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Li XM, Gao J, Li JG, Song JB, Li SJ. Experimental study of early evaluation of radiosensitivity in mouse models of lung cancers using 89Zr-anti-γH2AX-TAT PET imaging. EJNMMI Res 2024; 14:108. [PMID: 39543016 PMCID: PMC11564693 DOI: 10.1186/s13550-024-01178-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2024] [Accepted: 11/07/2024] [Indexed: 11/17/2024] Open
Abstract
BACKGROUND Early evaluation of radiation sensitivity in lung cancer patients can facilitate the transition to personalized treatment strategies. To this end, we assessed the capability of 89Zr-anti-γH2AX-TAT microPET imaging in determining the radiosensitivity of lung cancer xenograft models. We prepared and conducted quality control on 89Zr-anti-γH2AX-TAT. The radiosensitivity of human non-small cell lung cancer cells (H460) and adenocarcinoma cells (A549) was analyzed through clonogenic survival experiments. Additionally, the role of γH2AX as a biomarker for radiosensitivity was validated by quantifying γH2AX foci via fluorescence staining. Subsequently, the H460 and A549 xenograft mouse models were subjected to irradiation, followed by 89Zr-anti-γH2AX-TAT microPET imaging. Concurrently, we performed immunofluorescence staining for γH2AX in tumor tissues to establish a correlation between the uptake of 89Zr-anti-γH2AX-TAT and γH2AX expression. RESULTS The surviving fraction 2 Gy (SF2) values of H460 and A549 indicating that A549 adenocarcinoma has higher radiosensitivity. The cell immunofluorescence experiment showed that the repair of γH2AX foci in H460 cells after irradiation was significantly higher than that in A549 cells, which also confirmed that A549 has higher radiosensitivity. The microPET imaging results showed the uptake of 89Zr-anti-γH2AX-TAT in the tumor of the A549 models after radiotherapy was higher than H460 models. The immunofluorescence staining of tumor tissue confirmed that the expression level of γH2AX was higher and the correlation with microPET imaging uptake was good. CONCLUSION 89Zr-anti-γH2AX-TAT allows PET imaging of radiosensitivity in lung cancer xenograft models, and is expected to become an early evaluation method for lung cancer radiosensitivity.
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Affiliation(s)
- Xiao-Min Li
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
- Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
- Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Jie Gao
- China Institute for Radiation Protection, No. 102 Xuefu Str, Taiyuan, 030006, Shanxi, China
- China National Atomic Energy Agency nuclear technology (Nonclinical evaluation of radiopharmaceuticals) research and Development Center, No. 102 Xuefu Str, Taiyuan, 030006, Shanxi, China
| | - Jian-Guo Li
- China Institute for Radiation Protection, No. 102 Xuefu Str, Taiyuan, 030006, Shanxi, China
- China National Atomic Energy Agency nuclear technology (Nonclinical evaluation of radiopharmaceuticals) research and Development Center, No. 102 Xuefu Str, Taiyuan, 030006, Shanxi, China
| | - Jian-Bo Song
- Tongji Shanxi Hospital, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Third Hospital of Shanxi Medical University, Taiyuan, 030032, China
| | - Si-Jin Li
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China.
- Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China.
- Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China.
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Alakonya H, Koustoulidou S, Hopkins SL, Veal M, Ajenjo J, Sneddon D, Dias G, Mosley M, Baguña Torres J, Amoroso F, Anderson A, Banham AH, Cornelissen B. Molecular Imaging of p53 in Mouse Models of Cancer Using a Radiolabeled Antibody TAT Conjugate with SPECT. J Nucl Med 2024; 65:1626-1632. [PMID: 39266290 PMCID: PMC11448609 DOI: 10.2967/jnumed.124.267736] [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: 03/07/2024] [Accepted: 08/02/2024] [Indexed: 09/14/2024] Open
Abstract
Mutations of p53 protein occur in over half of all cancers, with profound effects on tumor biology. We present the first-to our knowledge-method for noninvasive visualization of p53 in tumor tissue in vivo, using SPECT, in 3 different models of cancer. Methods: Anti-p53 monoclonal antibodies were conjugated to the cell-penetrating transactivator of transcription (TAT) peptide and a metal ion chelator and then radiolabeled with 111In to allow SPECT imaging. 111In-anti-p53-TAT conjugates were retained longer in cells overexpressing p53-specific than non-p53-specific 111In-mIgG (mouse IgG from murine plasma)-TAT controls, but not in null p53 cells. Results: In vivo SPECT imaging showed enhanced uptake of 111In-anti-p53-TAT, versus 111In-mIgG-TAT, in high-expression p53R175H and medium-expression wild-type p53 but not in null p53 tumor xenografts. The results were confirmed in mice bearing genetically engineered KPC mouse-derived pancreatic ductal adenocarcinoma tumors. Imaging with 111In-anti-p53-TAT was possible in KPC mice bearing spontaneous p53R172H pancreatic ductal adenocarcinoma tumors. Conclusion: We demonstrate the feasibility of noninvasive in vivo molecular imaging of p53 in tumor tissue using a radiolabeled TAT-modified monoclonal antibody.
