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Sakamoto Y, Shiraishi K, Kodama S. Enhanced induction of abnormal telomere FISH signals in response to oxidative DNA damage. JOURNAL OF RADIATION RESEARCH 2024; 65:187-193. [PMID: 38171574 PMCID: PMC10959432 DOI: 10.1093/jrr/rrad102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/16/2023] [Indexed: 01/05/2024]
Abstract
Telomere dysfunction induces chromosomal instability, which is a driving force in the development of cancers. To examine X-irradiation's effect on telomere integrity, we investigated X-ray-induced abnormalities in telomere signals detected by fluorescence in situ hybridization (telomere FISH) in mouse embryo fibroblast cells. The abnormalities were categorized as either extra telomere signals (ETSs) or loss of telomere signals (LTSs). The results indicated that low doses (0.3-0.5 Gy) of X-rays significantly induced ETS but not LTS and that ETS induction was saturated at doses above 0.5 Gy. In addition, treatment with hydrogen peroxide also induced ETS but not LTS. To clarify the involvement of radicals in inducing ETS, we examined the effect of ascorbic acid (AsA) on telomere FISH signals and found that pre-treatment with AsA (5 mM, 2 h), but not post-treatment, significantly suppressed the induction of ETS by X-irradiation. Importantly, neither pre- nor post-treatment with AsA affected X-ray-induced chromosome aberrations. These results suggest that oxidative DNA damage induced by radicals is involved in the induction of ETS. Furthermore, combined treatment with aphidicolin, a DNA replication inhibitor, elevated the induction of ETS by X-irradiation. This observation suggests that DNA replication stress, potentially triggered by oxidative DNA lesions within telomeres, may contribute to the induction of ETS resulting from X-irradiation. Based on these results, we propose that ETS is a sensitive biological marker of oxidative DNA damage in telomere structures.
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Affiliation(s)
- Yoshimi Sakamoto
- Radiation Biology Group, Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan
| | - Kazunori Shiraishi
- Radiation Biology Group, Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan
| | - Seiji Kodama
- Radiation Biology Group, Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan
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2
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Bolzán AD. Mutagen-induced telomere instability in human cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2021; 868-869:503387. [PMID: 34454696 DOI: 10.1016/j.mrgentox.2021.503387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/13/2021] [Accepted: 07/18/2021] [Indexed: 11/27/2022]
Abstract
Telomere instability is one of the main sources of genome instability and may result from chromosome end loss (due to chromosome breakage at one or both ends) or, more frequently, telomere dysfunction. Dysfunctional telomeres arise when they lose their end-capping function or become critically short, which causes chromosomal termini to behave like a DNA double-strand break. Telomere instability may occur at the chromosomal or at the molecular level, giving rise, respectively, to telomere-related chromosomal aberrations or the loss or modification of any of the components of the telomere (telomere DNA, telomere-associated proteins, or telomere RNA). Since telomeres play a fundamental role in maintaining genome stability, the study of telomere instability in cells exposed to mutagens is of great importance to understand the telomere-driven genomic instability present in those cells. In the present review, we will focus on the current knowledge about telomere instability induced by physical, chemical, and biological mutagens in human cells.
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Affiliation(s)
- Alejandro D Bolzán
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CONICET-CICPBA-UNLP), calle 526 y Camino General Belgrano, B1906APO La Plata, Buenos Aires, Argentina; Universidad Nacional de La Plata, Facultad de Ciencias Naturales y Museo, calle 60 y 122, La Plata, Buenos Aires, Argentina.
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3
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Hirose E, Suzuki K, Yokoya A. Molecular Configuration of Human Genome Neighboring Megabase-Sized Large Deletions Induced by X-Ray Irradiation. Radiat Res 2021; 195:561-567. [PMID: 33826740 DOI: 10.1667/rr15229.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 03/15/2021] [Indexed: 11/03/2022]
Abstract
The genomic landscape neighboring large deletions including the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus on human X chromosome in 6-thioguanine-resistant mutants originating from immortalized human fibroblast cells exposed to X rays was characterized by real-time quantitative PCR (qPCR)-based analyses. Among the 13 mutant clones with large deletions extending over several Mb, including the HPRT locus, revealed by 10 conventional sequence-tagged site (STS) markers, three clones bearing the largest deletions were selected for further qPCR analysis using another 21 STS markers and 15 newly designed PCR primer pairs. The results indicated that the major deletions were in very specific regions between the 130-Mb and 140-Mb positions containing the HPRT locus on the X chromosome and, contrary to our initial expectations, additional minor deletions were distributed in a patchwork pattern. These findings strongly indicate that the complex deletion patterns in the affected chromosome are related to the radiation track structure with spatially heterogeneous energy deposition and the specific structure of the chromatin-nuclear membrane complex. The uncovered complex deletion patterns are in agreement with the idea of complex chromatin damage, which is frequently associated with carcinogenesis.
