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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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Diaz J, Kuhlman BM, Edenhoffer NP, Evans AC, Martin KA, Guida P, Rusek A, Atala A, Coleman MA, Wilson PF, Almeida-Porada G, Porada CD. Immediate effects of acute Mars mission equivalent doses of SEP and GCR radiation on the murine gastrointestinal system-protective effects of curcumin-loaded nanolipoprotein particles (cNLPs). FRONTIERS IN ASTRONOMY AND SPACE SCIENCES 2023; 10:1117811. [PMID: 38741937 PMCID: PMC11089821 DOI: 10.3389/fspas.2023.1117811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Introduction Missions beyond low Earth orbit (LEO) will expose astronauts to ionizing radiation (IR) in the form of solar energetic particles (SEP) and galactic cosmic rays (GCR) including high atomic number and energy (HZE) nuclei. The gastrointestinal (GI) system is documented to be highly radiosensitive with even relatively low dose IR exposures capable of inducing mucosal lesions and disrupting epithelial barrier function. IR is also an established risk factor for colorectal cancer (CRC) with several studies examining long-term GI effects of SEP/GCR exposure using tumor-prone APC mouse models. Studies of acute short-term effects of modeled space radiation exposures in wildtype mouse models are more limited and necessary to better define charged particle-induced GI pathologies and test novel medical countermeasures (MCMs) to promote astronaut safety. Methods In this study, we performed ground-based studies where male and female C57BL/6J mice were exposed to γ-rays, 50 MeV protons, or 1 GeV/n Fe-56 ions at the NASA Space Radiation Laboratory (NSRL) with histology and immunohistochemistry endpoints measured in the first 24 h post-irradiation to define immediate SEP/GCR-induced GI alterations. Results Our data show that unlike matched γ-ray controls, acute exposures to protons and iron ions disrupts intestinal function and induces mucosal lesions, vascular congestion, epithelial barrier breakdown, and marked enlargement of mucosa-associated lymphoid tissue. We also measured kinetics of DNA double-strand break (DSB) repair using gamma-H2AX- specific antibodies and apoptosis via TUNEL labeling, noting the induction and disappearance of extranuclear cytoplasmic DNA marked by gamma-H2AX only in the charged particle-irradiated samples. We show that 18 h pre-treatment with curcumin-loaded nanolipoprotein particles (cNLPs) delivered via IV injection reduces DSB-associated foci levels and apoptosis and restore crypt villi lengths. Discussion These data improve our understanding of physiological alterations in the GI tract immediately following exposures to modeled space radiations and demonstrates effectiveness of a promising space radiation MCM.
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Affiliation(s)
- Jonathan Diaz
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, United States
| | - Bradford M. Kuhlman
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, United States
| | | | - Angela C. Evans
- Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, CA, United States
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Kelly A. Martin
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Peter Guida
- NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, NY, United States
| | - Adam Rusek
- NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, NY, United States
| | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, United States
| | - Matthew A. Coleman
- Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, CA, United States
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Paul F. Wilson
- Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, CA, United States
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Graça Almeida-Porada
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, United States
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Increased Gene Targeting in Hyper-Recombinogenic LymphoBlastoid Cell Lines Leaves Unchanged DSB Processing by Homologous Recombination. Int J Mol Sci 2022; 23:ijms23169180. [PMID: 36012445 PMCID: PMC9409177 DOI: 10.3390/ijms23169180] [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: 07/06/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
In the cells of higher eukaryotes, sophisticated mechanisms have evolved to repair DNA double-strand breaks (DSBs). Classical nonhomologous end joining (c-NHEJ), homologous recombination (HR), alternative end joining (alt-EJ) and single-strand annealing (SSA) exploit distinct principles to repair DSBs throughout the cell cycle, resulting in repair outcomes of different fidelity. In addition to their functions in DSB repair, the same repair pathways determine how cells integrate foreign DNA or rearrange their genetic information. As a consequence, random integration of DNA fragments is dominant in somatic cells of higher eukaryotes and suppresses integration events at homologous genomic locations, leading to very low gene-targeting efficiencies. However, this response is not universal, and embryonic stem cells display increased targeting efficiency. Additionally, lymphoblastic chicken and human cell lines DT40 and NALM6 show up to a 1000-fold increased gene-targeting efficiency that is successfully harnessed to generate knockouts for a large number of genes. We inquired whether the increased gene-targeting efficiency of DT40 and NALM6 cells is linked to increased rates of HR-mediated DSB repair after exposure to ionizing radiation (IR). We analyzed IR-induced γ-H2AX foci as a marker for the total number of DSBs induced in a cell and RAD51 foci as a marker for the fraction of those DSBs undergoing repair by HR. We also evaluated RPA accretion on chromatin as evidence for ongoing DNA end resection, an important initial step for all pathways of DSB repair except c-NHEJ. We finally employed the DR-GFP reporter assay to evaluate DSB repair by HR in DT40 cells. Collectively, the results obtained, unexpectedly show that DT40 and NALM6 cells utilized HR for DSB repair at levels very similar to those of other somatic cells. These observations uncouple gene-targeting efficiency from HR contribution to DSB repair and suggest the function of additional mechanisms increasing gene-targeting efficiency. Indeed, our results show that analysis of the contribution of HR to DSB repair may not be used as a proxy for gene-targeting efficiency.