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Affiliation(s)
- Hudson Alakonya
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Sofia Koustoulidou
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Samantha L Hopkins
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Mathew Veal
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Javier Ajenjo
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Deborah Sneddon
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Gemma Dias
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael Mosley
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Julia Baguña Torres
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Francesca Amoroso
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Amanda Anderson
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom; and
| | - Alison H Banham
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom; and
| | - Bart Cornelissen
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom;
- Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
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Garaulet G, Báez BB, Medrano G, Rivas-Sánchez M, Sánchez-Alonso D, Martinez-Torrecuadrada JL, Mulero F. Radioimmunotheragnosis in Cancer Research. Cancers (Basel) 2024; 16:2896. [PMID: 39199666 PMCID: PMC11352548 DOI: 10.3390/cancers16162896] [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: 06/13/2024] [Revised: 08/02/2024] [Accepted: 08/13/2024] [Indexed: 09/01/2024] Open
Abstract
The combination of immunoPET-where an antibody (Ab) is labeled with an isotope for PET imaging-and radioimmunotherapy (RIT), using the same antibody with a therapeutic isotope, offers significant advantages in cancer management. ImmunoPET allows non-invasive imaging of antigen expression, which aids in patient selection for subsequent radioimmunotherapy. It also facilitates the assessment of tumor response to therapy, allowing for treatment adjustments if necessary. In addition, immunoPET provides critical pharmacokinetic data, including antibody biodistribution and clearance rates, which are essential for dosimetry calculations and treatment protocol optimization. There are still challenges to overcome. Identifying appropriate target antigens that are selectively expressed on cancer cells while minimally expressed on normal tissues remains a major hurdle to reduce off-target toxicity. In addition, it is critical to optimize the pharmacokinetics of radiolabeled antibodies to maximize tumor uptake and minimize normal tissue uptake, particularly in vital organs such as the liver and kidney. This approach offers the potential for targeted and personalized cancer therapy with reduced systemic toxicity by exploiting the specificity of monoclonal antibodies and the cytotoxic effects of radiation. However, further research is needed to address remaining challenges and to optimize these technologies for clinical use.
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Affiliation(s)
- Guillermo Garaulet
- Molecular Imaging Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (G.G.); (B.B.B.); (G.M.)
| | - Bárbara Beatriz Báez
- Molecular Imaging Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (G.G.); (B.B.B.); (G.M.)
| | - Guillermo Medrano
- Molecular Imaging Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (G.G.); (B.B.B.); (G.M.)
| | - María Rivas-Sánchez
- Protein Production Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (M.R.-S.); (D.S.-A.)
| | - David Sánchez-Alonso
- Protein Production Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (M.R.-S.); (D.S.-A.)
| | | | - Francisca Mulero
- Molecular Imaging Unit, Spanish National Cancer Center—CNIO, 28029 Madrid, Spain; (G.G.); (B.B.B.); (G.M.)