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Affiliation(s)
- Eri Hirose
- Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Keiji Suzuki
- Tokai Quantum Beam Science Center, National Institutes of Quantum and Radiological Sciences, Tokai, Ibaraki 319-1106, Japan
| | - Akinari Yokoya
- Ibaraki University, Mito, Ibaraki 310-8512, Japan.,Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
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4
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Using telomeric chromosomal aberrations to evaluate clastogen-induced genomic instability in mammalian cells. Chromosome Res 2020; 28:259-276. [DOI: 10.1007/s10577-020-09641-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/06/2020] [Accepted: 09/06/2020] [Indexed: 12/13/2022]
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5
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Marcu LG. Photons – Radiobiological issues related to the risk of second malignancies. Phys Med 2017; 42:213-220. [DOI: 10.1016/j.ejmp.2017.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/21/2017] [Accepted: 02/14/2017] [Indexed: 12/23/2022] Open
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6
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Ojima M, Iwashita K, Kashino G, Kobashigawa S, Sasano N, Takeshita A, Ban N, Kai M. Early and Delayed Induction of DSBs by Nontargeted Effects in ICR Mouse Lymphocytes after In Vivo X Irradiation. Radiat Res 2016; 186:65-70. [PMID: 27351761 DOI: 10.1667/rr14053.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The goal of this study was to determine whether in vivo X irradiation induces nontargeted effects, such as delayed effects and bystander effects in ICR mouse lymphocytes. We first examined the generation of DNA double-strand breaks (DSBs) in lymphocytes, isolated from ICR mice exposed to 1 Gy X irradiation, by enumeration of p53 binding protein 1 (53BP1) foci, and observed that the number of 53BP1 foci reached their maximum 3 days postirradiation and decreased to background level 30 days postirradiation. However, the number of 53BP1 foci was significantly increased in lymphocytes isolated from ICR mice 90-365 days postirradiation. This result indicates that in vivo X irradiation induced delayed DSBs in ICR mouse lymphocytes. We next counted the number of 53BP1 foci in lymphocytes isolated from sham-irradiated ICR mice that had been co-cultured with lymphocytes isolated from 1 Gy X-irradiated ICR mice, and observed a significant increase in the number of 53BP1 foci 1-7 days postirradiation. This result indicates that in vivo X irradiation induced bystander effects in ICR mouse lymphocytes. These findings suggest that in vivo X irradiation induces early and delayed nontargeted effects in ICR mouse lymphocytes.
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Affiliation(s)
- Mitsuaki Ojima
- a Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan
| | - Keiko Iwashita
- a Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan
| | - Genro Kashino
- b Advanced Molecular Center, Faculty of Medicine, Oita University, Yufu 879-5593, Japan
| | - Shinko Kobashigawa
- b Advanced Molecular Center, Faculty of Medicine, Oita University, Yufu 879-5593, Japan
| | - Noriko Sasano
- a Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan
| | - Akiko Takeshita
- a Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan
| | - Nobuhiko Ban
- c Tokyo Healthcare University, Tokyo 152-8558, Japan
| | - Michiaki Kai
- a Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan
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7
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Sridharan DM, Asaithamby A, Blattnig SR, Costes SV, Doetsch PW, Dynan WS, Hahnfeldt P, Hlatky L, Kidane Y, Kronenberg A, Naidu MD, Peterson LE, Plante I, Ponomarev AL, Saha J, Snijders AM, Srinivasan K, Tang J, Werner E, Pluth JM. Evaluating biomarkers to model cancer risk post cosmic ray exposure. LIFE SCIENCES IN SPACE RESEARCH 2016; 9:19-47. [PMID: 27345199 PMCID: PMC5613937 DOI: 10.1016/j.lssr.2016.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens.