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Utilizing Carbon Ions to Treat Medulloblastomas that Exhibit Chromothripsis. CURRENT STEM CELL REPORTS 2022. [DOI: 10.1007/s40778-022-00213-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Abstract
Purpose of Review
Novel radiation therapies with accelerated charged particles such as protons and carbon ions have shown encouraging results in oncology. We present recent applications as well as benefits and risks associated with their use.
Recent Findings
We discuss the use of carbon ion radiotherapy to treat a specific type of aggressive pediatric brain tumors, namely medulloblastomas with chromothripsis. Potential reasons for the resistance to conventional treatment, such as the presence of cancer stem cells with unique properties, are highlighted. Finally, advantages of particle radiation alone and in combination with other therapies to overcome resistance are featured.
Summary
Provided that future preclinical studies confirm the evidence of high effectiveness, favorable toxicity profiles, and no increased risk of secondary malignancy, carbon ion therapy may offer a promising tool in pediatric (neuro)oncology and beyond.
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Wallace SS. Consequences and repair of radiation-induced DNA damage: fifty years of fun questions and answers. Int J Radiat Biol 2021; 98:367-382. [PMID: 34187282 DOI: 10.1080/09553002.2021.1948141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To summarize succinctly the 50 years of research undertaken in my laboratory and to provide an overview of my career in science. It is certainly a privilege to have been asked by Carmel Mothersill and Penny Jeggo to contribute to this special issue of the International Journal of Radiation Biology focusing on the work of women in the radiation sciences. CONCLUSION My students, post-docs and I identified and characterized a number of the enzymes that recognize and remove radiation-damaged DNA bases, the DNA glycosylases, which are the first enzymes in the Base Excision Repair (BER) pathway. Although this pathway actually evolved to repair oxidative and other endogenous DNA damages, it is also responsible for removing the vast majority of radiation-induced DNA damages including base damages, alkali-labile lesions and single strand breaks. However, because of its high efficiency, attempted BER of clustered lesions produced by ionizing radiation, can have disastrous effects on cellular DNA. We also evaluated the potential biological consequences of many of the radiation-induced DNA lesions. In addition, with collaborators, we employed computational techniques, x-ray crystallography and single molecule approaches to answer many questions at the molecular level.
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Affiliation(s)
- Susan S Wallace
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
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Mladenova V, Mladenov E, Scholz M, Stuschke M, Iliakis G. Strong Shift to ATR-Dependent Regulation of the G 2-Checkpoint after Exposure to High-LET Radiation. Life (Basel) 2021; 11:life11060560. [PMID: 34198619 PMCID: PMC8232161 DOI: 10.3390/life11060560] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/09/2021] [Indexed: 12/29/2022] Open
Abstract
The utilization of high linear-energy-transfer (LET) ionizing radiation (IR) modalities is rapidly growing worldwide, causing excitement but also raising concerns, because our understanding of their biological effects is incomplete. Charged particles such as protons and heavy ions have increasing potential in cancer therapy, due to their advantageous physical properties over X-rays (photons), but are also present in the space environment, adding to the health risks of space missions. Therapy improvements and the protection of humans during space travel will benefit from a better understanding of the mechanisms underpinning the biological effects of high-LET IR. There is evidence that high-LET IR induces DNA double-strand breaks (DSBs) of increasing complexity, causing enhanced cell killing, owing, at least partly, to the frequent engagement of a low-fidelity DSB-repair pathway: alternative end-joining (alt-EJ), which is known to frequently induce severe structural chromosomal abnormalities (SCAs). Here, we evaluate the radiosensitivity of A549 lung adenocarcinoma cells to X-rays, α-particles and 56Fe ions, as well as of HCT116 colorectal cancer cells to X-rays and α-particles. We observe the expected increase in cell killing following high-LET irradiation that correlates with the increased formation of SCAs as detected by mFISH. Furthermore, we report that cells exposed to low doses of α-particles and 56Fe ions show an enhanced G2-checkpoint response which is mainly regulated by ATR, rather than the coordinated ATM/ATR-dependent regulation observed after exposure to low doses of X-rays. These observations advance our understanding of the mechanisms underpinning high-LET IR effects, and suggest the potential utility for ATR inhibitors in high-LET radiation therapy.
