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Belchior A, Fernandes A, Lamotte M, da Silva AFF, Seixas RSGR, Silva AMS, Marques F. Exploring the Physical and Biological Aspects of BNCT with a Carboranylmethylbenzo[ b]acridone Compound in U87 Glioblastoma Cells. Int J Mol Sci 2022; 23:ijms232314929. [PMID: 36499256 PMCID: PMC9737597 DOI: 10.3390/ijms232314929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 12/02/2022] Open
Abstract
Boron neutron capture therapy (BNCT) is a re-emerging technique for selectively killing tumor cells. Briefly, the mechanism can be described as follows: after the uptake of boron into cells, the thermal neutrons trigger the fission of the boron atoms, releasing the α-particles and recoiling lithium particles and high-energy photons that damage the cells. We performed a detailed study of the reactor dosimetry, cellular dose assessment, and radiobiological effects induced by BNCT in glioblastoma (GBM) cells. At maximum reactor power, neutron fluence rates were ϕ0 = 6.6 × 107 cm−2 s−1 (thermal) and θ = 2.4 × 104 cm−2 s−1 with a photon dose rate of 150 mGy·h−1. These values agreed with simulations to within 85% (thermal neutrons), 78% (epithermal neutrons), and 95% (photons), thereby validating the MCNPX model. The GEANT4 simulations, based on a realistic cell model and measured boron concentrations, showed that >95% of the dose in cells was due to the BNC reaction. Carboranylmethylbenzo[b]acridone (CMBA) is among the different proposed boron delivery agents that has shown promising properties due to its lower toxicity and important cellular uptake in U87 glioblastoma cells. In particular, the results obtained for CBMA reinforce radiobiological effects demonstrating that damage is mostly induced by the incorporated boron with negligible contribution from the culture medium and adjacent cells, evidencing extranuclear cell radiosensitivity.
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Affiliation(s)
- Ana Belchior
- Centre for Nuclear Sciences and Technologies, Instituto Superior Técnico, Lisbon University, Nuclear and Technological Campus, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
| | - Ana Fernandes
- Centre for Nuclear Sciences and Technologies, Instituto Superior Técnico, Lisbon University, Nuclear and Technological Campus, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
- Department of Nuclear Sciences and Engineering, Instituto Superior Técnico, Lisbon University, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
| | - Maxime Lamotte
- Centre for Nuclear Sciences and Technologies, Instituto Superior Técnico, Lisbon University, Nuclear and Technological Campus, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
| | | | | | - Artur M. S. Silva
- Department of Chemistry QOPNA, Aveiro University, 3810-193 Aveiro, Portugal
| | - Fernanda Marques
- Centre for Nuclear Sciences and Technologies, Instituto Superior Técnico, Lisbon University, Nuclear and Technological Campus, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
- Department of Nuclear Sciences and Engineering, Instituto Superior Técnico, Lisbon University, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal
- Correspondence:
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da Silva AFF, Seixas RSGR, Silva AMS, Coimbra J, Fernandes AC, Santos JP, Matos A, Rino J, Santos I, Marques F. Synthesis, characterization and biological evaluation of carboranylmethylbenzo[b]acridones as novel agents for boron neutron capture therapy. Org Biomol Chem 2015; 12:5201-11. [PMID: 24915168 DOI: 10.1039/c4ob00644e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we present the synthesis and characterization of benzo[b]acridin-12(7H)-ones bearing carboranyl moieties and test their biological effectiveness as boron neutron capture therapy (BNCT) agents in cancer treatment. The cellular uptake of these novel compounds into the U87 human glioblastoma cells was evaluated by boron analysis (ICP-MS) and by fluorescence imaging (confocal microscopy). The compounds enter the U87 cells exhibiting a similar profile, i.e., preferential accumulation in the cytoskeleton and membranes and a low cytotoxic activity (IC50 values higher than 200 μM). The cytotoxic activity and cellular morphological alterations after neutron irradiation in the Portuguese Research Reactor (6.6 × 10(7) neutrons cm(-2) s(-1), 1 MW) were evaluated by the MTT assay and by electron microscopy (TEM). Post-neutron irradiation revealed that BNCT has a higher cytotoxic effect on the cells. Accumulation of membranous whorls in the cytoplasm of cells treated with one of the compounds correlates well with the cytotoxic effect induced by radiation. Results provide a strong rationale for considering one of these compounds as a lead candidate for a new generation of BNCT agents.
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Affiliation(s)
- A Filipa F da Silva
- Departamento de Química-QOPNA, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Beasley DG, Fernandes AC, Santos JP, Ramos AR, Marques JG, King A. Characterisation of the epithermal neutron irradiation facility at the Portuguese research reactor using MCNP. Appl Radiat Isot 2015; 99:186-92. [PMID: 25796059 DOI: 10.1016/j.apradiso.2015.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 02/16/2015] [Accepted: 03/03/2015] [Indexed: 11/28/2022]
Abstract
The radiation field at the epithermal beamline and irradiation chamber installed at the Portuguese Research Reactor (RPI) at the Campus Tecnológico e Nuclear of Instituto Superior Técnico was characterised in the context of Prompt Gamma Neutron Activation Analysis (PGNAA) applications. Radiographic films, activation foils and thermoluminescence dosimeters were used to measure the neutron fluence and photon dose rates in the irradiation chamber. A fixed-source MCNPX model of the beamline and chamber was developed and compared to measurements in the first step towards planning a new irradiation chamber. The high photon background from the reactor results in the saturation of the detector and the current facility configuration yields an intrinsic insensitivity to various elements of interest for PGNAA. These will be addressed in future developments.
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Affiliation(s)
- D G Beasley
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Potugal.
| | - A C Fernandes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Potugal
| | - J P Santos
- Laboratório de Engenharia Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Portugal
| | - A R Ramos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Potugal; Laboratório de Engenharia Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Portugal
| | - J G Marques
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Potugal; Laboratório de Engenharia Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Portugal
| | - A King
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela LRS, Potugal
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Karimi-Shahri K, Rafat-Motavalli L, Miri-Hakimabad H. Study of size, type and the kerma approximation for thermoluminescent dosimetry. J Radioanal Nucl Chem 2013. [DOI: 10.1007/s10967-013-2580-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Fernandes A, Santos J, Marques J, Kling A, Ramos A, Barradas N. Validation of the Monte Carlo model supporting core conversion of the Portuguese Research Reactor (RPI) for neutron fluence rate determinations. ANN NUCL ENERGY 2010. [DOI: 10.1016/j.anucene.2010.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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