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Belov O, Chigasova A, Pustovalova M, Osipov A, Eremin P, Vorobyeva N, Osipov AN. Dose-Dependent Shift in Relative Contribution of Homologous Recombination to DNA Repair after Low-LET Ionizing Radiation Exposure: Empirical Evidence and Numerical Simulation. Curr Issues Mol Biol 2023; 45:7352-7373. [PMID: 37754249 PMCID: PMC10528584 DOI: 10.3390/cimb45090465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
Understanding the relative contributions of different repair pathways to radiation-induced DNA damage responses remains a challenging issue in terms of studying the radiation injury endpoints. The comparative manifestation of homologous recombination (HR) after irradiation with different doses greatly determines the overall effectiveness of recovery in a dividing cell after irradiation, since HR is an error-free mechanism intended to perform the repair of DNA double-strand breaks (DSB) during S/G2 phases of the cell cycle. In this article, we present experimentally observed evidence of dose-dependent shifts in the relative contributions of HR in human fibroblasts after X-ray exposure at doses in the range 20-1000 mGy, which is also supported by quantitative modeling of DNA DSB repair. Our findings indicate that the increase in the radiation dose leads to a dose-dependent decrease in the relative contribution of HR in the entire repair process.
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Affiliation(s)
- Oleg Belov
- Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Russia;
- Institute of Biomedical Problems, Russian Academy of Sciences, 76A Khoroshevskoye Shosse, 123007 Moscow, Russia
- Institute of System Analysis and Management, Dubna State University, 19 Universitetskaya St., 141980 Dubna, Russia
| | - Anna Chigasova
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; (A.C.); (A.O.); (N.V.)
- Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Margarita Pustovalova
- State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC—FMBC), 123098 Moscow, Russia;
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Andrey Osipov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; (A.C.); (A.O.); (N.V.)
| | - Petr Eremin
- FSBI “National Medical Research Center for Rehabilitation and Balneology”, Ministry of Health of Russia, 121099 Moscow, Russia;
| | - Natalia Vorobyeva
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; (A.C.); (A.O.); (N.V.)
- State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC—FMBC), 123098 Moscow, Russia;
| | - Andreyan N. Osipov
- Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Russia;
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; (A.C.); (A.O.); (N.V.)
- State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC—FMBC), 123098 Moscow, Russia;
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
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Liang Y, Wu J, Ding Z, Liu C, Fu Q. Evaluation of the Yield of DNA Double-Strand Breaks for Carbon Ions Using Monte Carlo Simulation and DNA Fragment Distribution. Int J Radiat Oncol Biol Phys 2023; 117:252-261. [PMID: 36966847 DOI: 10.1016/j.ijrobp.2023.03.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/07/2023] [Accepted: 03/15/2023] [Indexed: 04/07/2023]
Abstract
PURPOSE The aim of this work was to provide a method to evaluate the yield of DNA double-strand breaks (DSBs) for carbon ions, overcoming the bias in existing methods due to the nonrandom distribution of DSBs. METHODS AND MATERIALS A previously established biophysical program based on the radiation track structure and a multilevel chromosome model was used to simulate DNA damage induced by x-rays and carbon ions. The fraction of activity retained (FAR) as a function of absorbed dose or particle fluence was obtained by counting the fraction of DNA fragments larger than 6 Mbp. Simulated FAR curves for the 250 kV x-rays and carbon ions at various energies were compared with measurements using constant-field gel electrophoresis. The doses or fluences at the FAR of 0.7 based on linear interpolation were used to estimate the simulation error for the production of DSBs. RESULTS The relative difference of doses at the FAR of 0.7 between simulation and experiment was -8.5% for the 250 kV x-rays. The relative differences of fluences at the FAR of 0.7 between simulations and experiments were -17.5%, -42.2%, -18.2%, -3.1%, 10.8%, and -14.5% for the 34, 65, 130, 217, 2232, and 3132 MeV carbon ions, respectively. In comparison, the measurement uncertainty was about 20%. Carbon ions produced remarkably more DSBs and DSB clusters per unit dose than x-rays. The yield of DSBs for carbon ions, ranging from 10 to 16 Gbp-1Gy-1, increased with linear energy transfer (LET) but plateaued in the high-LET end. The yield of DSB clusters first increased and then decreased with LET. This pattern was similar to the relative biological effectiveness for cell survival for heavy ions. CONCLUSIONS The estimated yields of DSBs for carbon ions increased from 10 Gbp-1Gy-1 in the low-LET end to 16 Gbp-1Gy-1 in the high-LET end with 20% uncertainty.
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Affiliation(s)
- Ying Liang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China.
| | - Jianan Wu
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China
| | - Zhen Ding
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China
| | - Chenbin Liu
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China
| | - Qibin Fu
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, China
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Yachi Y, Matsuya Y, Yoshii Y, Fukunaga H, Date H, Kai T. An Analytical Method for Quantifying the Yields of DNA Double-Strand Breaks Coupled with Strand Breaks by γ-H2AX Focus Formation Assay Based on Track-Structure Simulation. Int J Mol Sci 2023; 24:ijms24021386. [PMID: 36674901 PMCID: PMC9864015 DOI: 10.3390/ijms24021386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/27/2022] [Accepted: 01/06/2023] [Indexed: 01/13/2023] Open
Abstract
Complex DNA double-strand break (DSB), which is defined as a DSB coupled with additional strand breaks within 10 bp in this study, induced after ionizing radiation or X-rays, is recognized as fatal damage which can induce cell death with a certain probability. In general, a DSB site inside the nucleus of live cells can be experimentally detected using the γ-H2AX focus formation assay. DSB complexity is believed to be detected by analyzing the focus size using such an assay. However, the relationship between focus size and DSB complexity remains uncertain. In this study, using Monte Carlo (MC) track-structure simulation codes, i.e., an in-house WLTrack code and a Particle and Heavy Ion Transport code System (PHITS), we developed an analytical method for qualifying the DSB complexity induced by photon irradiation from the microscopic image of γ-H2AX foci. First, assuming that events (i.e., ionization and excitation) potentially induce DNA strand breaks, we scored the number of events in a water cube (5.03 × 5.03 × 5.03 nm3) along electron tracks. Second, we obtained the relationship between the number of events and the foci size experimentally measured by the γ-H2AX focus formation assay. Third, using this relationship, we evaluated the degree of DSB complexity induced after photon irradiation for various X-ray spectra using the foci size, and the experimental DSB complexity was compared to the results estimated by the well-verified DNA damage estimation model in the PHITS code. The number of events in a water cube was found to be proportional to foci size, suggesting that the number of events intrinsically related to DSB complexity at the DNA scale. The developed method was applicable to focus data measured for various X-ray spectral situations (i.e., diagnostic kV X-rays and therapeutic MV X-rays). This method would contribute to a precise understanding of the early biological impacts of photon irradiation by means of the γ-H2AX focus formation assay.
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Affiliation(s)
- Yoshie Yachi
- Graduate School of Health Sciences, Hokkaido University, Kita-12 Nishi-5, Kita-ku, Sapporo 060-0812, Japan
| | - Yusuke Matsuya
- Faculty of Health Sciences, Hokkaido University, Kita-12 Nishi-5, Kita-ku, Sapporo 060-0812, Japan
- Japan Atomic Energy Agency (JAEA), Nuclear Science and Engineering Centre, Research Group for Radiation Transport Analysis, 2-4 Shirakata, Tokai, Naka-gun 319-1195, Japan
- Correspondence: or (Y.M.); (T.K.)
| | - Yuji Yoshii
- Central Institute of Isotope Science, Hokkaido University, Kita-15 Nishi-7, Kita-ku, Sapporo 060-0815, Japan
| | - Hisanori Fukunaga
- Faculty of Health Sciences, Hokkaido University, Kita-12 Nishi-5, Kita-ku, Sapporo 060-0812, Japan
| | - Hiroyuki Date
- Faculty of Health Sciences, Hokkaido University, Kita-12 Nishi-5, Kita-ku, Sapporo 060-0812, Japan
| | - Takeshi Kai
- Japan Atomic Energy Agency (JAEA), Nuclear Science and Engineering Centre, Research Group for Radiation Transport Analysis, 2-4 Shirakata, Tokai, Naka-gun 319-1195, Japan
- Correspondence: or (Y.M.); (T.K.)
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Matsuya Y, Kai T, Parisi A, Yoshii Y, Sato T. Application of a simple DNA damage model developed for electrons to proton irradiation. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac9a20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/13/2022] [Indexed: 01/18/2023]
Abstract
Abstract
Proton beam therapy allows irradiating tumor volumes with reduced side effects on normal tissues with respect to conventional x-ray radiotherapy. Biological effects such as cell killing after proton beam irradiations depend on the proton kinetic energy, which is intrinsically related to early DNA damage induction. As such, DNA damage estimation based on Monte Carlo simulations is a research topic of worldwide interest. Such simulation is a mean of investigating the mechanisms of DNA strand break formations. However, past modellings considering chemical processes and DNA structures require long calculation times. Particle and heavy ion transport system (PHITS) is one of the general-purpose Monte Carlo codes that can simulate track structure of protons, meanwhile cannot handle radical dynamics simulation in liquid water. It also includes a simple model enabling the efficient estimation of DNA damage yields only from the spatial distribution of ionizations and excitations without DNA geometry, which was originally developed for electron track-structure simulations. In this study, we investigated the potential application of the model to protons without any modification. The yields of single-strand breaks, double-strand breaks (DSBs) and the complex DSBs were assessed as functions of the proton kinetic energy. The PHITS-based estimation showed that the DSB yields increased as the linear energy transfer (LET) increased, and reproduced the experimental and simulated yields of various DNA damage types induced by protons with LET up to about 30 keV μm−1. These results suggest that the current DNA damage model implemented in PHITS is sufficient for estimating DNA lesion yields induced after protons irradiation except at very low energies (below 1 MeV). This model contributes to evaluating early biological impacts in radiation therapy.