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Affiliation(s)
- Veronika Mladenova
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany; (V.M.); (E.M.); (M.S.)
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Emil Mladenov
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany; (V.M.); (E.M.); (M.S.)
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Michael Scholz
- Biophysics Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany;
| | - Martin Stuschke
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany; (V.M.); (E.M.); (M.S.)
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, 45122 Essen, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - George Iliakis
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany; (V.M.); (E.M.); (M.S.)
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
- Correspondence:
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Wallace SS. Molecular radiobiology and the origins of the base excision repair pathway: an historical perspective. Int J Radiat Biol 2021; 99:891-902. [DOI: 10.1080/09553002.2021.1908639] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Susan S. Wallace
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
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8
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Li Y, Lu K, Zhao B, Zeng X, Xu S, Ma X, Zhi Y. Depletion of insulin-like growth factor 1 receptor increases radiosensitivity in colorectal cancer. J Gastrointest Oncol 2020; 11:1135-1145. [PMID: 33456988 DOI: 10.21037/jgo-20-210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background Although radiation therapy for advanced colorectal cancer (CRC) is very effective in some patients, treatment resistance limits its efficacy. Insulin-like growth factor 1 receptor (IGF1R) can affect tumor responsiveness and sensitivity to radiation in several cancer types. Herein, we studied the underlying function of IGF1R in the resistance of advanced CRC to radiation therapy and the possible use of drugs targeting IGF1R to overcome this resistance in patients with CRC. Methods Differences in the expression levels of the IGF1R were assessed in CRC samples from patients who were radiosensitive or radioresistant. Two radio-resistant colorectal cancer cell lines, SW480 and HT29, were selected for in vitro studies, and the involvement of the IGF1R in their radiation resistance was elucidated by suppressing its expression through a targeted siRNA and through the use of a specific IGF1R inhibitor, BMS-754807. We assessed radiosensitivity in these human CRC cells lines by examining their proliferation and colony formation, as well as cell cycle analysis. Activation of the Akt pathway was assessed using western blotting. Results Compared with tissues from radiosensitive patients, higher IGF1R expression levels were found in patients with radiation-resistant colorectal cancer, while BMS-754807 had improved radiosensitivity and reversed radiation tolerance in both colorectal cancer cell lines. Pre-treatment with BMS-754807 prior to irradiation inhibited Akt phosphorylation, induced cell cycle arrest, and increased DNA damage. Therefore, the IGF1R contributes to radiation resistance of CRC cells in vitro. Conclusions This study supports the notion that the radiosensitivity of radiation-resistant colorectal cancer cells can be enhanced by directly targeting IGF1R expression or activity. Ultimately, the combination of radiotherapy with IGF1R targeted inhibitors could potentially increase its effectiveness in the treatment of advanced colorectal cancer.