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Rodriguez-Tirado C, Sosa MS. How much do we know about the metastatic process? Clin Exp Metastasis 2024; 41:275-299. [PMID: 38520475 PMCID: PMC11374507 DOI: 10.1007/s10585-023-10248-0] [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: 08/13/2023] [Accepted: 11/17/2023] [Indexed: 03/25/2024]
Abstract
Cancer cells can leave their primary sites and travel through the circulation to distant sites, where they lodge as disseminated cancer cells (DCCs), even during the early and asymptomatic stages of tumor progression. In experimental models and clinical samples, DCCs can be detected in a non-proliferative state, defined as cellular dormancy. This state can persist for extended periods until DCCs reawaken, usually in response to niche-derived reactivation signals. Therefore, their clinical detection in sites like lymph nodes and bone marrow is linked to poor survival. Current cancer therapy designs are based on the biology of the primary tumor and do not target the biology of the dormant DCC population and thus fail to eradicate the initial or subsequent waves of metastasis. In this brief review, we discuss the current methods for detecting DCCs and highlight new strategies that aim to target DCCs that constitute minimal residual disease to reduce or prevent metastasis formation. Furthermore, we present current evidence on the relevance of DCCs derived from early stages of tumor progression in metastatic disease and describe the animal models available for their study. We also discuss our current understanding of the dissemination mechanisms utilized by genetically less- and more-advanced cancer cells, which include the functional analysis of intermediate or hybrid states of epithelial-mesenchymal transition (EMT). Finally, we raise some intriguing questions regarding the clinical impact of studying the crosstalk between evolutionary waves of DCCs and the initiation of metastatic disease.
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Affiliation(s)
- Carolina Rodriguez-Tirado
- Department of Microbiology and Immunology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Department of Oncology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Montefiore Einstein Comprehensive Cancer Center, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Cancer Dormancy and Tumor Microenvironment Institute/Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
- Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
| | - Maria Soledad Sosa
- Department of Microbiology and Immunology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Department of Oncology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Montefiore Einstein Comprehensive Cancer Center, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
- Cancer Dormancy and Tumor Microenvironment Institute/Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
- Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, 10461, USA.
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Li Y, Liu Y, Zhang D, Chen J, Yang G, Tang P, Yang C, Liu J, Zhang J, Ouyang L. Discovery, Synthesis, and Evaluation of Novel Dual Inhibitors of a Vascular Endothelial Growth Factor Receptor and Poly(ADP-Ribose) Polymerase for BRCA Wild-Type Breast Cancer Therapy. J Med Chem 2023; 66:12069-12100. [PMID: 37616488 DOI: 10.1021/acs.jmedchem.3c00640] [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: 08/26/2023]
Abstract
Poly(ADP-ribose) polymerase (PARP) inhibitors have been approved for the treatment of breast cancer (BC) with breast cancer susceptibility (BRCA) gene mutation. Leveraging new synthetic lethal interactions may be an effective way to broaden the indication of PARP inhibitors for BC patients with wild-type BRCA. Vascular endothelial growth factor receptor (VEGFR)-mediated suppression of angiogenesis has been reported to improve the sensitivity of wild-type BRCA cells to PARP inhibitors through synthetic lethality. Herein, we reported the conjugation of a PARP inhibitor with a VEGFR inhibitor pharmacophore to construct dual VEGFR and PARP inhibitors. The most potent compound 14b is identified to exert promising activities against VEGFR and PARP in the nanomolar range and possesses significant in vitro and in vivo antitumor and antimetastasis features. It also presented a favorable pharmacokinetic characteristics in rats with an oral bioavailability of 60.1%. Collectively, 14b may be a promising therapeutic agent of BRCA wild-type BC.
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Affiliation(s)
- Yang Li
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yun Liu
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dan Zhang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Juncheng Chen
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Gaoxia Yang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Pan Tang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chengcan Yang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jie Liu
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jifa Zhang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
- Frontiers Medical Center, Tianfu Jincheng Laboratory, Chengdu, 610212, China
| | - Liang Ouyang
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy and Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
- Frontiers Medical Center, Tianfu Jincheng Laboratory, Chengdu, 610212, China
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O'Neill E, Mosley M, Cornelissen B. Imaging DNA damage response by γH2AX in vivo predicts treatment response to Lutetium-177 radioligand therapy and suggests senescence as a therapeutically desirable outcome. Theranostics 2023; 13:1302-1310. [PMID: 36923536 PMCID: PMC10008745 DOI: 10.7150/thno.82101] [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: 12/23/2022] [Accepted: 01/19/2023] [Indexed: 03/14/2023] Open
Abstract
Rationale: An effective absorbed dose response relationship is yet to be established for Lutetium-177 based radionuclide therapies such as 177Lu-DOTATATE and 177Lu-PSMA. The inherent biological heterogeneity of neuroendocrine and prostate cancers may make the prospect of establishing cohort-based dose-response relationships unobtainable. Instead, an individual-based approach, monitoring the dose-response within each tumor could provide the necessary metric to monitor treatment efficacy. Methods: We developed a dual isotope SPECT imaging strategy to monitor the change over time in the relationship between 177Lu-DOTATATE and 111In-anti-γH2AX-TAT, a modified radiolabelled antibody that allows imaging of DNA double strand breaks, in mice bearing rat pancreatic cancer xenografts. The dynamics of γH2AX foci, apoptosis and senescence following exposure to 177Lu-DOTATATE was further investigated in vitro and in ex vivo tumor sections. Results: The change in slope of the 111In-anti-γH2AX-TAT to 177Lu signal between days 5 and 7 was found to be highly predictive of survival (r = 0.955, P < 0.0001). This pivotal timeframe was investigated further in vitro: clonogenic survival correlated with the number of γH2AX foci at day 6 (r = -0.995, P < 0.0005). While there was evidence of continuously low levels of apoptosis, delayed induction of senescence in vitro appeared to better account for the γH2AX response to 177Lu. The induction of senescence was further investigated by ex vivo analysis and corresponded with sustained retention of 177Lu within tumor regions. Conclusions: Dual isotope SPECT imaging can provide individualized tumor dose-responses that can be used to predict lutetium-177 treatment efficacy. This bio-dosimeter metric appears to be dependent upon the extent of senescence induction and suggests an integral role that senescence plays in lutetium-177 treatment efficacy.