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Kolobynina KG, Rapp A, Cardoso MC. Chromatin Ubiquitination Guides DNA Double Strand Break Signaling and Repair. Front Cell Dev Biol 2022; 10:928113. [PMID: 35865631 PMCID: PMC9294282 DOI: 10.3389/fcell.2022.928113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Chromatin is the context for all DNA-based molecular processes taking place in the cell nucleus. The initial chromatin structure at the site of the DNA damage determines both, lesion generation and subsequent activation of the DNA damage response (DDR) pathway. In turn, proceeding DDR changes the chromatin at the damaged site and across large fractions of the genome. Ubiquitination, besides phosphorylation and methylation, was characterized as an important chromatin post-translational modification (PTM) occurring at the DNA damage site and persisting during the duration of the DDR. Ubiquitination appears to function as a highly versatile “signal-response” network involving several types of players performing various functions. Here we discuss how ubiquitin modifiers fine-tune the DNA damage recognition and response and how the interaction with other chromatin modifications ensures cell survival.
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Matsuya Y, Kai T, Sato T, Ogawa T, Hirata Y, Yoshii Y, Parisi A, Liamsuwan T. Track-structure modes in particle and heavy ion transport code system (PHITS): application to radiobiological research. Int J Radiat Biol 2021; 98:148-157. [PMID: 34930091 DOI: 10.1080/09553002.2022.2013572] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE In radiation physics, Monte Carlo radiation transport simulations are powerful tools to evaluate the cellular responses after irradiation. When investigating such radiation-induced biological effects, it is essential to perform track structure simulations by explicitly considering each atomic interaction in liquid water at the sub-cellular and DNA scales. The Particle and Heavy-Ion Transport code System (PHITS) is a Monte Carlo code which enables to calculate track structure at DNA scale by employing the track-structure modes for electrons, protons and carbon ions. In this paper, we review the recent development status and future prospects of the track-structure modes in the PHITS code. CONCLUSIONS To date, the physical features of these modes have been verified using the available experimental data and Monte Carlo simulation results reported in literature. These track-structure modes can be used for calculating microdosimetric distributions to estimate cell survival and for estimating initial DNA damage yields. The use of PHITS track-structure mode is expected not only to clarify the underlying mechanisms of radiation effects but also to predict curative effects in radiation therapy. The results of PHITS simulations coupled with biophysical models will contribute to the radiobiological studies by precisely predicting radiation-induced biological effects based on the Monte Carlo approach.
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Affiliation(s)
- Yusuke Matsuya
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Takeshi Kai
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Tatsuhiko Ogawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Yuho Hirata
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Yuji Yoshii
- Central Institute of Isotope Science, Hokkaido University, Sapporo, Japan
| | - Alessio Parisi
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida
| | - Thiansin Liamsuwan
- Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
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Rucinski A, Biernacka A, Schulte R. Applications of nanodosimetry in particle therapy planning and beyond. Phys Med Biol 2021; 66. [PMID: 34731854 DOI: 10.1088/1361-6560/ac35f1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 11/03/2021] [Indexed: 12/28/2022]
Abstract
This topical review summarizes underlying concepts of nanodosimetry. It describes the development and current status of nanodosimetric detector technology. It also gives an overview of Monte Carlo track structure simulations that can provide nanodosimetric parameters for treatment planning of proton and ion therapy. Classical and modern radiobiological assays that can be used to demonstrate the relationship between the frequency and complexity of DNA lesion clusters and nanodosimetric parameters are reviewed. At the end of the review, existing approaches of treatment planning based on relative biological effectiveness (RBE) models or dose-averaged linear energy transfer are contrasted with an RBE-independent approach based on nandosimetric parameters. Beyond treatment planning, nanodosimetry is also expected to have applications and give new insights into radiation protection dosimetry.
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Affiliation(s)
| | - Anna Biernacka
- University of Gdansk, Intercollegiate Faculty of Biotechnology of University of Gdańsk and Medical University of Gdansk, 80-307 Gdansk, Poland
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Ray U, Sharma S, Kapoor I, Kumari S, Gopalakrishnan V, Vartak SV, Kumari N, Varshney U, Raghavan SC. G4 DNA present at human telomeric DNA contributes toward reduced sensitivity to γ-radiation induced oxidative damage, but not bulky adduct formation. Int J Radiat Biol 2021; 97:1166-1180. [PMID: 34259614 DOI: 10.1080/09553002.2021.1955997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE DNA, the hereditary material of a human cell generally exists as Watson-Crick base paired double-stranded B-DNA. Studies suggest that DNA can also exist in non-B forms, such as four stranded G-quadruplexes (G4 DNA). Recently, our studies revealed that the regions of DNA that can fold into G-quadruplex structures are less sensitive to ionizing radiation (IR) compared to B-DNA. Importantly, we reported that the planar G-quartet of a G4 structure is shielded from radiation induced DNA breaks, while the single- and double-stranded DNA regions remained susceptible. Thus, in the present study, we investigate whether telomeric repeat DNA present at the end of telomere, known to fold into G4 DNA can protect from radiation induced damages including strand breaks, oxidation of purines and bulky adduct formation on DNA. MATERIALS AND METHODS For plasmid irradiation assay, plasmids containing human telomeric repeat DNA sequence TTAGGG (0.8 kb or 1.8 kb) were irradiated with increasing doses of IR along with appropriate control plasmids and products were resolved on 1% agarose gel. Radioprotection was evaluated based on extent of conversion of supercoiled to nicked or linear forms of the DNA following irradiation. Formation of G-quadruplex structure on supercoiled DNA was evaluated based on circular dichroism (CD) spectroscopy studies. Cleavage of radiation induced oxidative damage and extent of formation of nicks was further evaluated using base and nucleotide excision repair proteins. RESULTS Results from CD studies showed that the plasmid DNA harboring human telomeric repeats (TTAGGG) can fold into G-quadruplex DNA structures. Further, results showed that human telomeric repeat sequence when present on a plasmid can protect the plasmid DNA against IR induced DNA strand breaks, unlike control plasmids bearing random DNA sequence. CONCLUSIONS Human telomeric repeat sequence when present on plasmids can fold into G-quadruplex DNA structures, and can protect the DNA against IR induced DNA strand breaks and oxidative damage. These results in conjunction with our previous studies suggest that telomeric repeat sequence imparts less sensitivity to IR and thus telomeres of chromosomes are protected from radiation.
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Affiliation(s)
- Ujjayinee Ray
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Shivangi Sharma
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Indu Kapoor
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Susmita Kumari
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Vidya Gopalakrishnan
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India.,Department of Zoology, St. Joseph's College, Irinjalakuda, India
| | - Supriya V Vartak
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Nitu Kumari
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Sathees C Raghavan
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
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Tabocchini MA. A forty-year journey from "classical" biophysics and radiobiology to hadrontherapy, space radiation and low dose rate underground radiobiology. Int J Radiat Biol 2021; 98:383-394. [PMID: 34259611 DOI: 10.1080/09553002.2021.1948142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE As a biologist who, since the beginning of her involvement in science, has collaborated closely with physicists, I want to share my forty years of experience describing the events that introduced me to the world of charged particle radiation biology as well as that of low doses/dose rates, with related implications in medicine and radiation protection. CONCLUSION The main features of my experience can be summarized in the development of an interdisciplinary culture and in the interest in technological advances for the study of biological responses to radiation in different scenarios, relevant for public health. Mine was a journey that began by chance, but which led me to a world that proved to be of great interest to me. With the current advances in science, the new generations of scientists have new opportunities that I wish them to face with the same interest and enthusiasm that I felt for such an interdisciplinary field as that of radiation biology.
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Affiliation(s)
- Maria Antonella Tabocchini
- Istituto Nazionale di Fisica Nucleare (INFN), Rome, Italy.,Formerly: Istituto Superiore di Sanità (ISS), National Center for Innovative Technologies in Public Health, Rome, Italy
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Zhang YZ, Ge SJ, Leng QZ, Ma JJ, Liu HC. Preliminary study of the toxicity and radioprotective effects of zymosan in vitro and in vivo. BMC Pharmacol Toxicol 2021; 22:16. [PMID: 33731220 PMCID: PMC7968253 DOI: 10.1186/s40360-021-00482-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 03/07/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aimed to confirm the cytotoxicity of zymosan in vitro and in vivo and determine the appropriate treatment time and the dose of zymosan. METHODS AHH-1 cells and HIECs were administered by 0, 20, 40, 80 or 160 μg/mL zymosan. The CCK-8 assay and flow cytometry were used to evaluate the cell viability and apoptosis 24 h, 48 h, and 72 h after administration. Furthermore, 12 h before irradiation, the cells were treated with 0, 5, 10, or 20 μg/mL zymosan and then irradiated with 4 Gy X-rays. Cell viability and apoptosis were measured by the CCK-8 assay and flow cytometry at 24 h. In addition, the protective effect of zymosan against radiation in vitro was compared to that of 20 μg/mL LPS. In vivo, weight, the spleen index, and the thymus index were measured to evaluate the toxicity of 0, 5, 10, 20, and 10 mg/kg zymosan. In addition, rats were treated with 0, 2, 4, 8, or 10 mg/kg zymosan and then irradiated with 7 Gy X-rays. The survival rate, organ index were evaluated. The protective effect of zymosan against radiation in vivo was compared to that of 10 mg/kg LPS a positive control. RESULTS The viability and apoptosis of cells treated with different doses and treatment times of zymosan were not different from those of control cells (p < 0.05). Furthermore, cell viability and apoptosis were clearly improved after zymosan preadministration (p < 0.05). The radioprotective effect of zymosan was dose-dependent. In addition, the viability of cells pretreated with zymosan was higher than that of cells pretreated with LPS, and the apoptosis rate of zymosan-treated cells was lower than that of cells pretreated with LPS (p < 0.05). In vivo, weight, the spleen index and the thymus index were significantly decreased by zymosan at a concentration of 20 mg/kg (p < 0.05). Further experiments showed that the concentration at which zymosan exerted radioprotective effects was 10 mg/kg. The survival curves in the irradiated rats were barely separated between the LPS treatment and zymosan treatment. CONCLUSION Zymosan administration before radiation exposure significantly increased cell viability and the survival rates of rats.
