry, which showed that the site-specific conjugate had a similar melting temperature to the parent Fab. Binding assays by biolayer interferometry showed that the site-specific anti-frizzled-2 conjugate maintained high affinity to the antigen, while the random conjugate showed a 10-fold decrease in affinity, which was largely due to changes in association rates. Radioligand cell-binding assays on frizzled-2+ PANC-1 cells and frizzled-2- CHO cells showed that the site-specific anti-frizzled-2 conjugate had ca. 4-fold lower nonspecific binding compared to the random conjugate. Site-specific conjugation appeared to reduce nonspecific binding associated with random conjugation of the polymer in polymer RICs.
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Affiliation(s)
- Penny J Le
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 1H6, Canada
| | - Shane Miersch
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Matthew W Forbes
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 1H6, Canada
| | - Nick Jarvik
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Anthony Ku
- Department of Pharmaceutical Sciences, University of Toronto, 144 College Street, Toronto, ON M5S 3M2, Canada
| | - Sachdev S Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, 144 College Street, Toronto, ON M5S 3M2, Canada.,Joint Department of Medical Imaging and Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Mitchell A Winnik
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 1H6, Canada.,Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E2, Canada
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23
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Lin R, Ma B, Liu N, Zhang L, He T, Liu X, Chen T, Liu W, Liang Y, Wang T, Ni G, Liu X, Yang N, Zhang J, Yuan J. Targeted radioimmunotherapy with the iodine-131-labeled caerin 1.1 peptide for human anaplastic thyroid cancer in nude mice. Ann Nucl Med 2021; 35:811-822. [PMID: 33948902 PMCID: PMC8197720 DOI: 10.1007/s12149-021-01618-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/20/2021] [Indexed: 12/19/2022]
Abstract
Objective The combination of two or more drugs with different mechanisms is a promising strategy for cancer treatment, and radioimmunotherapy (RIT) is a trending antitumor strategy. Radiotherapy (RT) can promote and activate antitumor immune effects, and immunotherapy can strengthen the effects of selective internal radiotherapy (SIRT); the RIT combination is synergistic and can overcome the adverse side effects of monotherapy. In this study, we developed a radioimmunoconjugate (RIC)—the iodine-131 (131I)-labeled caerin 1.1 peptide—to treat human anaplastic thyroid cancer (ATC). Methods Antitumor activity of caerin 1.1 peptide was determined by MTT assay, plate colony formation and cell wound scratch assays, and the mechanism of the inhibition of carein 1.1 peptide on the growth of CAL-62 cells was identified by cell cycle and western blot. Then, we investigated the efficacy of the caerin 1.1 peptide as a single drug and the 131I-labeled caerin 1.1 peptide for ATC. H&E and TUNEL staining was performed to detect dead cells in the tumor tissue sections. Results We found that caerin 1.1 arrested cells in the S phase to induce apoptosis and inhibited tumor growth to inhibit phosphorylation of Akt. In vivo, the iodine-131 (131I)-labeled caerin 1.1 peptide achieved better antitumor efficacy than radiotherapy alone and showed a good biosafety profile. Conclusions Our study demonstrates for the first time that the iodine-131 (131I)-labeled caerin 1.1 peptide can inhibit CAL-62 tumor growth and migration. The iodine-131 (131I)-labeled caerin 1.1 peptide, which represents a radioimmunotherapy strategy based on the combination of SIRT with a peptide–drug conjugate, could provide a treatment means for the radical cure of ATC.