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Affiliation(s)
| | | | - Steve R Blattnig
- Langley Research Center, Langley Research Center (LaRC), VA, United States
| | - Sylvain V Costes
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | | | | | | | - Lynn Hlatky
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Yared Kidane
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Amy Kronenberg
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Mamta D Naidu
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Leif E Peterson
- Houston Methodist Research Institute, Houston, TX, United States
| | - Ianik Plante
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Artem L Ponomarev
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Janapriya Saha
- UT Southwestern Medical Center, Dallas, TX, United States
| | | | | | - Jonathan Tang
- Exogen Biotechnology, Inc., Berkeley, CA, United States
| | | | - Janice M Pluth
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
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8
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Paviolo NS, Santiñaque FF, Castrogiovanni DC, Folle GA, Bolzán AD. The methylating agent streptozotocin induces persistent telomere dysfunction in mammalian cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 794:17-24. [DOI: 10.1016/j.mrgentox.2015.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/23/2015] [Accepted: 09/28/2015] [Indexed: 01/17/2023]
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9
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A novel ATM/TP53/p21-mediated checkpoint only activated by chronic γ-irradiation. PLoS One 2014; 9:e104279. [PMID: 25093836 PMCID: PMC4122452 DOI: 10.1371/journal.pone.0104279] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 07/05/2014] [Indexed: 01/19/2023] Open
Abstract
Different levels or types of DNA damage activate distinct signaling pathways that elicit various cellular responses, including cell-cycle arrest, DNA repair, senescence, and apoptosis. Whereas a range of DNA-damage responses have been characterized, mechanisms underlying subsequent cell-fate decision remain elusive. Here we exposed cultured cells and mice to different doses and dose rates of γ-irradiation, which revealed cell-type-specific sensitivities to chronic, but not acute, γ-irradiation. Among tested cell types, human fibroblasts were associated with the highest levels of growth inhibition in response to chronic γ-irradiation. In this context, fibroblasts exhibited a reversible G1 cell-cycle arrest or an irreversible senescence-like growth arrest, depending on the irradiation dose rate or the rate of DNA damage. Remarkably, when the same dose of γ-irradiation was delivered chronically or acutely, chronic delivery induced considerably more cellular senescence. A similar effect was observed with primary cells isolated from irradiated mice. We demonstrate a critical role for the ataxia telangiectasia mutated (ATM)/tumor protein p53 (TP53)/p21 pathway in regulating DNA-damage-associated cell fate. Indeed, blocking the ATM/TP53/p21 pathway deregulated DNA damage responses, leading to micronucleus formation in chronically irradiated cells. Together these results provide insights into the mechanisms governing cell-fate determination in response to different rates of DNA damage.
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10
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Guan JZ, Guan WP, Maeda T, Makino N. Changes in telomere length distribution in low-dose X-ray-irradiated human umbilical vein endothelial cells. Mol Cell Biochem 2014; 396:129-35. [PMID: 25060906 DOI: 10.1007/s11010-014-2149-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/11/2014] [Indexed: 01/04/2023]
Abstract
Ionizing radiation (IR) is known to be a cause of telomere dysfunction in tumor cells; however, very few studies have investigated X-ray-related changes in telomere length and the telomerase activity in normal human cells, such as umbilical vein endothelial cells (HUVECs). The loss of a few hundred base pairs from a shortened telomere has been shown to be important with respect to cellular senescence, although it may not be detected according to traditional mean telomere length [assessed as the terminal restriction fragment (TRF)] analyses. In the present study, a continuous time window from irradiation was selected to examine changes in the telomere length, including the mean TRF length, percentage of the telomere length, telomerase activity, apoptotic rate, and survival rate in HUVECs from the first day to the fourth day after the administration of a 0.5-Gy dose of irradiation. The mean TRF length in the irradiated HUVECs showed shorter telomere length in first 3 days, but they were not statistically significant. On the other hand, according to the percentage analysis of the telomere length, a decreasing tendency was noted in the longer telomere lengths (9.4-4.4 kb), with a significant increase in the shortest telomeres (4.4-2.3 kb) among the irradiated cells versus the controls from the first day to the third after irradiation; no significant differences were noted on the fourth day. These results suggest that the shortest telomeres are sensitive to the late stage of radiation damage. The proliferation of irradiated cells was suppressed after IR in contrast to the non-irradiated cells. The apoptotic rate was elevated initially both in IR- and non-IR-cells, but that of IR-cells was maintained at an elevated level thereafter in contrast to that of non-IR-cells decreasing promptly. Therefore, a 0.5-Gy dose of IR induces persistent apoptosis leading to an apparent growth arrest of the normal HUVECs.