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Affiliation(s)
- Yue-Zhi Zhang
- Laboratory of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, 264000, China
| | - Shu-Jing Ge
- Nursing Department, 970 Hospital of Chinese People's Liberation Army, Yantai, 264002, China
| | - Qing-Zhen Leng
- Cancer Non-Invasive Diagnosis and Treatment Center, 970 Hospital of Chinese People's Liberation Army, No. 7, ZhiChu South Road, Yantai, 264002, China
| | - Jian-Jun Ma
- Cancer Non-Invasive Diagnosis and Treatment Center, 970 Hospital of Chinese People's Liberation Army, No. 7, ZhiChu South Road, Yantai, 264002, China
| | - Han-Chen Liu
- Cancer Non-Invasive Diagnosis and Treatment Center, 970 Hospital of Chinese People's Liberation Army, No. 7, ZhiChu South Road, Yantai, 264002, China.
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Kumari N, Raghavan SC. G-quadruplex DNA structures and their relevance in radioprotection. Biochim Biophys Acta Gen Subj 2021; 1865:129857. [PMID: 33508382 DOI: 10.1016/j.bbagen.2021.129857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND DNA, the genetic material of most of the organisms, is the crucial element of life. Integrity of DNA needs to be maintained for transmission of genetic material from one generation to another. All organisms are constantly challenged by the environmental conditions which can lead to the induction of DNA damage. Ionizing radiation (IR) has been known to induce DNA damage and IR sensitivity varies among different organisms. The causes for differential radiosensitivity among various organisms have not been studied in great detail. SCOPE OF REVIEW We discuss DNA secondary structure formation, GC content of the genome, role of G-quadruplex formation, and its relationship with radiosensitivity of the genome. MAJOR CONCLUSION In Deinococcus radiodurans, the bacterium that exhibits maximum radio resistance, multiple G-quadruplex forming motifs are reported. In human cells, G-quadruplex formation led to differential radiosensitivity. In this article, we have discussed, the role of secondary DNA structure formation like G-quadruplex in shielding the genome from radiation and its implications in understanding evolution of radio protective effect of an organism. We also discuss role of GC content and its correlation with radio resistance. GENERAL SIGNIFICANCE This review provides an insight into the role of G-quadruplexes in providing differential radiosensitivity at different site of the genome and in different organisms. It further discusses the possibility of higher GC content contributing towards reduced radiosensitivity in different organisms, evolution of radiosensitivity, and regulation of multiple cellular processes.
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Affiliation(s)
- Nitu Kumari
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Sathees C Raghavan
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
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Mirsch J, Hintz L, Maier A, Fournier C, Löbrich M. An Assessment of Radiation Doses From Radon Exposures Using a Mouse Model System. Int J Radiat Oncol Biol Phys 2020; 108:770-778. [PMID: 32473181 DOI: 10.1016/j.ijrobp.2020.05.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/08/2020] [Accepted: 05/18/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND Radon and its progenies contribute significantly to the natural background radiation and cause several thousands of lung cancer cases per year worldwide. Moreover, patients with chronic inflammatory joint diseases are treated in radon galleries. Due to the complex nature of radon exposure, the doses associated with radon exposures are difficult to assess. Hence, there is a clear need to directly measure dose depositions from radon exposures to provide reliable risk estimates for radiation protection guidelines. OBJECTIVES We aimed to assess tissue-specific radiation doses associated with radon activity concentrations, that deposit similar dose levels as the annual natural radon exposure or radon gallery visits. METHODS We exposed mice to defined radon concentrations, quantified the number of 53BP1 foci as a measure of induced DNA damage, and compared it with the number of foci induced by known doses of reference-type radiations. An image-based analysis of the 3-dimensional foci pattern provided information about the radiation type inflicting the DNA damage. RESULTS A 1-hour exposure to 440 kBq/m3 radon-induced DNA damage corresponding to a dose of ∼10 mGy in the lung and ∼3.3 mGy in the kidney, heart, and liver. A 1-hour exposure to 44 kBq/m3 provided values consistent with a linear relationship between dose and radon concentration. Two-thirds of the dose in the lung was caused by α-particles. The dose in the kidney, heart, and liver and one-third of the dose in the lung likely resulted from β- and γ-rays. DISCUSSION We found that radon exposures mainly lead to α-particle-induced DNA damage in the lung, consistent with the lung cancer risk obtained in epidemiologic studies. Our presented biodosimetric approach can be used to benchmark risk model calculations for radiation protection guidelines and can help to understand the therapeutic success of radon gallery treatments.
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Affiliation(s)
- Johanna Mirsch
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Lisa Hintz
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Andreas Maier
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
| | - Claudia Fournier
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany.
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13
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Ma W, Gu C, Ma L, Fan C, Zhang C, Sun Y, Li C, Yang G. Mixed secondary chromatin structure revealed by modeling radiation-induced DNA fragment length distribution. SCIENCE CHINA-LIFE SCIENCES 2020; 63:825-834. [PMID: 32279284 DOI: 10.1007/s11427-019-1638-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/20/2020] [Indexed: 10/24/2022]
Abstract
Spatial chromatin structure plays fundamental roles in many vital biological processes including DNA replication, transcription, damage and repair. However, the current understanding of the secondary structure of chromatin formed by local nucleosome-nucleosome interactions remains controversial, especially for the existence and conformation of 30 nm structure. Since chromatin structure influences the fragment length distribution (FLD) of ionizing radiation-induced DNA strand breaks, a 3D chromatin model fitting FLD patterns can help to distinguish different models of chromatin structure. Here, we developed a novel "30-C" model combining 30 nm chromatin structure models with Hi-C data, which measured the spatial contact frequency between different loci in the genome. We first reconstructed the 3D coordinates of the 25 kb bins from Hi-C heatmaps. Within the 25 kb bins, lower level chromatin structures supported by recent studies were filled. Simulated FLD patterns based on the 30-C model were compared to published FLD patterns induced by heavy ion radiation to validate the models. Importantly, the 30-C model predicted that the most probable chromatin fiber structure for human interphase fibroblasts in vivo was 45% zig-zag 30 nm fibers and 55% 10 nm fibers.
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Affiliation(s)
- Wenzong Ma
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China
| | - Chenyang Gu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China.,Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Lin Ma
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China.,Medical Artificial Intelligence and Automation, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Caoqi Fan
- Center for Bioinformatics, School of Life Sciences and Center for Statistical Science, Peking University, Beijing, 100871, China
| | - Chao Zhang
- Center for Bioinformatics, School of Life Sciences and Center for Statistical Science, Peking University, Beijing, 100871, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Cheng Li
- Center for Bioinformatics, School of Life Sciences and Center for Statistical Science, Peking University, Beijing, 100871, China.
| | - Gen Yang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China.
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14
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Xu X, Nakano T, Tsuda M, Kanamoto R, Hirayama R, Uzawa A, Ide H. Direct observation of damage clustering in irradiated DNA with atomic force microscopy. Nucleic Acids Res 2020; 48:e18. [PMID: 31840169 PMCID: PMC7026632 DOI: 10.1093/nar/gkz1159] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 11/23/2019] [Accepted: 11/29/2019] [Indexed: 11/13/2022] Open
Abstract
Ionizing radiation produces clustered DNA damage that contains two or more lesions in 10–20 bp. It is believed that the complexity of clustered damage (i.e., the number of lesions per damage site) is related to the biological severity of ionizing radiation. However, only simple clustered damage containing two vicinal lesions has been demonstrated experimentally. Here we developed a novel method to analyze the complexity of clustered DNA damage. Plasmid DNA was irradiated with densely and sparsely ionizing Fe-ion beams and X-rays, respectively. Then, the resulting DNA lesions were labeled with biotin/streptavidin and observed with atomic force microscopy. Fe-ion beams produced complex clustered damage containing 2–4 lesions. Furthermore, they generated two or three clustered damage sites in a single plasmid molecule that resulted from the hit of a single track of Fe-ion beams. Conversely, X-rays produced relatively simple clustered damage. The present results provide the first experimental evidence for complex cluster damage.
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Affiliation(s)
- Xu Xu
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Toshiaki Nakano
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Masataka Tsuda
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Ryota Kanamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Ryoichi Hirayama
- Department of Charged Particle Therapy Research, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan
| | - Akiko Uzawa
- Department of Charged Particle Therapy Research, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan
| | - Hiroshi Ide
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
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15
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Vítor AC, Huertas P, Legube G, de Almeida SF. Studying DNA Double-Strand Break Repair: An Ever-Growing Toolbox. Front Mol Biosci 2020; 7:24. [PMID: 32154266 PMCID: PMC7047327 DOI: 10.3389/fmolb.2020.00024] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/04/2020] [Indexed: 12/29/2022] Open
Abstract
To ward off against the catastrophic consequences of persistent DNA double-strand breaks (DSBs), eukaryotic cells have developed a set of complex signaling networks that detect these DNA lesions, orchestrate cell cycle checkpoints and ultimately lead to their repair. Collectively, these signaling networks comprise the DNA damage response (DDR). The current knowledge of the molecular determinants and mechanistic details of the DDR owes greatly to the continuous development of ground-breaking experimental tools that couple the controlled induction of DSBs at distinct genomic positions with assays and reporters to investigate DNA repair pathways, their impact on other DNA-templated processes and the specific contribution of the chromatin environment. In this review, we present these tools, discuss their pros and cons and illustrate their contribution to our current understanding of the DDR.