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Affiliation(s)
- Ruoting Lin
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Bowei Ma
- Department of TCM Resident Training, The First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510405, Guangdong, China
| | - Na Liu
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Lu Zhang
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Tiantian He
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Xiongying Liu
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Tongsheng Chen
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Wenjuan Liu
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Yongnan Liang
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Tianfang Wang
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
- Genecology Research Centre, University of Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Guoying Ni
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
- Genecology Research Centre, University of Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Xiaosong Liu
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
- The First People's Hospital of Foshan, Foshan, 528000, Guangdong, China
- Genecology Research Centre, University of Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Ning Yang
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China
| | - Jinhe Zhang
- Department of Nuclear Medicine, General Hospital of the Southern Theatre Command, People's Liberation Army of China, Guangzhou, 510010, Guangdong, China
| | - Jianwei Yuan
- Department of Nuclear Medicine, The First Affiliated Hospital/Clinical Medical School, Guangdong Pharmaceutical University, Guangzhou, 510080, Guangdong, China.
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24
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Filippi L, Nervi C, Proietti I, Pirisino R, Potenza C, Martelli O, Equitani F, Bagni O. Molecular imaging in immuno-oncology: current status and translational perspectives. Expert Rev Mol Diagn 2020; 20:1199-1211. [PMID: 33215963 DOI: 10.1080/14737159.2020.1854090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Only 20-40% of patients respond to therapy with immune checkpoint inhibitors (ICIs). Therefore, the early identification of subjects that can benefit from such therapeutic regimen is mandatory. Areas covered: The immunobiological mechanisms of ICIs are briefly illustrated. Furthermore, the limitations of traditional radiological approaches are covered. Then, the pros and cons of molecular imaging through positron emission computed tomography (PET/CT) are reviewed, with a particular focus on 18f-fluorodeoxyglucose (18F-FDG) and PET-derived metabolic parameters. Lastly, translational perspective of radiopharmaceuticals others than 18F-FDG such as 89zirconium (89Zr) or fluorine-18 (18F) labeled monoclonal antibodies (e.g.89Zr-atezolizumab, 89Zr-nivolumab) binding to specific biomarkers are discussed. Expert opinion: Molecular imaging presents a prominent role for the management of oncological patients treated with ICIs. Preliminary clinical data indicate that PET/CT with 18F-FDG is useful for assessing the response to treatment and for the imaging of immune-related adverse effects. Nevertheless, the methodological approach (iPERCIST, PERCIMT, or others) to be used for an optimal diagnostic accuracy and patients' evaluation is still a debated issue. PET/CT with radioligands directed toward ICIs biomarkers, although is still in a translational phase, holds the promise of accurately predicting the response to treatment and revealing the acquired resistance to immunotherapy.
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Affiliation(s)
- Luca Filippi
- Department of Nuclear Medicine, Santa Maria Goretti Hospital, AUSL , Latina, Italy
| | - Clara Nervi
- Department of Medical and Surgical Sciences and Biotechnology, University of Rome "La Sapienza" , Latina, Italy
| | - Ilaria Proietti
- Dermatology Unit Daniele Innocenzi, A. Fiorini Hospital, Polo Pontino , Terracina, Italy
| | - Riccardo Pirisino
- Department of Nuclear Medicine, Santa Maria Goretti Hospital, AUSL , Latina, Italy
| | - Concetta Potenza
- Dermatology Unit Daniele Innocenzi, A. Fiorini Hospital, Polo Pontino , Terracina, Italy
| | | | - Francesco Equitani
- Department of Transfusion Medicine, Santa Maria Goretti Hospital, AUSL , Latina, Italy
| | - Oreste Bagni
- Department of Nuclear Medicine, Santa Maria Goretti Hospital, AUSL , Latina, Italy
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25