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Affiliation(s)
- Jing-Zhi Guan
- The 309th Hospital of Chinese People's Liberation Army, Beijing, 100091, China
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11
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Paviolo NS, Castrogiovanni DC, Bolzán AD. The radiomimetic compound streptonigrin induces persistent telomere dysfunction in mammalian cells. Mutat Res 2014; 760:16-23. [PMID: 24406867 DOI: 10.1016/j.mrfmmm.2013.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/07/2013] [Accepted: 11/24/2013] [Indexed: 06/03/2023]
Abstract
We analyzed the chromosomal aberrations involving telomeres in the progeny of mammalian cells exposed to the radiomimetic compound streptonigrin (SN) in order to determine if this antineoplastic drug induces long-term telomere instability. To this end, rat cells (ADIPO-P2 cell line, derived from adipose cells from Sprague-Dawley rat) were treated with a single concentration of SN (100ng/ml), and chromosomal aberrations were analyzed 18h and 10 and 15 days after treatment by using PNA-FISH with a pan-telomeric probe [Cy3-(CCCTAA)3] to detect (TTAGGG)n repeats. Cytogenetic analysis revealed a higher frequency of telomere dysfunction-related aberrations (additional telomeric FISH signals, extra-chromosomal telomeric FISH signals, and telomere FISH signal loss and duplications) in SN-exposed cultures vs. untreated cultures at every time points analyzed. The yield of SN-induced aberrations remained very similar at 18h, 10 days as well as 15 days after treatment. Thus, our data demonstrate that SN induces persistent telomere dysfunction in mammalian cells. Moreover, we found that the level of telomerase activity in SN-treated cells was significantly lower (up to 77%) than that of untreated control cells at each time points analyzed. This fact suggests that telomerase could be involved in SN-induced telomere dysfunction.
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Affiliation(s)
- Natalia S Paviolo
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CCT-CONICET La Plata-CICPBA), C.C. 403, 1900 La Plata, Buenos Aires, Argentina
| | - Daniel C Castrogiovanni
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CCT-CONICET La Plata-CICPBA), C.C. 403, 1900 La Plata, Buenos Aires, Argentina
| | - Alejandro D Bolzán
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CCT-CONICET La Plata-CICPBA), C.C. 403, 1900 La Plata, Buenos Aires, Argentina.
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12
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Nieri D, Berardinelli F, Sgura A, Cherubini R, De Nadal V, Gerardi S, Tanzarella C, Antoccia A. Cyogenetics effects in AG01522 human primary fibroblasts exposed to low doses of radiations with different quality. Int J Radiat Biol 2013; 89:698-707. [DOI: 10.3109/09553002.2013.797126] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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13
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Paviolo NS, Quiroga IY, Castrogiovanni DC, Bianchi MS, Bolzán AD. Telomere instability is present in the progeny of mammalian cells exposed to bleomycin. Mutat Res 2012; 734:5-11. [PMID: 22564429 DOI: 10.1016/j.mrfmmm.2012.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Revised: 04/11/2012] [Accepted: 04/26/2012] [Indexed: 05/31/2023]
Abstract
We analyzed the chromosomal aberrations involving telomeres in the progeny of mammalian cells exposed to the radiomimetic compound bleomycin (BLM) in order to determine if this antineoplastic drug induces long-term telomere instability. To this end, rat cells (ADIPO-P2 cell line, derived from adipose cells from Sprague-Dawley rat) were treated with a single concentration of BLM (2.5 μg/ml), and chromosomal aberrations were analyzed 18 h and 10 days after treatment by using PNA-FISH with a pan-telomeric probe [(TTAGGG)n repeats]. Cytogenetic analysis revealed a higher frequency of aberrations at 18 h and 10 days after treatment in BLM-exposed cultures vs. untreated cultures, although the yield of BLM-induced aberrations 10 days after treatment decreased about 25% compared with the one at 18 h after treatment. Moreover, the level of telomerase activity in BLM-treated cells compared with that of untreated control cells was significantly higher at 10 days after treatment, but did not differ at 18 h after treatment. These data indicate that in terms of unstable aberrations, the in vitro clastogenic effect of BLM on ADIPO-P2 cells persists for at least 10 days after exposure. In addition, our data demonstrate, for the first time, that BLM-induced telomere instability in mammalian cells (cytogenetically detectable as incomplete chromosome elements and telomere FISH signal loss and duplication) persists for several generations after exposure. Moreover, the appearance of telomere fusions in BLM-exposed cells 10 days after treatment suggests that this compound can induce delayed telomere instability. The increase in telomerase activity in BLM-exposed cells 10 days after treatment is accompanied by the presence of aberrations directly related to telomere dysfunction. This fact suggests that telomerase is not directly involved in BLM-induced telomere instability.