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Affiliation(s)
- Alexandra C Vítor
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Pablo Huertas
- Department of Genetics, University of Seville, Seville, Spain.,Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Gaëlle Legube
- LBCMCP, Centre de Biologie Integrative (CBI), CNRS, Université de Toulouse, Toulouse, France
| | - Sérgio F de Almeida
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
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16
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G-quadruplex Structures Contribute to Differential Radiosensitivity of the Human Genome. iScience 2019; 21:288-307. [PMID: 31678912 PMCID: PMC6838516 DOI: 10.1016/j.isci.2019.10.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 06/12/2019] [Accepted: 10/16/2019] [Indexed: 02/04/2023] Open
Abstract
DNA, the fundamental unit of human cell, generally exists in Watson-Crick base-paired B-DNA form. Often, DNA folds into non-B forms, such as four-stranded G-quadruplexes. It is generally believed that ionizing radiation (IR) induces DNA strand-breaks in a random manner. Here, we show that regions of DNA enriched in G-quadruplex structures are less sensitive to IR compared with B-DNA in vitro and inside cells. Planar G-quartet of G4-DNA is shielded from IR-induced free radicals, unlike single- and double-stranded DNA. Whole-genome sequence analysis and real-time PCR reveal that genomic regions abundant in G4-DNA are protected from radiation-induced breaks and can be modulated by G4 stabilizers. Thus, our results reveal that formation of G4 structures contribute toward differential radiosensitivity of the human genome. G4 DNA contributes to genome-wide radioprotection and is modulated by G4 resolvases Radiation causes minimal damage at the G4 structures at telomeres Formation of G4 DNA contributes toward differential radiosensitivity of human genome Planar quartet of G4 DNA is shielded from IR-induced free radicals and thus DNA breaks
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17
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The Effect of Waterpipe Smoking on DNA Integrity Among Youth in Jordan. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2019. [DOI: 10.1007/s13369-019-03794-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Hada M, Ikeda H, Rhone JR, Beitman AJ, Plante I, Souda H, Yoshida Y, Held KD, Fujiwara K, Saganti PB, Takahashi A. Increased Chromosome Aberrations in Cells Exposed Simultaneously to Simulated Microgravity and Radiation. Int J Mol Sci 2018; 20:E43. [PMID: 30583489 PMCID: PMC6337712 DOI: 10.3390/ijms20010043] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/17/2018] [Accepted: 12/19/2018] [Indexed: 12/16/2022] Open
Abstract
Space radiation and microgravity (μG) are two major environmental stressors for humans in space travel. One of the fundamental questions in space biology research is whether the combined effects of μG and exposure to cosmic radiation are interactive. While studies addressing this question have been carried out for half a century in space or using simulated μG on the ground, the reported results are ambiguous. For the assessment and management of human health risks in future Moon and Mars missions, it is necessary to obtain more basic data on the molecular and cellular responses to the combined effects of radiation and µG. Recently we incorporated a μG⁻irradiation system consisting of a 3D clinostat synchronized to a carbon-ion or X-ray irradiation system. Our new experimental setup allows us to avoid stopping clinostat rotation during irradiation, which was required in all other previous experiments. Using this system, human fibroblasts were exposed to X-rays or carbon ions under the simulated μG condition, and chromosomes were collected with the premature chromosome condensation method in the first mitosis. Chromosome aberrations (CA) were quantified by the 3-color fluorescent in situ hybridization (FISH) method. Cells exposed to irradiation under the simulated μG condition showed a higher frequency of both simple and complex types of CA compared to cells irradiated under the static condition by either X-rays or carbon ions.
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Affiliation(s)
- Megumi Hada
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA.
| | - Hiroko Ikeda
- Gunma University Initiative for Advanced Research, Gunma University, Maebashi, Gunma 371-8511, Japan.
| | - Jordan R Rhone
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA.
| | - Andrew J Beitman
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA.
| | - Ianik Plante
- KBRwyle, 2400 NASA Parkway, Houston, TX 77508, USA.
| | - Hikaru Souda
- Heavy Ion Medical Center, Gunma University, Maebashi, Gunma 371-8511, Japan.
| | - Yukari Yoshida
- Heavy Ion Medical Center, Gunma University, Maebashi, Gunma 371-8511, Japan.
| | - Kathryn D Held
- Gunma University Initiative for Advanced Research, Gunma University, Maebashi, Gunma 371-8511, Japan.
- Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA.
| | - Keigi Fujiwara
- Department of Cadiology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Premkumar B Saganti
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA.
| | - Akihisa Takahashi
- Heavy Ion Medical Center, Gunma University, Maebashi, Gunma 371-8511, Japan.
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19
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Paganetti H. Proton Relative Biological Effectiveness - Uncertainties and Opportunities. Int J Part Ther 2018; 5:2-14. [PMID: 30370315 DOI: 10.14338/ijpt-18-00011.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Proton therapy treatments are prescribed using a biological effectiveness relative to photon therapy of 1.1, that is, proton beams are considered to be 10% more biologically effective. Debate is ongoing as to whether this practice needs to be revised. This short review summarizes current knowledge on relative biological effectiveness variations and uncertainties in vitro and in vivo. Clinical relevance is discussed and strategies toward biologically guided treatment planning are presented.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
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20
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Cobler L, Zhang H, Suri P, Park C, Timmerman LA. xCT inhibition sensitizes tumors to γ-radiation via glutathione reduction. Oncotarget 2018; 9:32280-32297. [PMID: 30190786 PMCID: PMC6122354 DOI: 10.18632/oncotarget.25794] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/08/2018] [Indexed: 01/13/2023] Open
Abstract
About 3 million US cancer patients and 1.7 million EU cancer patients received multiple doses of radiation therapy (RT) in 2012, with treatment duration limited by normal adjacent tissue damage. Tumor-specific sensitization could allow treatment with lower radiation doses, reducing normal tissue damage. This is a longstanding, largely unrealized therapeutic goal. The cystine:glutamate exchanger xCT is expressed on poor prognosis subsets of most solid tumors, but not on most normal cells. xCT provides cells with environmental cystine for enhanced glutathione synthesis. Glutathione is used to control reactive oxygen species (ROS), which are therapeutic effectors of RT. We tested whether xCT inhibition would sensitize xCT+ tumor cells to ionizing radiation. We found that pretreatment with the xCT inhibitor erastin potently sensitized xCT+ but not xCT- cells, in vitro and in xenograft. Similarly, targeted gene inactivation also sensitized cells, and both modes of sensitization were overcome by glutathione supplementation. Sensitization prolongs DNA damage signaling, increases genome instability, and enhances cell death, revealing an unforeseen role for cysteine in genome integrity maintenance. We conclude that an xCT-specific therapeutic would provide tumor-specific sensitization to RT, allowing treatment with lower radiation doses, and producing far fewer side effects than other proposed sensitizers. Our data speaks to the need for the rapid development of such a drug.
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Affiliation(s)
- Lara Cobler
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Hui Zhang
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Poojan Suri
- University of California, San Francisco, CA, USA
| | - Catherine Park
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Luika A Timmerman
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
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21
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Cao Q, Liu W, Wang J, Cao J, Yang H. A single low dose of Fe ions can cause long-term biological responses in NL20 human bronchial epithelial cells. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2018; 57:31-40. [PMID: 29127482 DOI: 10.1007/s00411-017-0719-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
Space radiation cancer risk may be a potential obstacle for long-duration spaceflight. Among all types of cancer space radiation may induce, lung cancer has been estimated to be the largest potential risk. Although previous animal study has shown that Fe ions, the most important contributor to the total dose equivalent of space radiation, induced a higher incidence of lung tumorigenesis per dose than X-rays, the underlying mechanisms at cellular level remained unclear. Therefore, in the present study, we investigated long-term biological changes in NL20 human bronchial epithelial cells after exposure to Fe ion or X-ray irradiation. We found that compared with sham control, the progeny of NL20 cells irradiated with 0.1 Gy of Fe ions showed slightly increased micronucleus formation, significantly decreased cell proliferation, disturbed cell cycle distribution, and obviously elevated intracellular ROS levels accompanied by reduced SOD1 and SOD2 expression, but the progeny of NL20 cells irradiated with 0.9 Gy of X-rays did not show any significant changes. More importantly, Fe ion exposure caused much greater soft-agar colony formation than X-rays did in the progeny of irradiated NL20 cells, clearly suggesting higher cell transformation potential of Fe ions compared with X-rays. These data may shed the light on the potential lung tumorigenesis risk from Fe ion exposure. In addition, ATM inhibition by Ku55933 reversed some of the changes in the progeny of Fe ion-irradiated cells but not others such as soft-agar colony formation, suggesting complex processes from DNA damage to carcinogenesis. These data indicate that even a single low dose of Fe ions can induce long-term biological responses such as cell transformation, etc., suggesting unignorable health risk from space radiation to astronauts.
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Affiliation(s)
- Qianlin Cao
- School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, 215123, Jiangsu, People's Republic of China
| | - Wei Liu
- Department of Radiotherapy and Oncology, Second Affiliated Hospital, Soochow University, 1055 Sanxiang Road, Suzhou, 215004, Jiangsu, People's Republic of China
| | - Jingdong Wang
- School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, 215123, Jiangsu, People's Republic of China
| | - Jianping Cao
- School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, 215123, Jiangsu, People's Republic of China
| | - Hongying Yang
- School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, 215123, Jiangsu, People's Republic of China.
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22
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Processing-Challenges Generated by Clusters of DNA Double-Strand Breaks Underpin Increased Effectiveness of High-LET Radiation and Chromothripsis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1044:149-168. [DOI: 10.1007/978-981-13-0593-1_10] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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23
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Hagiwara Y, Niimi A, Isono M, Yamauchi M, Yasuhara T, Limsirichaikul S, Oike T, Sato H, Held KD, Nakano T, Shibata A. 3D-structured illumination microscopy reveals clustered DNA double-strand break formation in widespread γH2AX foci after high LET heavy-ion particle radiation. Oncotarget 2017; 8:109370-109381. [PMID: 29312614 PMCID: PMC5752527 DOI: 10.18632/oncotarget.22679] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/08/2017] [Indexed: 01/09/2023] Open
Abstract
DNA double-strand breaks (DSBs) induced by ionising radiation are considered the major cause of genotoxic mutations and cell death. While DSBs are dispersed throughout chromatin after X-rays or γ-irradiation, multiple types of DNA damage including DSBs, single-strand breaks and base damage can be generated within 1–2 helical DNA turns, defined as a complex DNA lesion, after high Linear Energy Transfer (LET) particle irradiation. In addition to the formation of complex DNA lesions, recent evidence suggests that multiple DSBs can be closely generated along the tracks of high LET particle irradiation. Herein, by using three dimensional (3D)-structured illumination microscopy, we identified the formation of 3D widespread γH2AX foci after high LET carbon-ion irradiation. The large γH2AX foci in G2-phase cells encompassed multiple foci of replication protein A (RPA), a marker of DSBs undergoing resection during homologous recombination. Furthermore, we demonstrated by 3D analysis that the distance between two individual RPA foci within γH2AX foci was approximately 700 nm. Together, our findings suggest that high LET heavy-ion particles induce clustered DSB formation on a scale of approximately 1 μm3. These closely localised DSBs are considered to be a risk for the formation of chromosomal rearrangement after heavy-ion irradiation.
