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Chailapakul P, Maloney O, Hirakawa H, Fujimori A, Kitamura H, Kato TA. The contribution of high-LET track to DNA damage formation and cell death for Monoenergy and SOBP carbon ion irradiation. Biochem Biophys Res Commun 2024; 696:149500. [PMID: 38219488 DOI: 10.1016/j.bbrc.2024.149500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 01/08/2024] [Indexed: 01/16/2024]
Abstract
Carbon ion radiotherapy (CIRT) is a heavy ion charge particle therapy with 29 years of prominent use. Despite advantages like high relative biological effectiveness (RBE), improved quality of life, and reduced treatment time, challenges persist, especially regarding heavy nuclear fragments. Our research addresses these challenges in horizontal irradiation, aiming to comprehend Monoenergetic and Spread-Out Bragg peak (SOBP) carbon ion beam trajectories using cell survival analysis and visualizing biological effects through DNA damage (γ-H2AX). This reveals repair-related protein foci near the Bragg peak. CR-39, a plastic nuclear track detector, was explored to understand high-linear energy transfer (LET) tracks and radiation quality near the Bragg peak. Findings unveil high-LET DNA damage signatures through aligned γ-H2AX foci, correlating with LET values in SOBP. CR-39 visualized high-LET particle exposure, indicating comet-type etch-pits at the Bragg peak and suggesting carbon ion fragmentation. Unexpectedly, dot-type etch-pits in irradiated and post-Bragg peak regions indicated high-LET neutron production. This investigation highlights the intricate interplay of carbon ion beams, stressing the importance of understanding LET variations, DNA damage patterns, and undesired secondary exposure.
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Affiliation(s)
- Piyawan Chailapakul
- Department of Environmental & Radiological Health Sciences, Colorado State University, USA
| | - Olivia Maloney
- Department of Environmental & Radiological Health Sciences, Colorado State University, USA
| | - Hirokazu Hirakawa
- Institute for Quantum Science, National Institutes for Quantum Science and Technology, Japan
| | - Akira Fujimori
- Institute for Quantum Science, National Institutes for Quantum Science and Technology, Japan
| | - Hisashi Kitamura
- Institute for Radiological Science, National Institutes for Quantum Science and Technology, Japan
| | - Takamitsu A Kato
- Department of Environmental & Radiological Health Sciences, Colorado State University, USA.
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2
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Maeda J, Nagai A, Aizawa Y, Kato TA. Palmitoyl ascorbic acid glucoside enhanced cell survival with post irradiation treatment. Biochem Biophys Res Commun 2024; 694:149386. [PMID: 38134476 DOI: 10.1016/j.bbrc.2023.149386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023]
Abstract
Radiation exposure poses a significant threat to cellular integrity by inducing DNA damage through the generation of free radicals and reactive oxygen species. Ascorbic acid, particularly its derivative Palmitoyl Ascorbic Acid 2-Glucoside (PA2G), has demonstrated remarkable radioprotective properties. While previous research focused on its pre-irradiation application, this study explores the post-irradiation radiomitigation potential of PA2G. Our findings reveal that post-irradiation treatment with PA2G enhances cell survival and accelerates DNA repair processes, particularly the non-homologous end-joining (NHEJ) repair pathway. Notably, PA2G treatment reduces the frequency of lethal chromosomal aberrations and micronuclei formation, indicating its ability to enhance the repair of complex DNA lesions. Furthermore, PA2G is shown to play a role in potentially lethal damage repair (PLDR). These radioprotective effects are specific to NHEJ and ATM pathways, as cells deficient in these mechanisms do not benefit from PA2G treatment. This study highlights PA2G as a versatile radioprotector, both pre- and post-irradiation, with significant potential for applications in radiation therapy and protection, offering new insights into its mechanism of action. Further research is required to elucidate the precise molecular mechanisms underlying PA2G's radiomitigation effects and its potential clinical applications.
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Affiliation(s)
- Junko Maeda
- Department of Environmental & Radiological Health Sciences, Colorado State University, USA
| | - Atsushi Nagai
- Research and Development Center, Carlit Holdings Co. Ltd, Japan
| | - Yasushi Aizawa
- Research and Development Center, Carlit Holdings Co. Ltd, Japan
| | - Takamitsu A Kato
- Department of Environmental & Radiological Health Sciences, Colorado State University, USA.
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3
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Abd Al-razaq MA, Isermann A, Hecht M, Rübe CE. Automated Image Analysis of Transmission Electron Micrographs: Nanoscale Evaluation of Radiation-Induced DNA Damage in the Context of Chromatin. Cells 2023; 12:2427. [PMID: 37887271 PMCID: PMC10605235 DOI: 10.3390/cells12202427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/03/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Heavy ion irradiation (IR) with high-linear energy transfer (LET) is characterized by a unique depth dose distribution and increased biological effectiveness. Following high-LET IR, localized energy deposition along the particle trajectories induces clustered DNA lesions, leading to low electron density domains (LEDDs). To investigate the spatiotemporal dynamics of DNA repair and chromatin remodeling, we established the automated image analysis of transmission electron micrographs. METHODS Human fibroblasts were irradiated with high-LET carbon ions or low-LET photons. At 0.1 h, 0.5 h, 5 h, and 24 h post-IR, nanoparticle-labeled repair factors (53BP1, pKu70, pKu80, DNA-PKcs) were visualized using transmission electron microscopy in interphase nuclei to monitor the formation and repair of DNA damage in the chromatin ultrastructure. Using AI-based software tools, advanced image analysis techniques were established to assess the DNA damage pattern following low-LET versus high-LET IR. RESULTS Low-LET IR induced single DNA lesions throughout the nucleus, and most DNA double-strand breaks (DSBs) were efficiently rejoined with no visible chromatin decondensation. High-LET IR induced clustered DNA damage concentrated along the particle trajectories, resulting in circumscribed LEDDs. Automated image analysis was used to determine the exact number of differently sized nanoparticles, their distance from one another, and their precise location within the micrographs (based on size, shape, and density). Chromatin densities were determined from grayscale features, and nanoparticles were automatically assigned to euchromatin or heterochromatin. High-LET IR-induced LEDDs were delineated using automated segmentation, and the spatial distribution of nanoparticles in relation to segmented LEDDs was determined. CONCLUSIONS The results of our image analysis suggest that high-LET IR induces chromatin relaxation along particle trajectories, enabling the critical repair of successive DNA damage. Following exposure to different radiation qualities, automated image analysis of nanoparticle-labeled DNA repair proteins in the chromatin ultrastructure enables precise characterization of specific DNA damage patterns.
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Affiliation(s)
| | | | | | - Claudia E. Rübe
- Department of Radiation Oncology, Saarland University Medical Center, Kirrbergerstr, Building 6.5, 66421 Homburg, Saar, Germany; (M.A.A.A.-r.)
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4
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Maeda J, Haskins JS, Kato TA. XRCC8 mutation causes hypersensitivity to PARP inhibition without Homologous recombination repair deficiency. Mutat Res 2023; 826:111815. [PMID: 36812659 DOI: 10.1016/j.mrfmmm.2023.111815] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023]
Abstract
PARP inhibitors inflict severe toxicity to homologous recombination (HR) repair deficient cells because DNA damages induced by PARP inhibition result in lethal DNA double strand breaks in the absence of HR repair during DNA replication. PARP inhibitors are the first clinically approved drugs designed for synthetic lethality. The synthetic lethal interaction of PARP inhibitors is not limited to HR repair deficient cells. We investigated radiosensitive mutants isolated from Chinese hamster lung origin V79 cells to identify novel synthetic lethal targets in the context of PARP inhibition. HR repair deficient BRCA2 mutant cells were used for positive control. Among tested cells, XRCC8 mutants presented hypersensitivity to PARP inhibitor, Olaparib. XRCC8 mutants showed elevated sensitivity to bleomycin and camptothecin similar to BRCA2 mutants. XRCC8 mutants presented an elevation of γ-H2AX foci formation frequency and S-phase dependent chromosome aberrations with Olaparib treatment. Enumerated damage foci following Olaparib treatment were observed to be elevated in XRCC8 as in BRCA2 mutants. Although this may suggest that XRCC8 plays a role in a similar DNA repair pathway as BRCA2 in HR repair, XRCC8 mutants presented functional HR repair including proper Rad51 foci formation and even elevated sister chromatid exchange frequencies with PARP inhibitor treatment. For comparison, RAD51 foci formation was suppressed in HR repair deficient BRCA2 mutants. Additionally, XRCC8 mutants did not display delayed mitotic entry with PARP inhibitors whereas BRCA2 mutants did. XRCC8 mutant cell line has previously been reported as possessing a mutation in the ATM gene. XRCC8 mutants displayed maximum cytotoxicity to ATM inhibitor among tested mutants and wild type cells. Furthermore, the ATM inhibitor sensitized XRCC8 mutant to ionzing radiation, however, XRCC8 mutant V-G8 expressed reduced levels of ATM protein. The gene responsible for XRCC8 phenotype may not be ATM but highly associated with ATM functions. These results suggest that XRCC8 mutation is a target for PARP inhibitor-induced synthetic lethality in HR repair independent manner via the disruption of cell cycle regulation. Our findings expand the potential application of PARP inhibitors in tumors lacking DNA damage responding genes other than HR repair, and further investigation of XRCC8 may contribute to this research.
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Affiliation(s)
- Junko Maeda
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Jeremy S Haskins
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Takamitsu A Kato
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA.
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5
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Helm A, Totis C, Durante M, Fournier C. Are charged particles a good match for combination with immunotherapy? Current knowledge and perspectives. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 376:1-36. [PMID: 36997266 DOI: 10.1016/bs.ircmb.2023.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Charged particle radiotherapy, mainly using protons and carbon ions, provides physical characteristics allowing for a volume conformal irradiation and a reduction of the integral dose to normal tissue. Carbon ion therapy additionally features an increased biological effectiveness resulting in peculiar molecular effects. Immunotherapy, mostly performed with immune checkpoint inhibitors, is nowadays considered a pillar in cancer therapy. Based on the advantageous features of charged particle radiotherapy, we review pre-clinical evidence revealing a strong potential of its combination with immunotherapy. We argue that the combination therapy deserves further investigation with the aim of translation in clinics, where a few studies have been set up already.
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Affiliation(s)
- A Helm
- Biophysics Department, GSI, Darmstadt, Germany
| | - C Totis
- Biophysics Department, GSI, Darmstadt, Germany
| | - M Durante
- Biophysics Department, GSI, Darmstadt, Germany.
| | - C Fournier
- Biophysics Department, GSI, Darmstadt, Germany
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6
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Baiocco G, Bartzsch S, Conte V, Friedrich T, Jakob B, Tartas A, Villagrasa C, Prise KM. A matter of space: how the spatial heterogeneity in energy deposition determines the biological outcome of radiation exposure. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:545-559. [PMID: 36220965 PMCID: PMC9630194 DOI: 10.1007/s00411-022-00989-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/03/2022] [Indexed: 05/10/2023]
Abstract
The outcome of the exposure of living organisms to ionizing radiation is determined by the distribution of the associated energy deposition at different spatial scales. Radiation proceeds through ionizations and excitations of hit molecules with an ~ nm spacing. Approaches such as nanodosimetry/microdosimetry and Monte Carlo track-structure simulations have been successfully adopted to investigate radiation quality effects: they allow to explore correlations between the spatial clustering of such energy depositions at the scales of DNA or chromosome domains and their biological consequences at the cellular level. Physical features alone, however, are not enough to assess the entity and complexity of radiation-induced DNA damage: this latter is the result of an interplay between radiation track structure and the spatial architecture of chromatin, and further depends on the chromatin dynamic response, affecting the activation and efficiency of the repair machinery. The heterogeneity of radiation energy depositions at the single-cell level affects the trade-off between cell inactivation and induction of viable mutations and hence influences radiation-induced carcinogenesis. In radiation therapy, where the goal is cancer cell inactivation, the delivery of a homogenous dose to the tumour has been the traditional approach in clinical practice. However, evidence is accumulating that introducing heterogeneity with spatially fractionated beams (mini- and microbeam therapy) can lead to significant advantages, particularly in sparing normal tissues. Such findings cannot be explained in merely physical terms, and their interpretation requires considering the scales at play in the underlying biological mechanisms, suggesting a systemic response to radiation.