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Affiliation(s)
- Yi Li
- Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Kui Lu
- Department of Oncology, the Second People's Hospital of Taizhou City, Taizhou, China
| | - Ben Zhao
- Division of Solid Tumor Translational Oncology, German Cancer Consortium and German Cancer Research Center, DKFZ, Heidelberg, Germany
| | - Xiaokui Zeng
- Department of Transplantation, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Shan Xu
- Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Xin Ma
- Department of Transplantation, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Department of Nephrology, the First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Yunqing Zhi
- Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China.,Department of Transplantation, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Department of Gynecology, Shanghai Changning Maternity and Infant Health Hospital, Shanghai, China
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Stanley FKT, Berger ND, Pearson DD, Danforth JM, Morrison H, Johnston JE, Warnock TS, Brenner DR, Chan JA, Pierce G, Cobb JA, Ploquin NP, Goodarzi AA. A high-throughput alpha particle irradiation system for monitoring DNA damage repair, genome instability and screening in human cell and yeast model systems. Nucleic Acids Res 2020; 48:e111. [PMID: 33010172 PMCID: PMC7641727 DOI: 10.1093/nar/gkaa782] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/27/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022] Open
Abstract
Ionizing radiation (IR) is environmentally prevalent and, depending on dose and linear energy transfer (LET), can elicit serious health effects by damaging DNA. Relative to low LET photon radiation (X-rays, gamma rays), higher LET particle radiation produces more disease causing, complex DNA damage that is substantially more challenging to resolve quickly or accurately. Despite the majority of human lifetime IR exposure involving long-term, repetitive, low doses of high LET alpha particles (e.g. radon gas inhalation), technological limitations to deliver alpha particles in the laboratory conveniently, repeatedly, over a prolonged period, in low doses and in an affordable, high-throughput manner have constrained DNA damage and repair research on this topic. To resolve this, we developed an inexpensive, high capacity, 96-well plate-compatible alpha particle irradiator capable of delivering adjustable, low mGy/s particle radiation doses in multiple model systems and on the benchtop of a standard laboratory. The system enables monitoring alpha particle effects on DNA damage repair and signalling, genome stability pathways, oxidative stress, cell cycle phase distribution, cell viability and clonogenic survival using numerous microscopy-based and physical techniques. Most importantly, this method is foundational for high-throughput genetic screening and small molecule testing in mammalian and yeast cells.
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Affiliation(s)
- Fintan K T Stanley
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - N Daniel Berger
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Dustin D Pearson
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - John M Danforth
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Hali Morrison
- Division of Medical Physics, Department of Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - James E Johnston
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Tyler S Warnock
- Robson DNA Science Centre, Departments of Cancer Epidemiology and Prevention Research and Community Health Sciences, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Darren R Brenner
- Robson DNA Science Centre, Departments of Cancer Epidemiology and Prevention Research and Community Health Sciences, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Jennifer A Chan
- Department of Pathology and Laboratory Medicine, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Greg Pierce
- Division of Medical Physics, Department of Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Jennifer A Cobb
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Nicolas P Ploquin
- Division of Medical Physics, Department of Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Aaron A Goodarzi
- Robson DNA Science Centre, Departments of Biochemistry and Molecular Biology and Oncology, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
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Interphase Cytogenetic Analysis of G0 Lymphocytes Exposed to α-Particles, C-Ions, and Protons Reveals their Enhanced Effectiveness for Localized Chromosome Shattering-A Critical Risk for Chromothripsis. Cancers (Basel) 2020; 12:cancers12092336. [PMID: 32825012 PMCID: PMC7563219 DOI: 10.3390/cancers12092336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/08/2020] [Accepted: 08/15/2020] [Indexed: 01/21/2023] Open
Abstract
For precision cancer radiotherapy, high linear energy transfer (LET) particle irradiation offers a substantial advantage over photon-based irradiation. In contrast to the sparse deposition of low-density energy by χ- or γ-rays, particle irradiation causes focal DNA damage through high-density energy deposition along the particle tracks. This is characterized by the formation of multiple damage sites, comprising localized clustered patterns of DNA single- and double-strand breaks as well as base damage. These clustered DNA lesions are key determinants of the enhanced relative biological effectiveness (RBE) of energetic nuclei. However, the search for a fingerprint of particle exposure remains open, while the mechanisms underlying the induction of chromothripsis-like chromosomal rearrangements by high-LET radiation (resembling chromothripsis in tumors) await to be elucidated. In this work, we investigate the transformation of clustered DNA lesions into chromosome fragmentation, as indicated by the induction and post-irradiation repair of chromosomal damage under the dynamics of premature chromosome condensation in G0 human lymphocytes. Specifically, this study provides, for the first time, experimental evidence that particle irradiation induces localized shattering of targeted chromosome domains. Yields of chromosome fragments and shattered domains are compared with those generated by γ-rays; and the RBE values obtained are up to 28.6 for α-particles (92 keV/μm), 10.5 for C-ions (295 keV/μm), and 4.9 for protons (28.5 keV/μm). Furthermore, we test the hypothesis that particle radiation-induced persistent clustered DNA lesions and chromatin decompaction at damage sites evolve into localized chromosome shattering by subsequent chromatin condensation in a single catastrophic event—posing a critical risk for random rejoining, chromothripsis, and carcinogenesis. Consistent with this hypothesis, our results highlight the potential use of shattered chromosome domains as a fingerprint of high-LET exposure, while conforming to the new model we propose for the mechanistic origin of chromothripsis-like rearrangements.