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Affiliation(s)
- Yoshihiko Hagiwara
- Education and Research Support Center (ERSC), Gunma University, Maebashi 371-8511, Japan.,Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Atsuko Niimi
- Research Program for Heavy Ion Therapy, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), Maebashi 371-8511, Japan
| | - Mayu Isono
- Department of Molecular Metabolic Regulation Research, Sasaki Institute, Tokyo 101-0062, Japan
| | - Motohiro Yamauchi
- Department of Radiation Biology and Protection, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
| | - Takaaki Yasuhara
- Laboratory of Molecular Radiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | | | - Takahiro Oike
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Hiro Sato
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Kathryn D Held
- Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA.,International Open Laboratory, Gunma University Initiative for Advanced Research (GIAR), Gunma 371-8511, Japan
| | - Takashi Nakano
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan.,Research Program for Heavy Ion Therapy, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), Maebashi 371-8511, Japan
| | - Atsushi Shibata
- Education and Research Support Center (ERSC), Gunma University, Maebashi 371-8511, Japan
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24
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Hawkins RB. A Microdosimetric-Kinetic Model of Cell Killing by Irradiation from Permanently Incorporated Radionuclides. Radiat Res 2017; 189:104-116. [PMID: 29045193 DOI: 10.1667/rr14681.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
An expression for the surviving fraction of a replicating population of cells exposed to permanently incorporated radionuclide is derived from the microdosimetric-kinetic model. It includes dependency on total implant dose, linear energy transfer (LET), decay rate of the radionuclide, the repair rate of potentially lethal lesions in DNA and the volume doubling time of the target population. This is used to obtain an expression for the biologically effective dose ( BEDα/β) based on the minimum survival achieved by the implant that is equivalent to, and can be compared and combined with, the BEDα/β calculated for a fractionated course of radiation treatment. Approximate relationships are presented that are useful in the calculation of BEDα/β for alpha- or beta-emitting radionuclides with half-life significantly greater than, or nearly equal to, the approximately 1-h repair half-life of radiation-induced potentially lethal lesions.
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Affiliation(s)
- Roland B Hawkins
- Ochsner Cancer Institute, Ochsner Medical System, New Orleans, Louisiana 70121
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25
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Streitmatter SW, Stewart RD, Jenkins PA, Jevremovic T. DNA double strand break (DSB) induction and cell survival in iodine-enhanced computed tomography (CT). Phys Med Biol 2017; 62:6164-6184. [PMID: 28703119 DOI: 10.1088/1361-6560/aa772d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A multi-scale Monte Carlo model is proposed to assess the dosimetric and biological impact of iodine-based contrast agents commonly used in computed tomography. As presented, the model integrates the general purpose MCNP6 code system for larger-scale radiation transport and dose assessment with the Monte Carlo damage simulation to determine the sub-cellular characteristics and spatial distribution of initial DNA damage. The repair-misrepair-fixation model is then used to relate DNA double strand break (DSB) induction to reproductive cell death. Comparisons of measured and modeled changes in reproductive cell survival for ultrasoft characteristic k-shell x-rays (0.25-4.55 keV) up to orthovoltage (200-500 kVp) x-rays indicate that the relative biological effectiveness (RBE) for DSB induction is within a few percent of the RBE for cell survival. Because of the very short range of secondary electrons produced by low energy x-ray interactions with contrast agents, the concentration and subcellular distribution of iodine within and near cellular targets have a significant impact on the estimated absorbed dose and number of DSB produced in the cell nucleus. For some plausible models of the cell-level distribution of contrast agent, the model predicts an increase in RBE-weighted dose (RWD) for the endpoint of DSB induction of 1.22-1.40 for a 5-10 mg ml-1 iodine concentration in blood compared to an RWD increase of 1.07 ± 0.19 from a recent clinical trial. The modeled RWD of 2.58 ± 0.03 is also in good agreement with the measured RWD of 2.3 ± 0.5 for an iodine concentration of 50 mg ml-1 relative to no iodine. The good agreement between modeled and measured DSB and cell survival estimates provides some confidence that the presented model can be used to accurately assess biological dose for other concentrations of the same or different contrast agents.
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Affiliation(s)
- Seth W Streitmatter
- Nuclear Engineering Program, The University of Utah, 50 S. Central Campus Drive, 1206 MEB, Salt Lake City, UT 84112, United States of America. Department of Radiology and Imaging Sciences, University of Utah Health, 30 North 1900 East #1A71, Salt Lake City, UT 84132, United States of America
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Liang Y, Fu Q, Wang X, Liu F, Yang G, Luo C, Ouyang Q, Wang Y. Relative biological effectiveness for photons: implication of complex DNA double-strand breaks as critical lesions. Phys Med Biol 2017; 62:2153-2175. [DOI: 10.1088/1361-6560/aa56ed] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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27
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Abstract
Histone acetylation/deacetylation constitute the most relevant chromatin remodelling mechanism to control DNA access to nuclear machinery as well as to mutagenic agents. Thus, these epigenetics mechanisms could be involved in processing DNA lesions into chromosomal aberrations. Although radiation-induced DNA lesions are believed to occur randomly, in most cases chromosome breakpoints appear distributed in a non-random manner. In order to study the distribution of chromosome damage induced by clastogenic agents in relation to chromosome histone acetylation patterns, an experimental model based on treating Chinese hamster cells with endonucleases and ionizing radiations as well as immunolabelling metaphase chromosomes with antibodies to acetylated histone H4 was developed. The analysis of intra- and interchromosome breakpoint distribution has been carried out on G-banded chromosomes, and results obtained were correlated with chromosome acetylated histone H4 profiles. A co-localization of intrachromosomal breakpoints induced by AluI, BamHI and DNase I as well as by neutrons and g-rays was observed. Radiation- and endonuclease-induced breakpoints tend to cluster in less condensed chromosome regions (G-light bands) that show the highest levels of acetylated histone H4. The analysis of interchromosomal distribution of radiation-induced lesions showed a concentration of breakpoints in Chinese hamster chromosomes with particular histone acetylation patterns. The fact that chromosome breakpoints occur more frequently in transcriptionally competent chromosome regions suggests that chromatin conformation and nuclear architecture could play a role in the distribution of chromosome lesions.
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Affiliation(s)
- W Martínez-López
- Department of Genetic Toxicology and Chromosome Pathology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
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Feng YL, Xiang JF, Kong N, Cai XJ, Xie AY. Buried territories: heterochromatic response to DNA double-strand breaks. Acta Biochim Biophys Sin (Shanghai) 2016; 48:594-602. [PMID: 27151295 DOI: 10.1093/abbs/gmw033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/28/2016] [Indexed: 12/22/2022] Open
Abstract
Cellular response to DNA double-strand breaks (DSBs), the most deleterious type of DNA damage, is highly influenced by higher-order chromatin structure in eukaryotic cells. Compared with euchromatin, the compacted structure of heterochromatin not only protects heterochromatic DNA from damage, but also adds an extra layer of control over the response to DSBs occurring in heterochromatin. One key step in this response is the decondensation of heterochromatin structure. This decondensation process facilitates the DNA damage signaling and promotes proper heterochromatic DSB repair, thus helping to prevent instability of heterochromatic regions of genomes. This review will focus on the functions of the ataxia telangiectasia mutated (ATM) signaling cascade involving ATM, heterochromatin protein 1 (HP1), Krüppel-associated box (KRAB)-associated protein-1 (KAP-1), tat-interacting protein 60 (Tip60), and many other protein factors in DSB-induced decondensation of heterochromatin and subsequent repair of heterochromatic DSBs. As some subsets of DSBs may be repaired in heterochromatin independently of the ATM signaling, a possible repair model is also proposed for ATM-independent repair of these heterochromatic DSBs.
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Affiliation(s)
- Yi-Li Feng
- Key Laboratory of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
| | - Ji-Feng Xiang
- Key Laboratory of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
| | - Na Kong
- Key Laboratory of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
| | - Xiu-Jun Cai
- Key Laboratory of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
| | - An-Yong Xie
- Key Laboratory of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
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Mladenova V, Mladenov E, Iliakis G. Novel Biological Approaches for Testing the Contributions of Single DSBs and DSB Clusters to the Biological Effects of High LET Radiation. Front Oncol 2016; 6:163. [PMID: 27446809 PMCID: PMC4923065 DOI: 10.3389/fonc.2016.00163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/15/2016] [Indexed: 01/28/2023] Open
Abstract
The adverse biological effects of ionizing radiation (IR) are commonly attributed to the generation of DNA double-strand breaks (DSBs). IR-induced DSBs are generated by clusters of ionizations, bear damaged terminal nucleotides, and frequently comprise base damages and single-strand breaks in the vicinity generating a unique DNA damage-clustering effect that increases DSB "complexity." The number of ionizations in clusters of different radiation modalities increases with increasing linear energy transfer (LET), and is thought to determine the long-known LET-dependence of the relative biological effectiveness (RBE). Multiple ionizations may also lead to the formation of DSB clusters, comprising two or more DSBs that destabilize chromatin further and compromise overall processing. DSB complexity and DSB-cluster formation are increasingly considered in the development of mathematical models of radiation action, which are then "tested" by fitting available experimental data. Despite a plethora of such mathematical models the ultimate goal, i.e., the "a priori" prediction of the radiation effect, has not yet been achieved. The difficulty partly arises from unsurmountable difficulties in testing the fundamental assumptions of such mathematical models in defined biological model systems capable of providing conclusive answers. Recently, revolutionary advances in methods allowing the generation of enzymatic DSBs at random or in well-defined locations in the genome, generate unique testing opportunities for several key assumptions frequently fed into mathematical modeling - including the role of DSB clusters in the overall effect. Here, we review the problematic of DSB-cluster formation in radiation action and present novel biological technologies that promise to revolutionize the way we address the biological consequences of such lesions. We describe new ways of exploiting the I-SceI endonuclease to generate DSB-clusters at random locations in the genome and describe the possible utility of Zn-finger nucleases and of TALENs in generating DSBs at defined genomic locations. Finally, we describe ways to harness the revolution of CRISPR/Cas9 technology to advance our understanding of the biological effects of DSBs. Collectively, these approaches promise to improve the focus of mathematical modeling of radiation action by providing testing opportunities for key assumptions on the underlying biology. They are also likely to further strengthen interactions between experimental radiation biologists and mathematical modelers.
