scholarly journals Targeted Radionuclide Therapy Using Auger Electron Emitters: The Quest for the Right Vector and the Right Radionuclide

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 980
Author(s):  
Malick Bio Idrissou ◽  
Alexandre Pichard ◽  
Bryan Tee ◽  
Tibor Kibedi ◽  
Sophie Poty ◽  
...  
Keyword(s):  
Radionuclide Therapy ◽  
Auger Electron ◽  
Nuclear Dna ◽  
Clonogenic Survival ◽  
Targeted Radionuclide Therapy ◽  
Nuclear Uptake ◽  
Tat Peptides ◽  
Electron Emitters ◽  
The Right

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.

scholarly journals Meitner-Auger Electron Emitters for Targeted Radionuclide Therapy: Mercury-197m/g and Antimony-119

2021 ◽  
Vol 14 ◽  
Author(s):  
Parmissa Randhawa ◽  
Aeli P. Olson ◽  
Shaohuang Chen ◽  
Kaley Lexi Gower-Fry ◽  
Cornelia Hoehr ◽  
...  
Keyword(s):  
Radionuclide Therapy ◽  
Auger Electron ◽  
State Of The Art ◽  
Delivery Systems ◽  
Cellular Level ◽  
The State ◽  
Targeted Radionuclide Therapy ◽  
University Of Wisconsin ◽  
Electron Emitters ◽  
The University

Abstract:: Targeted Radionuclide Therapies (TRTs) based on Auger emitting radionuclides have the potential to deliver extremely selective therapeutic payloads on the cellular level. However, to fully exploit this potential, suitable radionuclides need to be applied in combination with appropriate delivery systems. In this review, we summarize the state-of-the-art in production, purification, chelation and applications of two promising candidates for Targeted Auger Therapy, namely antimony-119 (119Sb) and mercury-197 (197Hg). Both radionuclides have great potential to become efficient tools for TRT. We also highlight our current progress on the production of both radionuclides at TRIUMF and the University of Wisconsin.

scholarly journals Radioimmunotherapy of PANC-1 human pancreatic cancer xenografts in NOD/SCID or NRG mice with Panitumumab labeled with Auger electron emitting, 111In or β-particle emitting, 177Lu

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Sadaf Aghevlian ◽  
Zhongli Cai ◽  
David Hedley ◽  
Mitchell A. Winnik ◽  
Raymond M. Reilly
Keyword(s):  
Normal Saline ◽  
Normal Tissue ◽  
Auger Electron ◽  
Absorbed Dose ◽  
Clonogenic Survival ◽  
Scid Mice ◽  
Human Pancreatic Cancer ◽  
Cell Counts ◽  
Normal Tissue Toxicity