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Affiliation(s)
- Natalia S Paviolo
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CCT-CONICET La Plata-CICPBA), C.C. 403, 1900 La Plata, Argentina
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14
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Bolzán AD. Chromosomal aberrations involving telomeres and interstitial telomeric sequences. Mutagenesis 2011; 27:1-15. [PMID: 21857006 DOI: 10.1093/mutage/ger052] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Telomeres are specialised nucleoproteic complexes localised at the physical ends of linear eukaryotic chromosomes that maintain their stability and integrity. In vertebrate chromosomes, the DNA component of telomeres is constituted by (TTAGGG)n repeats, which can be localised at the terminal regions of chromosomes (true telomeres) or at intrachromosomal sites (interstitial telomeric sequences or ITSs, located at the centromeric region or between the centromere and the telomere). In the past two decades, the use of molecular cytogenetic techniques has led to a new spectrum of spontaneous and clastogen-induced chromosomal aberrations being identified, involving telomeres and ITSs. Some aberrations involve the chromosome ends and, indirectly, the telomeric repeats located at the terminal regions of chromosomes (true telomeres). A second type of aberrations directly involves the telomeric sequences located at the chromosome ends. Finally, there is a third class of aberrations that specifically involves the ITSs. The aims of this review are to provide a detailed description of these aberrations and to summarise the available data regarding their induction by physical and chemical mutagens.
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Affiliation(s)
- Alejandro D Bolzán
- La Carrera del Investigador Científico y Tecnológico del CONICET, Argentina, Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (CCT-CONICET La Plata-CICPBA), C.C. 403, 1900 La Plata, Argentina.
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15
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Rodgers CC. Dental X-ray exposure and Alzheimer's disease: a hypothetical etiological association. Med Hypotheses 2011; 77:29-34. [PMID: 21458164 DOI: 10.1016/j.mehy.2011.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/23/2011] [Accepted: 03/07/2011] [Indexed: 11/17/2022]
Abstract
Despite the fact that Alzheimer's disease was identified more than 100 years ago, its cause remains elusive. Although the chance of developing Alzheimer's disease increases with age, it is not a natural consequence of aging. This article proposes that dental X-rays can damage microglia telomeres - the structures at the end of chromosomes that determine how many times cells divide before they die - causing them to age prematurely. Degenerated microglia lose their neuroprotective properties, resulting in the formation of neurofibrillary tau tangles and consequently, the neuronal death that causes Alzheimer's dementia. The hypothesis that Alzheimer's is caused specifically by microglia telomere damage would explain the delay of one decade or longer between the presence of Alzheimer's brain pathology and symptoms; telomere damage would not cause any change in microglial function, it would just reset the countdown clock so that senescence and apoptosis occurred earlier than they would have without the environmental insult. Once microglia telomere damage causes premature aging and death, the adjacent neurons are deprived of the physical support, maintenance and nourishment they require to survive. This sequence of events would explain why therapies and vaccines that eliminate amyloid plaques have been unsuccessful in stopping dementia. Regardless of whether clearing plaques is beneficial or harmful - which remains a subject of debate - it does not address the failing microglia population. If microglia telomere damage is causing Alzheimer's disease, self-donated bone marrow or dental pulp stem cell transplants could give rise to new microglia populations that would maintain neuronal health while the original resident microglia population died.
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16
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Hamasaki K, Kusunoki Y, Nakashima E, Takahashi N, Nakachi K, Nakamura N, Kodama Y. Clonally expanded T lymphocytes from atomic bomb survivors in vitro show no evidence of cytogenetic instability. Radiat Res 2009; 172:234-43. [PMID: 19630528 DOI: 10.1667/rr1705.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Abstract Genomic instability has been suggested as a mechanism by which exposure to ionizing radiation can lead to cancer in exposed humans. However, the data from human cells needed to support or refute this idea are limited. In our previous study on clonal lymphocyte populations carrying stable-type aberrations derived from A-bomb survivors, we found no increase in the frequency of sporadic additional aberrations among the clonal cell populations compared with the spontaneous frequency in vivo. That work has been extended by using multicolor FISH (mFISH) to quantify the various kinds of chromosome aberrations known to be indicative of genomic instability in cloned T lymphocytes after they were expanded in culture for 25 population doublings. The blood T cells used were obtained from each of two high-dose-exposed survivors (>1 Gy) and two control subjects, and a total of 66 clonal populations (36 from exposed and 30 from control individuals) were established. For each clone, 100 metaphases were examined. In the case of exposed lymphocytes, a total of 39 additional de novo stable, exchange-type aberrations [translocation (t) + derivative chromosome (der)] were found among 3600 cells (1.1%); the corresponding value in the control group was 0.6% (17/3000). Although the ratio (39/3600) obtained from the exposed cases was greater than that of the controls (17/3000), the difference was not statistically significant (P = 0.101). A similar lack of statistical difference was found for the total of all structural chromosome alterations including t, der, dicentrics, duplications, deletions and fragments (P = 0.142). Thus there was no clear evidence suggesting the presence of chromosome instabilities among the clonally expanded lymphocytes in vitro from A-bomb survivors.