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Affiliation(s)
- Giorgio Baiocco
- Radiation Biophysics and Radiobiology Group, Physics Department, University of Pavia, Pavia, Italy.
| | - Stefan Bartzsch
- Institute for Radiation Medicine, Helmholtz Centre Munich, Munich, Germany
- Department of Radiation Oncology, Technical University of Munich, Munich, Germany
| | - Valeria Conte
- Istituto Nazionale Di Fisica Nucleare INFN, Laboratori Nazionali Di Legnaro, Legnaro, Italy
| | - Thomas Friedrich
- Department of Biophysics, GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Adrianna Tartas
- Biomedical Physics Division, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland
| | - Carmen Villagrasa
- IRSN, Institut de Radioprotection et de Sûreté Nucléaire, Fontenay aux Roses, France
| | - Kevin M Prise
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
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7
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Averbeck NB, Barent C, Jakob B, Syzonenko T, Durante M, Taucher-Scholz G. The Ubiquitin Ligase RNF138 Cooperates with CtIP to Stimulate Resection of Complex DNA Double-Strand Breaks in Human G1-Phase Cells. Cells 2022; 11:cells11162561. [PMID: 36010636 PMCID: PMC9406464 DOI: 10.3390/cells11162561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
DNA double-strand breaks (DSBs) represent the molecular origin of ionizing-radiation inflicted biological effects. An increase in the ionization density causes more complex, clustered DSBs that can be processed by resection also in G1 phase, where repair of resected DSBs is considered erroneous and may contribute to the increased biological effectiveness of heavy ions in radiotherapy. To investigate the resection regulation of complex DSBs, we exposed G1 cells depleted for different candidate factors to heavy ions or α-particle radiation. Immunofluorescence microscopy was used to monitor the resection marker RPA, the DSB marker γH2AX and the cell-cycle markers CENP-F and geminin. The Fucci system allowed to select G1 cells, cell survival was measured by clonogenic assay. We show that in G1 phase the ubiquitin ligase RNF138 functions in resection regulation. RNF138 ubiquitinates the resection factor CtIP in a radiation-dependent manner to allow its DSB recruitment in G1 cells. At complex DSBs, RNF138′s participation becomes more relevant, consistent with the observation that also resection is more frequent at these DSBs. Furthermore, deficiency of RNF138 affects both DSB repair and cell survival upon induction of complex DSBs. We conclude that RNF138 is a regulator of resection that is influenced by DSB complexity and can affect the quality of DSB repair in G1 cells.
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Affiliation(s)
- Nicole B. Averbeck
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Correspondence:
| | - Carina Barent
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 11, 64287 Darmstadt, Germany
| | - Tatyana Syzonenko
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
| | - Marco Durante
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstr. 6–8, 64289 Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 11, 64287 Darmstadt, Germany
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8
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Human mesenchymal stromal cells maintain their stem cell traits after high-LET particle irradiation - Potential implications for particle radiotherapy and manned space missions. Cancer Lett 2022; 524:172-181. [PMID: 34688844 DOI: 10.1016/j.canlet.2021.10.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/19/2021] [Accepted: 10/11/2021] [Indexed: 12/14/2022]
Abstract
The influence of high-linear energy transfer (LET) particle radiation on the functionalities of mesenchymal stromal cells (MSCs) is largely unknown. Here, we analyzed the effects of proton (1H), helium (4He), carbon (12C) and oxygen (16O) ions on human bone marrow-MSCs. Cell cycle distribution and apoptosis induction were examined by flow cytometry, and DNA damage was quantified using γH2AX immunofluorescence and Western blots. Relative biological effectiveness values of MSCs amounted to 1.0-1.1 for 1H, 1.7-2.3 for 4He, 2.9-3.4 for 12C and 2.6-3.3 for 16O. Particle radiation did not alter the MSCs' characteristic surface marker pattern, and MSCs maintained their multi-lineage differentiation capabilities. Apoptosis rates ranged low for all radiation modalities. At 24 h after irradiation, particle radiation-induced ATM and CHK2 phosphorylation as well as γH2AX foci numbers returned to baseline levels. The resistance of human MSCs to high-LET irradiation suggests that MSCs remain functional after exposure to moderate doses of particle radiation as seen in normal tissues after particle radiotherapy or during manned space flights. In the future, in vivo models focusing on long-term consequences of particle irradiation on the bone marrow niche and MSCs are needed.
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9
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Bennett PV, Johnson AM, Ackerman SE, Chaudhary P, Keszenman DJ, Wilson PF. Dose-Rate Effects of Protons and Light Ions for DNA Damage Induction, Survival and Transformation in Apparently Normal Primary Human Fibroblasts. Radiat Res 2021; 197:298-313. [PMID: 34910217 DOI: 10.1667/rade-21-00138.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/09/2021] [Indexed: 11/03/2022]
Abstract
We report on effects of low-dose exposures of accelerated protons delivered at high-dose rate (HDR) or a simulated solar-particle event (SPE) like low-dose rate (LDR) on immediate DNA damage induction and processing, survival and in vitro transformation of low passage NFF28 apparently normal primary human fibroblasts. Cultures were exposed to 50, 100 and 1,000 MeV monoenergetic protons in the Bragg entrance/plateau region and cesium-137 γ rays at 20 Gy/h (HDR) or 1 Gy/h (LDR). DNA double-strand breaks (DSB) and clustered DNA damages (containing oxypurines and abasic sites) were measured using transverse alternating gel electrophoresis (TAFE) and immunocytochemical detection/scoring of colocalized γ-H2AX pS139/53BP1 foci, with their induction being linear energy transfer (LET) dependent and dose-rate sparing observed for the different damage classes. Relative biological effectiveness (RBE) values for cell survival after proton irradiation at both dose-rates ranged from 0.61-0.73. Transformation RBE values were dose-rate dependent, ranging from ∼1.8-3.1 and ∼0.6-1.0 at low doses (≤30 cGy) for HDR and LDR irradiations, respectively. However peak transformation frequencies were significantly higher (1.3-7.3-fold) for higher doses of 0.5-1 Gy delivered at SPE-like LDR. Cell survival and transformation frequencies measured after low-dose 500 MeV/n He-4, 290 MeV/n C-12 and 600 MeV/n Si-28 ion irradiations also showed an inverse dose-rate effect for transformation at SPE-like LDR. This work demonstrates the existence of inverse dose-rate effects for proton and light-ion-induced postirradiation cell survival and in vitro transformation for space mission-relevant doses and dose rates.
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Affiliation(s)
- Paula V Bennett
- Biology Department, Brookhaven National Laboratory, Upton, New York
| | - Alicia M Johnson
- Biology Department, Brookhaven National Laboratory, Upton, New York
| | - Sarah E Ackerman
- Biology Department, Brookhaven National Laboratory, Upton, New York
| | - Pankaj Chaudhary
- Biology Department, Brookhaven National Laboratory, Upton, New York
| | | | - Paul F Wilson
- Biology Department, Brookhaven National Laboratory, Upton, New York
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10
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Johnson AM, Bennett PV, Sanidad KZ, Hoang A, Jardine JH, Keszenman DJ, Wilson PF. Evaluation of Histone Deacetylase Inhibitors as Radiosensitizers for Proton and Light Ion Radiotherapy. Front Oncol 2021; 11:735940. [PMID: 34513712 PMCID: PMC8426582 DOI: 10.3389/fonc.2021.735940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 07/29/2021] [Indexed: 12/23/2022] Open
Abstract
Significant opportunities remain for pharmacologically enhancing the clinical effectiveness of proton and carbon ion-based radiotherapies to achieve both tumor cell radiosensitization and normal tissue radioprotection. We investigated whether pretreatment with the hydroxamate-based histone deacetylase inhibitors (HDACi) SAHA (vorinostat), M344, and PTACH impacts radiation-induced DNA double-strand break (DSB) induction and repair, cell killing, and transformation (acquisition of anchorage-independent growth in soft agar) in human normal and tumor cell lines following gamma ray and light ion irradiation. Treatment of normal NFF28 primary fibroblasts and U2OS osteosarcoma, A549 lung carcinoma, and U87MG glioma cells with 5–10 µM HDACi concentrations 18 h prior to cesium-137 gamma irradiation resulted in radiosensitization measured by clonogenic survival assays and increased levels of colocalized gamma-H2AX/53BP1 foci induction. We similarly tested these HDACi following irradiation with 200 MeV protons, 290 MeV/n carbon ions, and 350 MeV/n oxygen ions delivered in the Bragg plateau region. Unlike uniform gamma ray radiosensitization, effects of HDACi pretreatment were unexpectedly cell type and ion species-dependent with C-12 and O-16 ion irradiations showing enhanced G0/G1-phase fibroblast survival (radioprotection) and in some cases reduced or absent tumor cell radiosensitization. DSB-associated foci levels were similar for proton-irradiated DMSO control and SAHA-treated fibroblast cultures, while lower levels of induced foci were observed in SAHA-pretreated C-12 ion-irradiated fibroblasts. Fibroblast transformation frequencies measured for all radiation types were generally LET-dependent and lowest following proton irradiation; however, both gamma and proton exposures showed hyperlinear transformation induction at low doses (≤25 cGy). HDACi pretreatments led to overall lower transformation frequencies at low doses for all radiation types except O-16 ions but generally led to higher transformation frequencies at higher doses (>50 cGy). The results of these in vitro studies cast doubt on the clinical efficacy of using HDACi as radiosensitizers for light ion-based hadron radiotherapy given the mixed results on their radiosensitization effectiveness and related possibility of increased second cancer induction.
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Affiliation(s)
- Alicia M Johnson
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Paula V Bennett
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Katherine Z Sanidad
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Anthony Hoang
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - James H Jardine
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Deborah J Keszenman
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States.,Laboratorio de Radiobiología Médica y Ambiental, Grupo de Biofisicoquímica, Centro Universitario Regional Litoral Norte, Universidad de la República (UdelaR), Salto, Uruguay
| | - Paul F Wilson
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States.,Department of Radiation Oncology, University of California-Davis, Sacramento, CA, United States
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11
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Horendeck D, Walsh KD, Hirakawa H, Fujimori A, Kitamura H, Kato TA. High LET-Like Radiation Tracks at the Distal Side of Accelerated Proton Bragg Peak. Front Oncol 2021; 11:690042. [PMID: 34178687 PMCID: PMC8222778 DOI: 10.3389/fonc.2021.690042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/10/2021] [Indexed: 12/29/2022] Open
Abstract
Proton therapy is a type of hadron radiotherapy used for treating solid tumors. Unlike heavy charged elements, proton radiation is considered to be low LET (Linear Energy Transfer) radiation, like X-rays. However, the clinical SOBP (Spread Out Bragg Peak) proton radiation is considered to be higher in relative biological effectiveness (RBE) than both X-ray and their own entrance region. The RBE is estimated to be 1.1–1.2, which can be attributed to the higher LET at the SOBP region than at the entrance region. In order to clarify the nature of higher LET near the Bragg peak of proton radiation and its potential cytotoxic effects, we utilized a horizontal irradiation system with CHO cells. Additionally, we examined DNA repair mutants, analyzed cytotoxicity with colony formation, and assessed DNA damage and its repair with γ-H2AX foci assay in a high-resolution microscopic scale analysis along with the Bragg peak. Besides confirming that the most cytotoxic effects occurred at the Bragg peak, extended cytotoxicity was observed a few millimeters after the Bragg peak. γ-H2AX foci numbers reached a maximum at the Bragg peak and reduced dramatically after the Bragg peak. However, in the post-Bragg peak region, particle track-like structures were sporadically observed. This region contains foci that are more difficult to repair. The peak and post-Bragg peak regions contain rare high LET-like radiation tracks and can cause cellular lethality. This may have caused unwanted side effects and complexities of outputs for the proton therapy treatment.