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11
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Brás A, Rodrigues AS, Rueff J. Copy number variations and constitutional chromothripsis (Review). Biomed Rep 2020; 13:11. [PMID: 32765850 PMCID: PMC7391299 DOI: 10.3892/br.2020.1318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/13/2020] [Indexed: 02/07/2023] Open
Abstract
Both copy number variations (CNVs) and chromothripsis are phenomena that involve complex genomic rearrangements. Chromothripsis results in CNVs and other structural changes. CNVs are frequently observed in the human genome. Studies on CNVs have been increasing exponentially; the Database of Genomic Variants shows an increase in the number of data published on structural variations added to the database in the last 15 years. CNVs may be a result of replicative and non-replicative mechanisms, and are hypothesized to serve important roles in human health and disease. Chromothripsis is a phenomena of chromosomal rearrangement following chromosomal breaks at multiple locations and involves impaired DNA repair. In 2011, Stephens et al coined the term chromothripsis for this type of fragmenting event. Several proposed mechanisms have been suggested to underlie chromothripsis, such as p53 inactivation, micronuclei formation, abortive apoptosis and telomere fusions in telomere crisis. Chromothripsis gives rise to normal or abnormal phenotypes. In this review, constitutional chromothripsis, which may coexist with multiple de novo CNVs are described and discussed. This reviews aims to summarize recent advances in our understanding of CNVs and chromothripsis, and describe the effects of these phenomena on human health and birth defects.
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Affiliation(s)
- Aldina Brás
- Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculty of Medical Sciences, NOVA University of Lisbon, Lisbon 1169-056, Portugal
| | - António Sebastião Rodrigues
- Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculty of Medical Sciences, NOVA University of Lisbon, Lisbon 1169-056, Portugal
| | - José Rueff
- Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculty of Medical Sciences, NOVA University of Lisbon, Lisbon 1169-056, Portugal
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Akagawa R, Trinh HT, Saha LK, Tsuda M, Hirota K, Yamada S, Shibata A, Kanemaki MT, Nakada S, Takeda S, Sasanuma H. UBC13-Mediated Ubiquitin Signaling Promotes Removal of Blocking Adducts from DNA Double-Strand Breaks. iScience 2020; 23:101027. [PMID: 32283528 PMCID: PMC7155233 DOI: 10.1016/j.isci.2020.101027] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/22/2020] [Accepted: 03/26/2020] [Indexed: 12/25/2022] Open
Abstract
Chemical modifications and adducts at DNA double-strand break (DSB) ends must be cleaned before re-joining by non-homologous end-joining (NHEJ). MRE11 nuclease is essential for efficient removal of Topoisomerase II (TOP2)-DNA adducts from TOP2 poison-induced DSBs. However, mechanisms in MRE11 recruitment to DSB sites in G1 phase remain poorly understood. Here, we report that TOP2-DNA adducts are expeditiously removed through UBC13-mediated polyubiquitination, which promotes DSB resection in G2 phase. We found that this ubiquitin signaling is required for efficient recruitment of MRE11 onto DSB sites in G1 by facilitating localization of RAP80 and BRCA1 to DSB sites and complex formation between BRCA1 and MRE11 at DSB sites. UBC13 and MRE11 are dispensable for restriction-enzyme-induced "clean" DSBs repair but responsible for over 50% and 70% of NHEJ-dependent repair of γ-ray-induced "dirty" DSBs, respectively. In conclusion, ubiquitin signaling promotes nucleolytic removal of DSB blocking adducts by MRE11 before NHEJ.
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Affiliation(s)
- Remi Akagawa
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hai Thanh Trinh
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Liton Kumar Saha
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan
| | - Shintaro Yamada
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan; Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Atsushi Shibata
- Signal Transduction Program, Gunma University Initiative for Advanced Research (GIAR), Gunma University, Maebashi, Gunma 371-8511, Japan
| | - Masato T Kanemaki
- National Institute of Genetics, Research Organization of Information and Systems (ROIS), and Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Shinichiro Nakada
- Department of Bioregulation and Cellular Response, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Hiroyuki Sasanuma
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan.