Abstract Background Epidermal growth factor receptors (EGFR) are overexpressed on > 90% of pancreatic cancers (PnCa) and represent an attractive target for the development of novel therapies, including radioimmunotherapy (RIT). Our aim was to study RIT of subcutaneous (s.c.) PANC-1 human PnCa xenografts in mice using the anti-EGFR monoclonal antibody, panitumumab labeled with Auger electron (AE)-emitting, 111In or β-particle emitting, 177Lu at amounts that were non-toxic to normal tissues. Results Panitumumab was conjugated to DOTA chelators for complexing 111In or 177Lu (panitumumab-DOTA-[111In]In and panitumumab-DOTA-[177Lu]Lu) or to a metal-chelating polymer (MCP) with multiple DOTA to bind 111In (panitumumab-MCP-[111In]In). Panitumumab-DOTA-[177Lu]Lu was more effective per MBq exposure at reducing the clonogenic survival in vitro of PANC-1 cells than panitumumab-DOTA-[111In]In or panitumumab-MCP-[111In]In. Panitumumab-DOTA-[177Lu]Lu caused the greatest density of DNA double-strand breaks (DSBs) in the nucleus measured by immunofluorescence for γ-H2AX. The absorbed dose in the nucleus was 3.9-fold higher for panitumumab-DOTA-[177Lu]Lu than panitumumab-DOTA-[111In]In and 7.7-fold greater than panitumumab-MCP-[111In]In. No normal tissue toxicity was observed in NOD/SCID mice injected intravenously (i.v.) with 10.0 MBq (10 μg; ~ 0.07 nmoles) of panitumumab-DOTA-[111In]In or panitumumab-MCP-[111In]In or in NRG mice injected i.v. with 6.0 MBq (10 μg; ~ 0.07 nmoles) of panitumumab-DOTA-[177Lu]Lu. There was no decrease in complete blood cell counts (CBC) or increased serum alanine aminotransferase (ALT) or creatinine (Cr) or decreased body weight. RIT inhibited the growth of PANC-1 tumours but a 5-fold greater total amount of panitumumab-DOTA-[111In]In or panitumumab-MCP-[111In]In (30 MBq; 30 μg; ~ 0.21 nmoles) administered in three fractionated amounts every three weeks was required to achieve greater or equivalent tumour growth inhibition, respectively, compared to a single amount of panitumumab-DOTA-[177Lu]Lu (6 MBq; 10 μg; ~ 0.07 nmoles). The tumour doubling time (TDT) for NOD/SCID mice with s.c. PANC-1 tumours treated with panitumumab-DOTA-[111In]In or panitumumab-MCP-[111In]In was 51.8 days and 28.1 days, respectively. Panitumumab was ineffective yielding a TDT of 15.3 days vs. 15.6 days for normal saline treated mice. RIT of NRG mice with s.c. PANC-1 tumours with 6.0 MBq (10 μg; ~ 0.07 nmoles) of panitumumab-DOTA-[177Lu]Lu increased the TDT to 20.9 days vs. 11.5 days for panitumumab and 9.1 days for normal saline. The absorbed doses in PANC-1 tumours were 8.8 ± 3.0 Gy and 2.6 ± 0.3 Gy for panitumumab-DOTA-[111In]In and panitumumab-MCP-[111In]In, respectively, and 11.6 ± 4.9 Gy for panitumumab-DOTA-[177Lu]Lu. Conclusion RIT with panitumumab labeled with Auger electron-emitting, 111In or β-particle-emitting, 177Lu inhibited the growth of s.c. PANC-1 tumours in NOD/SCID or NRG mice, at administered amounts that caused no normal tissue toxicity. We conclude that EGFR-targeted RIT is a promising approach to treatment of PnCa.

scholarly journals Multifunctional Cyanine-Based Theranostic Probe for Cancer Imaging and Therapy

2021 ◽  
Vol 22 (22) ◽  
pp. 12214
Author(s):  
Cheng-Liang Peng ◽  
Ying-Hsia Shih ◽  
Ping-Fang Chiang ◽  
Chun-Tang Chen ◽  
Ming-Cheng Chang
Keyword(s):  
Photothermal Therapy ◽  
Radionuclide Therapy ◽  
Nuclear Imaging ◽  
Biological Evaluation ◽  
Targeted Radionuclide Therapy ◽  
Nir Fluorescence ◽  
Tumor Accumulation ◽  
Selective Accumulation

Cancer is one of the leading causes of death in the world. A cancer-targeted multifunctional probe labeled with the radionuclide has been developed to provide multi-modalities for NIR fluorescence and nuclear imaging (PET, SPECT), for photothermal therapy (PTT), and targeted radionuclide therapy of cancer. In this study, synthesis, characterization, in vitro, and in vivo biological evaluation of the cyanine-based probe (DOTA-NIR790) were demonstrated. The use of cyanine dyes for the selective accumulation of cancer cells were used to achieve the characteristics of tumor markers. Therefore, all kinds of organ tumors can be targeted for diagnosis and treatment. The DOTA-NIR790 labeled with lutetium-111 could detect original or metastatic tumors by using SPECT imaging and quantify tumor accumulation. The β-emission of 177Lu-DOTA-NIR790 can be used for targeted radionuclide therapy of tumors. The DOTA-NIR790 enabled imaging by NIR fluorescence and by nuclear imaging (SPECT) to monitor in real-time the tumor accumulation and the situation of cancer therapy, and to guide the surgery or the photothermal therapy of the tumor. The radionuclide-labeled heptamethine cyanine based probe (DOTA-NIR790) offers multifunctional modalities for imaging and therapies of cancer.

