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Filippi L, Urso L, Evangelista L. PARP-Targeted Radiotheranostics with Auger Electrons: An Updated Overview. Curr Issues Mol Biol 2024; 46:3039-3049. [PMID: 38666920 PMCID: PMC11048897 DOI: 10.3390/cimb46040190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Auger electrons (AEs) represent an intriguing topic in the field of radionuclide therapy. They are emitted by several radionuclides commonly used in nuclear medicine (indium-111, iodine-123, iodine-125), allowing for highly localized energy deposition and thus exerting a radiotoxic effect on specific cellular and sub-cellular targets. However, due to their short range in matter, AEs have had limited use in therapeutic applications so far. In recent years, the synthesis of various radiopharmaceuticals capable of binding to the enzyme poly(ADP-ribose) polymerase 1 has reignited interest in this type of therapy, laying the groundwork for a theranostic approach based on radionuclides emitting AEs. The enzyme PARP-1 operates enzymatically in close proximity to DNA that represents the prime target of radionuclide therapies. Following this trend, several PARP-targeted radiopharmaceuticals for AE-based theranostics have been developed. We provide an updated overview of preclinical studies focused on the applications of this new theranostic approach in glioblastoma, breast, prostate and ovarian carcinoma, and pancreatic adenocarcinoma.
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Affiliation(s)
- Luca Filippi
- Nuclear Medicine Unit, Department of Oncohaematology, Fondazione PTV Policlinico Tor Vergata University Hospital, 00133 Rome, Italy
| | - Luca Urso
- Department of Translational Medicine, University of Ferrara, 44124 Ferrara, Italy;
- Nuclear Medicine Unit, Onco-Haematology Department, University Hospital of Ferrara, 44124 Ferrara, Italy
| | - Laura Evangelista
- Department of Biomedical Sciences, Humanitas University, 20072 Milan, Italy;
- IRCCS Humanitas Research Hospital, 20089 Milan, Italy
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Facca VJ, Cai Z, Ku A, Georgiou CJ, Reilly RM. Adjuvant Auger Electron-Emitting Radioimmunotherapy with [ 111In]In-DOTA-Panitumumab in a Mouse Model of Local Recurrence and Metastatic Progression of Human Triple-Negative Breast Cancer. Mol Pharm 2023; 20:6407-6419. [PMID: 37983089 DOI: 10.1021/acs.molpharmaceut.3c00780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Triple-negative breast cancer (TNBC) has a high risk for recurrence and metastasis. We studied the effectiveness of Auger electron (AE) radioimmunotherapy (RIT) with antiepidermal growth factor receptor (EGFR) panitumumab conjugated with DOTA complexed to 111In ([111In]In-DOTA-panitumumab) for preventing metastatic progression after local treatment of 231/LM2-4 Luc+ human TNBC tumors in the mammary fat pad of NRG mice. Prior to RIT, the primary tumor was resected, and tumor margins were treated with X-irradiation (XRT; 5 days × 6 Gy/d). RIT was administered 1 day post-XRT by intravenous injection of 26 MBq (15 μg) or 2 × 10 MBq (15 μg each) separated by 7 d. These treatments were compared to tumor resection with or without XRT combined with DOTA-panitumumab (15 μg) or irrelevant [111In]In-DOTA-IgG2 (24 MBq; 15 μg), and efficacy was evaluated by Kaplan-Meier survival curves. The effect of [111In]In-DOTA-panitumumab (23 MBq; 15 μg) after tumor resection without local XRT was also studied. Tumor resection followed by XRT and RIT with 26 MBq [111In]In-DOTA-panitumumab significantly increased the median survival to 35 d compared to tumor resection with or without XRT (23-24 d; P < 0.0001). Local treatment with tumor resection and XRT followed by 2 × 10 MBq of [111In]In-DOTA-panitumumab, DOTA-panitumumab, or [111In]In-DOTA-IgG2 did not significantly improve median survival (26 days for all treatments). RIT alone with [111In]In-DOTA-panitumumab postresection of the tumor without XRT increased median survival to 29 days, though this was not significant. Despite significantly improved survival in mice treated with tumor resection, XRT, and RIT with [111In]In-DOTA-panitumumab, all mice eventually succumbed to advanced metastatic disease by 45 d post-tumor resection. SPECT/CT with [111In]In-DOTA-panitumumab, PET/MRI with [64Cu]Cu-DOTA-panitumumab F(ab')2, and PET/CT with [18F]FDG were used to detect recurrent and metastatic disease. Uptake of [111In]In-DOTA-panitumumab at 4 d p.i. in the MFP tumor was 26.8 ± 9.7% ID/g and in metastatic lymph nodes (LN), lungs, and liver was 34.2 ± 26.9% ID/g, 17.5 ± 6.0% ID/g, and 9.4 ± 2.4%ID/g, respectively, while uptake in the lungs (6.0 ± 0.9% ID/g) and liver (5.2 ± 2.9% ID/g) of non-tumor-bearing NRG was significantly lower (P < 0.05). Radiation-absorbed doses in metastatic LN, lungs, and liver were 9.7 ± 6.1, 6.4 ± 2.1, and 10.9 ± 2.7 Gy, respectively. In conclusion, we demonstrated that RIT with [111In]In-DOTA-panitumumab combined with tumor resection and XRT significantly improved the survival of mice with recurrent TNBC. However, the aggressive nature of 231/LM2-4 Luc+ tumors in NRG mice may have contributed to the tumor recurrence and progression observed.
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Affiliation(s)
- Valerie J Facca
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Zhongli Cai
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Anthony Ku
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Constantine J Georgiou
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, Ontario M5S 3M2, Canada
- Department of Medical Imaging, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Joint Department of Medical Imaging and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2C1, Canada
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Garcia-Prada CD, Carmes L, Atis S, Parach A, Bertolet A, Jarlier M, Poty S, Garcia DS, Shin WG, Du Manoir S, Schuemann J, Tillement O, Lux F, Constanzo J, Pouget JP. Gadolinium-Based Nanoparticles Sensitize Ovarian Peritoneal Carcinomatosis to Targeted Radionuclide Therapy. J Nucl Med 2023; 64:1956-1964. [PMID: 37857502 PMCID: PMC10690115 DOI: 10.2967/jnumed.123.265418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 08/28/2023] [Indexed: 10/21/2023] Open
Abstract
Ovarian cancer (OC) is the most lethal gynecologic malignancy (5-y overall survival rate, 46%). OC is generally detected when it has already spread to the peritoneal cavity (peritoneal carcinomatosis). This study investigated whether gadolinium-based nanoparticles (Gd-NPs) increase the efficacy of targeted radionuclide therapy using [177Lu]Lu-DOTA-trastuzumab (an antibody against human epidermal growth factor receptor 2). Gd-NPs have radiosensitizing effects in conventional external-beam radiotherapy and have been tested in clinical phase II trials. Methods: First, the optimal activity of [177Lu]Lu-DOTA-trastuzumab (10, 5, or 2.5 MBq) combined or not with 10 mg of Gd-NPs (single injection) was investigated in athymic mice bearing intraperitoneal OC cell (human epidermal growth factor receptor 2-positive) tumor xenografts. Next, the therapeutic efficacy and toxicity of 5 MBq of [177Lu]Lu-DOTA-trastuzumab with Gd-NPs (3 administration regimens) were evaluated. NaCl, trastuzumab plus Gd-NPs, and [177Lu]Lu-DOTA-trastuzumab alone were used as controls. Biodistribution and dosimetry were determined, and Monte Carlo simulation of energy deposits was performed. Lastly, Gd-NPs' subcellular localization and uptake, and the cytotoxic effects of the combination, were investigated in 3 cancer cell lines to obtain insights into the involved mechanisms. Results: The optimal [177Lu]Lu-DOTA-trastuzumab activity when combined with Gd-NPs was 5 MBq. Moreover, compared with [177Lu]Lu-DOTA-trastuzumab alone, the strongest therapeutic efficacy (tumor mass reduction) was obtained with 2 injections of 5 mg of Gd-NPs/d (separated by 6 h) at 24 and 72 h after injection of 5 MBq of [177Lu]Lu-DOTA-trastuzumab. In vitro experiments showed that Gd-NPs colocalized with lysosomes and that their radiosensitizing effect was mediated by oxidative stress and inhibited by deferiprone, an iron chelator. Exposure of Gd-NPs to 177Lu increased the Auger electron yield but not the absorbed dose. Conclusion: Targeted radionuclide therapy can be combined with Gd-NPs to increase the therapeutic effect and reduce the injected activities. As Gd-NPs are already used in the clinic, this combination could be a new therapeutic approach for patients with ovarian peritoneal carcinomatosis.
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Affiliation(s)
- Clara Diaz Garcia-Prada
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Léna Carmes
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
- NH TherAguix S.A., Meylan, France
| | - Salima Atis
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Ali Parach
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Alejandro Bertolet
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Marta Jarlier
- Biometrics Unit, Montpellier Cancer Institute, University of Montpellier, Montpellier, France; and
| | - Sophie Poty
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Daniel Suarez Garcia
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Wook-Geun Shin
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Stanislas Du Manoir
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Olivier Tillement
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - François Lux
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
- Institut Universitaire de France, Paris, France
| | - Julie Constanzo
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France;
| | - Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France;
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Dellepiane G, Casolaro P, Favaretto C, Gottstein A, Grundler PV, Mateu I, Renaldin E, Scampoli P, Talip Z, van der Meulen NP, Braccini S. Cross-section measurement of thulium radioisotopes with an 18 MeV medical PET cyclotron for an optimized 165Er production. Appl Radiat Isot 2023; 200:110954. [PMID: 37527621 DOI: 10.1016/j.apradiso.2023.110954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023]
Abstract
165Er is a pure Auger-electron emitter with promising characteristics for therapeutic applications in nuclear medicine. The short penetration path and high Linear Energy Transfer (LET) of the emitted Auger electrons make 165Er particularly suitable for treating small tumor metastases. Several production methods based on the irradiation with charged particles of Er and Ho targets can be found in the literature. In this paper, we report on the study of 165Er indirect production performed via the 166Er(p,2n)165Tm →165Er reaction at the 18 MeV Bern medical cyclotron. Despite the use of highly enriched 166Er2O3 targets, several Tm radioisotopes are produced during the irradiation, making the knowledge of the cross sections involved crucial. For this reason, a precise investigation of the cross sections of the relevant nuclear reactions in the energy range of interest was performed by irradiating Er2O3 targets with different isotopic enrichment levels and using a method based on the inversion of a linear system of equations. For the reactions 164Er(p, γ)165Tm, 166Er(p,n)166Tm, 166Er(p, γ)167Tm, 167Er(p,3n)165Tm, 167Er(p, γ)168Tm, 168Er(p,2n)167Tm and 170Er(p,3n)168Tm, the nuclear cross section was measured for the first time. From the results obtained, the production yield and purity of the parent radioisotope 165Tm were calculated to assess the optimal irradiation conditions. Several production tests with solid targets were performed to confirm these findings.
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Affiliation(s)
- Gaia Dellepiane
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
| | - Pierluigi Casolaro
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland
| | - Chiara Favaretto
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland; Division of Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland
| | - Alexander Gottstein
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland
| | - Pascal V Grundler
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Isidre Mateu
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland
| | - Edoardo Renaldin
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Paola Scampoli
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland; Department of Physics "Ettore Pancini", University of Napoli Federico II, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy
| | - Zeynep Talip
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland; Laboratory of Radiochemistry, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Saverio Braccini
- Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland
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Karam J, Constanzo J, Pichard A, Gros L, Chopineau J, Morille M, Pouget JP. Rapid communication: insights into the role of extracellular vesicles during Auger radioimmunotherapy. Int J Radiat Biol 2023; 99:109-118. [PMID: 34270378 DOI: 10.1080/09553002.2021.1955999] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE Non-targeted effects, including bystander and systemic effects, play a crucial role during Auger targeted radionuclide therapy. Here, we investigated whether small extracellular vesicles (sEVs) produced by irradiated cells could contribute to the bystander cytotoxic effects in vitro and also to therapeutic efficacy in vivo, after their injection in tumor xenografts. MATERIALS AND METHODS B16F10 melanoma donor cells were exposed to radiolabeled antibodies (Auger radioimmunotherapy, RIT) for 48 h or to X-rays (donor cells). Then, donor cells were incubated with fresh medium for 2 h to prepare conditioned medium (CM) that was transferred onto recipient cells for bystander effect assessment, or used for sEVs enrichment. Resulting sEVs were incubated in vitro with recipient cells for determining bystander cytotoxicity, or injected in B16F10 melanoma tumors harbored by athymic and C57BL/6 mice. RESULTS In vitro analysis of bystander cytotoxic effects showed that CM killed about 30-40% of melanoma cells. SEVs isolated from CM contributed to this effect. Moreover, the double-stranded DNA (dsDNA) content was increased in sEVs isolated from CM of exposed cells compared to control (not exposed), but the difference was significant only for the X-ray condition. These results were supported by immunodetection of cytosolic dsDNA in donor cells, a phenomenon that should precede dsDNA enrichment in sEVs. However, sEVs cytotoxicity could not be detected in vivo. Indeed, in athymic and in immunocompetent mice that received four intratumoral injections of sEVs (1/day), tumor growth was not delayed compared with untreated controls. Tumor growth was slightly (not significantly) delayed in immunocompetent mice treated with sEVs from X-ray-exposed cells, and significantly with sEVs purified from CM collected after 48 h of incubation. These results highlight the need to determine the optimal conditions, including radiation absorbed dose and sEVs collection time, to obtain the strongest cytotoxic effects. CONCLUSIONS This study demonstrates that sEVs could play a role during Auger RIT through bystander effects in vitro. No systemic effects were observed in vivo, under our experimental conditions. However, X-rays experiments showed that sEVs collection time might be influencing the nature of sEVs, a parameter that should also be investigated during Auger RIT.