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13
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Fucic A, Druzhinin V, Aghajanyan A, Slijepcevic P, Bakanova M, Baranova E, Minina V, Golovina T, Kourdakov K, Timofeeva A, Titov V. Rogue versus chromothriptic cell as biomarker of cancer. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 784:108299. [PMID: 32430100 DOI: 10.1016/j.mrrev.2020.108299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 11/30/2022]
Abstract
New molecular cytogenetic biomarkers may significantly contribute to biodosimetry, whose application is still globally diverse and not fully standardized. In 2011, a new term, chromothripsis, was introduced raising great interest among researchers and soon motivating further investigations of the phenomenon. Chromothripsis is described as a single event in which one or more chromosomes go through severe DNA damage very much resembling rogue cells (RC) described more than 50 years ago. In this review, we for the first time compare these two multi-aberrant cells types, RC versus chromothriptic cells, giving insight into the similarities of the mechanisms involved in their etiology. In order to make a better comparison, data on RC in 3366 subjects from studies on cancer patients, Chernobyl liquidators, child victims of the Chernobyl nuclear plant accident, residentially and occupationally exposed population have been summarized for the first time. Results of experimental and epidemiological analysis show that chromothriptic cells and RC may be caused by exposure to high LET ionizing radiation. Experience and knowledge collected on RC may be used in future for further investigations of chromothripsis, introducing a new class of cells which include both chromothriptic and RC, and better insight into the frequency of chromothriptic cell per subject, which is currently absent. Both cell types are relevant in investigations of cancer etiology, biomonitoring of accidentally exposed population to ionizing radiation and biomonitoring of astronauts due to their exposure to high LET ionizing radiation during interplanetary voyages.
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Affiliation(s)
- Aleksandra Fucic
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
| | | | - Anna Aghajanyan
- Medical Institute Peoples' Friendship University of Russia (RUDN University), Moscow, Russia Federation
| | - Predrag Slijepcevic
- Brunel University London, Department of Life Sciences, College of Health and Life Sciences, Uxbridge, UK
| | | | | | | | | | | | | | - Victor Titov
- Kemerovo Regional Oncology Center, Kemerovo, Russian Federation
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14
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Nickoloff JA, Sharma N, Taylor L. Clustered DNA Double-Strand Breaks: Biological Effects and Relevance to Cancer Radiotherapy. Genes (Basel) 2020; 11:E99. [PMID: 31952359 PMCID: PMC7017136 DOI: 10.3390/genes11010099] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/08/2020] [Accepted: 01/14/2020] [Indexed: 01/03/2023] Open
Abstract
Cells manage to survive, thrive, and divide with high accuracy despite the constant threat of DNA damage. Cells have evolved with several systems that efficiently repair spontaneous, isolated DNA lesions with a high degree of accuracy. Ionizing radiation and a few radiomimetic chemicals can produce clustered DNA damage comprising complex arrangements of single-strand damage and DNA double-strand breaks (DSBs). There is substantial evidence that clustered DNA damage is more mutagenic and cytotoxic than isolated damage. Radiation-induced clustered DNA damage has proven difficult to study because the spectrum of induced lesions is very complex, and lesions are randomly distributed throughout the genome. Nonetheless, it is fairly well-established that radiation-induced clustered DNA damage, including non-DSB and DSB clustered lesions, are poorly repaired or fail to repair, accounting for the greater mutagenic and cytotoxic effects of clustered lesions compared to isolated lesions. High linear energy transfer (LET) charged particle radiation is more cytotoxic per unit dose than low LET radiation because high LET radiation produces more clustered DNA damage. Studies with I-SceI nuclease demonstrate that nuclease-induced DSB clusters are also cytotoxic, indicating that this cytotoxicity is independent of radiogenic lesions, including single-strand lesions and chemically "dirty" DSB ends. The poor repair of clustered DSBs at least in part reflects inhibition of canonical NHEJ by short DNA fragments. This shifts repair toward HR and perhaps alternative NHEJ, and can result in chromothripsis-mediated genome instability or cell death. These principals are important for cancer treatment by low and high LET radiation.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA; (N.S.); (L.T.)