scholarly journals Therapeutic Potential of 47Sc in Comparison to 177Lu and 90Y: Preclinical Investigations

Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 424 ◽  
Author(s):  
Klaudia Siwowska ◽  
Patrycja Guzik ◽  
Katharina A. Domnanich ◽  
Josep M. Monné Rodríguez ◽  
Peter Bernhardt ◽  
...  
Keyword(s):  
Radionuclide Therapy ◽  
Therapeutic Potential ◽  
Folate Receptor ◽  
Tumor Growth Inhibition ◽  
Therapeutic Effects ◽  
Targeted Radionuclide Therapy ◽  
Decay Properties ◽  
Therapeutic Properties ◽  
Folate Conjugate

Targeted radionuclide therapy with 177Lu- and 90Y-labeled radioconjugates is a clinically-established treatment modality for metastasized cancer. 47Sc is a therapeutic radionuclide that decays with a half-life of 3.35 days and emits medium-energy β−-particles. In this study, 47Sc was investigated, in combination with a DOTA-folate conjugate, and compared to the therapeutic properties of 177Lu-folate and 90Y-folate, respectively. In vitro, 47Sc-folate demonstrated effective reduction of folate receptor-positive ovarian tumor cell viability similar to 177Lu-folate, but 90Y-folate was more potent at equal activities due to the higher energy of emitted β−-particles. Comparable tumor growth inhibition was observed in mice that obtained the same estimated absorbed tumor dose (~21 Gy) when treated with 47Sc-folate (12.5 MBq), 177Lu-folate (10 MBq), and 90Y-folate (5 MBq), respectively. The treatment resulted in increased median survival of 39, 43, and 41 days, respectively, as compared to 26 days in untreated controls. There were no statistically significant differences among the therapeutic effects observed in treated groups. Histological assessment revealed no severe side effects two weeks after application of the radiofolates, even at double the activity used for therapy. Based on the decay properties and our results, 47Sc is likely to be comparable to 177Lu when employed for targeted radionuclide therapy. It may, therefore, have potential for clinical translation and be of particular interest in tandem with 44Sc or 43Sc as a diagnostic match, enabling the realization of radiotheragnostics in future.

Evaluation of new iodinated acridine derivatives for targeted radionuclide therapy of melanoma using 125I, an Auger electron emitter

2010 ◽  
Vol 29 (6) ◽  
pp. 1253-1263 ◽  
Author(s):  
Maryline Gardette ◽  
Janine Papon ◽  
Mathilde Bonnet ◽  
Nicolas Desbois ◽  
Pierre Labarre ◽  
...  
Keyword(s):  
Radionuclide Therapy ◽  
Auger Electron ◽  
Targeted Radionuclide Therapy ◽  
Electron Emitter ◽  
Acridine Derivatives ◽  
Auger Electron Emitter

scholarly journals In vitro proof of concept studies of radiotoxicity from Auger electron-emitter thallium-201

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katarzyna M. Osytek ◽  
Philip J. Blower ◽  
Ines M. Costa ◽  
Gareth E. Smith ◽  
Vincenzo Abbate ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Lines ◽  
Cellular Uptake ◽  
Auger Electron ◽  
Nuclear Dna ◽  
Thallium 201 ◽  
Cell Uptake ◽  
High Potassium ◽  
Du145 Cells

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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