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Affiliation(s)
- Jihad Karam
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, Montpellier, France
| | - Julie Constanzo
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, Montpellier, France
| | - Alexandre Pichard
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, Montpellier, France
| | - Laurent Gros
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, Montpellier, France
| | - Joël Chopineau
- ICGM, ENSCM, CNRS, Université de Montpellier, Montpellier, France
| | - Marie Morille
- ICGM, ENSCM, CNRS, Université de Montpellier, Montpellier, France
| | - Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, Montpellier, France
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Cai Z, Al-Saden N, Georgiou CJ, Reilly RM. Cellular dosimetry of 197Hg, 197mHg and 111In: comparison of dose deposition and identification of the cell and nuclear membrane as important targets. Int J Radiat Biol 2023; 99:53-63. [PMID: 33179984 DOI: 10.1080/09553002.2020.1849850] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE To examine the reliability to model cellular S-values for the Auger electron (AE) emitters, 111In, 197Hg and 197mHg with MCNP6 and their relative dose deposition in subcellular targets. METHODS A model cell was defined as four concentric spheres consisting of the nucleus (N), cytoplasm (Cy), cell and nuclear membranes (CM, NM) in which radionuclides distributed homogeneously. The transport of AE, conversion electrons and photons were simulated by MCNP6 to calculate cellular S values (SN←CM, SN←Cy, SN←NM, SN←N, SCM←CM, SNM←NM). SN←CM, SN←Cy and SN←N were also calculated with MIRDcell. RESULTS MIRDcell and MCNP6-calculated SN←N were in excellent agreement, but a slight discrepancy on SN←Cy and SN←CM was observed. The ratios of SCM←CM or SNM←NM vs. SN←N were 9.7-51.0 or 10.5-37.4, 7.9-41.8 or 8.4-31.8 and 7.2-36.9 or 8.0-28.1 for 111In, 197Hg, 197mHg, respectively. The mean S(197Hg)/S(111In) and S(197mHg)/S(111In) were 2.5 ± 0.5 and 2.5 ± 0.6, respectively. CONCLUSIONS Cellular S-values were reliably calculated with MCNP6. 197Hg and 197mHg deposit two-fold more doses than 111In at the subcellular scale. All AE emitters deposit a higher self-dose in the CM and NM than in the N, which warrants studies on the effects of targeting the CM and NM by AE emitters.
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Affiliation(s)
- Zhongli Cai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada
| | - Noor Al-Saden
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada
| | | | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada.,Department of Medical Imaging, University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre and Joint Department of Medical Imaging, University Health Network, Toronto, Canada
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Abstract
The application of radiopharmaceutical therapy for the treatment of certain diseases is well established, and the field is expanding. New therapeutic radiopharmaceuticals have been developed in recent years, and more are in the research pipeline. Concurrently, there is growing interest in the use of internal dosimetry as a means of personalizing, and potentially optimizing, such therapy for patients. Internal dosimetry is multifaceted, and the current state of the art is discussed in this continuing education article. Topics include the context of dosimetry, internal dosimetry methods, the advantages and disadvantages of incorporating dosimetry calculations in radiopharmaceutical therapy, a description of the workflow for implementing patient-specific dosimetry, and future prospects in the field.
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Affiliation(s)
- Joe O'Donoghue
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Pat Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - John Humm
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Adam Kesner
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
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8
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Dawry FP, Serafini AN. Proposal on the use of Xenon-133 against COVID-19. Radiat Phys Chem Oxf Engl 1993 2021; 191:109839. [PMID: 34690452 PMCID: PMC8527351 DOI: 10.1016/j.radphyschem.2021.109839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/05/2021] [Accepted: 10/18/2021] [Indexed: 10/27/2022]
Abstract
Since we are able to bring ionizing radiation in the form of a gas cloud to the respiratory system, we have wondered whether Xenon-133 inhalation could be exploited as a treatment option against Covid-19 respiratory virus infections, and urge colleagues in the scientific research community who have the capability to do so to explore the merits of using Xenon-133 in this way to determine whether its usefulness against the Covid-19 virus is indeed genuine.
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Affiliation(s)
- Frank P Dawry
- Miller School of Medicine, University of Miami, Florida, USA
| | - Aldo N Serafini
- Miller School of Medicine, University of Miami, Florida, USA
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Heinke R, Chevallay E, Chrysalidis K, Cocolios TE, Duchemin C, Fedosseev VN, Hurier S, Lambert L, Leenders B, Marsh BA, van der Meulen NP, Sprung P, Stora T, Tosato M, Wilkins SG, Zhang H, Talip Z. Efficient Production of High Specific Activity Thulium-167 at Paul Scherrer Institute and CERN-MEDICIS. Front Med (Lausanne) 2021; 8:712374. [PMID: 34712674 PMCID: PMC8546370 DOI: 10.3389/fmed.2021.712374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/14/2021] [Indexed: 11/13/2022] Open
Abstract
Thulium-167 is a promising radionuclide for nuclear medicine applications with potential use for both diagnosis and therapy ("theragnostics") in disseminated tumor cells and small metastases, due to suitable gamma-line as well as conversion/Auger electron energies. However, adequate delivery methods are yet to be developed and accompanying radiobiological effects to be investigated, demanding the availability of 167Tm in appropriate activities and quality. We report herein on the production of radionuclidically pure 167Tm from proton-irradiated natural erbium oxide targets at a cyclotron and subsequent ion beam mass separation at the CERN-MEDICIS facility, with a particular focus on the process efficiency. Development of the mass separation process with studies on stable 169Tm yielded 65 and 60% for pure and erbium-excess samples. An enhancement factor of thulium ion beam over that of erbium of up to several 104 was shown by utilizing laser resonance ionization and exploiting differences in their vapor pressures. Three 167Tm samples produced at the IP2 irradiation station, receiving 22.8 MeV protons from Injector II at Paul Scherrer Institute (PSI), were mass separated with collected radionuclide efficiencies between 11 and 20%. Ion beam sputtering from the collection foils was identified as a limiting factor. In-situ gamma-measurements showed that up to 45% separation efficiency could be fully collected if these limits are overcome. Comparative analyses show possible neighboring mass suppression factors of more than 1,000, and overall 167Tm/Er purity increase in the same range. Both the actual achieved collection and separation efficiencies present the highest values for the mass separation of external radionuclide sources at MEDICIS to date.
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Affiliation(s)
- Reinhard Heinke
- Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | - Eric Chevallay
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | | | | | - Charlotte Duchemin
- Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | | | - Sophie Hurier
- Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium
- Belgian Nuclear Research Centre SCK CEN, Mol, Belgium
| | - Laura Lambert
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | - Benji Leenders
- Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium
- Belgian Nuclear Research Centre SCK CEN, Mol, Belgium
- Department of Electromechanical, Systems and Metal Engineering, Ghent University, Ghent, Belgium
| | - Bruce A. Marsh
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | - Nicholas P. van der Meulen
- Laboratory of Radiochemistry, Paul Scherrer Institute, Villigen, Switzerland
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen, Switzerland
| | - Peter Sprung
- Analytic Radioactive Materials, Paul Scherrer Institute, Villigen, Switzerland
| | - Thierry Stora
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | - Marianna Tosato
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen, Switzerland
| | - Shane G. Wilkins
- European Organization for Nuclear Research CERN, Geneva, Switzerland
| | - Hui Zhang
- Division Large Research Facilities, Paul Scherrer Institute, Villigen, Switzerland
| | - Zeynep Talip
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen, Switzerland
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10
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Borgna F, Haller S, Rodriguez JMM, Ginj M, Grundler PV, Zeevaart JR, Köster U, Schibli R, van der Meulen NP, Müller C. Combination of terbium-161 with somatostatin receptor antagonists-a potential paradigm shift for the treatment of neuroendocrine neoplasms. Eur J Nucl Med Mol Imaging 2021; 49:1113-1126. [PMID: 34625828 PMCID: PMC8921065 DOI: 10.1007/s00259-021-05564-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/09/2021] [Indexed: 12/17/2022]
Abstract
PURPOSE The β¯-emitting terbium-161 also emits conversion and Auger electrons, which are believed to be effective in killing single cancer cells. Terbium-161 was applied with somatostatin receptor (SSTR) agonists that localize in the cytoplasm (DOTATOC) and cellular nucleus (DOTATOC-NLS) or with a SSTR antagonist that localizes at the cell membrane (DOTA-LM3). The aim was to identify the most favorable peptide/terbium-161 combination for the treatment of neuroendocrine neoplasms (NENs). METHODS The capability of the 161Tb- and 177Lu-labeled somatostatin (SST) analogues to reduce viability and survival of SSTR-positive AR42J tumor cells was investigated in vitro. The radiopeptides' tissue distribution profiles were assessed in tumor-bearing mice. The efficacy of terbium-161 compared to lutetium-177 was investigated in therapy studies in mice using DOTATOC or DOTA-LM3, respectively. RESULTS In vitro, [161Tb]Tb-DOTA-LM3 was 102-fold more potent than [177Lu]Lu-DOTA-LM3; however, 161Tb-labeled DOTATOC and DOTATOC-NLS were only 4- to fivefold more effective inhibiting tumor cell viability than their 177Lu-labeled counterparts. This result was confirmed in vivo and demonstrated that [161Tb]Tb-DOTA-LM3 was significantly more effective in delaying tumor growth than [177Lu]Lu-DOTA-LM3, thereby, prolonging survival of the mice. A therapeutic advantage of terbium-161 over lutetium-177 was also manifest when applied with DOTATOC. Since the nuclear localizing sequence (NLS) compromised the in vivo tissue distribution of DOTATOC-NLS, it was not used for therapy. CONCLUSION The use of membrane-localizing DOTA-LM3 was beneficial and profited from the short-ranged electrons emitted by terbium-161. Based on these preclinical data, [161Tb]Tb-DOTA-LM3 may outperform the clinically employed [177Lu]Lu-DOTATOC for the treatment of patients with NENs.
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Affiliation(s)
- Francesca Borgna
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Stephanie Haller
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Josep M Monné Rodriguez
- Laboratory for Animal Model Pathology, Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland
| | - Mihaela Ginj
- The Joint Department of Medical Imaging, University Health Network, 200 Elizabeth St, Toronto, ON, M5G 2C4, Canada
| | - Pascal V Grundler
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Jan Rijn Zeevaart
- South African Nuclear Energy Corporation (Necsa), Pelindaba, Brits, 0240, South Africa
| | - Ulli Köster
- Institut Laue-Langevin, 38042, Grenoble, France
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.,Laboratory of Radiochemistry, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland. .,Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
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11
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Bavelaar BM, Song L, Jackson MR, Able S, Tietz O, Skaripa-Koukelli I, Waghorn PA, Gill MR, Carlisle RC, Tarsounas M, Vallis KA. Oligonucleotide-Functionalized Gold Nanoparticles for Synchronous Telomerase Inhibition, Radiosensitization, and Delivery of Theranostic Radionuclides. Mol Pharm 2021; 18:3820-3831. [PMID: 34449222 PMCID: PMC8493550 DOI: 10.1021/acs.molpharmaceut.1c00442] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/07/2021] [Accepted: 08/11/2021] [Indexed: 12/13/2022]
Abstract
Telomerase represents an attractive target in oncology as it is expressed in cancer but not in normal tissues. The oligonucleotide inhibitors of telomerase represent a promising anticancer strategy, although poor cellular uptake can restrict their efficacy. In this study, gold nanoparticles (AuNPs) were used to enhance oligonucleotide uptake. "match" oligonucleotides complementary to the telomerase RNA template subunit (hTR) and "scramble" (control) oligonucleotides were conjugated to diethylenetriamine pentaacetate (DTPA) for 111In-labeling. AuNPs (15.5 nm) were decorated with a monofunctional layer of oligonucleotides (ON-AuNP) or a multifunctional layer of oligonucleotides, PEG(polethylene glycol)800-SH (to reduce AuNP aggregation) and the cell-penetrating peptide Tat (ON-AuNP-Tat). Match-AuNP enhanced the cellular uptake of radiolabeled oligonucleotides while retaining the ability to inhibit telomerase activity. The addition of Tat to AuNPs increased nuclear localization. 111In-Match-AuNP-Tat induced DNA double-strand breaks and caused a dose-dependent reduction in clonogenic survival of telomerase-positive cells but not telomerase-negative cells. hTR inhibition has been reported to sensitize cancer cells to ionizing radiation, and 111In-Match-AuNP-Tat therefore holds promise as a vector for delivery of radionuclides into cancer cells while simultaneously sensitizing them to the effects of the emitted radiation.