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Svedjehed J, Kutyreff CJ, Engle JW, Gagnon K. Automated, cassette-based isolation and formulation of high-purity [ 61Cu]CuCl 2 from solid Ni targets. EJNMMI Radiopharm Chem 2020; 5:21. [PMID: 33151400 PMCID: PMC7644601 DOI: 10.1186/s41181-020-00108-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND A need for improved, cassette-based automation of 61Cu separation from irradiated Ni targets was identified given the growing interest in theranostics, and generally lengthy separation chemistries for 64Cu/64Ni, upon which 61Cu chemistry is often based. METHODS A method for separating 61Cu from irradiated natNi targets was therefore developed, with provision for target recycling. Following deuteron irradiation, electroplated natNi targets were remotely transferred from the cyclotron and dissolved in acid. The dissolved target solution was then transferred to an automated FASTlab chemistry module, where sequential TBP and TK201 (Triskem) resins isolated the [61Cu]CuCl2, removed Ni, Co, and Fe, and concentrated the product into a formulation suitable for anticipated radiolabelling reactions. RESULTS 61Cu saturation yields of 190 ± 33 MBq/μA from energetically thick natNi targets were measured. The average, decay-corrected, activity-based dissolution efficiency was 97.5 ± 1.4% with an average radiochemical yield of 90.4 ± 3.2% (N = 5). The isolated activity was collected approximately 65 min post end of bombardment in ~ 2 mL of 0.06 M HCl (HCl concentration was verified by titration). Quality control of the isolated [61Cu]CuCl2 (N = 5) measured 58Co content of (8.3 ± 0.6) × 10- 5% vs. 61Cu by activity, Ni separation factors ≥ (2.2 ± 1.8) × 106, EoB molar activities 85 ± 23 GBq/μmol and NOTA-based EoB apparent molar activities of 31 ± 8 MBq/nmol and 201 MBq/nmol for the 30 min and 3.3 h (N = 1) irradiations, respectively. CONCLUSION High purity 61Cu was produced with the developed automated method using a single-use, cassette-based approach. It was also applicable for 64Cu, as demonstrated with a single proof-of-concept 64Ni target production run.
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Affiliation(s)
- Johan Svedjehed
- Cyclotrons and TRACERcenter, GE Healthcare, GEMS PET Systems AB, Uppsala, Sweden
| | - Christopher J Kutyreff
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Jonathan W Engle
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.,Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine Gagnon
- Cyclotrons and TRACERcenter, GE Healthcare, GEMS PET Systems AB, Uppsala, Sweden.
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Li L, Rousseau J, Jaraquemada-Peláez MDG, Wang X, Robertson A, Radchenko V, Schaffer P, Lin KS, Bénard F, Orvig C. 225Ac-H 4py4pa for Targeted Alpha Therapy. Bioconjug Chem 2020; 32:1348-1363. [PMID: 32216377 DOI: 10.1021/acs.bioconjchem.0c00171] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Herein, we present the syntheses and characterization of a new undecadendate chelator, H4py4pa, and its bifunctional analog H4py4pa-phenyl-NCS, conjugated to the monoclonal antibody, Trastuzumab, which targets the HER2+ cancer. H4py4pa possesses excellent affinity for 225Ac (α, t1/2 = 9.92 d) for targeted alpha therapy (TAT), where quantitative radiolabeling yield was achieved at ambient temperature, pH = 7, in 30 min at 10-6 M chelator concentration, leading to a complex highly stable in mouse serum for at least 9 d. To investigate the chelation of H4py4pa with large metal ions, lanthanum (La3+), which is the largest nonradioactive metal of the lanthanide series, was adopted as a surrogate for 225Ac to enable a series of nonradioactive chemical studies. In line with the 1H NMR spectrum, the DFT (density functional theory)-calculated structure of the [La(py4pa)]- anion possessed a high degree of symmetry, and the La3+ ion was secured by two distinct pairs of picolinate arms. Furthermore, the [La(py4pa)]- complex also demonstrated a superb thermodynamic stability (log K[La(py4pa)]- ∼ 20.33, pLa = 21.0) compared to those of DOTA (log K[La(DOTA)]- ∼ 24.25, pLa = 19.2) or H2macropa (log K[La(macropa)]- = 14.99, pLa ∼ 8.5). Moreover, the functional versatility offered by the bifunctional py4pa precursor permits facile incorporation of various linkers for bioconjugation through direct nucleophilic substitution. In this work, a short phenyl-NCS linker was incorporated to tether H4py4pa to Trastuzumab. Radiolabeling studies, in vitro serum stability, and animal studies were performed in parallel with the DOTA-benzyl-Trastuzumab. Both displayed excellent in vivo stability and tumor specificity.