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Affiliation(s)
- Veronika Mladenova
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School , Essen , Germany
| | - Emil Mladenov
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School , Essen , Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School , Essen , Germany
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Pang D, Chasovskikh S, Rodgers JE, Dritschilo A. Short DNA Fragments Are a Hallmark of Heavy Charged-Particle Irradiation and May Underlie Their Greater Therapeutic Efficacy. Front Oncol 2016; 6:130. [PMID: 27376024 PMCID: PMC4901041 DOI: 10.3389/fonc.2016.00130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/16/2016] [Indexed: 11/13/2022] Open
Abstract
Growing interest in proton and heavy ion therapy has reinvigorated research into the fundamental biological mechanisms underlying the therapeutic efficacy of charged-particle radiation. To improve our understanding of the greater biological effectiveness of high-LET radiations, we have investigated DNA double-strand breaks (DSBs) following exposure of plasmid DNA to low-LET Co-60 gamma photon and electron irradiation and to high-LET Beryllium and Argon ions with atomic force microscopy. The sizes of DNA fragments following radiation exposure were individually measured to construct fragment size distributions from which the DSB per DNA molecule and DSB spatial distributions were derived. We report that heavy charged particles induce a significantly larger proportion of short DNA fragments in irradiated DNA molecules, reflecting densely and clustered damage patterns of high-LET energy depositions. We attribute the enhanced short DNA fragmentation following high-LET radiations as an important determinant of the observed, enhanced biological effectiveness of high-LET irradiations.
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Affiliation(s)
- Dalong Pang
- Radiation Medicine, Georgetown University Medical Center , Washington, DC , USA
| | - Sergey Chasovskikh
- Radiation Medicine, Georgetown University Medical Center , Washington, DC , USA
| | - James E Rodgers
- Radiation Oncology, Medstar Franklin Square Medical Center , Rosedale, MD , USA
| | - Anatoly Dritschilo
- Radiation Medicine, Georgetown University Medical Center , Washington, DC , USA
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Lopez Perez R, Best G, Nicolay NH, Greubel C, Rossberger S, Reindl J, Dollinger G, Weber KJ, Cremer C, Huber PE. Superresolution light microscopy shows nanostructure of carbon ion radiation-induced DNA double-strand break repair foci. FASEB J 2016; 30:2767-76. [PMID: 27166088 DOI: 10.1096/fj.201500106r] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/12/2016] [Indexed: 12/13/2022]
Abstract
Carbon ion radiation is a promising new form of radiotherapy for cancer, but the central question about the biologic effects of charged particle radiation is yet incompletely understood. Key to this question is the understanding of the interaction of ions with DNA in the cell's nucleus. Induction and repair of DNA lesions including double-strand breaks (DSBs) are decisive for the cell. Several DSB repair markers have been used to investigate these processes microscopically, but the limited resolution of conventional microscopy is insufficient to provide structural insights. We have applied superresolution microscopy to overcome these limitations and analyze the fine structure of DSB repair foci. We found that the conventionally detected foci of the widely used DSB marker γH2AX (Ø 700-1000 nm) were composed of elongated subfoci with a size of ∼100 nm consisting of even smaller subfocus elements (Ø 40-60 nm). The structural organization of the subfoci suggests that they could represent the local chromatin structure of elementary DSB repair units at the DSB damage sites. Subfocus clusters may indicate induction of densely spaced DSBs, which are thought to be associated with the high biologic effectiveness of carbon ions. Superresolution microscopy might emerge as a powerful tool to improve our knowledge of interactions of ionizing radiation with cells.-Lopez Perez, R., Best, G., Nicolay, N. H., Greubel, C., Rossberger, S., Reindl, J., Dollinger, G., Weber, K.-J., Cremer, C., Huber, P. E. Superresolution light microscopy shows nanostructure of carbon ion radiation-induced DNA double-strand break repair foci.
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Affiliation(s)
- Ramon Lopez Perez
- Clinical Cooperation Unit and Molecular Radiation Oncology, German Cancer Research Center, Heidelberg University Hospital, Heidelberg, Germany; Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany;
| | - Gerrit Best
- Department of Ophthalmology, Heidelberg University Hospital, Heidelberg, Germany; Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
| | - Nils H Nicolay
- Clinical Cooperation Unit and Molecular Radiation Oncology, German Cancer Research Center, Heidelberg University Hospital, Heidelberg, Germany; Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christoph Greubel
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany; and
| | - Sabrina Rossberger
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
| | - Judith Reindl
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany; and
| | - Günther Dollinger
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany; and
| | - Klaus-Josef Weber
- Clinical Cooperation Unit and Molecular Radiation Oncology, German Cancer Research Center, Heidelberg University Hospital, Heidelberg, Germany; Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christoph Cremer
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany; Superresolution Microscopy of Functional Nuclear Nanostructure, Institute of Molecular Biology, Mainz, Germany
| | - Peter E Huber
- Clinical Cooperation Unit and Molecular Radiation Oncology, German Cancer Research Center, Heidelberg University Hospital, Heidelberg, Germany; Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany;
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Hellweg CE, Spitta LF, Henschenmacher B, Diegeler S, Baumstark-Khan C. Transcription Factors in the Cellular Response to Charged Particle Exposure. Front Oncol 2016; 6:61. [PMID: 27047795 PMCID: PMC4800317 DOI: 10.3389/fonc.2016.00061] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 03/03/2016] [Indexed: 12/23/2022] Open
Abstract
Charged particles, such as carbon ions, bear the promise of a more effective cancer therapy. In human spaceflight, exposure to charged particles represents an important risk factor for chronic and late effects such as cancer. Biological effects elicited by charged particle exposure depend on their characteristics, e.g., on linear energy transfer (LET). For diverse outcomes (cell death, mutation, transformation, and cell-cycle arrest), an LET dependency of the effect size was observed. These outcomes result from activation of a complex network of signaling pathways in the DNA damage response, which result in cell-protective (DNA repair and cell-cycle arrest) or cell-destructive (cell death) reactions. Triggering of these pathways converges among others in the activation of transcription factors, such as p53, nuclear factor κB (NF-κB), activated protein 1 (AP-1), nuclear erythroid-derived 2-related factor 2 (Nrf2), and cAMP responsive element binding protein (CREB). Depending on dose, radiation quality, and tissue, p53 induces apoptosis or cell-cycle arrest. In low LET radiation therapy, p53 mutations are often associated with therapy resistance, while the outcome of carbon ion therapy seems to be independent of the tumor's p53 status. NF-κB is a central transcription factor in the immune system and exhibits pro-survival effects. Both p53 and NF-κB are activated after ionizing radiation exposure in an ataxia telangiectasia mutated (ATM)-dependent manner. The NF-κB activation was shown to strongly depend on charged particles' LET, with a maximal activation in the LET range of 90-300 keV/μm. AP-1 controls proliferation, senescence, differentiation, and apoptosis. Nrf2 can induce cellular antioxidant defense systems, CREB might also be involved in survival responses. The extent of activation of these transcription factors by charged particles and their interaction in the cellular radiation response greatly influences the destiny of the irradiated and also neighboring cells in the bystander effect.
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Affiliation(s)
- Christine E. Hellweg
- Cellular Biodiagnostics, Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
| | - Luis F. Spitta
- Cellular Biodiagnostics, Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
| | - Bernd Henschenmacher
- Cellular Biodiagnostics, Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
| | - Sebastian Diegeler
- Cellular Biodiagnostics, Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
| | - Christa Baumstark-Khan
- Cellular Biodiagnostics, Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
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Cannan WJ, Pederson DS. Mechanisms and Consequences of Double-Strand DNA Break Formation in Chromatin. J Cell Physiol 2016; 231:3-14. [PMID: 26040249 DOI: 10.1002/jcp.25048] [Citation(s) in RCA: 234] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 05/14/2015] [Indexed: 12/14/2022]
Abstract
All organisms suffer double-strand breaks (DSBs) in their DNA as a result of exposure to ionizing radiation. DSBs can also form when replication forks encounter DNA lesions or repair intermediates. The processing and repair of DSBs can lead to mutations, loss of heterozygosity, and chromosome rearrangements that result in cell death or cancer. The most common pathway used to repair DSBs in metazoans (non-homologous DNA end joining) is more commonly mutagenic than the alternative pathway (homologous recombination mediated repair). Thus, factors that influence the choice of pathways used DSB repair can affect an individual's mutation burden and risk of cancer. This review describes radiological, chemical, and biological mechanisms that generate DSBs, and discusses the impact of such variables as DSB etiology, cell type, cell cycle, and chromatin structure on the yield, distribution, and processing of DSBs. The final section focuses on nucleosome-specific mechanisms that influence DSB production, and the possible relationship between higher order chromosome coiling and chromosome shattering (chromothripsis).