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Affiliation(s)
- K Hamasaki
- Departments of Radiobiology and Molecular Epidemiology, Radiation Effects Research Foundation, Minami-ku, Hiroshima, 732-0815, Japan
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17
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Toyokuni H, Maruo A, Suzuki K, Watanabe M. The Contribution of Radiation-Induced Large Deletion of the Genome to Chromosomal Instability. Radiat Res 2009; 171:198-203. [DOI: 10.1667/rr1464.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Mukaida N, Kodama S, Suzuki K, Oshimura M, Watanabe M. Transmission of Genomic Instability from a Single Irradiated Human Chromosome to the Progeny of Unirradiated Cells. Radiat Res 2007; 167:675-81. [PMID: 17523850 DOI: 10.1667/rr0835.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 02/15/2007] [Indexed: 11/03/2022]
Abstract
Ionizing radiation can induce chromosome instability that is transmitted over many generations after irradiation in the progeny of surviving cells, but it remains unclear why this instability can be transmitted to the progeny. To acquire knowledge about the transmissible nature of genomic instability, we transferred an irradiated human chromosome into unirradiated mouse recipient cells by microcell fusion and examined the stability of the transferred human chromosome in the microcell hybrids. The transferred chromosome was stable in all six microcell hybrids in which an unirradiated human chromosome had been introduced. In contrast, the transferred chromosome was unstable in four out of five microcell hybrids in which an irradiated human chromosome had been introduced. The aberrations included changes in the irradiated chromosome itself and rearrangements with recipient mouse chromosomes. Thus the present study demonstrates that genomic instability can be transmitted to the progeny of unirradiated cells by a chromosome exposed to ionizing radiation, implying that the instability is caused by the irradiated chromosome itself and also that the instability is induced by the nontargeted effect of radiation.
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Affiliation(s)
- Naoki Mukaida
- Division of Radiation Life Science, Department of Radiation Life Science and Radiation Medical Science, Kyoto University Research Reactor Institute, Osaka, Japan
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19
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Ariyoshi K, Suzuki K, Goto M, Watanabe M, Kodama S. Increased chromosome instability and accumulation of DNA double-strand breaks in Werner syndrome cells. JOURNAL OF RADIATION RESEARCH 2007; 48:219-31. [PMID: 17449919 DOI: 10.1269/jrr.07017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Werner syndrome (WS) is a premature aging syndrome caused by mutations of the WRN gene. Here, we demonstrate that a strain of WS fibroblast cells shows abnormal karyotypes characterized by several complex translocations and 50-fold more frequency of abnormal metaphases including dicentric chromosomes without fragments than normal cells when examined at a similar culture stage. Further, telomere fluorescence in situ hybridization indicates that the abnormal signals, extra telomere signal and loss of telomere signal, emerge two- to three-fold more frequently in WS cells than in normal cells. Taken together, these results indicate that chromosome instability including dysfunction of telomere maintenance is more prominent in WS cells than in normal cells. In addition, the accumulation of DNA double-strand breaks (DSBs) at the G(1) phase, including those at telomeres, detected by phosphorylated ATM (ataxia telangiectasia mutated) foci is accelerated in WS cells even at a low senescence level. The increased accumulation of DSBs in WS cells is reduced in the presence of anti-oxidative agents, suggesting that enhanced oxidative stress in WS cells is involved in accelerated accumulation of DSBs. These results indicate that WS cells are prone to accumulate DSBs spontaneously due to a defect of WRN, which leads to increased chromosome instability that could activate checkpoints, resulting in accelerated senescence.
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Affiliation(s)
- Kentaro Ariyoshi
- Laboratory of Radiation Biology, Research Reactor Institute, Kyoto University
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20
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Hamada N, Funayama T, Wada S, Sakashita T, Kakizaki T, Ni M, Kobayashi Y. LET-dependent survival of irradiated normal human fibroblasts and their descendents. Radiat Res 2006; 166:24-30. [PMID: 16808611 DOI: 10.1667/rr3579.1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Evidence has accumulated showing that ionizing radiations persistently perturb genomic stability and induce delayed reproductive death in the progeny of survivors; however, the linear energy transfer (LET) dependence of these inductions has not been fully characterized. We have investigated the cell killing effectiveness of gamma rays (0.2 keV/microm) and six different beams of heavy-ion particles with LETs ranging from 16.2 to 1610 keV/microm in normal human fibroblasts. First, irradiated confluent density-inhibited cultures were plated for primary colony formation, revealing that the relative biological effectiveness (RBE) based on the primary 10% survival dose peaked at 108 keV/microm and that the inactivation cross section increased proportionally up to 437 keV/microm. Second, cells harvested from primary colonies were plated for secondary colony formation, showing that delayed reproductive death occurred in a dose-dependent fashion. While the RBE based on the secondary 80% survival dose peaked at 108 keV/microm, very little difference in LET was observed in the RBE based on secondary survival at the primary 10% survival dose. Our present results indicate that delayed reproductive death arising only during secondary colony formation is independent of LET and is more likely to be dependent on initial damages having been fixed during primary colony formation.