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Affiliation(s)
- Dakota Horendeck
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO, United States
| | - Kade D Walsh
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO, United States
| | - Hirokazu Hirakawa
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Akira Fujimori
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Hisashi Kitamura
- Radiation Emergency Medical Assistance Team, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Takamitsu A Kato
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO, United States
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12
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Averbek S, Jakob B, Durante M, Averbeck NB. O-GlcNAcylation Affects the Pathway Choice of DNA Double-Strand Break Repair. Int J Mol Sci 2021; 22:ijms22115715. [PMID: 34071949 PMCID: PMC8198441 DOI: 10.3390/ijms22115715] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 12/13/2022] Open
Abstract
Exposing cells to DNA damaging agents, such as ionizing radiation (IR) or cytotoxic chemicals, can cause DNA double-strand breaks (DSBs), which are crucial to repair to maintain genetic integrity. O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) is a post-translational modification (PTM), which has been reported to be involved in the DNA damage response (DDR) and chromatin remodeling. Here, we investigated the impact of O-GlcNAcylation on the DDR, DSB repair and chromatin status in more detail. We also applied charged particle irradiation to analyze differences of O-GlcNAcylation and its impact on DSB repair in respect of spatial dose deposition and radiation quality. Various techniques were used, such as the γH2AX foci assay, live cell microscopy and Fluorescence Lifetime Microscopy (FLIM) to detect DSB rejoining, protein accumulation and chromatin states after treating the cells with O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) inhibitors. We confirmed that O-GlcNAcylation of MDC1 is increased upon irradiation and identified additional repair factors related to Homologous Recombination (HR), CtIP and BRCA1, which were increasingly O-GlcNAcyated upon irradiation. This is consistent with our findings that the function of HR is affected by OGT inhibition. Besides, we found that OGT and OGA activity modulate chromatin compaction states, providing a potential additional level of DNA-repair regulation.
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Affiliation(s)
- Sera Averbek
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany; (S.A.); (B.J.); (M.D.)
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany; (S.A.); (B.J.); (M.D.)
| | - Marco Durante
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany; (S.A.); (B.J.); (M.D.)
- Department of Physics, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Nicole B. Averbeck
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany; (S.A.); (B.J.); (M.D.)
- Correspondence:
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13
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Differential Repair Protein Recruitment at Sites of Clustered and Isolated DNA Double-Strand Breaks Produced by High-Energy Heavy Ions. Sci Rep 2020; 10:1443. [PMID: 31996740 PMCID: PMC6989695 DOI: 10.1038/s41598-020-58084-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/06/2020] [Indexed: 01/17/2023] Open
Abstract
DNA double-strand break (DSB) repair is crucial to maintain genomic stability. The fidelity of the repair depends on the complexity of the lesion, with clustered DSBs being more difficult to repair than isolated breaks. Using live cell imaging of heavy ion tracks produced at a high-energy particle accelerator we visualised simultaneously the recruitment of different proteins at individual sites of complex and simple DSBs in human cells. NBS1 and 53BP1 were recruited in a few seconds to complex DSBs, but in 40% of the isolated DSBs the recruitment was delayed approximately 5 min. Using base excision repair (BER) inhibitors we demonstrate that some simple DSBs are generated by enzymatic processing of base damage, while BER did not affect the complex DSBs. The results show that DSB processing and repair kinetics are dependent on the complexity of the breaks and can be different even for the same clastogenic agent.
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14
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Nickoloff JA, Sharma N, Taylor L. Clustered DNA Double-Strand Breaks: Biological Effects and Relevance to Cancer Radiotherapy. Genes (Basel) 2020; 11:E99. [PMID: 31952359 PMCID: PMC7017136 DOI: 10.3390/genes11010099] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/08/2020] [Accepted: 01/14/2020] [Indexed: 01/03/2023] Open
Abstract
Cells manage to survive, thrive, and divide with high accuracy despite the constant threat of DNA damage. Cells have evolved with several systems that efficiently repair spontaneous, isolated DNA lesions with a high degree of accuracy. Ionizing radiation and a few radiomimetic chemicals can produce clustered DNA damage comprising complex arrangements of single-strand damage and DNA double-strand breaks (DSBs). There is substantial evidence that clustered DNA damage is more mutagenic and cytotoxic than isolated damage. Radiation-induced clustered DNA damage has proven difficult to study because the spectrum of induced lesions is very complex, and lesions are randomly distributed throughout the genome. Nonetheless, it is fairly well-established that radiation-induced clustered DNA damage, including non-DSB and DSB clustered lesions, are poorly repaired or fail to repair, accounting for the greater mutagenic and cytotoxic effects of clustered lesions compared to isolated lesions. High linear energy transfer (LET) charged particle radiation is more cytotoxic per unit dose than low LET radiation because high LET radiation produces more clustered DNA damage. Studies with I-SceI nuclease demonstrate that nuclease-induced DSB clusters are also cytotoxic, indicating that this cytotoxicity is independent of radiogenic lesions, including single-strand lesions and chemically "dirty" DSB ends. The poor repair of clustered DSBs at least in part reflects inhibition of canonical NHEJ by short DNA fragments. This shifts repair toward HR and perhaps alternative NHEJ, and can result in chromothripsis-mediated genome instability or cell death. These principals are important for cancer treatment by low and high LET radiation.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA; (N.S.); (L.T.)
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15
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Dünker N, Jendrossek V. Implementation of the Chick Chorioallantoic Membrane (CAM) Model in Radiation Biology and Experimental Radiation Oncology Research. Cancers (Basel) 2019; 11:cancers11101499. [PMID: 31591362 PMCID: PMC6826367 DOI: 10.3390/cancers11101499] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023] Open
Abstract
Radiotherapy (RT) is part of standard cancer treatment. Innovations in treatment planning and increased precision in dose delivery have significantly improved the therapeutic gain of radiotherapy but are reaching their limits due to biologic constraints. Thus, a better understanding of the complex local and systemic responses to RT and of the biological mechanisms causing treatment success or failure is required if we aim to define novel targets for biological therapy optimization. Moreover, optimal treatment schedules and prognostic biomarkers have to be defined for assigning patients to the best treatment option. The complexity of the tumor environment and of the radiation response requires extensive in vivo experiments for the validation of such treatments. So far in vivo investigations have mostly been performed in time- and cost-intensive murine models. Here we propose the implementation of the chick chorioallantoic membrane (CAM) model as a fast, cost-efficient model for semi high-throughput preclinical in vivo screening of the modulation of the radiation effects by molecularly targeted drugs. This review provides a comprehensive overview on the application spectrum, advantages and limitations of the CAM assay and summarizes current knowledge of its applicability for cancer research with special focus on research in radiation biology and experimental radiation oncology.
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Affiliation(s)
- Nicole Dünker
- Institute for Anatomy II, Department of Neuroanatomy, University of Duisburg-Essen, University Medicine Essen, 45122 Essen, Germany.
| | - Verena Jendrossek
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, University Medicine Essen, 45122 Essen, Germany.
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16
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Gonon G, Villagrasa C, Voisin P, Meylan S, Bueno M, Benadjaoud MA, Tang N, Langner F, Rabus H, Barquinero JF, Giesen U, Gruel G. From Energy Deposition of Ionizing Radiation to Cell Damage Signaling: Benchmarking Simulations by Measured Yields of Initial DNA Damage after Ion Microbeam Irradiation. Radiat Res 2019; 191:566-584. [PMID: 31021733 DOI: 10.1667/rr15312.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Advances in accelerator technology, which have enabled conforming radiotherapy with charged hadronic species, have brought benefits as well as potential new risks to patients. To better understand the effects of ionizing radiation on tumor and surrounding tissue, it is important to investigate and quantify the relationship between energy deposition at the nanometric scale and the initial biological events. Monte Carlo track structure simulation codes provide a powerful tool for investigating this relationship; however, their success and reliability are dependent on their improvement and development accordingly to the dedicated biological data to which they are challenged. For this aim, a microbeam facility that allows for fluence control, down to one ion per cell nucleus, was used to evaluate relative frequencies of DNA damage after interaction between the incoming ion and DNA according to radiation quality. Primary human cells were exposed to alpha particles of three different energies with respective linear energy transfers (LETs) of approximately 36, 85 or 170 keV·µm-1 at the cells' center position, or to protons (19 keV·µm-1). Statistical evaluation of nuclear foci formation (53BP1/γ-H2AX), observed using immunofluorescence and related to a particle traversal, was undertaken in a large population of cell nuclei. The biological results were adjusted to consider the factors that drive the experimental uncertainties, then challenged with results using Geant4-DNA code modeling of the ionizing particle interactions on a virtual phantom of the cell nucleus with the same mean geometry and DNA density as the cells used in our experiments. Both results showed an increase of relative frequencies of foci (or simulated DNA damage) in cell nuclei as a function of increasing LET of the traversing particles, reaching a quasi-plateau when the LET exceeded 80-90 keV·µm-1. For the LET of an alpha particle ranging from 80-90 to 170 keV·µm-1, 10-30% of the particle hits did not lead to DNA damage inducing 53BP1 or γ-H2AX foci formation.
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Affiliation(s)
| | | | | | | | | | - Mohamed Amine Benadjaoud
- c Radiobiology and Regenerative Medicine Research Service, Direction of Human Health, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses, France
| | | | - Frank Langner
- d Department 6.5 Radiation Effects, Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
| | - Hans Rabus
- d Department 6.5 Radiation Effects, Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
| | | | - Ulrich Giesen
- d Department 6.5 Radiation Effects, Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
| | - Gaëtan Gruel
- a Radiobiology of Accidental Exposure Laboratory
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17
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Hellweg CE, Chishti AA, Diegeler S, Spitta LF, Henschenmacher B, Baumstark-Khan C. Molecular Signaling in Response to Charged Particle Exposures and its Importance in Particle Therapy. Int J Part Ther 2018; 5:60-73. [PMID: 31773020 PMCID: PMC6871585 DOI: 10.14338/ijpt-18-00016.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/13/2018] [Indexed: 12/17/2022] Open
Abstract
Energetic, charged particles elicit an orchestrated DNA damage response (DDR) during their traversal through healthy tissues and tumors. Complex DNA damage formation, after exposure to high linear energy transfer (LET) charged particles, results in DNA repair foci formation, which begins within seconds. More protein modifications occur after high-LET, compared with low-LET, irradiation. Charged-particle exposure activates several transcription factors that are cytoprotective or cytodestructive, or that upregulate cytokine and chemokine expression, and are involved in bystander signaling. Molecular signaling for a survival or death decision in different tumor types and healthy tissues should be studied as prerequisite for shaping sensitizing and protective strategies. Long-term signaling and gene expression changes were found in various tissues of animals exposed to charged particles, and elucidation of their role in chronic and late effects of charged-particle therapy will help to develop effective preventive measures.
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Affiliation(s)
- Christine E. Hellweg
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
| | - Arif Ali Chishti
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
- The Karachi Institute of Biotechnology and Genetic Engineering, University of Karachi, Karachi, Pakistan
| | - Sebastian Diegeler
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
| | - Luis F. Spitta
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
| | - Bernd Henschenmacher
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
| | - Christa Baumstark-Khan
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
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18
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Abdollahi E, Taucher-Scholz G, Jakob B. Application of fluorescence lifetime imaging microscopy of DNA binding dyes to assess radiation-induced chromatin compaction changes. Int J Mol Sci 2018; 19:E2399. [PMID: 30110966 PMCID: PMC6121443 DOI: 10.3390/ijms19082399] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/02/2018] [Accepted: 08/10/2018] [Indexed: 01/19/2023] Open
Abstract
In recent years several approaches have been developed to address the chromatin status and its changes in eukaryotic cells under different conditions-but only few are applicable in living cells. Fluorescence lifetime imaging microscopy (FLIM) is a functional tool that can be used for the inspection of the molecular environment of fluorophores in living cells. Here, we present the use of single organic minor groove DNA binder dyes in FLIM for measuring chromatin changes following modulation of chromatin structure in living cells. Treatment with histone deacetylase inhibitors led to an increased fluorescence lifetime indicating global chromatin decompaction, whereas hyperosmolarity decreased the lifetime of the used dyes, thus reflecting the expected compaction. In addition, we demonstrate that time domain FLIM data based on single photon counting should be optimized using pile-up and counting loss correction, which affect the readout even at moderate average detector count rates in inhomogeneous samples. Using these corrections and utilizing Hoechst 34580 as chromatin compaction probe, we measured a pan nuclear increase in the lifetime following irradiation with X-rays in living NIH/3T3 cells thus providing a method to measure radiation-induced chromatin decompaction.
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Affiliation(s)
- Elham Abdollahi
- Department of Biophysics, GSI Helmholzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany.