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Affiliation(s)
- Wendy J Cannan
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont
| | - David S Pederson
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont
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Liang Y, Yang G, Liu F, Wang Y. Monte Carlo simulation of ionizing radiation induced DNA strand breaks utilizing coarse grained high-order chromatin structures. Phys Med Biol 2015; 61:445-60. [DOI: 10.1088/0031-9155/61/1/445] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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Gustafsson AS, Hartman T, Stenerlöw B. Formation and repair of clustered damaged DNA sites in high LET irradiated cells. Int J Radiat Biol 2015; 91:820-6. [DOI: 10.3109/09553002.2015.1068463] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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36
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Carante MP, Altieri S, Bortolussi S, Postuma I, Protti N, Ballarini F. Modeling radiation-induced cell death: role of different levels of DNA damage clustering. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2015; 54:305-316. [PMID: 25956821 DOI: 10.1007/s00411-015-0601-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 04/28/2015] [Indexed: 06/04/2023]
Abstract
Some open questions on the mechanisms underlying radiation-induced cell death were addressed by a biophysical model, focusing on DNA damage clustering and its consequences. DNA "cluster lesions" (CLs) were assumed to produce independent chromosome fragments that, if created within a micrometer-scale threshold distance (d), can lead to chromosome aberrations following mis-rejoining; in turn, certain aberrations (dicentrics, rings and large deletions) were assumed to lead to clonogenic cell death. The CL yield and d were the only adjustable parameters. The model, implemented as a Monte Carlo code called BIophysical ANalysis of Cell death and chromosome Aberrations (BIANCA), provided simulated survival curves that were directly compared with experimental data on human and hamster cells exposed to photons, protons, α-particles and heavier ions including carbon and iron. d = 5 μm, independent of radiation quality, and CL yields in the range ~2-20 CLs Gy(-1) cell(-1), depending on particle type and energy, led to good agreement between simulations and data. This supports the hypothesis of a pivotal role of DNA cluster damage at sub-micrometric scale, modulated by chromosome fragment mis-rejoining at micrometric scale. To investigate the features of such critical damage, the CL yields were compared with experimental or theoretical yields of DNA fragments of different sizes, focusing on the base-pair scale (related to the so-called local clustering), the kbp scale ("regional clustering") and the Mbp scale, corresponding to chromatin loops. Interestingly, the CL yields showed better agreement with kbp fragments rather than bp fragments or Mbp fragments; this suggests that also regional clustering, in addition to other clustering levels, may play an important role, possibly due to its relationship with nucleosome organization in the chromatin fiber.
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Affiliation(s)
- M P Carante
- Physics Department, University of Pavia, Via Bassi 6, 27100, Pavia, Italy
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Huang YW, Pan CY, Hsiao YY, Chao TC, Lee CC, Tung CJ. Monte Carlo simulations of the relative biological effectiveness for DNA double strand breaks from 300 MeV u(-1) carbon-ion beams. Phys Med Biol 2015; 60:5995-6012. [PMID: 26183156 DOI: 10.1088/0031-9155/60/15/5995] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Monte Carlo simulations are used to calculate the relative biological effectiveness (RBE) of 300 MeV u(-1) carbon-ion beams at different depths in a cylindrical water phantom of 10 cm radius and 30 cm long. RBE values for the induction of DNA double strand breaks (DSB), a biological endpoint closely related to cell inactivation, are estimated for monoenergetic and energy-modulated carbon ion beams. Individual contributions to the RBE from primary ions and secondary nuclear fragments are simulated separately. These simulations are based on a multi-scale modelling approach by first applying the FLUKA (version 2011.2.17) transport code to estimate the absorbed doses and fluence energy spectra, then using the MCDS (version 3.10A) damage code for DSB yields. The approach is efficient since it separates the non-stochastic dosimetry problem from the stochastic DNA damage problem. The MCDS code predicts the major trends of the DSB yields from detailed track structure simulations. It is found that, as depth is increasing, RBE values increase slowly from the entrance depth to the plateau region and change substantially in the Bragg peak region. RBE values reach their maxima at the distal edge of the Bragg peak. Beyond this edge, contributions to RBE are entirely from nuclear fragments. Maximum RBE values at the distal edges of the Bragg peak and the spread-out Bragg peak are, respectively, 3.0 and 2.8. The present approach has the flexibility to weight RBE contributions from different DSB classes, i.e. DSB0, DSB+ and DSB++.
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Affiliation(s)
- Y W Huang
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Kweishan Taoyuan, Taiwan
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Tracy BL, Stevens DL, Goodhead DT, Hill MA. Variation in RBE for Survival of V79-4 Cells as a Function of Alpha-Particle (Helium Ion) Energy. Radiat Res 2015; 184:33-45. [PMID: 26121227 DOI: 10.1667/rr13835.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
High linear energy transfer (LET) α particles are important with respect to the carcinogenic risk associated with human exposure to ionizing radiation, most notably to radon and its progeny. Additionally, the potential use of alpha-particle-emitting radionuclides in radiotherapy is increasingly being explored. Within the body the emitted alpha particles slow down, traversing a number of cells with a range of energies and therefore with varying efficiencies at inducing biological response. The LET of the particle typically rises from between ~70-90 keV μm(-1) at the start of the track (depending on initial energy) to a peak of ~237 keV μm(-1) towards the end of the track, before falling again at the very end of its range. To investigate the variation in biological response with incident energy, a plutonium-238 alpha-particle irradiator was calibrated to enable studies with incident energies ranging from 4.0 MeV down to 1.1 MeV. The variation in clonogenic survival of V79-4 cells was determined as a function of incident energy, along with the relative variation in the initial yields of DNA double-strand breaks (DSB) measured using the FAR assay. The clonogenic survival data also extends previously published data obtained at the Medical Research Council (MRC), Harwell using the same cells irradiated with helium ions, with energies ranging from 34.9 MeV to 5.85 MeV. These studies were performed in conjunction with cell morphology measurements on live cells enabling the determination of absorbed dose and calculation of the average LET in the cell. The results show an increase in relative biological effectiveness (RBE) for cell inactivation with decreasing helium ion energy (increasing LET), reaching a maximum for incident energies of ~3.2 MeV and corresponding average LET of 131 keV μm(-1), above which the RBE is observed to fall at lower energies (higher LETs). The effectiveness of single alpha-particle traversals (relevant to low-dose exposure) at inducing cell inactivation was observed to increase with decreasing energy to a peak of ~68% survival probability for incident energies of ~1.8 MeV (average LET of 190 keV μm(-1)) producing ~0.39 lethal lesions per track. However, the efficiency of a single traversal will also vary significantly with cell morphology and angle of incidence, as well as cell type.
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Affiliation(s)
- Bliss L Tracy
- a Medical Research Council, Harwell, Oxfordshire OX11 0RD, United Kingdom;,b Radiation Protection Bureau, Health Canada 6302D1, Ottawa, Ontario K1A 1C1, Canada; and
| | - David L Stevens
- a Medical Research Council, Harwell, Oxfordshire OX11 0RD, United Kingdom;,c Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Dudley T Goodhead
- a Medical Research Council, Harwell, Oxfordshire OX11 0RD, United Kingdom
| | - Mark A Hill
- a Medical Research Council, Harwell, Oxfordshire OX11 0RD, United Kingdom;,c Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford OX3 7DQ, United Kingdom
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Wargo JA, Reuben A, Cooper ZA, Oh KS, Sullivan RJ. Immune Effects of Chemotherapy, Radiation, and Targeted Therapy and Opportunities for Combination With Immunotherapy. Semin Oncol 2015; 42:601-16. [PMID: 26320064 DOI: 10.1053/j.seminoncol.2015.05.007] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There have been significant advances in cancer treatment over the past several years through the use of chemotherapy, radiation therapy, molecularly targeted therapy, and immunotherapy. Despite these advances, treatments such as monotherapy or monomodality have significant limitations. There is increasing interest in using these strategies in combination; however, it is not completely clear how best to incorporate molecularly targeted and immune-targeted therapies into combination regimens. This is particularly pertinent when considering combinations with immunotherapy, as other types of therapy may have significant impact on host immunity, the tumor microenvironment, or both. Thus, the influence of chemotherapy, radiation therapy, and molecularly targeted therapy on the host anti-tumor immune response and the host anti-host response (ie, autoimmune toxicity) must be taken into consideration when designing immunotherapy-based combination regimens. We present data related to many of these combination approaches in the context of investigations in patients with melanoma and discuss their potential relationship to management of patients with other tumor types. Importantly, we also highlight challenges of these approaches and emphasize the need for continued translational research.
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Affiliation(s)
- Jennifer A Wargo
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX; Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Alexandre Reuben
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Zachary A Cooper
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX; Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Kevin S Oh
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Ryan J Sullivan
- Department of Medical Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA.
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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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Belov OV, Krasavin EA, Lyashko MS, Batmunkh M, Sweilam NH. A quantitative model of the major pathways for radiation-induced DNA double-strand break repair. J Theor Biol 2015; 366:115-30. [DOI: 10.1016/j.jtbi.2014.09.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 09/11/2014] [Accepted: 09/17/2014] [Indexed: 12/11/2022]
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42
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Palmans H, Rabus H, Belchior AL, Bug MU, Galer S, Giesen U, Gonon G, Gruel G, Hilgers G, Moro D, Nettelbeck H, Pinto M, Pola A, Pszona S, Schettino G, Sharpe PHG, Teles P, Villagrasa C, Wilkens JJ. Future development of biologically relevant dosimetry. Br J Radiol 2014; 88:20140392. [PMID: 25257709 DOI: 10.1259/bjr.20140392] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Proton and ion beams are radiotherapy modalities of increasing importance and interest. Because of the different biological dose response of these radiations as compared with high-energy photon beams, the current approach of treatment prescription is based on the product of the absorbed dose to water and a biological weighting factor, but this is found to be insufficient for providing a generic method to quantify the biological outcome of radiation. It is therefore suggested to define new dosimetric quantities that allow a transparent separation of the physical processes from the biological ones. Given the complexity of the initiation and occurrence of biological processes on various time and length scales, and given that neither microdosimetry nor nanodosimetry on their own can fully describe the biological effects as a function of the distribution of energy deposition or ionization, a multiscale approach is needed to lay the foundation for the aforementioned new physical quantities relating track structure to relative biological effectiveness in proton and ion beam therapy. This article reviews the state-of-the-art microdosimetry, nanodosimetry, track structure simulations, quantification of reactive species, reference radiobiological data, cross-section data and multiscale models of biological response in the context of realizing the new quantities. It also introduces the European metrology project, Biologically Weighted Quantities in Radiotherapy, which aims to investigate the feasibility of establishing a multiscale model as the basis of the new quantities. A tentative generic expression of how the weighting of physical quantities at different length scales could be carried out is presented.