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Affiliation(s)
- Bas M. Bavelaar
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Lei Song
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Mark R. Jackson
- Institute
of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, University Avenue, Glasgow G12 8QQ, U.K.
| | - Sarah Able
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Ole Tietz
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Irini Skaripa-Koukelli
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Philip A. Waghorn
- Charles
River Laboratories, Elphinstone Research Centre, Elphinstone, Tranent EH33 2NE, U.K.
| | - Martin R. Gill
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Robert C. Carlisle
- Institute
of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, U.K.
| | - Madalena Tarsounas
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Katherine A. Vallis
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
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12
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Verger E, Cheng J, de Santis V, Iafrate M, Jackson JA, Imberti C, Fruhwirth GO, Blower PJ, Ma MT, Burnham DR, Terry SYA. Validation of the plasmid study to relate DNA damaging effects of radionuclides to those from external beam radiotherapy. Nucl Med Biol 2021; 100-101:36-43. [PMID: 34153932 PMCID: PMC7611685 DOI: 10.1016/j.nucmedbio.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/31/2021] [Accepted: 06/10/2021] [Indexed: 12/29/2022]
Abstract
INTRODUCTION The biological consequences of absorbed radiation doses are ill-defined for radiopharmaceuticals, unlike for external beam radiotherapy (EBRT). A reliable assay that assesses the biological consequences of any radionuclide is much needed. Here, we evaluated the cell-free plasmid DNA assay to determine the relative biological effects of radionuclides such as Auger electron-emitting [67Ga]GaCl3 or [111In]InCl3 compared to EBRT. METHODS Supercoiled pBR322 plasmid DNA (1.25 or 5 ng/μL) was incubated with 0.5 or 1 MBq [67Ga]GaCl3 or [111In]InCl3 for up to 73 h or was exposed to EBRT (137Cs; 5 Gy/min; 0-40 Gy). The induction of relaxed and linear plasmid DNA, representing single and double strand breaks, respectively, was assessed by gel electrophoresis. Chelated forms of 67Ga were also investigated using DOTA and THP. Topological conversion rates for supercoiled-to-relaxed (ksrx) or relaxed-to-linear (krlx) DNA were obtained by fitting a kinetic model. RESULTS DNA damage increased both with EBRT dose and incubation time for [67Ga]GaCl3 and [111In]InCl3. Damage caused by [67Ga]GaCl3 decreased when chelated. [67Ga]GaCl3 proved more damaging than [111In]InCl3; 1.25 ng/μL DNA incubated with 0.5 MBq [67Ga]GaCl3 for 2 h led to a 70% decrease of intact plasmid DNA as opposed to only a 19% decrease for [111In]InCl3. For both EBRT and radionuclides, conversion rates were slower for 5 ng/μL than 1.25 ng/μL plasmid DNA. DNA damage caused by 1 Gy EBRT was the equivalent to damage caused by 0.5 MBq unchelated [67Ga]GaCl3 and [111In]InCl3 after 2.05 ± 0.36 and 9.3 ± 0.77 h of incubation, respectively. CONCLUSIONS This work has highlighted the power of the plasmid DNA assay for a rapid determination of the relative biological effects of radionuclides compared to external beam radiotherapy. It is envisaged this approach will enable the systematic assessment of imaging and therapeutic radionuclides, including Auger electron-emitters, to further inform radiopharmaceutical design and application.
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Affiliation(s)
- Elise Verger
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jordan Cheng
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Vittorio de Santis
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Madeleine Iafrate
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jessica A Jackson
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Cinzia Imberti
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Gilbert O Fruhwirth
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom; Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, Guy's Hospital Campus, London SE1 1UL, United Kingdom
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Daniel R Burnham
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
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13
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Osytek KM, Blower PJ, Costa IM, Smith GE, Abbate V, Terry SYA. In vitro proof of concept studies of radiotoxicity from Auger electron-emitter thallium-201. EJNMMI Res 2021; 11:63. [PMID: 34224019 PMCID: PMC8257813 DOI: 10.1186/s13550-021-00802-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/03/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Auger electron-emitting radionuclides have potential in targeted treatment of small tumors. Thallium-201 (201Tl), a gamma-emitting radionuclide used in myocardial perfusion scintigraphy, decays by electron capture, releasing around 37 Auger and Coster-Kronig electrons per decay. However, its therapeutic and toxic effects in cancer cells remain largely unexplored. Here, we assess 201Tl in vitro kinetics, radiotoxicity and potential for targeted molecular radionuclide therapy, and aim to test the hypothesis that 201Tl is radiotoxic only when internalized. METHODS Breast cancer MDA-MB-231 and prostate cancer DU145 cells were incubated with 200-8000 kBq/mL [201Tl]TlCl. Potassium concentration varied between 0 and 25 mM to modulate cellular uptake of 201Tl. Cell uptake and efflux rates of 201Tl were measured by gamma counting. Clonogenic assays were used to assess cell survival after 90 min incubation with 201Tl. Nuclear DNA damage was measured with γH2AX fluorescence imaging. Controls included untreated cells and cells treated with decayed [201Tl]TlCl. RESULTS 201Tl uptake in both cell lines reached equilibrium within 90 min and washed out exponentially (t1/2 15 min) after the radioactive medium was exchanged for fresh medium. Cellular uptake of 201Tl in DU145 cells ranged between 1.6 (25 mM potassium) and 25.9% (0 mM potassium). Colony formation by both cell lines decreased significantly as 201Tl activity in cells increased, whereas 201Tl excluded from cells by use of high potassium buffer caused no significant toxicity. Non-radioactive TlCl at comparable concentrations caused no toxicity. An estimated average 201Tl intracellular activity of 0.29 Bq/cell (DU145 cells) and 0.18 Bq/cell (MDA-MB-231 cells) during 90 min exposure time caused 90% reduction in clonogenicity. 201Tl at these levels caused on average 3.5-4.6 times more DNA damage per nucleus than control treatments. CONCLUSIONS 201Tl reduces clonogenic survival and increases nuclear DNA damage only when internalized. These findings justify further development and evaluation of 201Tl therapeutic radiopharmaceuticals.
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Affiliation(s)
- Katarzyna M Osytek
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Ines M Costa
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Gareth E Smith
- Theragnostics Limited, 2 Arlington Square, Bracknell, RG12 1WA, UK
| | - Vincenzo Abbate
- Department of Analytical, Environmental and Forensic Sciences, King's College London, London, UK.
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
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Idrissou MB, Pichard A, Tee B, Kibedi T, Poty S, Pouget JP. Targeted Radionuclide Therapy Using Auger Electron Emitters: The Quest for the Right Vector and the Right Radionuclide. Pharmaceutics 2021; 13:pharmaceutics13070980. [PMID: 34209637 PMCID: PMC8309076 DOI: 10.3390/pharmaceutics13070980] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/20/2021] [Accepted: 06/24/2021] [Indexed: 12/25/2022] Open
Abstract
Auger electron emitters (AEEs) are attractive tools in targeted radionuclide therapy to specifically irradiate tumour cells while sparing healthy tissues. However, because of their short range, AEEs need to be brought close to sensitive targets, particularly nuclear DNA, and to a lower extent, cell membrane. Therefore, radioimmunoconjugates (RIC) have been developed for specific tumour cell targeting and transportation to the nucleus. Herein, we assessed, in A-431CEA-luc and SK-OV-31B9 cancer cells that express low and high levels of HER2 receptors, two 111In-RIC consisting of the anti-HER2 antibody trastuzumab conjugated to NLS or TAT peptides for nuclear delivery. We found that NLS and TAT peptides improved the nuclear uptake of 111In-trastuzumab conjugates, but this effect was limited and non-specific. Moreover, it did not result in a drastic decrease of clonogenic survival. Indium-111 also contributed to non-specific cytotoxicity in vitro due to conversion electrons (30% of the cell killing). Comparison with [125I]I-UdR showed that the energy released in the cell nucleus by increasing the RIC’s nuclear uptake or by choosing an AEE that releases more energy per decay should be 5 to 10 times higher to observe a significant therapeutic effect. Therefore, new Auger-based radiopharmaceuticals need to be developed.
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Affiliation(s)
- Malick Bio Idrissou
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, 34298 Montpellier, France; (M.B.I.); (A.P.); (S.P.)
| | - Alexandre Pichard
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, 34298 Montpellier, France; (M.B.I.); (A.P.); (S.P.)
| | - Bryan Tee
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia; (B.T.); (T.K.)
| | - Tibor Kibedi
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia; (B.T.); (T.K.)
| | - Sophie Poty
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, 34298 Montpellier, France; (M.B.I.); (A.P.); (S.P.)
| | - Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, 34298 Montpellier, France; (M.B.I.); (A.P.); (S.P.)
- Correspondence:
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15
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Rigby A, Blower JE, Blower PJ, Terry SY, Abbate V. Targeted Auger electron-emitter therapy: Radiochemical approaches for thallium-201 radiopharmaceuticals. Nucl Med Biol 2021; 98-99:1-7. [PMID: 33906122 PMCID: PMC7610824 DOI: 10.1016/j.nucmedbio.2021.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Thallium-201 is a radionuclide that has previously been used clinically for myocardial perfusion scintigraphy. Although in this role it has now been largely replaced by technetium-99 m radiopharmaceuticals, thallium-201 remains attractive in the context of molecular radionuclide therapy for cancer micrometastases or single circulating tumour cells. This is due to its Auger electron (AE) emissions, which are amongst the highest in total energy and number per decay for AE-emitters. Currently, chemical platforms to achieve this potential through developing thallium-201-labelled targeted radiopharmaceuticals are not available. Here, we describe convenient methods to oxidise [201Tl]Tl(I) to chelatable [201Tl]Tl(III) and identify challenges in stable chelation of thallium to support future synthesis of effective [201Tl]-labelled radiopharmaceuticals. METHODS A plasmid pBR322 assay was carried out to determine the DNA damaging properties of [201Tl]Tl(III). A range of oxidising agents (ozone, oxygen, hydrogen peroxide, chloramine-T, iodogen, iodobeads, trichloroisocyanuric acid) and conditions (acidity, temperature) were assessed using thin layer chromatography. Chelators EDTA, DTPA and DOTA were investigated for their [201Tl]Tl(III) radiolabelling efficacy and complex stability. RESULTS Isolated plasmid studies demonstrated that [201Tl]Tl(III) can induce single and double-stranded DNA breaks. Iodo-beads, iodogen and trichloroisocyanuric acid enabled more than 95% conversion from [201Tl]Tl(I) to [201Tl]Tl(III) under conditions compatible with future biomolecule radiolabelling (mild pH, room temperature and post-oxidation removal of oxidising agent). Although chelation of [201Tl]Tl(III) was possible with EDTA, DTPA and DOTA, only radiolabeled DOTA showed good stability in serum. CONCLUSIONS Decay of [201Tl]Tl(III) in proximity to DNA causes DNA damage. Iodobeads provide a simple, mild method to convert thallium-201 from a 1+ to 3+ oxidation state and [201Tl]Tl(III) can be chelated by DOTA with moderate stability. Of the well-established chelators evaluated, DOTA is most promising for future molecular radionuclide therapy using thallium-201; nevertheless, a new generation of chelating agents offering resistance to reduction and dissociation of [201Tl]Tl(III) complexes is required.
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Affiliation(s)
- Alex Rigby
- King’s College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Julia E. Blower
- King’s College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Philip J. Blower
- King’s College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Samantha Y.A. Terry
- King’s College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas’ Hospital, London SE1 7EH, United Kingdom,Corresponding authors. (S.Y.A. Terry), (V. Abbate)
| | - Vincenzo Abbate
- King’s College London, School of Population Health and Environmental Sciences, Analytical, Environmental and Forensic Sciences, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, United Kingdom,Corresponding authors. (S.Y.A. Terry), (V. Abbate)
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Madsen KL, Therkelsen ASN, Langkjær N, Olsen BB, Thisgaard H. Auger electron therapy of glioblastoma using [ 125I]5-iodo-2'-deoxyuridine and concomitant chemotherapy - Evaluation of a potential treatment strategy. Nucl Med Biol 2021; 96-97:35-40. [PMID: 33784592 DOI: 10.1016/j.nucmedbio.2021.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/15/2021] [Accepted: 03/07/2021] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Treatment of glioblastomas (GBM) using the Auger electron emitting compound [125I]5-Iodo-2'-deoxyuridine ([125I]I-UdR), combined with the thymidylate synthase inhibitor methotrexate (MTX) and concomitant chemotherapy with temozolomide (TMZ) has recently shown very promising therapeutic effects in vitro and in vivo in animals. The aim of the current study was to investigate if the therapeutic effects of this multimodal treatment strategy could be further increased by the thymidylate synthase inhibitor, 5-fluoro-2'-deoxyuridine (F-UdR), in comparison to MTX, and if the co-treatment should be given in a neoadjuvant or adjuvant setting. METHODS A patient-derived GBM cancer stem cell (CSC)-enriched cell line, grown as neurospheres, was employed to evaluate DNA-incorporation of [125I]I-UdR, determined by a DNA precipitation assay, using either pre-treatment or co-treatment with MTX or F-UdR. The therapeutic effects in the CSC-enriched cell line after exposure to various combinations of MTX, F-UdR, TMZ and [125I]I-UdR were also investigated by a CellTiter-Blue assay. RESULTS The highest general increase in [125I]I-UdR incorporation was observed with F-UdR co-treatment, which resulted in approx. 2.5-fold increase in the DNA-associated activity. Also the cell viability was significantly decreased when F-UdR was combined with [125I]I-UdR compared to [125I]I-UdR alone at all activity concentrations tested. MTX was redundant when combined with 400 and 500 Bq/ml [125I]I-UdR. TMZ was effective in combination with either [125I]I-UdR alone or with both thymidylate synthase inhibitors combined with 50-100 Bq/ml [125I]I-UdR. CONCLUSIONS Overall, our study revealed a higher incorporation and therapeutic effect of [125I]I-UdR when GBM cells were co-treated with F-UdR compared to MTX. The therapeutic effects were further increased when TMZ was combined with [125I]I-UdR in combination with the thymidylate synthase inhibitors. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE Auger electron therapy in combination with thymidylate synthase inhibition and concomitant chemotherapy has the potential to become a future therapeutic treatment option for patients with glioblastoma.