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
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19
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Timm S, Lorat Y, Jakob B, Taucher-Scholz G, Rübe CE. Clustered DNA damage concentrated in particle trajectories causes persistent large-scale rearrangements in chromatin architecture. Radiother Oncol 2018; 129:600-610. [PMID: 30049456 DOI: 10.1016/j.radonc.2018.07.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/07/2018] [Accepted: 07/05/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE High linear-energy-transfer (LET) irradiation (IR) is characterized by unique depth-dose distribution and advantageous biologic effectiveness compared to low-LET-IR, offering promising alternatives for radio-resistant tumors in clinical oncology. While low-LET-IR induces single DNA lesions such as double-strand breaks (DSBs), localized energy deposition along high-LET particle trajectories induces clustered DNA lesions that are more challenging to repair. During DNA damage response (DDR) 53BP1 and ATM are required for Kap1-dependent chromatin relaxation, thereby sustaining heterochromatic DSB repair. Here, spatiotemporal dynamics of chromatin restructuring were visualized during DDR after high-LET and low-LET-IR. MATERIAL AND METHODS Human fibroblasts were irradiated with high-LET carbon/calcium ions or low-LET photons. At 0.1 h, 0.5 h, 5 h and 24 h post-IR fluorophore- and gold-labeled repair factors (53BP1, pATM, pKAP-1, pKu70) were visualized by immunofluorescence and transmission electron microscopy, to monitor formation and repair of DNA damage in chromatin ultrastructure. To track chromatin remodeling at damage sites, decondensed regions (DCR) were delineated based on local chromatin concentration densities. RESULTS Low-LET-IR induced single DNA lesions throughout the nucleus, but nearly all DSBs were efficiently rejoined without visible chromatin decompaction. High-LET-IR induced clustered DNA damage and triggered profound changes in chromatin structure along particle trajectories. In DCR multiple heterochromatic DSBs exhibited delayed repair despite cooperative activity of 53BP1, pATM, pKap-1. These closely localized DSBs may disturb efficient repair and subsequent chromatin restoration, thereby affecting large-scale genome organization. CONCLUSION Clustered damage concentrated in particle trajectories causes persistent rearrangements in chromatin architecture, which may affect structural and functional organization of cell nuclei.
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Affiliation(s)
- Sara Timm
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Yvonne Lorat
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Claudia E Rübe
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany.
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20
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Jezkova L, Zadneprianetc M, Kulikova E, Smirnova E, Bulanova T, Depes D, Falkova I, Boreyko A, Krasavin E, Davidkova M, Kozubek S, Valentova O, Falk M. Particles with similar LET values generate DNA breaks of different complexity and reparability: a high-resolution microscopy analysis of γH2AX/53BP1 foci. NANOSCALE 2018; 10:1162-1179. [PMID: 29271466 DOI: 10.1039/c7nr06829h] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Biological effects of high-LET (linear energy transfer) radiation have received increasing attention, particularly in the context of more efficient radiotherapy and space exploration. Efficient cell killing by high-LET radiation depends on the physical ability of accelerated particles to generate complex DNA damage, which is largely mediated by LET. However, the characteristics of DNA damage and repair upon exposure to different particles with similar LET parameters remain unexplored. We employed high-resolution confocal microscopy to examine phosphorylated histone H2AX (γH2AX)/p53-binding protein 1 (53BP1) focus streaks at the microscale level, focusing on the complexity, spatiotemporal behaviour and repair of DNA double-strand breaks generated by boron and neon ions accelerated at similar LET values (∼135 keV μm-1) and low energies (8 and 47 MeV per n, respectively). Cells were irradiated using sharp-angle geometry and were spatially (3D) fixed to maximize the resolution of these analyses. Both high-LET radiation types generated highly complex γH2AX/53BP1 focus clusters with a larger size, increased irregularity and slower elimination than low-LET γ-rays. Surprisingly, neon ions produced even more complex γH2AX/53BP1 focus clusters than boron ions, consistent with DSB repair kinetics. Although the exposure of cells to γ-rays and boron ions eliminated a vast majority of foci (94% and 74%, respectively) within 24 h, 45% of the foci persisted in cells irradiated with neon. Our calculations suggest that the complexity of DSB damage critically depends on (increases with) the particle track core diameter. Thus, different particles with similar LET and energy may generate different types of DNA damage, which should be considered in future research.
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Affiliation(s)
- Lucie Jezkova
- Joint Institute for Nuclear Research, Dubna, Russia and University of Chemistry and Technology Prague, Prague, Czech Republic
- University of Chemistry and Technology Prague, Prague, Czech Republic
| | - Mariia Zadneprianetc
- Joint Institute for Nuclear Research, Dubna, Russia and Dubna State University, Dubna, Russia
- Dubna State University, Dubna, Russia
| | - Elena Kulikova
- Joint Institute for Nuclear Research, Dubna, Russia and Dubna State University, Dubna, Russia
- Dubna State University, Dubna, Russia
| | | | - Tatiana Bulanova
- Joint Institute for Nuclear Research, Dubna, Russia and Dubna State University, Dubna, Russia
- Dubna State University, Dubna, Russia
| | - Daniel Depes
- Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic.
| | - Iva Falkova
- Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic.
| | - Alla Boreyko
- Joint Institute for Nuclear Research, Dubna, Russia and Dubna State University, Dubna, Russia
- Dubna State University, Dubna, Russia
| | - Evgeny Krasavin
- Joint Institute for Nuclear Research, Dubna, Russia and Dubna State University, Dubna, Russia
- Dubna State University, Dubna, Russia
| | - Marie Davidkova
- Czech Academy of Sciences, Nuclear Physics Institute, Prague, Czech Republic
| | - Stanislav Kozubek
- Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic.
| | - Olga Valentova
- University of Chemistry and Technology Prague, Prague, Czech Republic
| | - Martin Falk
- Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic.
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21
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Abstract
Carbon ion therapy is a promising evolving modality in radiotherapy to treat tumors that are radioresistant against photon treatments. As carbon ions are more effective in normal and tumor tissue, the relative biological effectiveness (RBE) has to be calculated by bio-mathematical models and has to be considered in the dose prescription. This review (i) introduces the concept of the RBE and its most important determinants, (ii) describes the physical and biological causes of the increased RBE for carbon ions, (iii) summarizes available RBE measurements in vitro and in vivo, and (iv) describes the concepts of the clinically applied RBE models (mixed beam model, local effect model, and microdosimetric-kinetic model), and (v) the way they are introduced into clinical application as well as (vi) their status of experimental and clinical validation, and finally (vii) summarizes the current status of the use of the RBE concept in carbon ion therapy and points out clinically relevant conclusions as well as open questions. The RBE concept has proven to be a valuable concept for dose prescription in carbon ion radiotherapy, however, different centers use different RBE models and therefore care has to be taken when transferring results from one center to another. Experimental studies significantly improve the understanding of the dependencies and limitations of RBE models in clinical application. For the future, further studies investigating quantitatively the differential effects between normal tissues and tumors are needed accompanied by clinical studies on effectiveness and toxicity.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany. Author to whom any correspondence should be addressed
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22
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Kochan JA, Desclos EC, Bosch R, Meister L, Vriend LE, van Attikum H, Krawczyk PM. Meta-analysis of DNA double-strand break response kinetics. Nucleic Acids Res 2017; 45:12625-12637. [PMID: 29182755 PMCID: PMC5728399 DOI: 10.1093/nar/gkx1128] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/24/2017] [Accepted: 11/13/2017] [Indexed: 12/12/2022] Open
Abstract
Most proteins involved in the DNA double-strand break response (DSBR) accumulate at the damage sites, where they perform functions related to damage signaling, chromatin remodeling and repair. Over the last two decades, studying the accumulation of many DSBR proteins provided information about their functionality and underlying mechanisms of action. However, comparison and systemic interpretation of these data is challenging due to their scattered nature and differing experimental approaches. Here, we extracted, analyzed and compared the available results describing accumulation of 79 DSBR proteins at sites of DNA damage, which can be further explored using Cumulus (http://www.dna-repair.live/cumulus/)-the accompanying interactive online application. Despite large inter-study variability, our analysis revealed that the accumulation of most proteins starts immediately after damage induction, occurs in parallel and peaks within 15-20 min. Various DSBR pathways are characterized by distinct accumulation kinetics with major non-homologous end joining proteins being generally faster than those involved in homologous recombination, and signaling and chromatin remodeling factors accumulating with varying speeds. Our meta-analysis provides, for the first time, comprehensive overview of the temporal organization of the DSBR in mammalian cells and could serve as a reference for future mechanistic studies of this complex process.
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Affiliation(s)
- Jakub A. Kochan
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Emilie C.B. Desclos
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Ruben Bosch
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Luna Meister
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Lianne E.M. Vriend
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Przemek M. Krawczyk
- Department of Medical Biology and Laboratory of Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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23
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Vallard A, Rancoule C, Guy JB, Espenel S, Sauvaigo S, Rodriguez-Lafrasse C, Magné N. [Biomarkers of radiation-induced DNA repair processes]. Bull Cancer 2017; 104:981-987. [PMID: 29132682 DOI: 10.1016/j.bulcan.2017.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 09/21/2017] [Indexed: 12/18/2022]
Abstract
The identification of DNA repair biomarkers is of paramount importance. Indeed, it is the first step in the process of modulating radiosensitivity and radioresistance. Unlike tools of detection and measurement of DNA damage, DNA repair biomarkers highlight the variations of DNA damage responses, depending on the dose and the dose rate. The aim of the present review is to describe the main biomarkers of radiation-induced DNA repair. We will focus on double strand breaks (DSB), because of their major role in radiation-induced cell death. The most important DNA repair biomarkers are DNA damage signaling proteins, with ATM, DNA-PKcs, 53BP1 and γ-H2AX. They can be analyzed either using immunostaining, or using lived cell imaging. However, to date, these techniques are still time and money consuming. The development of "omics" technologies should lead the way to new (and usable in daily routine) DNA repair biomarkers.
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Affiliation(s)
- Alexis Vallard
- Institut de cancérologie Lucien-Neuwirth, département de radiothérapie, , 108, bis avenue Albert-Raimond, BP60008, 42271 Saint-Priest-en-Jarez cedex, France; Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France
| | - Chloé Rancoule
- Institut de cancérologie Lucien-Neuwirth, département de radiothérapie, , 108, bis avenue Albert-Raimond, BP60008, 42271 Saint-Priest-en-Jarez cedex, France; Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France
| | - Jean-Baptiste Guy
- Institut de cancérologie Lucien-Neuwirth, département de radiothérapie, , 108, bis avenue Albert-Raimond, BP60008, 42271 Saint-Priest-en-Jarez cedex, France; Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France
| | - Sophie Espenel
- Institut de cancérologie Lucien-Neuwirth, département de radiothérapie, , 108, bis avenue Albert-Raimond, BP60008, 42271 Saint-Priest-en-Jarez cedex, France; Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France
| | | | - Claire Rodriguez-Lafrasse
- Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France
| | - Nicolas Magné
- Institut de cancérologie Lucien-Neuwirth, département de radiothérapie, , 108, bis avenue Albert-Raimond, BP60008, 42271 Saint-Priest-en-Jarez cedex, France; Institut de physique nucléaire de Lyon, IPNL, CNRS-UMR-5822, laboratoire de radiobiologie cellulaire et moléculaire, 69622 Villeurbanne, France.
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24
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Allen CP, Hirakawa H, Nakajima NI, Moore S, Nie J, Sharma N, Sugiura M, Hoki Y, Araki R, Abe M, Okayasu R, Fujimori A, Nickoloff JA. Low- and High-LET Ionizing Radiation Induces Delayed Homologous Recombination that Persists for Two Weeks before Resolving. Radiat Res 2017; 188:82-93. [PMID: 28535128 DOI: 10.1667/rr14748.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Genome instability is a hallmark of cancer cells and dysregulation or defects in DNA repair pathways cause genome instability and are linked to inherited cancer predisposition syndromes. Ionizing radiation can cause immediate effects such as mutation or cell death, observed within hours or a few days after irradiation. Ionizing radiation also induces delayed effects many cell generations after irradiation. Delayed effects include hypermutation, hyper-homologous recombination, chromosome instability and reduced clonogenic survival (delayed death). Delayed hyperrecombination (DHR) is mechanistically distinct from delayed chromosomal instability and delayed death. Using a green fluorescent protein (GFP) direct repeat homologous recombination system, time-lapse microscopy and colony-based assays, we demonstrate that DHR increases several-fold in response to low-LET X rays and high-LET carbon-ion radiation. Time-lapse analyses of DHR revealed two classes of recombinants not detected in colony-based assays, including cells that recombined and then senesced or died. With both low- and high-LET radiation, DHR was evident during the first two weeks postirradiation, but resolved to background levels during the third week. The results indicate that the risk of radiation-induced genome destabilization via DHR is time limited, and suggest that there is little or no additional risk of radiation-induced genome instability mediated by DHR with high-LET radiation compared to low-LET radiation.