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15
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Averbeck D, Candéias S, Chandna S, Foray N, Friedl AA, Haghdoost S, Jeggo PA, Lumniczky K, Paris F, Quintens R, Sabatier L. Establishing mechanisms affecting the individual response to ionizing radiation. Int J Radiat Biol 2020; 96:297-323. [PMID: 31852363 DOI: 10.1080/09553002.2019.1704908] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Purpose: Humans are increasingly exposed to ionizing radiation (IR). Both low (<100 mGy) and high doses can cause stochastic effects, including cancer; whereas doses above 100 mGy are needed to promote tissue or cell damage. 10-15% of radiotherapy (RT) patients suffer adverse reactions, described as displaying radiosensitivity (RS). Sensitivity to IR's stochastic effects is termed radiosusceptibility (RSu). To optimize radiation protection we need to understand the range of individual variability and underlying mechanisms. We review the potential mechanisms contributing to RS/RSu focusing on RS following RT, the most tractable RS group.Conclusions: The IR-induced DNA damage response (DDR) has been well characterized. Patients with mutations in the DDR have been identified and display marked RS but they represent only a small percentage of the RT patients with adverse reactions. We review the impacting mechanisms and additional factors influencing RS/RSu. We discuss whether RS/RSu might be genetically determined. As a recommendation, we propose that a prospective study be established to assess RS following RT. The study should detail tumor site and encompass a well-defined grading system. Predictive assays should be independently validated. Detailed analysis of the inflammatory, stress and immune responses, mitochondrial function and life style factors should be included. Existing cohorts should also be optimally exploited.
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Affiliation(s)
| | - Serge Candéias
- CEA, CNRS, LCMB, University of Grenoble Alpes, Grenoble, France
| | - Sudhir Chandna
- Division of Radiation Biosciences, Institute of Nuclear Medicine & Allied Sciences, Delhi, India
| | - Nicolas Foray
- Inserm UA8 Unit Radiations: Defense, Health and Environment, Lyon, France
| | - Anna A Friedl
- Department of Radiation Oncology, University Hospital, LMU, Munich, Germany
| | - Siamak Haghdoost
- Cimap-Laria, Advanced Resource Center for HADrontherapy in Europe (ARCHADE,), University of Caen Normandy, France.,Centre for Radiation Protection Research, Department of Molecular Bioscience, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Penelope A Jeggo
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Katalin Lumniczky
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Center, Budapest, Hungary
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16
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Mavragani IV, Nikitaki Z, Kalospyros SA, Georgakilas AG. Ionizing Radiation and Complex DNA Damage: From Prediction to Detection Challenges and Biological Significance. Cancers (Basel) 2019; 11:E1789. [PMID: 31739493 PMCID: PMC6895987 DOI: 10.3390/cancers11111789] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Biological responses to ionizing radiation (IR) have been studied for many years, generally showing the dependence of these responses on the quality of radiation, i.e., the radiation particle type and energy, types of DNA damage, dose and dose rate, type of cells, etc. There is accumulating evidence on the pivotal role of complex (clustered) DNA damage towards the determination of the final biological or even clinical outcome after exposure to IR. In this review, we provide literature evidence about the significant role of damage clustering and advancements that have been made through the years in its detection and prediction using Monte Carlo (MC) simulations. We conclude that in the future, emphasis should be given to a better understanding of the mechanistic links between the induction of complex DNA damage, its processing, and systemic effects at the organism level, like genomic instability and immune responses.