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Affiliation(s)
- Karina Lindbøg Madsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Anne Sofie Nautrup Therkelsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Niels Langkjær
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | - Birgitte Brinkmann Olsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Helge Thisgaard
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
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Poignant F, Monini C, Testa É, Beuve M. Influence of gold nanoparticles embedded in water on nanodosimetry for keV photon irradiation. Med Phys 2021; 48:1874-1883. [PMID: 33150620 DOI: 10.1002/mp.14576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/13/2020] [Accepted: 10/21/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE For the past two decades, high-Z nanoparticles have been of high interest to improve the therapeutic outcomes of radiation therapy, especially for low-energy x-rays. Monte Carlo (MC) simulations have been used to evaluate the boost of dose deposition induced by Auger electrons near the nanoparticle surface, by calculating average energy deposition at the nanoscale. In this study, we propose to go beyond average quantities and quantify the stochastic nature of energy deposition at such a scale. We present results of probability density of the specific energy (restricted to ionization, excitation and electron attachment events) in cylindrical nanotargets of height and radius set at 10 nm. This quantity was evaluated for nanotargets located within 200 nm around 5-50 nm gold nanoparticles (GNPs), for 20-90 keV photon irradiation. METHODS This nanodosimetry study was based on the MC simulation MDM that allows tracking of electrons down to thermalization energy. We introduced a new quantity, namely the probability enhancement ratio (PER), by estimating the probability of imparting to nanotargets a restricted specific energy larger than a threshold z 0 (1, 10, and 20 kGy), normalized to the probability for pure water. The PER was calculated as a function of the distance between the nanotarget and the GNP surface. The threshold values were chosen in light of the biophysical model NanOx that predicts cell survival by calculating local lethal events based on the restricted specific energy and an effective local lethal function. z 0 then represents a threshold above which the nanotarget damages induce efficiently cell death. RESULTS Our calculations showed that the PER varied a lot with the GNP radius, the photon energy, z 0 and the distance of the GNP to the nanotarget. The highest PER was 95 when the nanotarget was located at 5 nm from the GNP surface, for a photon energy of 20 keV, a threshold of 20 kGy, and a GNP radius of 50 nm. This enhancement dramatically decreased with increasing GNP-nanotarget distances as it went below 1.5 for distances larger than 200 nm. CONCLUSIONS The PER seems better adapted than the mean dose deposition to describe the formation of biological damages. The significant increase of the PER within 200 nm around the GNP suggests that severe damages could occur for biological nanotargets located near the GNP. These calculations will be used as an input of the biophysical model NanOx to convert PER into estimation of radiation-induced cell death enhanced by GNPs.
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Affiliation(s)
- Floriane Poignant
- Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, F-69622, Villeurbanne, France
| | - Caterina Monini
- Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, F-69622, Villeurbanne, France
| | - Étienne Testa
- Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, F-69622, Villeurbanne, France
| | - Michaël Beuve
- Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, F-69622, Villeurbanne, France
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18
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Baum RP, Singh A, Kulkarni HR, Bernhardt P, Rydén T, Schuchardt C, Gracheva N, Grundler PV, Köster U, Müller D, Pröhl M, Zeevaart JR, Schibli R, van der Meulen NP, Müller C. First-in-Humans Application of 161Tb: A Feasibility Study Using 161Tb-DOTATOC. J Nucl Med 2021; 62:1391-1397. [PMID: 33547209 DOI: 10.2967/jnumed.120.258376] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/19/2021] [Indexed: 12/16/2022] Open
Abstract
161Tb has decay properties similar to those of 177Lu but, additionally, emits a substantial number of conversion and Auger electrons. The aim of this study was to apply 161Tb in a clinical setting and to investigate the feasibility of visualizing the physiologic and tumor biodistributions of 161Tb-DOTATOC. Methods: 161Tb was shipped from Paul Scherrer Institute, Villigen-PSI, Switzerland, to Zentralklinik Bad Berka, Bad Berka, Germany, where it was used for the radiolabeling of DOTATOC. In 2 separate studies, 596 and 1,300 MBq of 161Tb-DOTATOC were administered to a 35-y-old male patient with a metastatic, well-differentiated, nonfunctional malignant paraganglioma and a 70-y-old male patient with a metastatic, functional neuroendocrine neoplasm of the pancreatic tail, respectively. Whole-body planar γ-scintigraphy images were acquired over a period of several days for dosimetry calculations. SPECT/CT images were reconstructed using a recently established protocol and visually analyzed. Patients were observed for adverse events after the application of 161Tb-DOTATOC. Results: The radiolabeling of DOTATOC with 161Tb was readily achieved with a high radiochemical purity suitable for patient application. Planar images and dosimetry provided the expected time-dependent biodistribution of 161Tb-DOTATOC in the liver, kidneys, spleen, and urinary bladder. SPECT/CT images were of high quality and visualized even small metastases in bones and liver. The application of 161Tb-DOTATOC was well tolerated, and no related adverse events were reported. Conclusion: This study demonstrated the feasibility of imaging even small metastases after the injection of relatively low activities of 161Tb-DOTATOC using γ-scintigraphy and SPECT/CT. On the basis of this essential first step in translating 161Tb to clinics, further efforts will be directed toward the application of 161Tb for therapeutic purposes.
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Affiliation(s)
- Richard P Baum
- Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany;
| | - Aviral Singh
- Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany.,GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Harshad R Kulkarni
- Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany
| | - Peter Bernhardt
- Department of Radiation Physics, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Medical Physics and Medical Bioengineering, Sahlgrenska University Hospital, Gothenburg, Gothenburg, Sweden
| | - Tobias Rydén
- Department of Radiation Physics, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Medical Physics and Medical Bioengineering, Sahlgrenska University Hospital, Gothenburg, Gothenburg, Sweden
| | - Christiane Schuchardt
- Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany
| | - Nadezda Gracheva
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Switzerland
| | - Pascal V Grundler
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Switzerland
| | | | - Dirk Müller
- Department of Radiopharmacy, Zentralklinik Bad Berka, Bad Berka, Germany
| | - Michael Pröhl
- Department of Radiopharmacy, Zentralklinik Bad Berka, Bad Berka, Germany
| | - Jan Rijn Zeevaart
- Radiochemistry, South African Nuclear Energy Corporation (Necsa), Pelindaba, South Africa
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland; and
| | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Switzerland.,Laboratory of Radiochemistry, Paul Scherrer Institute, Villigen-PSI, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Switzerland;
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Fiaccabrino DE, Kunz P, Radchenko V. Potential for production of medical radionuclides with on-line isotope separation at the ISAC facility at TRIUMF and particular discussion of the examples of 165Er and 155Tb. Nucl Med Biol 2021; 94-95:81-91. [PMID: 33607326 DOI: 10.1016/j.nucmedbio.2021.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/25/2020] [Accepted: 01/14/2021] [Indexed: 02/06/2023]
Abstract
Production of medical radionuclides with ISOL facilities is a unique production method that may provide access to preclinical quantities of some rare and potent radionuclides for nuclear medicine. Particularly attention over the past years was focused on several promising candidates for Targeted Radionuclides Therapy (TRT). With this review, we provide some perspectives of using the TRIUMF ISOL facility (ISAC) to produce medical radionuclides for TRT application and highlight our current effort to collect of 165Er and 155Tb for Auger Therapy and SPECT imaging, respectively.
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Affiliation(s)
- Desiree Erika Fiaccabrino
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada; Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Peter Kunz
- Accelerator Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
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20
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Tomasi M. Potassium Radioisotope 40 as Component of Mitochondria Physiology: Therapy Proposal for Mitochondrial Disfunction Diseases. Front Public Health 2020; 8:578392. [PMID: 33163472 PMCID: PMC7581862 DOI: 10.3389/fpubh.2020.578392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/24/2020] [Indexed: 11/21/2022] Open
Affiliation(s)
- Maurizio Tomasi
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
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21
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Howell RW. Advancements in the use of Auger electrons in science and medicine during the period 2015-2019. Int J Radiat Biol 2020; 99:2-27. [PMID: 33021416 PMCID: PMC8062591 DOI: 10.1080/09553002.2020.1831706] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/01/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023]
Abstract
Auger electrons can be highly radiotoxic when they are used to irradiate specific molecular sites. This has spurred basic science investigations of their radiobiological effects and clinical investigations of their potential for therapy. Focused symposia on the biophysical aspects of Auger processes have been held quadrennially. This 9th International Symposium on Physical, Molecular, Cellular, and Medical Aspects of Auger Processes at Oxford University brought together scientists from many different fields to review past findings, discuss the latest studies, and plot the future work to be done. This review article examines the research in this field that was published during the years 2015-2019 which corresponds to the period since the last meeting in Japan. In addition, this article points to future work yet to be done. There have been a plethora of advancements in our understanding of Auger processes. These advancements range from basic atomic and molecular physics to new ways to implement Auger electron emitters in radiopharmaceutical therapy. The highly localized doses of radiation that are deposited within a 10 nm of the decay site make them precision tools for discovery across the physical, chemical, biological, and medical sciences.
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Affiliation(s)
- Roger W Howell
- Division of Radiation Research, Department of Radiology, New Jersey Medical School, Rutgers University, Newark, NJ, USA
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22
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Bordes J, Incerti S, Mora-Ramirez E, Tranel J, Rossi C, Bezombes C, Bordenave J, Bardiès M, Brown R, Bordage MC. Monte Carlo dosimetry of a realistic multicellular model of follicular lymphoma in a context of radioimmunotherapy. Med Phys 2020; 47:5222-5234. [PMID: 32623743 DOI: 10.1002/mp.14370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/20/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Small-scale dosimetry studies generally consider an artificial environment where the tumors are spherical and the radionuclides are homogeneously biodistributed. However, tumor shapes are irregular and radiopharmaceutical biodistributions are heterogeneous, impacting the energy deposition in targeted radionuclide therapy. To bring realism, we developed a dosimetric methodology based on a three-dimensional in vitro model of follicular lymphoma incubated with rituximab, an anti-CD20 monoclonal antibody used in the treatment of non-Hodgkin lymphomas, which might be combined with a radionuclide. The effects of the realistic geometry and biodistribution on the absorbed dose were highlighted by comparison with literature data. Additionally, to illustrate the possibilities of this methodology, the effect of different radionuclides on the absorbed dose distribution delivered to the in vitro tumor were compared. METHODS The starting point was a model named multicellular aggregates of lymphoma cells (MALC). Three MALCs of different dimensions and their rituximab biodistribution were considered. Geometry, antibody location and concentration were extracted from selective plane illumination microscopy. Assuming antibody radiolabeling with Auger electron (125 I and 111 In) and β- particle emitters (177 Lu, 131 I and 90 Y), we simulated energy deposition in MALCs using two Monte Carlo codes: Geant4-DNA with "CPA100" physics models for Auger electron emitters and Geant4 with "Livermore" physics models for β- particle emitters. RESULTS MALCs had ellipsoid-like shapes with major radii, r, of ~0.25, ~0.5 and ~1.3 mm. Rituximab was concentrated in the periphery of the MALCs. The absorbed doses delivered by 177 Lu, 131 I and 90 Y in MALCs were compared with literature data for spheres with two types of homogeneous biodistributions (on the surface or throughout the volume). Compared to the MALCs, the mean absorbed doses delivered in spheres with surface biodistributions were between 18% and 38% lower, while with volume biodistribution they were between 15% and 29% higher. Regarding the radionuclides comparison, the relationship between MALC dimensions, rituximab biodistribution and energy released per decay impacted the absorbed doses. Despite releasing less energy, 125 I delivered a greater absorbed dose per decay than 111 In in the r ~ 0.25 mm MALC (6.78·10-2 vs 6.26·10-2 µGy·Bq-1 ·s-1 ). Similarly, the absorbed doses per decay in the r ~ 0.5 mm MALC for 177 Lu (2.41·10-2 µGy·Bq-1 ·s-1 ) and 131 I (2.46·10-2 µGy·Bq-1 ·s-1 ) are higher than for 90 Y (1.98·10-2 µGy·Bq-1 ·s-1 ). Furthermore, radionuclides releasing more energy per decay delivered absorbed dose more uniformly through the MALCs. Finally, when considering the radiopharmaceutical effective half-life, due to the biological half-life of rituximab being best matched by the physical half-life of 177 Lu and 131 I compared to 90 Y, the first two radionuclides delivered higher absorbed doses. CONCLUSION In the simulated configurations, β- emitters delivered higher and more uniform absorbed dose than Auger electron emitters. When considering radiopharmaceutical half-lives, 177 Lu and 131 I delivered absorbed doses higher than 90 Y. In view of real irradiation of MALCs, such a work may be useful to select suited radionuclides and to help explain the biological effects.
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Affiliation(s)
- Julien Bordes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Sébastien Incerti
- Université de Bordeaux, CENBG, UMR 5797, Gradignan, F-33170, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, F-33170, France
| | - Erick Mora-Ramirez
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Escuela de Física, CICANUM, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Jonathan Tranel
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Cédric Rossi
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,CHU Dijon, Hématologie Clinique, Hôpital François Mitterand, Dijon, 21000, France
| | - Christine Bezombes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Julie Bordenave
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Manuel Bardiès
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Richard Brown
- Institute of Nuclear Medicine, University College London, 235 Euston Road, London, NW1 2BU, UK
| | - Marie-Claude Bordage
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
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23
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Othman MFB, Verger E, Costa I, Tanapirakgul M, Cooper MS, Imberti C, Lewington VJ, Blower PJ, Terry SYA. In vitro cytotoxicity of Auger electron-emitting [ 67Ga]Ga-trastuzumab. Nucl Med Biol 2019; 80-81:57-64. [PMID: 31889612 PMCID: PMC7099941 DOI: 10.1016/j.nucmedbio.2019.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 12/03/2019] [Accepted: 12/12/2019] [Indexed: 02/07/2023]
Abstract
Introduction Molecular radiotherapy exploiting short-range Auger electron-emitting radionuclides has potential for targeted cancer treatment and, in particular, is an attractive option for managing micrometastatic disease. Here, an approach using chelator-trastuzumab conjugates to target radioactivity to breast cancer cells was evaluated as a proof-of-concept to assess the suitability of 67Ga as a therapeutic radionuclide. Methods THP-trastuzumab and DOTA-trastuzumab were synthesised and radiolabelled with Auger electron-emitters 67Ga and 111In, respectively. Radiopharmaceuticals were tested for HER2-specific binding and internalisation, and their effects on viability (dye exclusion) and clonogenicity of HER2-positive HCC1954 and HER2–negative MDA-MB-231 cell lines was measured. Labelled cell populations were studied by microautoradiography. Results Labelling efficiencies for [67Ga]Ga-THP-trastuzumab and [111In]In-DOTA-trastuzumab were 90% and 98%, respectively, giving specific activities 0.52 ± 0.16 and 0.61 ± 0.11 MBq/μg (78–92 GBq/μmol). At 4 nM total antibody concentration and 200 × 103 cells/mL, [67Ga]Ga-THP-trastuzumab showed higher percentage of cell association (10.7 ± 1.3%) than [111In]In-DOTA-trastuzumab (6.2 ± 1.6%; p = 0.01). The proportion of bound activity that was internalised did not differ significantly for the two tracers (62.1 ± 1.4% and 60.8 ± 15.5%, respectively). At 100 nM, percentage cell binding of both radiopharmaceuticals was greatly reduced compared to 4 nM and did not differ significantly between the two (1.2 ± 1.0% [67Ga]Ga-THP-trastuzumab and 0.8 ± 0.9% for [111In]In-DOTA-trastuzumab). Viability and clonogenicity of HER2-positive cells decreased when each radionuclide was incorporated into cells by conjugation with trastuzumab, but not when the same level of radioactivity was confined to the medium by omitting the antibody conjugation, suggesting that 67Ga needs to be cell-bound or internalised for a therapeutic effect. Microautoradiography showed that radioactivity bound to individual cells varied considerably within the population. Conclusions [67Ga]Ga-THP-trastuzumab reduced cell viability and clonogenicity only when cell-bound, suggesting 67Ga holds promise as a therapeutic radionuclide as part of a targeted radiopharmaceutical. The causes and consequences of non-homogeneous uptake among the cell population should be explored.