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Affiliation(s)
- Christopher P Allen
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Hirokazu Hirakawa
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Nakako Izumi Nakajima
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Sophia Moore
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Jingyi Nie
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Neelam Sharma
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Mayumi Sugiura
- c Division of Natural Sciences, Research Group of Biological Sciences, Nara Women's University, Nara, Japan
| | - Yuko Hoki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryoko Araki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Masumi Abe
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryuichi Okayasu
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Akira Fujimori
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Jac A Nickoloff
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
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25
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Wang Y, Guan H, Xie DF, Xie Y, Liu XD, Wang Q, Sui L, Song M, Zhang H, Zhou J, Zhou PK. Proteomic Analysis Implicates Dominant Alterations of RNA Metabolism and the Proteasome Pathway in the Cellular Response to Carbon-Ion Irradiation. PLoS One 2016; 11:e0163896. [PMID: 27711237 PMCID: PMC5053480 DOI: 10.1371/journal.pone.0163896] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 09/18/2016] [Indexed: 12/25/2022] Open
Abstract
Radiotherapy with heavy ions is considered advantageous compared to irradiation with photons due to the characteristics of the Braggs peak and the high linear energy transfer (LET) value. To understand the mechanisms of cellular responses to different LET values and dosages of heavy ion radiation, we analyzed the proteomic profiles of mouse embryo fibroblast MEF cells exposed to two doses from different LET values of heavy ion 12C. Total proteins were extracted from these cells and examined by Q Exactive with Liquid Chromatography (LC)—Electrospray Ionization (ESI) Tandem MS (MS/MS). Using bioinformatics approaches, differentially expressed proteins with 1.5 or 2.0-fold changes between different dosages of exposure were compared. With the higher the dosage and/or LET of ion irradiation, the worse response the cells were in terms of protein expression. For instance, compared to the control (0 Gy), 771 (20.2%) proteins in cells irradiated at 0.2 Gy of carbon-ion radiation with 12.6 keV/μm, 313 proteins (8.2%) in cells irradiated at 2 Gy of carbon-ion radiation with 12.6 keV/μm, and 243 proteins (6.4%) in cells irradiated at 2 Gy of carbon-ion radiation with 31.5 keV/μm exhibited changes of 1.5-fold or greater. Gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Munich Information Center for Protein Sequences (MIPS) analysis, and BioCarta analysis all indicated that RNA metabolic processes (RNA splicing, destabilization and deadenylation) and proteasome pathways may play key roles in the cellular response to heavy-ion irradiation. Proteasome pathways ranked highest among all biological processes associated with heavy carbon-ion irradiation. In addition, network analysis revealed that cellular pathways involving proteins such as Col1a1 and Fn1 continued to respond to high dosages of heavy-ion irradiation, suggesting that these pathways still protect cells against damage. However, pathways such as those involving Ikbkg1 responded better at lower dosages than at higher dosages, implying that cell damage would occur when the networks involving these proteins stop responding. Our investigation provides valuable proteomic information for elucidating the mechanism of biological effects induced by carbon ions in general.
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Affiliation(s)
- Yu Wang
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Hua Guan
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Da-Fei Xie
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yi Xie
- Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiao-Dan Liu
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Qi Wang
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Li Sui
- China Institute of Atomic Energy, Beijing 102413, China
| | - Man Song
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, School of Radiation Medicine and Protection, Soochow University, Suzhou, China
| | - Hong Zhang
- Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jianhua Zhou
- iBioinfo Groups, Lexington, Massachusetts 02421, United States of America
- Department of Neuroregeneration, Nantong University, Nantong, China
- * E-mail: (PKZ); (JZ)
| | - Ping-Kun Zhou
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiation Biology, Beijing Institute of Radiation Medicine, Beijing, China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- * E-mail: (PKZ); (JZ)
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26
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Lorat Y, Timm S, Jakob B, Taucher-Scholz G, Rübe CE. Clustered double-strand breaks in heterochromatin perturb DNA repair after high linear energy transfer irradiation. Radiother Oncol 2016; 121:154-161. [PMID: 27637859 DOI: 10.1016/j.radonc.2016.08.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/05/2016] [Accepted: 08/18/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE High linear energy transfer (LET) radiotherapy offers superior dose conformity and biological effectiveness compared with low-LET radiotherapy, representing a promising alternative for radioresistant tumours. A prevailing hypothesis is that energy deposition along the high-LET particle trajectories induces DNA lesions that are more complex and clustered and therefore more challenging to repair. The precise molecular mechanisms underlying the differences in radiobiological effects between high-LET and low-LET radiotherapies remain unclear. MATERIAL AND METHODS Human fibroblasts were irradiated with high-LET carbon ions or low-LET photons. At 0.5h and 5h post exposure, the DNA-damage pattern in the chromatin ultrastructure was visualised using gold-labelled DNA-repair factors. The induction and repair of single-strand breaks, double-strand breaks (DSBs), and clustered lesions were analysed in combination with terminal dUTP nick-end labelling of DNA breaks. RESULTS High-LET irradiation induced clustered lesions with multiple DSBs along ion trajectories predominantly in heterochromatic regions. The cluster size increased over time, suggesting inefficient DSB repair. Low-LET irradiation induced many isolated DSBs throughout the nucleus, most of which were efficiently rejoined. CONCLUSIONS The clustering of DSBs in heterochromatin following high-LET irradiation perturbs efficient DNA repair, leading to greater biological effectiveness of high-LET irradiation versus that of low-LET irradiation.
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Affiliation(s)
- Yvonne Lorat
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Sara Timm
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Claudia E Rübe
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany.
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27
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Progress on Molecular Mechanism of Phosphorylation/Dephosphorylation and Detection Technology of γH2AX. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1016/s1872-2040(16)60952-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Penterling C, Drexler GA, Böhland C, Stamp R, Wilke C, Braselmann H, Caldwell RB, Reindl J, Girst S, Greubel C, Siebenwirth C, Mansour WY, Borgmann K, Dollinger G, Unger K, Friedl AA. Depletion of Histone Demethylase Jarid1A Resulting in Histone Hyperacetylation and Radiation Sensitivity Does Not Affect DNA Double-Strand Break Repair. PLoS One 2016; 11:e0156599. [PMID: 27253695 PMCID: PMC4890786 DOI: 10.1371/journal.pone.0156599] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 05/17/2016] [Indexed: 12/31/2022] Open
Abstract
Histone demethylases have recently gained interest as potential targets in cancer treatment and several histone demethylases have been implicated in the DNA damage response. We investigated the effects of siRNA-mediated depletion of histone demethylase Jarid1A (KDM5A, RBP2), which demethylates transcription activating tri- and dimethylated lysine 4 at histone H3 (H3K4me3/me2), on growth characteristics and cellular response to radiation in several cancer cell lines. In unirradiated cells Jarid1A depletion lead to histone hyperacetylation while not affecting cell growth. In irradiated cells, depletion of Jarid1A significantly increased cellular radiosensitivity. Unexpectedly, the hyperacetylation phenotype did not lead to disturbed accumulation of DNA damage response and repair factors 53BP1, BRCA1, or Rad51 at damage sites, nor did it influence resolution of radiation-induced foci or rejoining of reporter constructs. We conclude that the radiation sensitivity observed following depletion of Jarid1A is not caused by a deficiency in repair of DNA double-strand breaks.
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Affiliation(s)
- Corina Penterling
- Department of Radiation Oncology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Guido A. Drexler
- Department of Radiation Oncology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Claudia Böhland
- Department of Radiation Oncology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Ramona Stamp
- Department of Radiation Oncology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Christina Wilke
- Research Unit Radiation Cytogenetics, Helmholtz Center Munich, Neuherberg, Germany
| | - Herbert Braselmann
- Research Unit Radiation Cytogenetics, Helmholtz Center Munich, Neuherberg, Germany
| | - Randolph B. Caldwell
- Research Unit Radiation Cytogenetics, Helmholtz Center Munich, Neuherberg, Germany
| | - Judith Reindl
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany
| | - Stefanie Girst
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany
| | - Christoph Greubel
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany
| | | | - Wael Y. Mansour
- Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Tumor Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Kerstin Borgmann
- Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Günther Dollinger
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany
| | - Kristian Unger
- Research Unit Radiation Cytogenetics, Helmholtz Center Munich, Neuherberg, Germany
- Clinical Cooperation Group ‘Personalized Radiotherapy of Head and Neck Cancer’, Helmholtz Center Munich, Neuherberg, Germany
| | - Anna A. Friedl
- Department of Radiation Oncology, Ludwig-Maximilians-University of Munich, Munich, Germany
- Clinical Cooperation Group ‘Personalized Radiotherapy of Head and Neck Cancer’, Helmholtz Center Munich, Neuherberg, Germany
- * E-mail:
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29
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Sridharan DM, Asaithamby A, Blattnig SR, Costes SV, Doetsch PW, Dynan WS, Hahnfeldt P, Hlatky L, Kidane Y, Kronenberg A, Naidu MD, Peterson LE, Plante I, Ponomarev AL, Saha J, Snijders AM, Srinivasan K, Tang J, Werner E, Pluth JM. Evaluating biomarkers to model cancer risk post cosmic ray exposure. LIFE SCIENCES IN SPACE RESEARCH 2016; 9:19-47. [PMID: 27345199 PMCID: PMC5613937 DOI: 10.1016/j.lssr.2016.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens.
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Affiliation(s)
| | | | - Steve R Blattnig
- Langley Research Center, Langley Research Center (LaRC), VA, United States
| | - Sylvain V Costes
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | | | | | | | - Lynn Hlatky
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Yared Kidane
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Amy Kronenberg
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Mamta D Naidu
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Leif E Peterson
- Houston Methodist Research Institute, Houston, TX, United States
| | - Ianik Plante
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Artem L Ponomarev
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Janapriya Saha
- UT Southwestern Medical Center, Dallas, TX, United States
| | | | | | - Jonathan Tang
- Exogen Biotechnology, Inc., Berkeley, CA, United States
| | | | - Janice M Pluth
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
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30
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Suetens A, Konings K, Moreels M, Quintens R, Verslegers M, Soors E, Tabury K, Grégoire V, Baatout S. Higher Initial DNA Damage and Persistent Cell Cycle Arrest after Carbon Ion Irradiation Compared to X-irradiation in Prostate and Colon Cancer Cells. Front Oncol 2016; 6:87. [PMID: 27148479 PMCID: PMC4830044 DOI: 10.3389/fonc.2016.00087] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/28/2016] [Indexed: 12/12/2022] Open
Abstract
The use of charged-particle beams, such as carbon ions, is becoming a more and more attractive treatment option for cancer therapy. Given the precise absorbed dose-localization and an increased biological effectiveness, this form of therapy is much more advantageous compared to conventional radiotherapy, and is currently being used for treatment of specific cancer types. The high ballistic accuracy of particle beams deposits the maximal dose to the tumor, while damage to the surrounding healthy tissue is limited. In order to better understand the underlying mechanisms responsible for the increased biological effectiveness, we investigated the DNA damage and repair kinetics and cell cycle progression in two p53 mutant cell lines, more specifically a prostate (PC3) and colon (Caco-2) cancer cell line, after exposure to different radiation qualities. Cells were irradiated with various absorbed doses (0, 0.5, and 2 Gy) of accelerated 13C-ions at the Grand Accélérateur National d’Ions Lourds facility (Caen, France) or with X-rays (0, 0.1, 0.5, 1, 2, and 5 Gy). Microscopic analysis of DNA double-strand breaks showed dose-dependent increases in γ-H2AX foci numbers and foci occupancy after exposure to both types of irradiation, in both cell lines. However, 24 h after exposure, residual damage was more pronounced after lower doses of carbon ion irradiation compared to X-irradiation. Flow cytometric analysis showed that carbon ion irradiation induced a permanent G2/M arrest in PC3 cells at lower doses (2 Gy) compared to X-rays (5 Gy), while in Caco-2 cells the G2/M arrest was transient after irradiation with X-rays (2 and 5 Gy) but persistent after exposure to carbon ions (2 Gy).