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Affiliation(s)
- Lily Li
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Julie Rousseau
- Department of Molecular Oncology, BC Cancer, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - María de Guadalupe Jaraquemada-Peláez
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Xiaozhu Wang
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Andrew Robertson
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Department of Physics and Astronomy, University of British Columbia, 325-6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Department of Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, British Columbia V5Z 1M9, Canada.,Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Karges J, Jakubaszek M, Mari C, Zarschler K, Goud B, Stephan H, Gasser G. Synthesis and Characterization of an Epidermal Growth Factor Receptor-Selective Ru II Polypyridyl-Nanobody Conjugate as a Photosensitizer for Photodynamic Therapy. Chembiochem 2020; 21:531-542. [PMID: 31339225 PMCID: PMC7065149 DOI: 10.1002/cbic.201900419] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Indexed: 02/06/2023]
Abstract
There is a current surge of interest in the development of novel photosensitizers (PSs) for photodynamic therapy (PDT), as those currently approved are not completely ideal. Among the tested compounds, we have previously investigated the use of RuII polypyridyl complexes with a [Ru(bipy)2 (dppz)]2+ and [Ru(phen)2 (dppz)]2+ scaffold (bipy=2,2'-bipyridine; dppz=dipyrido[3,2-a:2',3'-c]phenazine; phen=1,10-phenanthroline). These complexes selectively target DNA. However, because DNA is ubiquitous, it would be of great interest to increase the selectivity of our PDT PSs by linking them to a targeting vector in view of targeted PDT. Herein, we present the synthesis, characterization, and in-depth photophysical evaluation of a nanobody-containing RuII polypyridyl conjugate selective for the epidermal growth factor receptor (EGFR) in view of targeted PDT. Using ICP-MS and confocal microscopy, we could demonstrate that our conjugate has high selectivity for the EGFR receptor, which is a crucial oncological target because it is overexpressed and/or deregulated in a variety of solid tumors. However, in contrast to expectations, this conjugate was found to not produce reactive oxygen species (ROS) in cancer cells and is therefore not phototoxic.
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Affiliation(s)
- Johannes Karges
- Chimie ParisTechPSL UniversityCNRSInstitute of Chemistry for Life and Health SciencesLaboratory for Inorganic Chemical Biology75005ParisFrance
| | - Marta Jakubaszek
- Chimie ParisTechPSL UniversityCNRSInstitute of Chemistry for Life and Health SciencesLaboratory for Inorganic Chemical Biology75005ParisFrance
- Institut CuriePSL UniversityCNRS UMR 14426 rue d'Ulm75005ParisFrance
| | - Cristina Mari
- Department of ChemistryUniversity of ZürichWinterthurerstrasse 1908057ZürichSwitzerland
| | - Kristof Zarschler
- Helmholtz-Zentrum Dresden–RossendorfInstitute of Radiopharmaceutical Cancer ResearchBautzner Landstrasse 40001328DresdenGermany
| | - Bruno Goud
- Institut CuriePSL UniversityCNRS UMR 14426 rue d'Ulm75005ParisFrance
| | - Holger Stephan
- Helmholtz-Zentrum Dresden–RossendorfInstitute of Radiopharmaceutical Cancer ResearchBautzner Landstrasse 40001328DresdenGermany
| | - Gilles Gasser
- Chimie ParisTechPSL UniversityCNRSInstitute of Chemistry for Life and Health SciencesLaboratory for Inorganic Chemical Biology75005ParisFrance
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Chitneni SK, Koumarianou E, Vaidyanathan G, Zalutsky MR. Observations on the Effects of Residualization and Dehalogenation on the Utility of N-Succinimidyl Ester Acylation Agents for Radioiodination of the Internalizing Antibody Trastuzumab. Molecules 2019; 24:molecules24213907. [PMID: 31671554 PMCID: PMC6864793 DOI: 10.3390/molecules24213907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 11/16/2022] Open
Abstract