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Affiliation(s)
- Muhamad Faiz Bin Othman
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Elise Verger
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Ines Costa
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Meena Tanapirakgul
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Margaret S Cooper
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Cinzia Imberti
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Valerie J Lewington
- Guy's & St Thomas' NHS Foundation Trust, Kings College London, London SE1 9RT, UK
| | - Philip J Blower
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Samantha Y A Terry
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, London, SE1 7EH, United Kingdom.
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Chan C, Fonge H, Lam K, Reilly RM. Effectiveness and normal tissue toxicity of Auger electron (AE) radioimmunotherapy (RIT) with [ 111In]In-Bn-DTPA-nimotuzumab in mice with triple-negative or trastuzumab-resistant human breast cancer xenografts that overexpress EGFR. Nucl Med Biol 2019; 80-81:37-44. [PMID: 31706737 DOI: 10.1016/j.nucmedbio.2019.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/21/2019] [Accepted: 10/03/2019] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Our objective was to evaluate the effectiveness and normal tissue toxicity of nimotuzumab labeled with the Auger electron (AE)-emitter, 111In ([111In]In-Bn-DTPA-nimotuzumab) for radioimmunotherapy (RIT) of human triple-negative breast cancer (TNBC) or trastuzumab-resistant HER2-positive BC tumors overexpressing epidermal growth factor receptors (EGFR) in athymic mice. METHODS Normal tissue toxicity was studied in non-tumor-bearing Balb/c mice i.v. administered 9.0 or 28.6 MBq (3 mg/kg) of [111In]In-Bn-DTPA-nimotuzumab, unlabeled nimotuzumab (3 mg/kg) or normal saline. A complete blood cell count (CBC) and serum alanine aminotransferase (ALT) and creatinine (Cr) were measured at 14 days. Body weight was monitored. RIT studies were performed in CD-1 athymic mice engrafted s.c. with MDA-MB-468 human TNBC tumors or TrR1 HER2-positive but trastuzumab-resistant BC tumors. Mice were i.v. administered two amounts (15.5 MBq; 3 mg/kg) of [111In]In-Bn-DTPA-nimotuzumab separated by 14 days. Control mice received unlabeled Bn-DTPA-nimotuzumab (3 mg/kg) or anti-HER2 [111In]In-Bn-DTPA-trastuzumab or normal saline. Tumor growth and body weight were measured for 6 weeks. A tumor growth index (TGI) and body weight index (BWI) were calculated to compare the tumor size and body weight post-treatment with the pre-treatment values. A tumor doubling ratio (TDR) was calculated for each treatment group compared to control mice receiving normal saline. RESULTS There was no loss of body weight or decreased red blood cells (RBC) or platelets (PLT) or increased serum ALT or Cr in Balb/c mice administered 9.0 or 28.6 MBq (3 mg/kg) of [111In]In-Bn-DTPA-nimotuzumab compared to mice treated with unlabeled Bn-DTPA-nimotuzumab (3 mg/kg) or normal saline. There was a significant decrease in white blood cell (WBC) counts in Balb/c mice receiving 28.6 MBq but not 9.0 MBq of [111In]In-Bn-DTPA-nimotuzumab. Based on these results, an administered amount of 15.5 MBq (3 mg/kg) was selected for RIT studies. Administration of two amounts (15.5 MBq; 3 mg/kg) separated by 14 days to CD-1 athymic mice with s.c. MDA-MB-468 xenografts strongly inhibited tumor growth. The TDR for mice treated with [111In]In-Bn-DTPA-nimotuzumab was 2.15 compared to control mice receiving normal saline. In contrast, treatment with unlabeled Bn-DTPA-nimotuzumab or [111In]In-Bn-DTPA-trastuzumab had no significant effect on tumor growth (TDR = 0.96 and 1.08, respectively). RIT with [111In]In-Bn-DTPA-nimotuzumab also strongly inhibited the growth of TrR1 tumors in athymic mice (TDR = 2.13) compared to unlabeled Bn-DTPA-nimotuzumab (TDR = 0.91). There were no losses in body weight over 6 weeks in tumor bearing mice receiving [111In]In-Bn-DTPA-nimotuzumab, unlabeled Bn-DTPA-nimotuzumab, [111In]In-Bn-DTPA-trastuzumab or normal saline. CONCLUSIONS [111In]In-Bn-DTPA-nimotuzumab was effective for treatment of TNBC or trastuzumab-resistant HER2-positive human BC tumors in mice that overexpress EGFR at administered amounts that caused no decrease in body weight or normal tissue toxicity in non-tumor-bearing Balb/c mice. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE Our results suggest that Auger electron RIT with [111In]In-Bn-DTPA-nimotuzumab may provide a novel therapeutic option for patients with TNBC or trastuzumab-resistant HER2-positive BC that overexpresses EGFR. The low normal tissue toxicity of this approach may allow combination with other targeted therapies such as antibody-drug conjugates (ADCs).
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Affiliation(s)
- Conrad Chan
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Humphrey Fonge
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada; Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK, Canada
| | - Karen Lam
- Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada; Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
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25
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Abstract
Background Auger electrons (AEs) are very low energy electrons that are emitted by radionuclides that decay by electron capture (e.g. 111In, 67Ga, 99mTc, 195mPt, 125I and 123I). This energy is deposited over nanometre-micrometre distances, resulting in high linear energy transfer (LET) that is potent for causing lethal damage in cancer cells. Thus, AE-emitting radiotherapeutic agents have great potential for treatment of cancer. In this review, we describe the radiobiological properties of AEs, their radiation dosimetry, radiolabelling methods, and preclinical and clinical studies that have been performed to investigate AEs for cancer treatment. Results AEs are most lethal to cancer cells when emitted near the cell nucleus and especially when incorporated into DNA (e.g. 125I-IUdR). AEs cause DNA damage both directly and indirectly via water radiolysis. AEs can also kill targeted cancer cells by damaging the cell membrane, and kill non-targeted cells through a cross-dose or bystander effect. The radiation dosimetry of AEs considers both organ doses and cellular doses. The Medical Internal Radiation Dose (MIRD) schema may be applied. Radiolabelling methods for complexing AE-emitters to biomolecules (antibodies and peptides) and nanoparticles include radioiodination (125I and 123I) or radiometal chelation (111In, 67Ga, 99mTc). Cancer cells exposed in vitro to AE-emitting radiotherapeutic agents exhibit decreased clonogenic survival correlated at least in part with unrepaired DNA double-strand breaks (DSBs) detected by immunofluorescence for γH2AX, and chromosomal aberrations. Preclinical studies of AE-emitting radiotherapeutic agents have shown strong tumour growth inhibition in vivo in tumour xenograft mouse models. Minimal normal tissue toxicity was found due to the restricted toxicity of AEs mostly on tumour cells targeted by the radiotherapeutic agents. Clinical studies of AEs for cancer treatment have been limited but some encouraging results were obtained in early studies using 111In-DTPA-octreotide and 125I-IUdR, in which tumour remissions were achieved in several patients at administered amounts that caused low normal tissue toxicity, as well as promising improvements in the survival of glioblastoma patients with 125I-mAb 425, with minimal normal tissue toxicity. Conclusions Proof-of-principle for AE radiotherapy of cancer has been shown preclinically, and clinically in a limited number of studies. The recent introduction of many biologically-targeted therapies for cancer creates new opportunities to design novel AE-emitting agents for cancer treatment. Pierre Auger did not conceive of the application of AEs for targeted cancer treatment, but this is a tremendously exciting future that we and many other scientists in this field envision.
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Affiliation(s)
- Anthony Ku
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Valerie J Facca
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Zhongli Cai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada. .,Department of Medical Imaging, University of Toronto, Toronto, ON, Canada. .,Joint Department of Medical Imaging and Toronto General Research Institute, University Health Network, Toronto, ON, Canada. .,Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, ON, M5S 3M2, Canada.
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Müller C, Umbricht CA, Gracheva N, Tschan VJ, Pellegrini G, Bernhardt P, Zeevaart JR, Köster U, Schibli R, van der Meulen NP. Terbium-161 for PSMA-targeted radionuclide therapy of prostate cancer. Eur J Nucl Med Mol Imaging 2019; 46:1919-1930. [PMID: 31134301 PMCID: PMC6820371 DOI: 10.1007/s00259-019-04345-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/29/2019] [Indexed: 12/14/2022]
Abstract
Purpose The prostate-specific membrane antigen (PSMA) has emerged as an
interesting target for radionuclide therapy of metastasized castration-resistant
prostate cancer (mCRPC). The aim of this study was to investigate
161Tb (T1/2 = 6.89 days;
Eβ-uperscript>av = 154 keV) in
combination with PSMA-617 as a potentially more effective therapeutic alternative
to 177Lu-PSMA-617, due to the abundant co-emission of
conversion and Auger electrons, resulting in an improved absorbed dose
profile. Methods 161Tb was used for the radiolabeling of
PSMA-617 at high specific activities up to 100 MBq/nmol.
161Tb-PSMA-617 was tested in vitro and in
tumor-bearing mice to confirm equal properties, as previously determined for
177Lu-PSMA-617. The effects of
161Tb-PSMA-617 and
177Lu-PSMA-617 on cell viability (MTT assay) and
survival (clonogenic assay) were compared in vitro using PSMA-positive PC-3 PIP
tumor cells. 161Tb-PSMA-617 was further investigated in
therapy studies using PC-3 PIP tumor-bearing mice. Results 161Tb-PSMA-617 and
177Lu-PSMA-617 displayed equal in-vitro properties
and tissue distribution profiles in tumor-bearing mice. The viability and survival
of PC-3 PIP tumor cells were more reduced when exposed to
161Tb-PSMA-617 as compared to the effect obtained
with the same activities of 177Lu-PSMA-617 over the
whole investigated concentration range. Treatment of mice with
161Tb-PSMA-617 (5.0 MBq/mouse and 10 MBq/mouse,
respectively) resulted in an activity-dependent increase of the median survival
(36 vs 65 days) compared to untreated control animals (19 days). Therapy studies
to compare the effects of 161Tb-PSMA-617 and
177Lu-PSMA-617 indicated the anticipated superiority
of 161Tb over 177Lu. Conclusion 161Tb-PSMA-617 showed superior in-vitro
and in-vivo results as compared to 177Lu-PSMA-617,
confirming theoretical dose calculations that indicate an additive therapeutic
effect of conversion and Auger electrons in the case of
161Tb. These data warrant more preclinical research
for in-depth investigations of the proposed concept, and present a basis for
future clinical translation of 161Tb-PSMA-617 for the
treatment of mCRPC. Electronic supplementary material The online version of this article (10.1007/s00259-019-04345-0) contains supplementary material, which is available to authorized
users.
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Affiliation(s)
- Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland.
| | - Christoph A Umbricht
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Nadezda Gracheva
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Viviane J Tschan
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Giovanni Pellegrini
- Laboratory for Animal Model Pathology, Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland
| | - Peter Bernhardt
- Department of Radiation Physics, Institution of Clinical Science, Sahlgrenska Academy, University of Gothenburg, 413 45, Gothenburg, Sweden
| | - Jan Rijn Zeevaart
- Radiochemistry, South African Nuclear Energy Corporation (Necsa), Brits, 0240, South Africa
| | - Ulli Köster
- Institut Laue-Langevin, 38042, Grenoble, France
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Laboratory of Radiochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
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Abstract
For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.