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Affiliation(s)
- Annelies Suetens
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
- Radiation Oncology Department, Center for Molecular Imaging, Radiotherapy and Oncology, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCL), Bruxelles, Belgium
| | - Katrien Konings
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Marjan Moreels
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
- *Correspondence: Marjan Moreels,
| | - Roel Quintens
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
| | - Mieke Verslegers
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
| | - Els Soors
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
| | - Kevin Tabury
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
| | - Vincent Grégoire
- Radiation Oncology Department, Center for Molecular Imaging, Radiotherapy and Oncology, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCL), Bruxelles, Belgium
| | - Sarah Baatout
- Expert Group for Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Institute for Environment, Health and Safety, Mol, Belgium
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31
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Averbeck NB, Topsch J, Scholz M, Kraft-Weyrather W, Durante M, Taucher-Scholz G. Efficient Rejoining of DNA Double-Strand Breaks despite Increased Cell-Killing Effectiveness following Spread-Out Bragg Peak Carbon-Ion Irradiation. Front Oncol 2016; 6:28. [PMID: 26904506 PMCID: PMC4751252 DOI: 10.3389/fonc.2016.00028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/25/2016] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy of solid tumors with charged particles holds several advantages in comparison to photon therapy; among them conformal dose distribution in the tumor, improved sparing of tumor-surrounding healthy tissue, and an increased relative biological effectiveness (RBE) in the tumor target volume in the case of ions heavier than protons. A crucial factor of the biological effects is DNA damage, of which DNA double-strand breaks (DSBs) are the most deleterious. The reparability of these lesions determines the cell survival after irradiation and thus the RBE. Interestingly, using phosphorylated H2AX as a DSB marker, our data in human fibroblasts revealed that after therapy-relevant spread-out Bragg peak irradiation with carbon ions DSBs are very efficiently rejoined, despite an increased RBE for cell survival. This suggests that misrepair plays an important role in the increased RBE of heavy-ion radiation. Possible sources of erroneous repair will be discussed.
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Affiliation(s)
- Nicole B Averbeck
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH , Darmstadt , Germany
| | - Jana Topsch
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH , Darmstadt , Germany
| | - Michael Scholz
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH , Darmstadt , Germany
| | - Wilma Kraft-Weyrather
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH , Darmstadt , Germany
| | - Marco Durante
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany; Technische Universität Darmstadt, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany; Technische Universität Darmstadt, Darmstadt, Germany
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32
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Reindl J, Drexler GA, Girst S, Greubel C, Siebenwirth C, Drexler SE, Dollinger G, Friedl AA. Nanoscopic exclusion between Rad51 and 53BP1 after ion irradiation in human HeLa cells. Phys Biol 2015; 12:066005. [DOI: 10.1088/1478-3975/12/6/066005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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33
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Rall M, Kraft D, Volcic M, Cucu A, Nasonova E, Taucher-Scholz G, Bönig H, Wiesmüller L, Fournier C. Impact of Charged Particle Exposure on Homologous DNA Double-Strand Break Repair in Human Blood-Derived Cells. Front Oncol 2015; 5:250. [PMID: 26618143 PMCID: PMC4641431 DOI: 10.3389/fonc.2015.00250] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/26/2015] [Indexed: 12/12/2022] Open
Abstract
Ionizing radiation generates DNA double-strand breaks (DSB) which, unless faithfully repaired, can generate chromosomal rearrangements in hematopoietic stem and/or progenitor cells (HSPC), potentially priming the cells towards a leukemic phenotype. Using an enhanced green fluorescent protein (EGFP)-based reporter system, we recently identified differences in the removal of enzyme-mediated DSB in human HSPC versus mature peripheral blood lymphocytes (PBL), particularly regarding homologous DSB repair (HR). Assessment of chromosomal breaks via premature chromosome condensation or γH2AX foci indicated similar efficiency and kinetics of radiation-induced DSB formation and rejoining in PBL and HSPC. Prolonged persistence of chromosomal breaks was observed for higher LET charged particles which are known to induce more complex DNA damage compared to X-rays. Consistent with HR deficiency in HSPC observed in our previous study, we noticed here pronounced focal accumulation of 53BP1 after X-ray and carbon ion exposure (intermediate LET) in HSPC versus PBL. For higher LET, 53BP1 foci kinetics was similarly delayed in PBL and HSPC suggesting similar failure to repair complex DNA damage. Data obtained with plasmid reporter systems revealed a dose- and LET-dependent HR increase after X-ray, carbon ion and higher LET exposure, particularly in HR-proficient immortalized and primary lymphocytes, confirming preferential use of conservative HR in PBL for intermediate LET damage repair. HR measured adjacent to the leukemia-associated MLL breakpoint cluster sequence in reporter lines revealed dose dependency of potentially leukemogenic rearrangements underscoring the risk of leukemia-induction by radiation treatment.
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Affiliation(s)
- Melanie Rall
- Department of Obstetrics and Gynaecology, Ulm University, Ulm, Germany
| | - Daniela Kraft
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Meta Volcic
- Department of Obstetrics and Gynaecology, Ulm University, Ulm, Germany
| | - Aljona Cucu
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Elena Nasonova
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Halvard Bönig
- German Red Cross Blood Service Baden-Wuerttemberg – Hessen, Institute for Transfusion Medicine and Immunohematology, Johann Wolfgang Goethe-University Hospital, Frankfurt, Germany
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynaecology, Ulm University, Ulm, Germany
- *Correspondence: Lisa Wiesmüller, ; Claudia Fournier,
| | - Claudia Fournier
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
- *Correspondence: Lisa Wiesmüller, ; Claudia Fournier,
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Kijas AW, Lim YC, Bolderson E, Cerosaletti K, Gatei M, Jakob B, Tobias F, Taucher-Scholz G, Gueven N, Oakley G, Concannon P, Wolvetang E, Khanna KK, Wiesmüller L, Lavin MF. ATM-dependent phosphorylation of MRE11 controls extent of resection during homology directed repair by signalling through Exonuclease 1. Nucleic Acids Res 2015; 43:8352-67. [PMID: 26240375 PMCID: PMC4787824 DOI: 10.1093/nar/gkv754] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 07/14/2015] [Indexed: 02/07/2023] Open
Abstract
The MRE11/RAD50/NBS1 (MRN) complex plays a central role as a sensor of DNA double strand breaks (DSB) and is responsible for the efficient activation of ataxia-telangiectasia mutated (ATM) kinase. Once activated ATM in turn phosphorylates RAD50 and NBS1, important for cell cycle control, DNA repair and cell survival. We report here that MRE11 is also phosphorylated by ATM at S676 and S678 in response to agents that induce DNA DSB, is dependent on the presence of NBS1, and does not affect the association of members of the complex or ATM activation. A phosphosite mutant (MRE11S676AS678A) cell line showed decreased cell survival and increased chromosomal aberrations after radiation exposure indicating a defect in DNA repair. Use of GFP-based DNA repair reporter substrates in MRE11S676AS678A cells revealed a defect in homology directed repair (HDR) but single strand annealing was not affected. More detailed investigation revealed that MRE11S676AS678A cells resected DNA ends to a greater extent at sites undergoing HDR. Furthermore, while ATM-dependent phosphorylation of Kap1 and SMC1 was normal in MRE11S676AS678A cells, there was no phosphorylation of Exonuclease 1 consistent with the defect in HDR. These results describe a novel role for ATM-dependent phosphorylation of MRE11 in limiting the extent of resection mediated through Exonuclease 1.
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Affiliation(s)
- Amanda W Kijas
- The University of Queensland, UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland 4029, Australia
| | - Yi Chieh Lim
- Brain Cancer Research Unit, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4029, Australia
| | - Emma Bolderson
- Genome Stability Laboratory, Translational Research Institute, Queensland University of Technology, Queensland 4102, Australia
| | - Karen Cerosaletti
- Translational Research Program, Benaroya Research Institute, Seattle, WA 981010, USA
| | - Magtouf Gatei
- The University of Queensland, UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland 4029, Australia
| | - Burkhard Jakob
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany
| | - Frank Tobias
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany
| | | | - Nuri Gueven
- School of Medicine, Faculty of Health, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Greg Oakley
- University of Nebraska College of Dentistry, Lincoln, NE 68583-0740, USA
| | - Patrick Concannon
- Genetics Institute, University of Florida, Gainesville, Florida, FL 3261, USA
| | - Ernst Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane 4072, Australia
| | - Kum Kum Khanna
- Signal transduction, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4029, Australia
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynaecology, University of Ulm, Ulm 89075, Germany
| | - Martin F Lavin
- The University of Queensland, UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland 4029, Australia
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Tommasino F, Friedrich T, Jakob B, Meyer B, Durante M, Scholz M. Induction and Processing of the Radiation-Induced Gamma-H2AX Signal and Its Link to the Underlying Pattern of DSB: A Combined Experimental and Modelling Study. PLoS One 2015; 10:e0129416. [PMID: 26067661 PMCID: PMC4465900 DOI: 10.1371/journal.pone.0129416] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/10/2015] [Indexed: 12/23/2022] Open
Abstract
We present here an analysis of DSB induction and processing after irradiation with X-rays in an extended dose range based on the use of the γH2AX assay. The study was performed by quantitative flow cytometry measurements, since the use of foci counting would result in reasonable accuracy only in a limited dose range of a few Gy. The experimental data are complemented by a theoretical analysis based on the GLOBLE model. In fact, original aim of the study was to test GLOBLE predictions against new experimental data, in order to contribute to the validation of the model. Specifically, the γH2AX signal kinetics has been investigated up to 24 h after exposure to increasing photon doses between 2 and 500 Gy. The prolonged persistence of the signal at high doses strongly suggests dose dependence in DSB processing after low LET irradiation. Importantly, in the framework of our modelling analysis, this is related to a gradually increased fraction of DSB clustering at the micrometre scale. The parallel study of γH2AX dose response curves shows the onset of a pronounced saturation in two cell lines at a dose of about 20 Gy. This dose is much lower than expected according to model predictions based on the values usually adopted for the DSB induction yield (≈ 30 DSB/Gy) and for the γH2AX foci extension of approximately 2 Mbp around the DSB. We show and discuss how theoretical predictions and experimental findings can be in principle reconciled by combining an increased DSB induction yield with the assumption of a larger genomic extension for the single phosphorylated regions. As an alternative approach, we also considered in our model the possibility of a 3D spreading-mechanism of the H2AX phosphorylation around the induced DSB, and applied it to the analysis of both the aspects considered. Our results are found to be supportive for the basic assumptions on which GLOBLE is built. Apart from giving new insights into the H2AX phosphorylation process, experiments performed at high doses are of relevance in the context of radiation therapy, where hypo-fractionated schemes become increasingly popular.
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Affiliation(s)
- Francesco Tommasino
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
- * E-mail:
| | - Thomas Friedrich
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
| | - Burkhard Jakob
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
| | - Barbara Meyer
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Marco Durante
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
- Technische Universität Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany
| | - Michael Scholz
- GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, Germany
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Antonelli F, Campa A, Esposito G, Giardullo P, Belli M, Dini V, Meschini S, Simone G, Sorrentino E, Gerardi S, Cirrone GAP, Tabocchini MA. Induction and Repair of DNA DSB as Revealed by H2AX Phosphorylation Foci in Human Fibroblasts Exposed to Low- and High-LET Radiation: Relationship with Early and Delayed Reproductive Cell Death. Radiat Res 2015; 183:417-31. [PMID: 25844944 DOI: 10.1667/rr13855.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The spatial distribution of radiation-induced DNA breaks within the cell nucleus depends on radiation quality in terms of energy deposition pattern. It is generally assumed that the higher the radiation linear energy transfer (LET), the greater the DNA damage complexity. Using a combined experimental and theoretical approach, we examined the phosphorylation-dephosphorylation kinetics of radiation-induced γ-H2AX foci, size distribution and 3D focus morphology, and the relationship between DNA damage and cellular end points (i.e., cell killing and lethal mutations) after exposure to gamma rays, protons, carbon ions and alpha particles. Our results showed that the maximum number of foci are reached 30 min postirradiation for all radiation types. However, the number of foci after 0.5 Gy of each radiation type was different with gamma rays, protons, carbon ions and alpha particles inducing 12.64 ± 0.25, 10.11 ± 0.40, 8.84 ± 0.56 and 4.80 ± 0.35 foci, respectively, which indicated a clear influence of the track structure and fluence on the numbers of foci induced after a dose of 0.5 Gy for each radiation type. The γ-H2AX foci persistence was also dependent on radiation quality, i.e., the higher the LET, the longer the foci persisted in the cell nucleus. The γ-H2AX time course was compared with cell killing and lethal mutation and the results highlighted a correlation between cellular end points and the duration of γ-H2AX foci persistence. A model was developed to evaluate the probability that multiple DSBs reside in the same gamma-ray focus and such probability was found to be negligible for doses lower than 1 Gy. Our model provides evidence that the DSBs inside complex foci, such as those induced by alpha particles, are not processed independently or with the same time constant. The combination of experimental, theoretical and simulation data supports the hypothesis of an interdependent processing of closely associated DSBs, possibly associated with a diminished correct repair capability, which affects cell killing and lethal mutation.