Trastuzumab is an antibody used for the treatment of human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancers. Since trastuzumab is an internalizing antibody, two factors could play an important role in achieving high uptake and prolonged retention of radioactivity in HER2-positive tumors after radioiodination-residualizing capacity after receptor-mediated internalization and susceptibility to dehalogenation. To evaluate the contribution of these two factors, trastuzumab was radiolabeled using the residualizing reagent N-succinimidyl 4-guanidinomethyl-3-[*I]iodobenzoate ([*I]SGMIB) and the nonresidualizing reagent N-succinimidyl-3-[*I]iodobenzoate ([*I]SIB), both of which are highly dehalogenation-resistant. Paired-label uptake and intracellular retention of [125I]SGMIB-trastuzumab and [131I]SIB-trastuzumab was compared on HER2-expressing BT474 human breast carcinoma cells. Tumor uptake and normal tissue distribution characteristics for the two labeled conjugates were assessed in mice bearing BT474M1 xenografts. The internalization and intracellular retention of initially-bound radioactivity in BT474 cells was similar for the two labeled conjugates up to 4 h, but were significantly higher for [125I]SGMIB-trastuzumab at 6 and 24 h. Similarly, [*I]SGMIB labeling resulted in significantly higher uptake and retention of radioactivity in BT474M1 xenografts at all studied time points. Moreover, tumor-to-tissue ratios for [125I]SGMIB-trastuzumab were consistently higher than those for [131I]SIB-trastuzumab starting at 12 h postinjection. Thus, optimal targeting of HER2-positive breast cancers with a radioiodinated trastuzumab conjugate requires an acylation agent that imparts residualizing capacity in addition to high stability towards dehalogenation in vivo.
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Affiliation(s)
- Satish K Chitneni
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Eftychia Koumarianou
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
- ABX-CRO Advanced Pharmaceutical Services, D-01307 Dresden, Germany.
| | | | - Michael R Zalutsky
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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A rapid bead-based radioligand binding assay for the determination of target-binding fraction and quality control of radiopharmaceuticals. Nucl Med Biol 2019; 71:32-38. [PMID: 31128476 DOI: 10.1016/j.nucmedbio.2019.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 04/25/2019] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Determination of the target-binding fraction (TBF) of radiopharmaceuticals using cell-based assays is prone to inconsistencies arising from several intrinsic and extrinsic factors. Here, we report a cell-free quantitative method of analysis to determine the TBF of radioligands. METHODS Magnetic beads functionalized with Ni-NTA or streptavidin were incubated with 1 μg of histidine-tagged or biotinylated antigen of choice for 15 min, followed by incubating 1 ng of the radioligand for 30 min. The beads, supernatant and wash fractions were measured for radioactivity on a gamma counter. The TBF was determined by quantifying the percentage of activity associated with the magnetic beads. RESULTS The described method works robustly with a variety of radioisotopes and class of molecules used as radioligands. The entire assay can be completed within 2 h. CONCLUSION The described method yields results in a rapid and reliable manner whilst improving and extending the scope of previously described bead-based radioimmunoassays. ADVANCES IN KNOWLEDGE Using a bead-based radioligand binding assay overcomes the limitations of traditional cell-based assays. The described method is applicable to antibody as well as non-antibody based radioligands and is independent of the effect of target antigen density on cells, the choice of radioisotope used for synthesis of the radioligand and the temperature at which the assay is performed. IMPLICATIONS FOR PATIENT CARE The bead-based radioligand binding assay is significantly easier to perform and is ideally suited for adoption by the radiopharmacy as a quality control method of analysis to fulfill the criteria for release of radiopharmaceuticals in the clinic. The use of this assay is likely to ensure a more reliable validation of radiopharmaceutical quality and result in fewer failed doses, which could ultimately translate to an efficient release of radiopharmaceuticals for administration to patients in the clinic.
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