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Affiliation(s)
- Nobuyuki Hamada
- Department of Quantum Biology, Division of Bioregulatory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
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21
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Bolzán AD, Bianchi MS. Telomeres, interstitial telomeric repeat sequences, and chromosomal aberrations. Mutat Res 2006; 612:189-214. [PMID: 16490380 DOI: 10.1016/j.mrrev.2005.12.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 12/29/2005] [Accepted: 12/30/2005] [Indexed: 11/18/2022]
Abstract
Telomeres are specialized nucleoproteic complexes localized at the physical ends of linear eukaryotic chromosomes that maintain their stability and integrity. The DNA component of telomeres is characterized by being a G-rich double stranded DNA composed by short fragments tandemly repeated with different sequences depending on the species considered. At the chromosome level, telomeres or, more properly, telomeric repeats--the DNA component of telomeres--can be detected either by using the fluorescence in situ hybridization (FISH) technique with a DNA or a peptide nucleic acid (PNA) (pan)telomeric probe, i.e., which identifies simultaneously all of the telomeres in a metaphase cell, or by the primed in situ labeling (PRINS) reaction using an oligonucleotide primer complementary to the telomeric DNA repeated sequence. Using these techniques, incomplete chromosome elements, acentric fragments, amplification and translocation of telomeric repeat sequences, telomeric associations and telomeric fusions can be identified. In addition, chromosome orientation (CO)-FISH allows to discriminate between the different types of telomeric fusions, namely telomere-telomere and telomere-DNA double strand break fusions and to detect recombination events at the telomere, i.e., telomeric sister-chromatid exchanges (T-SCE). In this review, we summarize our current knowledge of chromosomal aberrations involving telomeres and interstitial telomeric repeat sequences and their induction by physical and chemical mutagens. Since all of the studies on the induction of these types of aberrations were conducted in mammalian cells, the review will be focused on the chromosomal aberrations involving the TTAGGG sequence, i.e., the telomeric repeat sequence that "caps" the chromosomes of all vertebrate species.
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Affiliation(s)
- Alejandro D Bolzán
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE), C.C. 403, 1900 La Plata, Argentina.
| | - Martha S Bianchi
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE), C.C. 403, 1900 La Plata, Argentina
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22
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Sgura A, Antoccia A, Berardinelli F, Cherubini R, Gerardi S, Zilio C, Tanzarella C. Telomere length in mammalian cells exposed to low- and high-LET radiations. RADIATION PROTECTION DOSIMETRY 2006; 122:176-9. [PMID: 17223635 DOI: 10.1093/rpd/ncl478] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Telomeres are specialised nucleoprotein complexes that serve as protective caps of linear eukaryotic chromosomes. The loss of the ends of the chromosomes due to these un-rejoined double strand breaks (DSBs) may not be lethal to the cell, but may instead result in the loss of functional telomeres, chromosome fusions and initiation of breakage/fusion/bridge cycle-induced chromosome instability. The telomeres also participate in the process of DNA repair, as evidenced by 'de novo' synthesis of telomere repeats at DSBs and by the capacity of telomeres to binding the essential components of the DNA repair machinery. Based on the observation that high-LET radiations efficiently induce chromosome aberrations, it was tested whether protons were able to affect telomere structure. Human primary fibroblasts (HFFF2) and mouse embryonic fibroblasts (MEFs) were irradiated with 4 Gy of 3 MeV protons at the radiobiology facility of the INFN-LNL. Experiments with X rays were also carried out. Cells were fixed after either 24 h or 15 d from treatment. A difference in average telomere length, measured by quantitative fluorescence in situ hybridisation (Q-FISH), between X rays and protons treatment was observed. X rays are able to modify telomere length in HFFF2 harvested at a later time. On the other hand, 3 MeV low-energy protons induced, both in HFFF2 and in MEFs, a significant increase in telomere length at short as well as at long harvesting time periods from treatment. These results seem to indicate that lesions characterised by different complexity, as those expected after low-energy protons and those induced by damage similar to that induced by sparsely ionising radiation, are able to modulate telomere elongation at different time periods.
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Affiliation(s)
- A Sgura
- Department of Biology, University Roma Tre, V.le Marconi, Roma, Italy.