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Affiliation(s)
- F Antonelli
- a Health and Technology Department, Istituto Superiore di Sanità, Roma, Italy
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Lorat Y, Brunner CU, Schanz S, Jakob B, Taucher-Scholz G, Rübe CE. Nanoscale analysis of clustered DNA damage after high-LET irradiation by quantitative electron microscopy--the heavy burden to repair. DNA Repair (Amst) 2015; 28:93-106. [PMID: 25659339 DOI: 10.1016/j.dnarep.2015.01.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 01/14/2015] [Accepted: 01/20/2015] [Indexed: 12/18/2022]
Abstract
Low- and high-linear energy transfer (LET) ionising radiation are effective cancer therapies, but produce structurally different forms of DNA damage. Isolated DNA damage is repaired efficiently; however, clustered lesions may be more difficult to repair, and are considered as significant biological endpoints. We investigated the formation and repair of DNA double-strand breaks (DSBs) and clustered lesions in human fibroblasts after exposure to sparsely (low-LET; delivered by photons) and densely (high-LET; delivered by carbon ions) ionising radiation. DNA repair factors (pKu70, 53BP1, γH2AX, and pXRCC1) were detected using immunogold-labelling and electron microscopy, and spatiotemporal DNA damage patterns were analysed within the nuclear ultrastructure at the nanoscale level. By labelling activated Ku-heterodimers (pKu70) the number of DSBs was determined in electron-lucent euchromatin and electron-dense heterochromatin. Directly after low-LET exposure (5 min post-irradiation), single pKu70 dimers, which reflect isolated DSBs, were randomly distributed throughout the entire nucleus with a linear dose correlation up to 30 Gy. Most euchromatic DSBs were sensed and repaired within 40 min, whereas heterochromatic DSBs were processed with slower kinetics. Essentially all DNA lesions induced by low-LET irradiation were efficiently rejoined within 24h post-irradiation. High-LET irradiation caused localised energy deposition within the particle tracks, and generated highly clustered DNA lesions with multiple DSBs in close proximity. The dimensions of these clustered lesions along the particle trajectories depended on the chromatin packing density, with huge DSB clusters predominantly localised in condensed heterochromatin. High-LET irradiation-induced clearly higher DSB yields than low-LET irradiation, with up to ∼ 500 DSBs per μm(3) track volume, and large fractions of these heterochromatic DSBs remained unrepaired. Hence, the spacing and quantity of DSBs in clustered lesions influence DNA repair efficiency, and may determine the radiobiological outcome.
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Affiliation(s)
- Yvonne Lorat
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Christina U Brunner
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Stefanie Schanz
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, Germany
| | - Claudia E Rübe
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany.
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38
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Saha J, Wilson P, Thieberger P, Lowenstein D, Wang M, Cucinotta FA. Biological characterization of low-energy ions with high-energy deposition on human cells. Radiat Res 2014; 182:282-91. [PMID: 25098728 DOI: 10.1667/rr13747.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
During space travel, astronauts are exposed to cosmic radiation that is comprised of high-energy nuclear particles. Cancer patients are also exposed to high-energy nuclear particles when treated with proton and carbon beams. Nuclear interactions from high-energy particles traversing shielding materials and tissue produce low-energy (<10 MeV/n) secondary particles of high-LET that contribute significantly to overall radiation exposures. Track structure theories suggest that high charge and energy (HZE) particles and low-energy secondary ions of similar LET will have distinct biological effects for cellular and tissue damage endpoints. We investigated the biological effects of low-energy ions of high LET utilizing the Tandem Van de Graaff accelerator at the Brookhaven National Laboratory (BNL), and compared these to experiments with HZE particles, that mimic the space environment produced at NASA Space Radiation Laboratory (NSRL) at BNL. Immunostaining for DNA damage response proteins was carried out after irradiation with 5.6 MeV/n boron (LET 205 keV/μm), 5.3 MeV/n silicon (LET 1241 keV/μm), 600 MeV/n Fe (LET 180 keV/μm) and 77 MeV/n oxygen (LET 58 keV/μm) particles. Low-energy ions caused more persistent DNA damage response (DDR) protein foci in irradiated human fibroblasts and esophageal epithelial cells compared to HZE particles. More detailed studies comparing boron ions to Fe particles, showed that boron-ion radiation resulted in a stronger G2 delay compared to Fe-particle exposure, and boron ions also showed an early recruitment of Rad51 at double-strand break (DSB) sites, which suggests a preference of homologous recombination for DSB repair in low-energy albeit high-LET particles. Our experiments suggest that the very high-energy radiation deposition by low-energy ions, representative of galactic cosmic radiation and solar particle event secondary radiation, generates massive but localized DNA damage leading to delayed DSB repair, and distinct cellular responses from HZE particles. Thus, low-energy heavy ions provide a valuable probe for studies of homologous recombination repair in radiation responses.
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Affiliation(s)
- Janapriya Saha
- a Division of Space Life Sciences, Universities Space Research Association, Houston, Texas
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39
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The repair of environmentally relevant DNA double strand breaks caused by high linear energy transfer irradiation – No simple task. DNA Repair (Amst) 2014; 17:64-73. [DOI: 10.1016/j.dnarep.2014.01.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/10/2014] [Accepted: 01/24/2014] [Indexed: 01/03/2023]
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Vandersickel V, Beukes P, Van Bockstaele B, Depuydt J, Vral A, Slabbert J. Induction and disappearance of γH2AX foci and formation of micronuclei after exposure of human lymphocytes to ⁶⁰Co γ-rays and p(66)+ Be(40) neutrons. Int J Radiat Biol 2014; 90:149-58. [PMID: 24168313 DOI: 10.3109/09553002.2014.860252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To investigate both the formation of micronuclei (MN) and the induction and subsequent loss of phosphorylated histone H2AX foci (γH2AX foci) after in vitro exposure of human lymphocytes to either (60)Co γ-rays or p(66)+ Be(40) neutrons. MATERIALS AND METHODS MN dose response (DR) curves were obtained by exposing isolated lymphocytes of 10 different donors to doses ranging from 0-4 Gy γ-rays or 0-2 Gy neutrons. Also, γH2AX foci DR curves were obtained following exposure to doses ranging from 0-0.5 Gy of either γ-rays or neutrons. Foci kinetics for lymphocytes for a single donor exposed to 0.5 Gy γ-rays or neutrons were studied up to 24 hours post-irradiation. RESULTS Micronuclei yields following neutron exposure were consistently higher compared to that from (60)Co γ-rays. All MN yields were over-dispersed compared to a Poisson distribution. Over-dispersion was higher after neutron irradiation for all doses > 0.1 Gy. Up to 4 hours post-irradiation lower yields of neutron-induced γH2AX foci were observed. Between 4 and 24 hours the numbers of foci from neutrons were consistently higher than that from γ-rays. The half-live of foci disappearance is only marginally longer for neutrons compared to that from γ-rays. Foci formations were more likely to be over-dispersed for neutron irradiations. CONCLUSION Although neutrons are more effective to induce MN, the absolute number of induced γH2AX foci are less at first compared to γ-rays. With time neutron-induced foci are more persistent. These findings are helpful for using γH2AX foci in biodosimetry and to understand the repair of neutron-induced cellular damage.
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Affiliation(s)
- Veerle Vandersickel
- NRF iThemba LABS (Laboratory for Accelerated Based Sciences), Somerset West, South Africa and Department of Medical Imaging and Clinical Oncology, University of Stellenbosch , South Africa
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Becker A, Durante M, Taucher-Scholz G, Jakob B. ATM alters the otherwise robust chromatin mobility at sites of DNA double-strand breaks (DSBs) in human cells. PLoS One 2014; 9:e92640. [PMID: 24651490 PMCID: PMC3961414 DOI: 10.1371/journal.pone.0092640] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/23/2014] [Indexed: 11/18/2022] Open
Abstract
Ionizing radiation induces DNA double strand breaks (DSBs) which can lead to the formation of chromosome rearrangements through error prone repair. In mammalian cells the positional stability of chromatin contributes to the maintenance of genome integrity. DSBs exhibit only a small, submicron scale diffusive mobility, but a slight increase in the mobility of chromatin domains by the induction of DSBs might influence repair fidelity and the formation of translocations. The radiation-induced local DNA decondensation in the vicinity of DSBs is one factor potentially enhancing the mobility of DSB-containing chromatin domains. Therefore in this study we focus on the influence of different chromatin modifying proteins, known to be activated by the DNA damage response, on the mobility of DSBs. IRIF (ionizing radiation induced foci) in U2OS cells stably expressing 53BP1-GFP were used as a surrogate marker of DSBs. Low angle charged particle irradiation, known to trigger a pronounced DNA decondensation, was used for the defined induction of linear tracks of IRIF. Our results show that movement of IRIF is independent of the investigated chromatin modifying proteins like ACF1 or PARP1 and PARG. Also depletion of proteins that tether DNA strands like MRE11 and cohesin did not alter IRIF dynamics significantly. Inhibition of ATM, a key component of DNA damage response signaling, resulted in a pronounced confinement of DSB mobility, which might be attributed to a diminished radiation induced decondensation. This confinement following ATM inhibition was confirmed using X-rays, proving that this effect is not restricted to densely ionizing radiation. In conclusion, repair sites of DSBs exhibit a limited mobility on a small spatial scale that is mainly unaffected by depletion of single remodeling or DNA tethering proteins. However, it relies on functional ATM kinase which is considered to influence the chromatin structure after irradiation.
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Affiliation(s)
- Annabelle Becker
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Marco Durante
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- Technical University of Darmstadt, Darmstadt, Germany
| | - Gisela Taucher-Scholz
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- Technical University of Darmstadt, Darmstadt, Germany
| | - Burkhard Jakob
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
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Girst S, Hable V, Drexler GA, Greubel C, Siebenwirth C, Haum M, Friedl AA, Dollinger G. Subdiffusion supports joining of correct ends during repair of DNA double-strand breaks. Sci Rep 2014; 3:2511. [PMID: 23979012 PMCID: PMC3753591 DOI: 10.1038/srep02511] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/18/2013] [Indexed: 12/03/2022] Open
Abstract
The mobility of damaged chromatin regions in the nucleus may affect the probability of mis-repair. In this work, live-cell observation and distance tracking of GFP-tagged DNA damage response protein MDC1 was used to study the random-walk behaviour of chromatin domains containing radiation-induced DNA double-strand breaks (DSB). Our measurements indicate a subdiffusion-type random walk process with similar time dependence for isolated and clustered DSBs that were induced by 20 MeV proton or 43 MeV carbon ion micro-irradiation. As compared to normal diffusion, subdiffusion enhances the probability that both ends of a DSB meet, thus promoting high efficiency DNA repair. It also limits their probability of long-range movements and thus lowers the probability of mis-rejoining and chromosome aberrations.
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Affiliation(s)
- S Girst
- Angewandte Physik und Messtechnik LRT2, Universität der Bundeswehr München, 85577 Neubiberg, Germany.
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Niklas M, Abdollahi A, Akselrod MS, Debus J, Jäkel O, Greilich S. Subcellular spatial correlation of particle traversal and biological response in clinical ion beams. Int J Radiat Oncol Biol Phys 2013; 87:1141-7. [PMID: 24113054 DOI: 10.1016/j.ijrobp.2013.08.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/05/2013] [Accepted: 08/27/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To report on the spatial correlation of physical track information (fluorescent nuclear track detectors, FNTDs) and cellular DNA damage response by using a novel hybrid detector (Cell-Fit-HD). METHODS AND MATERIALS The FNTDs were coated with a monolayer of human non-small cell lung carcinoma (A549) cells and irradiated with carbon ions (270.55 MeV u(-1), rising flank of the Bragg peak). Phosphorylated histone variant H2AX accumulating at the irradiation-induced double-strand break site was labeled (RIF). The position and direction of ion tracks in the FNTD were registered with the location of the RIF sequence as an ion track surrogate in the cell layer. RESULTS All RIF sequences could be related to their corresponding ion tracks, with mean deviations of 1.09 μm and -1.72 μm in position and of 2.38° in slope. The mean perpendicular between ion track and RIF sequence was 1.58 μm. The mean spacing of neighboring RIFs exhibited a regular rather than random spacing. CONCLUSIONS Cell-Fit-HD allows for unambiguous spatial correlation studies of cell damage with respect to the intracellular ion traversal under therapeutic beam conditions.