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Affiliation(s)
- H Palmans
- 1 Acoustics and Ionising Radiation Division, National Physical Laboratory (NPL), Teddington, Middlesex, UK
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43
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Balajee AS, Bertucci A, Taveras M, Brenner DJ. Multicolour FISH analysis of ionising radiation induced micronucleus formation in human lymphocytes. Mutagenesis 2014; 29:447-55. [PMID: 25217771 DOI: 10.1093/mutage/geu041] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Micronucleation of chromosomal DNA is an effective indicator of DNA damage and micronucleus (MN) analysis is a valuable tool for radiation biodosimetry studies. To gain a comprehensive knowledge of micronucleation process after ionising radiation (IR) exposure, whole genome-wide chromosome analysis is desirable. With this objective, multicolour fluorescence in situ hybridization (M-FISH) technique was utilised in the present study to characterise the chromosome content of spontaneous and IR-induced micronuclei in three human donors. M-FISH analysis revealed a radiation dose-dependant increase in the number of micronuclei with multi-chromosome material above 2 Gy and as many as 3-6 multicolour signals were detected in micronuclei after high γ-rays radiation doses (5-10 Gy). Involvement of each human chromosome material was more frequently detected in multicoloured micronuclei than in single-coloured micronuclei at high radiation doses (>2 Gy). Observation of dose-dependant increase in the MN frequency with multi-chromosome material may be due to misrepair of DNA double-strand breaks involving multiple chromosomes leading to asymmetric dicentric or ring chromosomes and acentric fragments. Chromosomes belonging to groups A (1, 2 and 3) and B (4 and 5) were frequently detected in 35-45% of the total micronuclei either as single entities or in combination with other chromosomes. Among the A and B groups, chromosome 1 material was consistently detected at high MN frequencies after radiation exposure in all the donors. Additionally, chromosomes 13 and 19 were more frequently observed in micronuclei than the expected frequency based on DNA content. Our whole genome approach utilising the M-FISH technique revealed that MN formation at high radiation doses might be complex involving multiple chromosome fragments. Understanding the fate and biological consequences of these multi-chromosome-containing micronuclei may provide key molecular insights for some aspects of IR-induced genomic instability and cancer development processes.
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Affiliation(s)
- Adayabalam S Balajee
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA.
| | - Antonella Bertucci
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
| | - Maria Taveras
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
| | - David J Brenner
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
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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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Lyckesvärd MN, Delle U, Kahu H, Lindegren S, Jensen H, Bäck T, Swanpalmer J, Elmroth K. Alpha particle induced DNA damage and repair in normal cultured thyrocytes of different proliferation status. Mutat Res 2014; 765:48-56. [PMID: 24769180 DOI: 10.1016/j.mrfmmm.2014.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 04/01/2014] [Accepted: 04/10/2014] [Indexed: 10/25/2022]
Abstract
Childhood exposure to ionizing radiation increases the risk of developing thyroid cancer later in life and this is suggested to be due to higher proliferation of the young thyroid. The interest of using high-LET alpha particles from Astatine-211 ((211)At), concentrated in the thyroid by the same mechanism as (131)I [1], in cancer treatment has increased during recent years because of its high efficiency in inducing biological damage and beneficial dose distribution when compared to low-LET radiation. Most knowledge of the DNA damage response in thyroid is from studies using low-LET irradiation and much less is known of high-LET irradiation. In this paper we investigated the DNA damage response and biological consequences to photons from Cobolt-60 ((60)Co) and alpha particles from (211)At in normal primary thyrocytes of different cell cycle status. For both radiation qualities the intensity levels of γH2AX decreased during the first 24h in both cycling and stationary cultures and complete repair was seen in all cultures but cycling cells exposed to (211)At. Compared to stationary cells alpha particles were more harmful for cycling cultures, an effect also seen at the pChk2 levels. Increasing ratios of micronuclei per cell nuclei were seen up to 1Gy (211)At. We found that primary thyrocytes were much more sensitive to alpha particle exposure compared with low-LET photons. Calculations of the relative biological effectiveness yielded higher RBE for cycling cells compared with stationary cultures at a modest level of damage, clearly demonstrating that cell cycle status influences the relative effectiveness of alpha particles.
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Affiliation(s)
| | - Ulla Delle
- Department of Oncology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Helena Kahu
- Department of Oncology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Sture Lindegren
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Holger Jensen
- The PET and Cyclotron Unit Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Tom Bäck
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - John Swanpalmer
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Kecke Elmroth
- Department of Oncology, Sahlgrenska Academy, University of Gothenburg, Sweden
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Lavelle C, Foray N. Chromatin structure and radiation-induced DNA damage: from structural biology to radiobiology. Int J Biochem Cell Biol 2014; 49:84-97. [PMID: 24486235 DOI: 10.1016/j.biocel.2014.01.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/13/2014] [Accepted: 01/18/2014] [Indexed: 10/25/2022]
Abstract
Genomic DNA in eukaryotic cells is basically divided into chromosomes, each consisting of a single huge nucleosomal fiber. It is now clear that chromatin structure and dynamics play a critical role in all processes involved in DNA metabolism, e.g. replication, transcription, repair and recombination. Radiation is a useful tool to study the biological effects of chromatin alterations. Conversely, radiotherapy and radiodiagnosis raise questions about the influence of chromatin integrity on clinical features and secondary effects. This review focuses on the link between DNA damage and chromatin structure at different scales, showing how a comprehensive multiscale vision is required to understand better the effect of radiations on DNA. Clinical aspects related to high- and low-dose of radiation and chromosomal instability will be discussed. At the same time, we will show that the analysis of the radiation-induced DNA damage distribution provides good insight on chromatin structure. Hence, we argue that chromatin "structuralists" and radiobiological "clinicians" would each benefit from more collaboration with the other. We hope that this focused review will help in this regard.
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Affiliation(s)
- Christophe Lavelle
- Genome Structure and Instability, National Museum of Natural History, Paris, France; CNRS UMR7196, Paris, France; INSERM U1154, Paris, France; Nuclear Architecture and Dynamics, CNRS GDR 3536, Paris, France.
| | - Nicolas Foray
- Nuclear Architecture and Dynamics, CNRS GDR 3536, Paris, France; INSERM, UMR1052, Radiobiology Group, Cancer Research Centre of Lyon, Lyon, France
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Tommasino F, Friedrich T, Scholz U, Taucher-Scholz G, Durante M, Scholz M. A DNA Double-Strand Break Kinetic Rejoining Model Based on the Local Effect Model. Radiat Res 2013; 180:524-38. [DOI: 10.1667/rr13389.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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48
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Georgakilas AG, O'Neill P, Stewart RD. Induction and Repair of Clustered DNA Lesions: What Do We Know So Far? Radiat Res 2013; 180:100-109. [DOI: 10.1667/rr3041.1] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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49
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Schipler A, Iliakis G. DNA double-strand-break complexity levels and their possible contributions to the probability for error-prone processing and repair pathway choice. Nucleic Acids Res 2013; 41:7589-605. [PMID: 23804754 PMCID: PMC3763544 DOI: 10.1093/nar/gkt556] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Although the DNA double-strand break (DSB) is defined as a rupture in the double-stranded DNA molecule that can occur without chemical modification in any of the constituent building blocks, it is recognized that this form is restricted to enzyme-induced DSBs. DSBs generated by physical or chemical agents can include at the break site a spectrum of base alterations (lesions). The nature and number of such chemical alterations define the complexity of the DSB and are considered putative determinants for repair pathway choice and the probability that errors will occur during this processing. As the pathways engaged in DSB processing show distinct and frequently inherent propensities for errors, pathway choice also defines the error-levels cells opt to accept. Here, we present a classification of DSBs on the basis of increasing complexity and discuss how complexity may affect processing, as well as how it may cause lethal or carcinogenic processing errors. By critically analyzing the characteristics of DSB repair pathways, we suggest that all repair pathways can in principle remove lesions clustering at the DSB but are likely to fail when they encounter clusters of DSBs that cause a local form of chromothripsis. In the same framework, we also analyze the rational of DSB repair pathway choice.
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Affiliation(s)
- Agnes Schipler
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
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Themis M, Garimberti E, Hill MA, Anderson RM. Reduced chromosome aberration complexity in normal human bronchial epithelial cells exposed to low-LET γ-rays and high-LET α-particles. Int J Radiat Biol 2013; 89:934-43. [PMID: 23679558 PMCID: PMC3836394 DOI: 10.3109/09553002.2013.805889] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Purpose: Cells of the lung are at risk from exposure to low and moderate doses of ionizing radiation from a range of environmental and medical sources. To help assess human health risks from such exposures, a better understanding of the frequency and types of chromosome aberration initially-induced in human lung cell types is required to link initial DNA damage and rearrangements with transmission potential and, to assess how this varies with radiation quality. Materials and methods: We exposed normal human bronchial lung epithelial (NHBE) cells in vitro to 0.5 and 1 Gy low-linear energy transfer (LET) γ-rays and a low fluence of high-LET α-particles and assayed for chromosome aberrations in premature chromosome condensation (PCC) spreads by 24-color multiplex-fluorescence in situ hybridization (M-FISH). Results: Both simple and complex aberrations were induced in a LET and dose-dependent manner; however, the frequency and complexity observed were reduced in comparison to that previously reported in spherical cell types after exposure to comparable doses or fluence of radiation. Approximately 1–2% of all exposed cells were categorized as being capable of transmitting radiation-induced chromosomal damage to future NHBE cell generations, irrespective of dose. Conclusion: One possible mechanistic explanation for this reduced complexity is the differing geometric organization of chromosome territories within ellipsoid nuclei compared to spherical nuclei. This study highlights the need to better understand the role of nuclear organization in the formation of exchange aberrations and, the influence three-dimensional (3D) tissue architecture may have on this in vivo.
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