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23
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Suzuki M, Suzuki K, Kodama S, Watanabe M. Interstitial chromatin alteration causes persistent p53 activation involved in the radiation-induced senescence-like growth arrest. Biochem Biophys Res Commun 2005; 340:145-50. [PMID: 16360120 DOI: 10.1016/j.bbrc.2005.11.167] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Accepted: 11/21/2005] [Indexed: 11/18/2022]
Abstract
Various stresses including ionizing radiation give normal human fibroblasts a phenotype of senescence-like growth arrest (SLGA), manifested by p53-dependent irreversible G1 arrest. To determine the mechanism of persistent activation of p53, we examined phosphorylated Ataxia telangiectasia mutated (ATM) and phosphorylated histone H2AX foci formation after X-irradiation. Although the multiple tiny foci, detected soon after (<30 min) irradiation, gradually disappeared, some of these foci changed to large foci and persisted for 5 days. Large foci containing phosphorylated ATM and gamma-H2AX co-localized and foci with p53 phosphorylated at serine 15 also showed the same distribution. Interestingly, the signals obtained by telomere fluorescence in situ hybridization (FISH) assay did not co-localize with 90% of the large foci. Our results indicate that chromatin alteration in interstitial chromosomal regions is the most likely cause of continuous activation of p53, which results in the induction of SLGA by ionizing radiation.
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Affiliation(s)
- Masatoshi Suzuki
- Division of Radiation Biology, Department of Radiology and Radiation Biology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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Kashino G, Kodama S, Suzuki K, Matsumoto T, Watanabe M. Exogenous expression of exonuclease domain-deleted WRN interferes with the repair of radiation-induced DNA damages. JOURNAL OF RADIATION RESEARCH 2005; 46:407-14. [PMID: 16394631 DOI: 10.1269/jrr.46.407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Werner syndrome (WS) is an autosomal recessive disease characterized by multiple progeroid features. The gene responsible for WS, WRN, is a member of the human RecQ helicase family. WRN is unique among this family, associated with an exonuclease activity. In the present study, we established the human 293-derived cell lines, which expressed exogenously truncated WRN protein, lacking the N-terminal exonuclease domain but having normal helicase activity, and found that they were slightly, but nonetheless significantly, radiosensitive than control cell lines, into which the empty vector had been introduced. The truncated WRN-expressing cells also exhibited increased numbers of micronuclei, chromosome aberrations, and the foci of phosphorylated histone H2AX with X-rays. These results suggested a function of WRN exonuclease activity that is separable from helicase activity and is essential for the repair of radiation-induced DNA damages.
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Affiliation(s)
- Genro Kashino
- Division of Radiation Biology, Department of Radiology and Radiation Biology, Course of Life Sciences and Radiation Research, Graduate School of Biomedical Sciences, Nagasaki University, Japan
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25
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Batra V, Kesavan V, Mishra KP. Modulation of enzymes involved in folate dependent one-carbon metabolism by gamma-radiation stress in mice. JOURNAL OF RADIATION RESEARCH 2004; 45:527-533. [PMID: 15635262 DOI: 10.1269/jrr.45.527] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The role of various enzymes in folate dependent one-carbon metabolism, which are involved in mobilizing the folate pool for DNA synthesis and the DNA methylation reaction, was investigated. Male Swiss mice (6 weeks old) were subjected to 2, 5 and 7 Gy total body gamma-irradiation. The animals were killed at intervals of 24, 48, 72, 96, 120 and 192 h and the livers were removed. Using a 12000 x g supernatant of 10% tissue homogenate, the activities of dihydrofolate reductase, thymidylate synthase and methylenetetrahydrofolate reductase were determined. The profiles of these folate enzymes were correlated to DNA damage by monitoring p53 protein profile and by comet tail moment analysis. A significant increase in activity of dihydrofolate reductase and thymidylate synthase was observed up to 96 h post-irradiation and the activity subsided thereafter, reaching control value after 192 h. A sharp decline in methylenetetrahydrofolate reductase activity was observed until 192 h after irradiation. Total folates declined by 54% after 96 h following irradiation, and p53 protein concentration in nuclei increased after irradiation, proportionate to radiation dose, and subsided slowly. Thus results indicate a significant drop in total folate levels and rise in p53 protein concentration in the liver after total body gamma-irradiation. It may appear that, under radiation stress conditions, levels of enzymes involved in one-carbon metabolism for DNA repair, are modulated up to a certain time interval, in a dose specific manner. It may also appear that the requirements of folate for nucleotide base synthesis seem to be met at the expense of other one-carbon transfer reactions.
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Affiliation(s)
- Vipen Batra
- Radiation Biology and Health Sciences Division Bhabha Atomic Research Centre, Mumbai, India
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