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Affiliation(s)
- Edward O'Neill
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Michael Mosley
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Bart Cornelissen
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
- Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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PET imaging of pancreatic cancer. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00207-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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8
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Veal M, Dias G, Kersemans V, Sneddon D, Faulkner S, Cornelissen B. A Model System to Explore the Detection Limits of Antibody-Based Immuno-SPECT Imaging of Exclusively Intranuclear Epitopes. J Nucl Med 2021; 62:1537-1544. [PMID: 33789931 PMCID: PMC8612322 DOI: 10.2967/jnumed.120.251173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 02/01/2021] [Indexed: 11/30/2022] Open
Abstract
Imaging of intranuclear epitopes using antibodies tagged to cell-penetrating peptides has great potential given its versatility, specificity, and sensitivity. However, this process is technically challenging because of the location of the target. Previous research has demonstrated a variety of intranuclear epitopes that can be targeted with antibody-based radioimmunoconjugates. Here, we developed a controlled-expression model of nucleus-localized green fluorescent protein (GFP) to interrogate the technical limitations of intranuclear SPECT using radioimmunoconjugates, notably the lower target-abundance detection threshold. Methods: We stably transfected the lung adenocarcinoma cell line H1299 with an enhanced GFP (EGFP)-tagged histone 2B (H2B) and generated 4 cell lines expressing increasing levels of GFP. EGFP levels were quantified using Western blot, flow cytometry, and enzyme-linked immunosorbent assay. An anti-GFP antibody (GFP-G1) was modified using dibenzocyclooctyne-N3-based strain-promoted azide-alkyne cycloaddition with the cell-penetrating peptide TAT (GRKKRRQRRRPPQGYG), which also includes a nuclear localization sequence, and the metal ion chelator N3-Bn-diethylenetriamine pentaacetate (DTPA) to allow radiolabeling with 111In. Cell uptake of 111In-GFP-G1-TAT was evaluated across 5 cell clones expressing different levels of H2B-EGFP in vitro. Tumor uptake in xenograft-bearing mice was quantified to determine the smallest amount of target epitope that could be detected using 111In-GFP-G1-TAT. Results: We generated 4 H1299 cell clones expressing different levels of H2B-EGFP (0-1 million copies per cell, including wild-type H1299 cells). GFP-G1 monoclonal antibody was produced and purified in house, and selective binding to H2B-EGFP was confirmed. The affinity (dissociation constant) of GFP-G1 was determined as 9.1 ± 3.0 nM. GFP-G1 was conjugated to TAT and DTPA. 111In-GFP-G1-TAT uptake in H2B-EGFP-expressing cell clones correlated linearly with H2B-EGFP expression (P < 0.001). In vivo xenograft studies demonstrated that 111In-GFP-G1-TAT uptake in tumor tissue correlated linearly with expression of H2B-EGFP (P = 0.004) and suggested a lower target-abundance detection threshold of approximately 240,000 copies per cell. Conclusion: Here, we present a proof-of-concept demonstration that antibody-based imaging of intranuclear targets is capable both of detecting the presence of an epitope of interest with a copy number above 240,000 copies per cell and of determining differences in expression level above this threshold.