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Grudzinski J, Marsh I, Titz B, Jeffery J, Longino M, Kozak K, Lange K, Larrabee J, Weichmann A, Moser A, Bednarz B. CLR 125 Auger Electrons for the Targeted Radiotherapy of Triple-Negative Breast Cancer. Cancer Biother Radiopharm 2018; 33:87-95. [PMID: 29641256 DOI: 10.1089/cbr.2017.2376] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Auger electrons emitted by radioisotopes such as 125I have a high linear energy transfer and short mean-free path in tissue (<10 μm), making them suitable for treating micrometastases while sparing normal tissues. The authors developed and subsequently investigated a cancer cell-selective small molecule phospholipid ether analog to deliver 125I to triple-negative breast cancer (TNBC) cells in vivo. METHODS A Current Good Manufacturing Practice (cGMP) method to radiolabel 125I-CLR1404 (CLR 125) with >95% radiochemical purity was established. To estimate CLR 125 in vivo dosimetry and identify dose-limiting organs, the biodistribution of the analog compound 124I-CLR1404 (CLR 124) was investigated using micro-positron emission tomography (PET)/computed tomography (CT) in conjunction with a Monte Carlo dosimetry platform to estimate CLR 125 dosimetry. In vivo antitumor efficacy was tested by injecting nude mice bearing either MDA-MB-231-luc orthotopic xenografts or lung metastases with 74 MBq (3.7 GBq/kg) of CLR 125 or an equivalent mass amount of nonradiolabeled CLR 125. Longitudinal tumor measurements using calipers and bioluminescence imaging were obtained for the xenografts and lung metastases, respectively. RESULTS Dosimetry analysis estimated that CLR 125 would impart the largest absorbed dose to the tumor per injected activity (0.261 ± 0.023 Gy/MBq) while the bone marrow, which is generally the dose-limiting organ for CLR1404, appears to have the lowest (0.063 ± 0.005 Gy/MBq). At administered activities of up to 74 MBq (3.7 GBq/kg), mice did not experience signs of toxicity. In addition, a single dose of CLR 125 reduced the volume of orthotopic primary TNBC xenografts by ∼60% compared to control vehicle (p < 0.001) and significantly extended survival. In addition, CLR 125 was efficacious against preclinical metastatic TNBC models by inhibiting the progression of micrometastases (p < 0.01). CONCLUSIONS Targeted radionuclide therapy with CLR 125 displayed significant antitumor efficacy in vivo, suggesting promise for treatment of TNBC micrometastases.
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Affiliation(s)
- Joseph Grudzinski
- 1 Department of Medical Physics, University of Wisconsin-Madison , Madison, Wisconsin
| | - Ian Marsh
- 1 Department of Medical Physics, University of Wisconsin-Madison , Madison, Wisconsin
| | | | - Justin Jeffery
- 3 University of Wisconsin Carbone Cancer Center , Madison, Wisconsin
| | - Marc Longino
- 2 Cellectar Biosciences, Inc. , Madison, Wisconsin
| | - Kevin Kozak
- 2 Cellectar Biosciences, Inc. , Madison, Wisconsin
| | | | | | - Ashley Weichmann
- 3 University of Wisconsin Carbone Cancer Center , Madison, Wisconsin
| | - Amy Moser
- 3 University of Wisconsin Carbone Cancer Center , Madison, Wisconsin.,4 Department of Human Oncology, University of Wisconsin-Madison , Madison, Wisconsin
| | - Bryan Bednarz
- 1 Department of Medical Physics, University of Wisconsin-Madison , Madison, Wisconsin.,3 University of Wisconsin Carbone Cancer Center , Madison, Wisconsin.,4 Department of Human Oncology, University of Wisconsin-Madison , Madison, Wisconsin
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Bari S, Egorov D, Jansen TLC, Boll R, Hoekstra R, Techert S, Zamudio‐Bayer V, Bülow C, Lindblad R, Leistner G, Ławicki A, Hirsch K, Miedema PS, von Issendorff B, Lau JT, Schlathölter T. Soft X-ray Spectroscopy as a Probe for Gas-Phase Protein Structure: Electron Impact Ionization from Within. Chemistry 2018; 24:7631-7636. [PMID: 29637635 PMCID: PMC6001477 DOI: 10.1002/chem.201801440] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/03/2018] [Indexed: 11/10/2022]
Abstract
Preservation of protein conformation upon transfer into the gas phase is key for structure determination of free single molecules, for example using X-ray free-electron lasers. In the gas phase, the helicity of melittin decreases strongly as the protein's protonation state increases. We demonstrate the sensitivity of soft X-ray spectroscopy to the gas-phase structure of melittin cations ([melittin+qH]q+ , q=2-4) in a cryogenic linear radiofrequency ion trap. With increasing helicity, we observe a decrease of the dominating carbon 1 s-π* transition in the amide C=O bonds for non-dissociative single ionization and an increase for non-dissociative double ionization. As the underlying mechanism we identify inelastic electron scattering. Using an independent atom model, we show that the more compact nature of the helical protein conformation substantially increases the probability for off-site intramolecular ionization by inelastic Auger electron scattering.
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Affiliation(s)
| | - Dmitrii Egorov
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Thomas L. C. Jansen
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | | | - Ronnie Hoekstra
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Simone Techert
- DESYNotkestr. 8522607HamburgGermany
- Institute of X-ray PhysicsUniversity of Göttingen37077GöttingenGermany
| | - Vicente Zamudio‐Bayer
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
- Physikalisches InstitutUniversität FreiburgHermann-Herder-Straße 379104FreiburgGermany
| | - Christine Bülow
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
- Institut für Optik und Atomare PhysikTechnische Universität Berlin10623BerlinGermany
| | - Rebecka Lindblad
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
- Department of PhysicsLund University22100LundSweden
| | - Georg Leistner
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
- Institut für Optik und Atomare PhysikTechnische Universität Berlin10623BerlinGermany
| | - Arkadiusz Ławicki
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
| | - Konstantin Hirsch
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
| | - Piter S. Miedema
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
| | - Bernd von Issendorff
- Physikalisches InstitutUniversität FreiburgHermann-Herder-Straße 379104FreiburgGermany
| | - J. Tobias Lau
- Institut für Methoden und Instrumentierung der Forschung mit, SynchrotronstrahlungHelmholtz Zentrum Berlin für Materialien und EnergieAlbert-Einstein-Str. 1512489BerlinGermany
- Physikalisches InstitutUniversität FreiburgHermann-Herder-Straße 379104FreiburgGermany
| | - Thomas Schlathölter
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
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Siragusa M, Fredericia PM, Jensen M, Groesser T. Radiobiological effects of tritiated water short-term exposure on V79 clonogenic cell survival. Int J Radiat Biol 2018; 94:157-165. [PMID: 29297716 DOI: 10.1080/09553002.2018.1419301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE We set out to improve the accuracy of absorbed dose calculations for in vitro measurements of the relative biological effectiveness (RBE) of tritiated water (HTO) for the clonogenic cell survival assay, also considering the influence of the end-of-track linear energy transfer (LET) of low-energy electrons. MATERIALS AND METHODS The COmputation Of Local Electron Release (COOLER) program was adopted to investigate the cell geometry and the tritium full beta-decay spectrum impact on the S-values and subsequently on the RBE of HTO for clonogenic cell survival at similar high dose rates (HDR). RESULTS S-values for cells growing in suspension are usually comparable to those for adherent cells. RBEs calculated at the 10% survival fraction through the use of the average energy are almost similar to those obtained with the beta-spectrum. For adherent cells, an RBE of 1.6 was found when HTO cell survival curves were compared to acute γ-ray exposures. Irrespective of the geometrical configuration, the RBE was 2.0 when the comparison was made with similar dose rates. CONCLUSIONS These results underline the importance of irradiating at equal dose rates and cell culture conditions when measuring in vitro RBE-values.
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Affiliation(s)
- Mattia Siragusa
- a The Hevesy Laboratory at DTU Nutech , Technical University of Denmark (DTU) , Copenhagen , Denmark
| | - Pil M Fredericia
- a The Hevesy Laboratory at DTU Nutech , Technical University of Denmark (DTU) , Copenhagen , Denmark
| | - Mikael Jensen
- a The Hevesy Laboratory at DTU Nutech , Technical University of Denmark (DTU) , Copenhagen , Denmark
| | - Torsten Groesser
- a The Hevesy Laboratory at DTU Nutech , Technical University of Denmark (DTU) , Copenhagen , Denmark
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Othman MFB, Mitry NR, Lewington VJ, Blower PJ, Terry SYA. Re-assessing gallium-67 as a therapeutic radionuclide. Nucl Med Biol 2017; 46:12-18. [PMID: 27915165 PMCID: PMC5303015 DOI: 10.1016/j.nucmedbio.2016.10.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/23/2016] [Accepted: 10/06/2016] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Despite its desirable half-life and low energy Auger electrons that travel further than for other radionuclides, 67Ga has been neglected as a therapeutic radionuclide. Here, 67Ga is compared with Auger electron emitter 111In as a potential therapeutic radionuclide. METHODS Plasmid pBR322 studies allowed direct comparison between 67Ga and 111In (1MBq) in causing DNA damage, including the effect of chelators (EDTA and DTPA) and the effects of a free radical scavenger (DMSO). The cytotoxicity of internalized (by means of delivery in the form of oxine complexes) and non-internalized 67Ga and 111In was measured in DU145 prostate cancer cells after a one-hour incubation using cell viability (trypan blue) and clonogenic studies. MDA-MB-231 and HCC1954 cells were also used. RESULTS Plasmid DNA damage was caused by 67Ga and was comparable to that caused by 111In; it was reduced in the presence of EDTA, DTPA and DMSO. The A50 values (internalized activity of oxine complexes per cell required to kill 50% of cells) as determined by trypan blue staining was 1.0Bq/cell for both 67Ga and 111In; the A50 values determined by clonogenic assay were 0.7Bq/cell and 0.3Bq/cell for 111In and 67Ga respectively. At the concentrations required to achieve these uptake levels, non-internalized 67Ga and 111In caused no cellular toxicity. Qualitatively similar results were found for MDA-MB-231 and HCC1954 cells. CONCLUSION 67Ga causes as much damage as 111In to plasmid DNA in solution and shows similar toxicity as 111In at equivalent internalized activity per cell. 67Ga therefore deserves further evaluation for radionuclide therapy. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE The data presented here is at the basic level of science. If future in vivo and clinical studies are successful, 67Ga could become a useful radionuclide with little healthy tissue toxicity in the arsenal of weapons for treating cancer.
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Affiliation(s)
- Muhamad F Bin Othman
- King's College London, Department of Imaging Chemistry and Biology, St. Thomas' Hospital, London, SE1 7EH, UK
| | - Nabil R Mitry
- King's College London, Department of Imaging Chemistry and Biology, St. Thomas' Hospital, London, SE1 7EH, UK
| | - Valerie J Lewington
- Guy's & St Thomas' NHS Foundation Trust, Nuclear Medicine Department, London, SE1 9RT, UK
| | - Philip J Blower
- King's College London, Department of Imaging Chemistry and Biology, St. Thomas' Hospital, London, SE1 7EH, UK
| | - Samantha Y A Terry
- King's College London, Department of Imaging Chemistry and Biology, St. Thomas' Hospital, London, SE1 7EH, UK.
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Aghevlian S, Boyle AJ, Reilly RM. Radioimmunotherapy of cancer with high linear energy transfer (LET) radiation delivered by radionuclides emitting α-particles or Auger electrons. Adv Drug Deliv Rev 2017; 109:102-118. [PMID: 26705852 DOI: 10.1016/j.addr.2015.12.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/26/2015] [Accepted: 12/06/2015] [Indexed: 12/31/2022]
Abstract
Radioimmunotherapy (RIT) aims to selectively deliver radionuclides emitting α-particles, β-particles or Auger electrons to tumors by conjugation to monoclonal antibodies (mAbs) that recognize tumor-associated antigens/receptors. The approach has been most successful for treatment of non-Hodgkin's B-cell lymphoma but challenges have been encountered in extending these promising results to the treatment of solid malignancies. These challenges include the low potency of β-particle emitters such as 131I, 177Lu or 90Y which have been commonly conjugated to the mAbs, due to their low linear energy transfer (LET=0.1-1.0keV/μm). Furthermore, since the β-particles have a 2-10mm range, there has been dose-limiting non-specific toxicity to hematopoietic stem cells in the bone marrow (BM) due to the cross-fire effect. Conjugation of mAbs to α-particle-emitters (e.g. 225Ac, 213Bi, 212Pb or 211At) or Auger electron-emitters (e.g. 111In, 67Ga, 123I or 125I) would increase the potency of RIT due to their high LET (50-230keV/μm and 4 to 26keV/μm, respectively). In addition, α-particles have a range in tissues of 28-100μm and Auger electrons are nanometer in range which greatly reduces or eliminates the cross-fire effect compared to β-particles, potentially reducing their non-specific toxicity to the BM. In this review, we describe the results of preclinical and clinical studies of RIT of cancer using radioimmunoconjugates emitting α-particles or Auger electrons, and discuss the potential of these high LET forms of radiation to improve the outcome of cancer patients.
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Affiliation(s)
- Sadaf Aghevlian
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Amanda J Boyle
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada; Toronto General Research Institute and Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada.
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Slastnikova TA, Rosenkranz AA, Morozova NB, Vorontsova MS, Petriev VM, Lupanova TN, Ulasov AV, Zalutsky MR, Yakubovskaya RI, Sobolev AS. Preparation, cytotoxicity, and in vivo antitumor efficacy of 111In-labeled modular nanotransporters. Int J Nanomedicine 2017; 12:395-410. [PMID: 28138237 PMCID: PMC5238804 DOI: 10.2147/ijn.s125359] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Modular nanotransporters (MNTs) are a polyfunctional platform designed to achieve receptor-specific delivery of short-range therapeutics into the cell nucleus by receptor-mediated endocytosis, endosome escape, and targeted nuclear transport. This study evaluated the potential utility of the MNT platform in tandem with Auger electron emitting 111In for cancer therapy. METHODS Three MNTs developed to target either melanocortin receptor-1 (MC1R), folate receptor (FR), or epidermal growth factor receptor (EGFR) that are overexpressed on cancer cells were modified with p-SCN-Bn-NOTA and then labeled with 111In in high specific activity. Cytotoxicity of the 111In-labeled MNTs was evaluated on cancer cell lines bearing the appropriate receptor target (FR: HeLa, SK-OV-3; EGFR: A431, U87MG.wtEGFR; and MC1R: B16-F1). In vivo micro-single-photon emission computed tomography/computed tomography imaging and antitumor efficacy studies were performed with intratumoral injection of MC1R-targeted 111In-labeled MNT in B16-F1 melanoma tumor-bearing mice. RESULTS The three NOTA-MNT conjugates were labeled with a specific activity of 2.7 GBq/mg with nearly 100% yield, allowing use without subsequent purification. The cytotoxicity of 111In delivered by these MNTs was greatly enhanced on receptor-expressing cancer cells compared with 111In nontargeted control. In mice with B16-F1 tumors, prolonged retention of 111In by serial imaging and significant tumor growth delay (82% growth inhibition) were found. CONCLUSION The specific in vitro cytotoxicity, prolonged tumor retention, and therapeutic efficacy of MC1R-targeted 111In-NOTA-MNT suggest that this Auger electron emitting conjugate warrants further evaluation as a locally delivered radiotherapeutic, such as for ocular melanoma brachytherapy. Moreover, the high cytotoxicity observed with FR- and EGFR-targeted 111In-NOTA-MNT suggests further applications of the MNT delivery strategy should be explored.