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Affiliation(s)
| | | | | | - Alexandros G. Georgakilas
- DNA Damage Laboratory, Department of Physics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), 15780 Athens, Greece
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17
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Zhuang H, Shi S, Guo Y, Wang Z. Increase of secondary mutations may be a drug-resistance mechanism for lung adenocarcinoma after radiation therapy combined with tyrosine kinase inhibitor. J Cancer 2019; 10:5371-5376. [PMID: 31632481 PMCID: PMC6775686 DOI: 10.7150/jca.35247] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/13/2019] [Indexed: 11/05/2022] Open
Abstract
Objective: To investigate changes in the secondary mutations of tumor in a drug-resistance mechanism for lung adenocarcinoma after radiation therapy combined with tyrosine kinase inhibitor (TKI). Methods: Lung adenocarcinoma cell line PC9 in vitro and xenograft model in nude mice were used to observe tumor inhibitory effects and drug-resistance under the effect of radiation therapy combined with erlotinib through apoptosis detection through in vitro survival curve and in vivo growth curve; changes in gene mutations before and after drug-resistance in nude mice xenografts were observed by the next generation sequencing, and the relationship between cancer drug-resistance and radiation therapy combined with TKI was observed. Results: Radiation therapy combined with erlotinib had a more reliable radio-sensitizing effect in vitro and in vivo, however, there were several drug-resistant tumor cells. Meanwhile, radiation therapy combined with erlotinib could significantly increase the number of mutations in tumor genes. The whole genome sequencing showed that the secondary mutation in the combined treatment group significantly increased in comparison with those of the single treatment group and the blank control group. Conclusion: The increase of secondary mutations may be an important drug-resistance mechanism for lung adenocarcinoma after radiation therapy combined with TKI, which provided further space exploration under the combined action of radiation and TKI.
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Affiliation(s)
- Hongqing Zhuang
- Department of Radiation Oncology, Peking University Third Hospital, Beijing, China
| | - Siyu Shi
- Stanford University School of Medicine, Stanford, CA94305, US
| | - Yihang Guo
- Department of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
| | - Zhongqiu Wang
- Department of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
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18
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Pantelias A, Karachristou I, Georgakilas AG, Terzoudi GI. Interphase Cytogenetic Analysis of Micronucleated and Multinucleated Cells Supports the Premature Chromosome Condensation Hypothesis as the Mechanistic Origin of Chromothripsis. Cancers (Basel) 2019; 11:E1123. [PMID: 31390832 PMCID: PMC6721583 DOI: 10.3390/cancers11081123] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/26/2019] [Accepted: 08/03/2019] [Indexed: 12/19/2022] Open
Abstract
The discovery of chromothripsis in cancer genomes challenges the long-standing concept of carcinogenesis as the result of progressive genetic events. Despite recent advances in describing chromothripsis, its mechanistic origin remains elusive. The prevailing conception is that it arises from a massive accumulation of fragmented DNA inside micronuclei (MN), whose defective nuclear envelope ruptures or leads to aberrant DNA replication, before main nuclei enter mitosis. An alternative hypothesis is that the premature chromosome condensation (PCC) dynamics in asynchronous micronucleated cells underlie chromosome shattering in a single catastrophic event, a hallmark of chromothripsis. Specifically, when main nuclei enter mitosis, premature chromatin condensation provokes the shattering of chromosomes entrapped inside MN, if they are still undergoing DNA replication. To test this hypothesis, the agent RO-3306, a selective ATP-competitive inhibitor of CDK1 that promotes cell cycle arrest at the G2/M boundary, was used in this study to control the degree of cell cycle asynchrony between main nuclei and MN. By delaying the entrance of main nuclei into mitosis, additional time was allowed for the completion of DNA replication and duplication of chromosomes inside MN. We performed interphase cytogenetic analysis using asynchronous micronucleated cells generated by exposure of human lymphocytes to γ-rays, and heterophasic multinucleated Chinese hamster ovary (CHO) cells generated by cell fusion procedures. Our results demonstrate that the PCC dynamics during asynchronous mitosis in micronucleated or multinucleated cells are an important determinant of chromosome shattering and may underlie the mechanistic origin of chromothripsis.
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Affiliation(s)
- Antonio Pantelias
- Laboratory of Health Physics, Radiobiology & Cytogenetics, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Centre for Scientific Research "Demokritos", 15341 Agia Paraskevi, Greece.
- DNA Damage Laboratory, Physics Department, School of Mathematical and Physical Sciences, National Technical University of Athens (NTUA), 15780 Zografou, Greece.
| | - Ioanna Karachristou
- Laboratory of Health Physics, Radiobiology & Cytogenetics, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Centre for Scientific Research "Demokritos", 15341 Agia Paraskevi, Greece
| | - Alexandros G Georgakilas
- DNA Damage Laboratory, Physics Department, School of Mathematical and Physical Sciences, National Technical University of Athens (NTUA), 15780 Zografou, Greece
| | - Georgia I Terzoudi
- Laboratory of Health Physics, Radiobiology & Cytogenetics, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Centre for Scientific Research "Demokritos", 15341 Agia Paraskevi, Greece.
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