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Affiliation(s)
- Mathew Veal
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom; and
| | - Gemma Dias
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom; and
| | - Veerle Kersemans
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom; and
| | - Deborah Sneddon
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom; and
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Stephen Faulkner
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom; and
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Beroske L, Van den Wyngaert T, Stroobants S, Van der Veken P, Elvas F. Molecular Imaging of Apoptosis: The Case of Caspase-3 Radiotracers. Int J Mol Sci 2021; 22:ijms22083948. [PMID: 33920463 PMCID: PMC8069194 DOI: 10.3390/ijms22083948] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022] Open
Abstract
The molecular imaging of apoptosis remains an important method for the diagnosis and monitoring of the progression of certain diseases and the evaluation of the efficacy of anticancer apoptosis-inducing therapies. Among the multiple biomarkers involved in apoptosis, activated caspase-3 is an attractive target, as it is the most abundant of the executioner caspases. Nuclear imaging is a good candidate, as it combines a high depth of tissue penetration and high sensitivity, features necessary to detect small changes in levels of apoptosis. However, designing a caspase-3 radiotracer comes with challenges, such as selectivity, cell permeability and transient caspase-3 activation. In this review, we discuss the different caspase-3 radiotracers for the imaging of apoptosis together with the challenges of the translation of various apoptosis-imaging strategies in clinical trials.
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Affiliation(s)
- Lucas Beroske
- Molecular Imaging Center Antwerp, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (T.V.d.W.); (S.S.)
- Department of Nuclear Medicine, Antwerp University Hospital, 2650 Edegem, Belgium
- Laboratory of Medicinal Chemistry, University of Antwerp, 2610 Wilrijk, Belgium;
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (T.V.d.W.); (S.S.)
- Department of Nuclear Medicine, Antwerp University Hospital, 2650 Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (T.V.d.W.); (S.S.)
- Department of Nuclear Medicine, Antwerp University Hospital, 2650 Edegem, Belgium
| | - Pieter Van der Veken
- Laboratory of Medicinal Chemistry, University of Antwerp, 2610 Wilrijk, Belgium;
| | - Filipe Elvas
- Molecular Imaging Center Antwerp, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (T.V.d.W.); (S.S.)
- Department of Nuclear Medicine, Antwerp University Hospital, 2650 Edegem, Belgium
- Correspondence:
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10
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Beekman FJ, Kamphuis C, Koustoulidou S, Ramakers RM, Goorden MC. Positron range-free and multi-isotope tomography of positron emitters. Phys Med Biol 2021; 66:065011. [PMID: 33578400 DOI: 10.1088/1361-6560/abe5fc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Despite improvements in small animal PET instruments, many tracers cannot be imaged at sufficiently high resolutions due to positron range, while multi-tracer PET is hampered by the fact that all annihilation photons have equal energies. Here we realize multi-isotope and sub-mm resolution PET of isotopes with several mm positron range by utilizing prompt gamma photons that are commonly neglected. A PET-SPECT-CT scanner (VECTor/CT, MILabs, The Netherlands) equipped with a high-energy cluster-pinhole collimator was used to image 124I and a mix of 124I and 18F in phantoms and mice. In addition to positrons (mean range 3.4 mm) 124I emits large amounts of 603 keV prompt gammas that-aided by excellent energy discrimination of NaI-were selected to reconstruct 124I images that are unaffected by positron range. Photons detected in the 511 keV window were used to reconstruct 18F images. Images were reconstructed iteratively using an energy dependent matrix for each isotope. Correction of 18F images for contamination with 124I annihilation photons was performed by Monte Carlo based range modelling and scaling of the 124I prompt gamma image before subtracting it from the 18F image. Additionally, prompt gamma imaging was tested for 89Zr that emits very high-energy prompts (909 keV). In Derenzo resolution phantoms 0.75 mm rods were clearly discernable for 124I, 89Zr and for simultaneously acquired 124I and 18F imaging. Image quantification in phantoms with reservoirs filled with both 124I and 18F showed excellent separation of isotopes and high quantitative accuracy. Mouse imaging showed uptake of 124I in tiny thyroid parts and simultaneously injected 18F-NaF in bone structures. The ability to obtain PET images at sub-mm resolution both for isotopes with several mm positron range and for multi-isotope PET adds to many other unique capabilities of VECTor's clustered pinhole imaging, including simultaneous sub-mm PET-SPECT and theranostic high energy SPECT.
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Affiliation(s)
- F J Beekman
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands. MILabs B.V., Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
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