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Affiliation(s)
- Tatiana A Slastnikova
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences
| | - Andrey A Rosenkranz
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University
| | - Natalia B Morozova
- Department of Anticancer Therapy Modifiers and Protectors, Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, Moscow
| | - Maria S Vorontsova
- Department of Anticancer Therapy Modifiers and Protectors, Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, Moscow
| | - Vasiliy M Petriev
- National Medical Research Radiological Center, Russian Ministry of Health Care, Obninsk, Moscow Region
- Department of Nuclear Medicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia
| | - Tatiana N Lupanova
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences
| | - Alexey V Ulasov
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences
| | - Michael R Zalutsky
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Raisa I Yakubovskaya
- Department of Anticancer Therapy Modifiers and Protectors, Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, Moscow
| | - Alexander S Sobolev
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University
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Schiwietz G, Kühn D, Föhlisch A, Holldack K, Kachel T, Pontius N. Laser-pump/X-ray-probe experiments with electrons ejected from a Cu(111) target: space-charge acceleration. J Synchrotron Radiat 2016; 23:1158-1170. [PMID: 27577771 DOI: 10.1107/s1600577516009115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
A comprehensive investigation of the emission characteristics for electrons induced by X-rays of a few hundred eV at grazing-incidence angles on an atomically clean Cu(111) sample during laser excitation is presented. Electron energy spectra due to intense infrared laser irradiation are investigated at the BESSY II slicing facility. Furthermore, the influence of the corresponding high degree of target excitation (high peak current of photoemission) on the properties of Auger and photoelectrons liberated by a probe X-ray beam is investigated in time-resolved pump and probe measurements. Strong electron energy shifts have been found and assigned to space-charge acceleration. The variation of the shift with laser power and electron energy is investigated and discussed on the basis of experimental as well as new theoretical results.
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Affiliation(s)
- G Schiwietz
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - D Kühn
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - A Föhlisch
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - K Holldack
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - T Kachel
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - N Pontius
- Institut Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung (FG-ISRR), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
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Cai Z, Chattopadhyay N, Yang K, Kwon YL, Yook S, Pignol JP, Reilly RM. 111In-labeled trastuzumab-modified gold nanoparticles are cytotoxic in vitro to HER2-positive breast cancer cells and arrest tumor growth in vivo in athymic mice after intratumoral injection. Nucl Med Biol 2016; 43:818-26. [PMID: 27788375 DOI: 10.1016/j.nucmedbio.2016.08.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 08/11/2016] [Accepted: 08/18/2016] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Gold nanoparticles (AuNP; 30nm) were modified with polyethylene glycol (PEG) chains linked to trastuzumab for binding to HER2-positive breast cancer (BC) cells and diethylenetriaminepentaacetic acid (DTPA) for complexing the Auger electron-emitter, 111In (trastuzumab-AuNP-111In). Our objective was to determine the cytotoxicity of trastuzumab-AuNP-111In on HER2-positive BC cells in vitro and evaluate its tumor growth inhibition properties and normal tissue toxicity in vivo following intratumoral (i.t.) injection in mice with s.c. HER2-overexpressing BC xenografts. METHODS Binding and internalization of trastuzumab-AuNP-111In or non-targeted AuNP-111In in SK-BR-3 (1-2×106 HER2/cell) and MDA-MB-361 (5×105 HER2/cell) human BC cells were studied. The surviving fraction (SF) of SK-BR-3 or MDA-MB-361 cells exposed to trastuzumab-AuNP-111In or AuNP-111In was determined. DNA double-strand breaks (DSBs) were assayed by probing for γ-H2AX. Tumor growth was monitored over 70days in CD1 athymic mice with s.c. MDA-MB-361 xenografts after i.t. injection of 10MBq (0.7mg; 2.6×1012 AuNP) of trastuzumab-AuNP-111In and normal tissue toxicity was assessed by monitoring body weight, complete blood cell (CBC) counts and serum alanine aminotransferase (ALT) and creatinine (Cr). RESULTS Trastuzumab-AuNP-111In was specifically bound by SK-BR-3 and MDA-MB-361 cells. Trastuzumab-AuNP-111In was more efficiently internalized than AuNP-111In and localized to a peri-nuclear region. The SF fraction of SK-BR-3 cells was reduced by 1.8-fold by treatment with 3nM (7MBq/mL) of trastuzumab-AuNP-111In. The SF of MDA-MB-361 cells was reduced by 3.7-fold at 14.4nM (33.6MBq/mL). In comparison, non-targeted AuNP-111In at these concentrations reduced the SF of SK-BR-3 or MDA-MB-361 cells by 1.2-fold (P=0.03) and 1.7-fold (P<0.0001), respectively. DNA DSBs were greater in SK-BR-3 and MDA-MB-361 cells exposed to trastuzumab-AuNP-111In compared to AuNP-111In, but unlabeled trastuzumab-AuNP did not increase DNA DSBs. Local i.t. injection of trastuzumab-AuNP-111In in CD1 athymic mice with s.c. MDA-MB-361 tumors arrested tumor growth for 70days. There was no apparent normal tissue toxicity. The radiation absorbed dose deposited in the tumor by trastuzumab-AuNP-111In was 60.5Gy, while normal organs received <0.9Gy. CONCLUSION These results are promising for further development of trastuzumab-AuNP-111In as a novel Auger electron-emitting radiation nanomedicine for local treatment of HER2-positive BC. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE A local radiation treatment for HER2-positive BC based on AuNP modified with trastuzumab and labeled with the Auger electron-emitter, 111In was developed and shown to arrest tumor growth with no normal tissue toxicity.
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Abstract
To identify the emergence of the recognition of the potential of the Auger effect for clinical application, and after tracing the salient milestones towards that goal, to evaluate the status quo and future prospects. It was not until 40 years after the discovery of Auger electrons, that the availability of radioactive DNA precursors enabled the biological power, and the clinical potential, of the Auger effect to be appreciated. Important milestones on the path to clinical translation have been identified and reached, but hurdles remain. Nevertheless the potential is still evident, and there is reasonable optimism that the goal of clinical translation is achievable.
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Affiliation(s)
- Roger F Martin
- a Molecular Radiation Biology Laboratory , Peter MacCallum Cancer Centre.,b The Sir Peter MacCallum Department of Oncology , The University of Melbourne.,c School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Melbourne , Australia
| | - Ludwig E Feinendegen
- d Heinrich-Heine-University Düsseldorf , Germany.,e Brookhaven National Laboratory , Upton , NY , USA
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Lobachevsky P, Clark GR, Pytel PD, Leung B, Skene C, Andrau L, White JM, Karagiannis T, Cullinane C, Lee BQ, Stuchbery A, Kibedi T, Hicks RJ, Martin RF. Strand breakage by decay of DNA-bound 124I provides a basis for combined PET imaging and Auger endoradiotherapy. Int J Radiat Biol 2016; 92:686-697. [PMID: 26902391 DOI: 10.3109/09553002.2015.1136852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Purpose DNA ligands labelled with 125I induce cytotoxic DNA double-strand breaks (DSB), suggesting a potential for Auger endoradiotherapy. Since the 60-day half-life of 125I is suboptimal for therapy, we have investigated another Auger-emitter 124I, with shorter half-life (4.18 days), and the additional feature of positron-emission, enabling positron emission tomography (PET) imaging. The purpose of this study was to compare the two radionuclides on the basis of DNA DSB per decay. Materials and methods Using a 124I- (or 125I)-labelled minor groove binding DNA ligand, we investigated DNA breakage using the plasmid DNA assay. Biodistribution of the conjugate of the labelled ligand with transferrin was investigated in nude mice bearing a K562 human lymphoma xenograft. Results The probability of DSB per decay was 0.58 and 0.85 for 124I and 125I, respectively, confirming the therapeutic potential of the former. The crystal structure of the ligand DNA complex shows the iodine atom deep within the minor groove, consistent with the high efficiency of induced damage. Biodistribution studies, including PET imaging, showed distinctive results for the conjugate, compared to the free ligand and transferrin, consistent with receptor-mediated delivery of the ligand. Conclusions Conjugation of 124I-labelled DNA ligands to tumor targeting peptides provides a feasible strategy for Auger endoradiotherapy, with the advantage of monitoring tumor targeting by PET imaging.
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Affiliation(s)
- Pavel Lobachevsky
- a Molecular Radiation Biology Laboratory , Peter MacCallum Cancer Centre , Melbourne.,b The Sir Peter MacCallum Department of Oncology , The University of Melbourne , Melbourne , Australia
| | - George R Clark
- c School of Chemical Sciences , The University of Auckland , New Zealand
| | - Patrycja D Pytel
- c School of Chemical Sciences , The University of Auckland , New Zealand
| | - Brenda Leung
- d School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Australia
| | - Colin Skene
- d School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Australia
| | - Laura Andrau
- d School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Australia
| | - Jonathan M White
- d School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Australia
| | - Tom Karagiannis
- a Molecular Radiation Biology Laboratory , Peter MacCallum Cancer Centre , Melbourne
| | - Carleen Cullinane
- b The Sir Peter MacCallum Department of Oncology , The University of Melbourne , Melbourne , Australia.,e Cancer Research Division , Peter MacCallum Cancer Centre , Melbourne
| | - Boon Q Lee
- f Department of Nuclear Physics, Research School of Physics and Engineering , Australian National University , Canberra
| | - Andrew Stuchbery
- f Department of Nuclear Physics, Research School of Physics and Engineering , Australian National University , Canberra
| | - Tibor Kibedi
- f Department of Nuclear Physics, Research School of Physics and Engineering , Australian National University , Canberra
| | - Rodney J Hicks
- b The Sir Peter MacCallum Department of Oncology , The University of Melbourne , Melbourne , Australia.,g Centre for Molecular Imaging, Peter MacCallum Cancer Centre , Melbourne , VIC , Australia
| | - Roger F Martin
- a Molecular Radiation Biology Laboratory , Peter MacCallum Cancer Centre , Melbourne.,b The Sir Peter MacCallum Department of Oncology , The University of Melbourne , Melbourne , Australia.,d School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute , University of Melbourne , Australia
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Isomura N, Kamada M, Nonaka T, Nakamura E, Takano T, Sugiyama H, Kimoto Y. A new EXAFS method for the local structure analysis of low-Z elements. J Synchrotron Radiat 2016; 23:281-285. [PMID: 26698075 DOI: 10.1107/s1600577515021165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/07/2015] [Indexed: 06/05/2023]
Abstract
A unique analytical method is proposed for local structure analysis via extended X-ray absorption fine structure (EXAFS) spectroscopy. The measurement of electron energy distribution curves at various excitation photon energies using an electron energy analyzer is applied to determine a specific elemental Auger spectrum. To demonstrate the method, the N K-edge EXAFS spectra for a silicon nitride film were obtained via simultaneous measurement of the N KLL Auger and background spectra using dual-energy windows. The background spectrum was then used to remove the photoelectrons and secondary electron mixing in the energy distribution curves. The spectrum obtained following this subtraction procedure represents the `true' N K-edge EXAFS spectrum without the other absorptions that are observed in total electron yield N K-edge EXAFS spectra. The first nearest-neighbor distance (N-Si) derived from the extracted N K-edge EXAFS oscillation was in good agreement with the value derived from Si K-edge analysis. This result confirmed that the present method, referred to as differential electron yield (DEY)-EXAFS, is valid for deriving local surface structure information for low-Z elements.
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Affiliation(s)
- Noritake Isomura
- Toyota Central R&D Laboratories, 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Masao Kamada
- Aichi Synchrotron Radiation Center (AichiSR), 250-3 Minamiyamaguchi-cho, Seto, Aichi 489-0965, Japan
| | - Takamasa Nonaka
- Toyota Central R&D Laboratories, 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Eiken Nakamura
- Aichi Synchrotron Radiation Center (AichiSR), 250-3 Minamiyamaguchi-cho, Seto, Aichi 489-0965, Japan
| | - Takumi Takano
- Aichi Synchrotron Radiation Center (AichiSR), 250-3 Minamiyamaguchi-cho, Seto, Aichi 489-0965, Japan
| | - Harue Sugiyama
- Aichi Synchrotron Radiation Center (AichiSR), 250-3 Minamiyamaguchi-cho, Seto, Aichi 489-0965, Japan
| | - Yasuji Kimoto
- Toyota Central R&D Laboratories, 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
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Leyton JV, Gao C, Williams B, Keating A, Minden M, Reilly RM. A radiolabeled antibody targeting CD123(+) leukemia stem cells - initial radioimmunotherapy studies in NOD/SCID mice engrafted with primary human AML. Leuk Res Rep 2015; 4:55-9. [PMID: 26500848 PMCID: PMC4588397 DOI: 10.1016/j.lrr.2015.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/17/2015] [Accepted: 07/25/2015] [Indexed: 11/03/2022] Open
Abstract
Radioimmunotherapy (RIT) with anti-CD123 monoclonal antibody CSL360 modified with nuclear translocation sequence (NLS) peptides and labeled with the Auger electron-emitter, (111)In ((111)In-NLS-CSL360) was studied in the prevalent NOD/SCID mouse AML engraftment assay. Significant decreases in CD123(+) leukemic cells and impairment of leukemic stem cell self-renewal were achieved with high doses of RIT. However, NOD/SCID mice were very radiosensitive to these doses. At low non-toxic treatment doses, (111)In-NLS-CSL360 demonstrated a trend towards improved survival associated with decreased spleen/body weight ratio, an indicator of leukemia burden, and almost complete eradication of leukemia from the bone marrow in some mice.