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Affiliation(s)
- Martin Niklas
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, National Center for Radiation Research in Oncology, Heidelberg Institute of Radiation Oncology, Heidelberg, Germany.
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Plante I, Ponomarev AL, Cucinotta FA. Calculation of the energy deposition in nanovolumes by protons and HZE particles: geometric patterns of initial distributions of DNA repair foci. Phys Med Biol 2013; 58:6393-405. [PMID: 23999659 DOI: 10.1088/0031-9155/58/18/6393] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The biological effects of high-linear energy transfer (LET) radiation are different from those caused by low-LET radiation due to the difference in the patterns of energy deposition in cells. In this work, we studied the role of the track structure in the spatial distribution of radiation-induced double-strand breaks (DSBs). In the first part, the irradiation of a cubic volume of 12 µm of side by 300 MeV protons (LET ∼0.3 keV µm(-1)) and by 1 GeV/amu iron ion particles (LET∼150 keV µm(-1)) was simulated with the Monte Carlo code RITRACKS (relativistic ion tracks) and the dose was calculated in voxels of different sizes. In the second part, dose calculations were combined with chromosomes simulated by a random walk (RW) model to assess the formation of DSBs. The number of DSBs was calculated as a function of the dose and particle fluence for 1 GeV protons, 293 MeV/u carbon, and 1 GeV/u iron particles. Finally, the DSB yield was obtained as a function of the LET for protons, helium, and carbon. In general, the number and distribution of calculated DSBs were similar to experimental DNA repair foci data. From this study, we concluded that a stochastic model combining nanoscopic dose calculations and chromosomes simulated by RWs is a useful approach to study radiation-induced DSBs.
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Affiliation(s)
- Ianik Plante
- Division of Space Life Sciences, Universities Space Research Association, 3600 Bay Area Blvd, Houston, TX 77058 USA.
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Müller I, Merk B, Voss KO, Averbeck N, Jakob B, Durante M, Taucher-Scholz G. Species conserved DNA damage response at the inactive human X chromosome. Mutat Res 2013; 756:30-36. [PMID: 23628434 DOI: 10.1016/j.mrgentox.2013.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 04/21/2013] [Indexed: 06/02/2023]
Abstract
Chromatin modifications are long known as an essential part of the orchestrated response resulting in the repair of radiation-induced DNA double-strand breaks (DSBs). Only recently, however, the influence of the chromatin architecture itself on the DNA damage response has been recognised. Thus for heterochromatic DSBs the sensing and early recruitment of repair factors to the lesion occurs within the heterochromatic compartments, but the damage sites are subsequently relocated from the inside to the outside of the heterochromatin. While previous studies were accomplished at the constitutive heterochromatin of centromeric regions in mouse and flies, here we examine the DSB repair at the facultative heterochromatin of the inactive X chromosome (Xi) in humans. Using heavy ion irradiation we show that at later times after irradiation the DSB damage streaks bend around the Xi verifying that the relocation process is conserved between species and not specialised to repetitive sequences only. In addition, to measure chromatin relaxation at rare positions within the genome, we established live cell microscopy at the GSI microbeam thus allowing the aimed irradiation of small nuclear structures like the Xi. Chromatin decondensation at DSBs within the Xi is clearly visible within minutes as a continuous decrease of the DNA staining over time, comparable to the DNA relaxation revealed at DSBs in mouse chromocenters. Furthermore, despite being conserved between species, slight differences in the underlying regulation of these processes in heterochromatic DSBs are apparent.
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Affiliation(s)
- Iris Müller
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany.
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Visualisation of γH2AX foci caused by heavy ion particle traversal; distinction between core track versus non-track damage. PLoS One 2013; 8:e70107. [PMID: 23967070 PMCID: PMC3743843 DOI: 10.1371/journal.pone.0070107] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 06/18/2013] [Indexed: 11/19/2022] Open
Abstract
Heavy particle irradiation produces complex DNA double strand breaks (DSBs) which can arise from primary ionisation events within the particle trajectory. Additionally, secondary electrons, termed delta-electrons, which have a range of distributions can create low linear energy transfer (LET) damage within but also distant from the track. DNA damage by delta-electrons distant from the track has not previously been carefully characterised. Using imaging with deconvolution, we show that at 8 hours after exposure to Fe (∼200 keV/µm) ions, γH2AX foci forming at DSBs within the particle track are large and encompass multiple smaller and closely localised foci, which we designate as clustered γH2AX foci. These foci are repaired with slow kinetics by DNA non-homologous end-joining (NHEJ) in G1 phase with the magnitude of complexity diminishing with time. These clustered foci (containing 10 or more individual foci) represent a signature of DSBs caused by high LET heavy particle radiation. We also identified simple γH2AX foci distant from the track, which resemble those arising after X-ray exposure, which we attribute to low LET delta-electron induced DSBs. They are rapidly repaired by NHEJ. Clustered γH2AX foci induced by heavy particle radiation cause prolonged checkpoint arrest compared to simple γH2AX foci following X-irradiation. However, mitotic entry was observed when ∼10 clustered foci remain. Thus, cells can progress into mitosis with multiple clusters of DSBs following the traversal of a heavy particle.
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Meyer B, Voss KO, Tobias F, Jakob B, Durante M, Taucher-Scholz G. Clustered DNA damage induces pan-nuclear H2AX phosphorylation mediated by ATM and DNA-PK. Nucleic Acids Res 2013; 41:6109-18. [PMID: 23620287 PMCID: PMC3695524 DOI: 10.1093/nar/gkt304] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
DNA double-strand breaks (DSB) are considered as the most deleterious DNA lesions, and their repair is further complicated by increasing damage complexity. However, the molecular effects of clustered lesions are yet not fully understood. As the locally restricted phosphorylation of H2AX to form γH2AX is a key step in facilitating efficient DSB repair, we investigated this process after localized induction of clustered damage by ionizing radiation. We show that in addition to foci at damaged sites, H2AX is also phosphorylated in undamaged chromatin over the whole-cell nucleus in human and rodent cells, but this is not related to apoptosis. This pan-nuclear γH2AX is mediated by the kinases ataxia telangiectasia mutated and DNA-dependent protein kinase (DNA-PK) that also phosphorylate H2AX at DSBs. The pan-nuclear response is dependent on the amount of DNA damage and is transient even under conditions of impaired DSB repair. Using fluorescence recovery after photobleaching (FRAP), we found that MDC1, but not 53BP1, binds to the nuclear-wide γH2AX. Consequently, the accumulation of MDC1 at DSBs is reduced. Altogether, we show that a transient dose-dependent activation of the kinases occurring on complex DNA lesions leads to their nuclear-wide distribution and H2AX phosphorylation, yet without eliciting a full pan-nuclear DNA damage response.
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Affiliation(s)
- Barbara Meyer
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Planckstrasse 1, D-64291 Darmstadt, Germany
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Fujii Y, Yurkon CR, Maeda J, Genet SC, Okayasu R, Kitamura H, Fujimori A, Kato TA. Influence of track directions on the biological consequences in cells irradiated with high LET heavy ions. Int J Radiat Biol 2013; 89:401-10. [PMID: 23363030 DOI: 10.3109/09553002.2013.767990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The impact of the damage distribution to cellular survival and chromosomal aberrations following high Linear Energy Transfer (LET) radiation was investigated. MATERIALS AND METHODS High LET iron-ions (500 MeV/n, LET 200 keV/μm) were delivered to G1-phase synchronized Chinese Hamster Ovary (CHO) cells located at a vertical or horizontal angle relative to the ion beam in order to give same dose but different fluence and damage distribution. RESULTS Horizontal irradiation produced DNA double-strand break (DSB) along each ion track represented as clustered lines, and vertical irradiation produced a greater fluence. The initial damages measured by premature chromosome condensation were equal per dose in both irradiation types. Horizontal irradiation proved to be less effective in cell killing than vertical at doses of more than 3 Gy. Vertical irradiation produced a higher number of metaphase chromosomal aberrations compared to horizontally irradiated samples. In particular, formation of exchange-type aberrations was the same, but that of deletion-type aberrations were significantly higher after vertical irradiation than horizontal irradiation. CONCLUSIONS Therefore, we concluded that high fluence per dose is more effective than low fluence per dose to produce radiation-induced chromosomal aberrations and to kill exposed cells following high LET heavy-ion exposure.
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Affiliation(s)
- Yoshihiro Fujii
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage, Chiba, Japan
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Tobias F, Löb D, Lengert N, Durante M, Drossel B, Taucher-Scholz G, Jakob B. Spatiotemporal dynamics of early DNA damage response proteins on complex DNA lesions. PLoS One 2013; 8:e57953. [PMID: 23469115 PMCID: PMC3582506 DOI: 10.1371/journal.pone.0057953] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/29/2013] [Indexed: 11/18/2022] Open
Abstract
The response of cells to ionizing radiation-induced DNA double-strand breaks (DSB) is determined by the activation of multiple pathways aimed at repairing the injury and maintaining genomic integrity. Densely ionizing radiation induces complex damage consisting of different types of DNA lesions in close proximity that are difficult to repair and may promote carcinogenesis. Little is known about the dynamic behavior of repair proteins on complex lesions. In this study we use live-cell imaging for the spatio-temporal characterization of early protein interactions at damage sites of increasing complexity. Beamline microscopy was used to image living cells expressing fluorescently-tagged proteins during and immediately after charged particle irradiation to reveal protein accumulation at damaged sites in real time. Information on the mobility and binding rates of the recruited proteins was obtained from fluorescence recovery after photobleaching (FRAP). Recruitment of the DNA damage sensor protein NBS1 accelerates with increasing lesion density and saturates at very high damage levels. FRAP measurements revealed two different binding modalities of NBS1 to damage sites and a direct impact of lesion complexity on the binding. Faster recruitment with increasing lesion complexity was also observed for the mediator MDC1, but mobility was limited at very high damage densities due to nuclear-wide binding. We constructed a minimal computer model of the initial response to DSB based on known protein interactions only. By fitting all measured data using the same set of parameters, we can reproduce the experimentally characterized steps of the DNA damage response over a wide range of damage densities. The model suggests that the influence of increasing lesion density accelerating NBS1 recruitment is only dependent on the different binding modes of NBS1, directly to DSB and to the surrounding chromatin via MDC1. This elucidates an impact of damage clustering on repair without the need of invoking extra processing steps.
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Affiliation(s)
- Frank Tobias
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Daniel Löb
- TU Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany
| | - Nicor Lengert
- TU Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany
| | - Marco Durante
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- TU Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany
| | - Barbara Drossel
- TU Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany
| | | | - Burkhard Jakob
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- * E-mail:
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Abstract
Development of new radiotherapy strategies based on the use of hadrons, as well as reduction of uncertainties associated with radiation health risk during long-term space flights, requires increasing knowledge of the mechanisms underlying the biological effects of charged particles. It is well known that charged particles are more effective in damaging biological systems than photons. This capability has been related to the production of spatially correlated and/or clustered DNA damage, in particular two or more double-strand breaks (DSB) in close proximity or DSB associated with other lesions within a localized DNA region. These kinds of complex damages are rarely induced by photons. They are difficult to repair accurately and are therefore expected to produce severe consequences at the cellular level. This paper provides a review of radiation-induced cellular effects and will discuss the dependence of cell death and mutation induction on the linear energy transfer of various light and heavy ions. This paper will show the inadequacy of a single physical parameter for describing radiation quality, underlining the importance of the characteristics of the track structure at the submicrometer level to determine the biological effects. This paper will give a description of the physical properties of the track structure that can explain the differences in the spatial distributions of DNA damage, in particular DSB, induced by radiation of different qualities. In addition, this paper will show how a combined experimental and theoretical approach based on Monte Carlo simulations can be useful for providing information on the damage distribution at the nanoscale level. It will also emphasize the importance, especially for DNA damage evaluation at low doses, of the more recent functional approaches based on the use of fluorescent antibodies against proteins involved in the cellular processing of DNA damage. Advantages and limitations of the different experimental techniques will be discussed with particular emphasis on the still unsolved problem of the clustered DNA damage resolution. Development of biophysical models aimed to describe the kinetics of the DNA repair process is underway, and it is expected to support the experimental investigation of the mechanisms underlying the cellular radiation response.
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