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Affiliation(s)
- Jeffrey V Leyton
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Catherine Gao
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Brent Williams
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada ; Division of Hematology-Oncology, The Hospital for Sick Children, Toronto, ON, Canada ; Cell Therapy Program, The Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Armand Keating
- Cell Therapy Program, The Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada ; Department of Hematology-Oncology, The Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Mark Minden
- Department of Hematology-Oncology, The Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada ; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada ; Toronto General Research Institute, University Health Network, Toronto, ON, Canada ; Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
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Kortylewicz ZP, Mack E, Enke CA, Estes KA, Mosley RL, Baranowska-Kortylewicz J. Preclinical evaluation of investigational radiopharmaceutical RISAD-P intended for use as a diagnostic and molecular radiotherapy agent for prostate cancer. Prostate 2015; 75:8-22. [PMID: 25283970 DOI: 10.1002/pros.22885] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/05/2014] [Indexed: 11/11/2022]
Abstract
BACKGROUND The androgen receptor (AR) plays a dominant role in the pathogenesis of prostate cancer. 5-Radioiodo-3'-O-(17β-succinyl-5α-androstan-3-one)-2'-deoxyuridin-5'-yl phosphate (RISAD-P) is an AR-targeting reagent developed for noninvasive assessment of AR and proliferative status of the AR-expressing tumors, and for molecular radiotherapy with Auger electron-emitting radionuclides. In this study, the preclinical toxicity and targeting potential of RISAD-P was evaluated. METHODS Effects of nonradioactive ISAD-P and RISAD-P labeled with (123) I, (124) I, and (125) I were evaluated in male mice. Expanded-acute single dose toxicity studies, hematologic toxicity, liver and kidney function, pharmacokinetics, biodistribution, and imaging studies were conducted. Imaging and pilot therapy studies were conducted in transgenic mice. RESULTS RISAD-P is not toxic at doses projected for clinical use. Its tissue distribution compares favorably with the distribution reported for (18) F-dihydrotestosterone derivatives. RISAD-P has excellent prostate cancer targeting properties. One hour after (125) IRISAD-P administration, nearly 10% of the injected dose is associated with prostate tumor. The tumor clearance is biphasic and plateaus between 24 and 48 hr post-injection. The estimated radiation doses calculated for 1 g tumor using the MIRD convention are well within the therapeutic range with values of 170, 250, 1,240 Gy × MBq(-1) × g(-1) for (125) I-, (123) I-, and (124) I-labeled RISAD-P, respectively. The transient uptake of radioactivity is observed in the genitourinary tract and stomach. Without the potassium iodide blockade, thyroid uptake is also observed. CONCLUSIONS Biodistribution, toxicity, and radiation dosimetry studies suggest that RISAD-P holds characteristics of a promising candidate for imaging of AR expression and tumor proliferation, as well as molecular radiotherapy for metastatic or locally, regionally advanced prostate cancer.
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Affiliation(s)
- Zbigniew P Kortylewicz
- Department of Radiation Oncology, J. Bruce Henriksen Cancer Research Laboratories, University of Nebraska Medical Center, Omaha, Nebraska
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Han G, Kortylewicz ZP, Enke T, Baranowska-Kortylewicz J. Co-targeting androgen receptor and DNA for imaging and molecular radiotherapy of prostate cancer: in vitro studies. Prostate 2014; 74:1634-46. [PMID: 25214432 DOI: 10.1002/pros.22880] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/21/2014] [Indexed: 11/11/2022]
Abstract
BACKGROUND The androgen receptor (AR) axis, the key growth and survival pathway in prostate cancer, remains a prime target for drug development. 5-Radioiodo-3'-O-(17β-succinyl-5α-androstan-3-one)-2'-deoxyuridin-5'-yl phosphate (RISAD-P) is the AR-seeking reagent developed for noninvasive assessment of AR and proliferative status, and for molecular radiotherapy of prostate cancer with Auger electron-emitting radionuclides. METHODS RISAD-P radiolabeled with 123I, 124I, and 125I were synthesized using a common stannylated precursor. The cellular uptake, subcellular distribution, and radiotoxicity of 123I-, 124I-, and (125) IRISAD-P were measured in LNCaP, DU145, and PC-3 cell lines expressing various levels of AR. RESULTS The uptake of RISAD-P by prostate cancer cells is proportional to AR levels and independent of the radionuclide. The intracellular accumulation of radioactivity is directly proportional to the extracellular concentration of RISAD-P and the duration of exposure. Initially, RISAD-P is trapped in the cytoplasm. Within 24 hr, radioactivity is associated exclusively with DNA. The RISAD-P radiotoxicity is determined by the radionuclide; however, the cellular responses are directly proportional to the AR expression levels. LNCaP cells expressing high levels of AR are killed at the rate of up to 60% per day after a brief 1 hr RISAD-P treatment. For the first time, the AR expression in PC-3 and DU 145 cells, generally reported as AR-negative, was quantitated by the ultra sensitive RISAD-P-based method. CONCLUSIONS RISAD-P is a theranostic drug, which targets AR. Its subcellular metabolite participates in DNA synthesis. RISAD-P is a promising candidate for imaging of the AR expression and tumor proliferation as well as molecular radiotherapy of prostate cancer.
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Affiliation(s)
- Guang Han
- Department of Radiation Oncology, J. Bruce Henriksen Cancer Research Laboratories, University of Nebraska Medical Center, Nebraska
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Thisgaard H, Olsen BB, Dam JH, Bollen P, Mollenhauer J, Høilund-Carlsen PF. Evaluation of cobalt-labeled octreotide analogs for molecular imaging and auger electron-based radionuclide therapy. J Nucl Med 2014; 55:1311-6. [PMID: 24876207 DOI: 10.2967/jnumed.114.137182] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 04/09/2014] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The somatostatin receptor, which is overexpressed by many neuroendocrine tumors, is a well-known target for molecular imaging and peptide receptor radionuclide therapy. Recently, (57)Co-labeled DOTATOC, an octreotide analog, was shown to have the highest affinity yet found for somatostatin receptor subtype 2. The aim of this study was to evaluate the biologic effects of novel cobalt-labeled octreotide analogs targeting the somatostatin receptor to identify promising candidates for molecular imaging and Auger electron-based radionuclide therapy. METHODS Cobalt-labeled DOTATATE, DOTATOC, and DOTANOC were prepared with (57)Co or (58m)Co for SPECT or Auger electron-based therapy, respectively. The cellular uptake and intracellular distribution of the radioligands were characterized with the pancreatic tumor cell line AR42J in vitro, including assessment of the therapeutic effects of (58m)Co-DOTATATE via DNA double-strand break and proliferation assays. Comparisons with the therapeutic effects of (111)In- and (177)Lu-DOTATATE were also performed. Tumor uptake and normal tissue uptake were characterized in a subcutaneous pancreatic tumor mouse model. RESULTS All 3 cobalt-conjugated peptides resulted in time-dependent and receptor-specific uptake, with a high level (≥88%) of cellular internalization in vitro of the total cell-associated radioactivity. The DNA double-strand break yield showed a dose-dependent increase with activity, whereas cell survival showed a dose-dependent decrease. (58m)Co-DOTATATE was significantly more efficient in cell killing per cumulated decay than (111)In- and (177)Lu-DOTATATE. The in vivo pharmacokinetic studies showed a high level of receptor-specific tumor uptake. CONCLUSION All cobalt-labeled radioligands showed a high level of receptor-specific uptake both in vitro and in vivo in tumor-bearing mice. Furthermore, (58m)Co-DOTATATE showed considerable therapeutic effects in vitro and, thus, could be an effective agent for eradicating disseminated tumor cells and micrometastases.
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Affiliation(s)
- Helge Thisgaard
- PET & Cyclotron Unit, Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Birgitte Brinkmann Olsen
- PET & Cyclotron Unit, Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | - Johan Hygum Dam
- PET & Cyclotron Unit, Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | - Peter Bollen
- Biomedical Laboratory, University of Southern Denmark, Odense, Denmark; and
| | - Jan Mollenhauer
- Lundbeckfonden Center of Excellence NanoCAN and Molecular Oncology Group, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Poul Flemming Høilund-Carlsen
- PET & Cyclotron Unit, Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
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Zereshkian A, Leyton JV, Cai Z, Bergstrom D, Weinfeld M, Reilly RM. The human polynucleotide kinase/phosphatase (hPNKP) inhibitor A12B4C3 radiosensitizes human myeloid leukemia cells to Auger electron-emitting anti-CD123 ¹¹¹In-NLS-7G3 radioimmunoconjugates. Nucl Med Biol 2014; 41:377-83. [PMID: 24637100 DOI: 10.1016/j.nucmedbio.2014.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 02/06/2014] [Accepted: 02/07/2014] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Leukemia stem cells (LSCs) are believed to be responsible for initiating and propagating acute myeloid leukemia (AML) and for causing relapse after treatment. Radioimmunotherapy (RIT) targeting these cells may improve the treatment of AML, but is limited by the low density of target epitopes. Our objective was to study a human polynucleotide kinase/phosphatase (hPNKP) inhibitor that interferes with DNA repair as a radiosensitizer for the Auger electron RIT agent, ¹¹¹In-NLS-7G3, which recognizes the CD123⁺/CD131⁻ phenotype uniquely displayed by LSCs. METHODS The surviving fraction (SF) of CD123⁺/CD131⁻ AML-5 cells exposed to ¹¹¹In-NLS-7G3 (33-266 nmols/L; 0.74MBq/μg) or to γ-radiation (0.25-5Gy) was determined by clonogenic assays. The effect of A12B4C3 (25 μmols/L) combined with ¹¹¹In-NLS-7G3 (16-66 nmols/L) or with γ-radiation (0.25-2Gy) on the SF of AML-5 cells was assessed. The density of DNA double-strand breaks (DSBs) in the nucleus was measured using the γ-H2AX assay. Cellular dosimetry was estimated based on the subcellular distribution of ¹¹¹In-NLS-7G3 measured by cell fractionation. RESULTS Binding of (111)In-NLS-7G3 to AML-5 cells was reduced by 2.2-fold in the presence of an excess (1μM) of unlabeled NLS-7G3, demonstrating specific binding to the CD123⁺/CD131⁻ epitope. ¹¹¹In-NLS-7G3 reduced the SF of AML-5 cells from 86.1 ± 11.0% at 33 nmols/L to 10.5 ± 3.6% at 266 nmols/L. Unlabeled NLS-7G3 had no significant effect on the SF. Treatment of AML-5 cells with γ-radiation reduced the SF from 98.9 ± 14.9% at 0.25Gy to 0.03 ± 0.1% at 5 Gy. A12B4C3 combined with ¹¹¹In-NLS-7G3 (16-66 nmols/L) enhanced the cytotoxicity up to 1.7-fold compared to treatment with radioimmunoconjugates alone and was associated with a 1.6-fold increase in DNA DSBs in the nucleus. A12B4C3 enhanced the cytotoxicity of γ-radiation (0.25-0.5Gy) on AML-5 cells by up to 1.5-fold, and DNA DSBs were increased by 1.7-fold. Exposure to ¹¹¹In-NLS-7G3 (66 nmols/L) delivered up to 0.6Gy to AML-5 cells. CONCLUSIONS We conclude that A12B4C3 radiosensitized AML cells to the DNA damaging effects of ¹¹¹In-NLS-7G3. Combination treatment may increase the effectiveness for Auger electron RIT of AML targeting the LSC subpopulation.
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Affiliation(s)
- Arman Zereshkian
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Jeffrey V Leyton
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Zhongli Cai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Dane Bergstrom
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | | | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada; Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
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Tavares AAS, Tavares JMRS. Computational modeling of cellular effects post-irradiation with low- and high-let particles and different absorbed doses. Dose Response 2012; 11:191-206. [PMID: 23930101 DOI: 10.2203/dose-response.11-049.tavares] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The use of computational methods to improve the understanding of biological responses to various types of radiation is an approach where multiple parameters can be modelled and a variety of data is generated. This study compares cellular effects modelled for low absorbed doses against high absorbed doses. The authors hypothesized that low and high absorbed doses would contribute to cell killing via different mechanisms, potentially impacting on targeted tumour radiotherapy outcomes. Cellular kinetics following irradiation with selective low- and high-linear energy transfer (LET) particles were investigated using the Virtual Cell (VC) radiobiology algorithm. Two different cell types were assessed using the VC radiobiology algorithm: human fibroblasts and human crypt cells. The results showed that at lower doses (0.01 to 0.2 Gy), all radiation sources used were equally able to induce cell death (p>0.05, ANOVA). On the other hand, at higher doses (1.0 to 8.0 Gy), the radiation response was LET and dose dependent (p<0.05, ANOVA). The data obtained suggests that the computational methods used might provide some insight into the cellular effects following irradiation. The results also suggest that it may be necessary to re-evaluate cellular radiation-induced effects, particularly at low doses that could affect therapeutic effectiveness.
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