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Bonisoli-Alquati A, Ostermiller S, Beasley DAE, Welch SM, Møller AP, Mousseau TA. Faster Development Covaries with Higher DNA Damage in Grasshoppers (Chorthippus albomarginatus) from Chernobyl. Physiol Biochem Zool 2018; 91:776-787. [DOI: 10.1086/696005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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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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Udroiu I, Sgura A. Genotoxic sensitivity of the developing hematopoietic system. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2015; 767:1-7. [PMID: 27036061 DOI: 10.1016/j.mrrev.2015.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/02/2015] [Accepted: 12/07/2015] [Indexed: 12/17/2022]
Abstract
Genotoxic sensitivity seems to vary during ontogenetic development. Animal studies have shown that the spontaneous mutation rate is higher during pregnancy and infancy than in adulthood. Human and animal studies have found higher levels of DNA damage and mutations induced by mutagens in fetuses/newborns than in adults. This greater susceptibility could be due to reduced DNA repair capacity. In fact, several studies indicated that some DNA repair pathways seem to be deficient during ontogenesis. This has been demonstrated also in murine hematopoietic stem cells. Genotoxicity in the hematopoietic system has been widely studied for several reasons: it is easy to assess, deals with populations cycling also in the adults and may be relevant for leukemogenesis. Reviewing the literature concerning the application of the micronucleus test (a validated assay to assess genotoxicity) in fetus/newborns and adults, we found that the former show almost always higher values than the latter, both in animals treated with genotoxic substances and in those untreated. Therefore, we draw the conclusion that the genotoxic sensitivity of the hematopoietic system is more pronounced during fetal life and decreases during ontogenic development.
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Affiliation(s)
- Ion Udroiu
- Dipartimento di Scienze, Università Roma Tre, Viale G. Marconi 446, 00146 Rome, Italy.
| | - Antonella Sgura
- Dipartimento di Scienze, Università Roma Tre, Viale G. Marconi 446, 00146 Rome, Italy
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4
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Sunaoshi M, Amasaki Y, Hirano-Sakairi S, Blyth BJ, Morioka T, Kaminishi M, Shang Y, Nishimura M, Shimada Y, Tachibana A, Kakinuma S. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas. Mutat Res 2015; 779:58-67. [PMID: 26141385 DOI: 10.1016/j.mrfmmm.2015.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/15/2015] [Accepted: 06/07/2015] [Indexed: 06/04/2023]
Abstract
Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2a and Ikaros are a prominent feature of young adult irradiation-induced T-cell lymphoma, tumors arising after irradiation from infancy suffer a second hit in Pten by mis-segregation or recombination. This is the first report showing an influence of age-at-exposure on genomic alterations of tumor suppressor genes and their relative involvement in radiation-induced T-cell lymphoma. These data are important for considering the risks associated with childhood exposure to radiation.
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Affiliation(s)
- Masaaki Sunaoshi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Yoshiko Amasaki
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Shinobu Hirano-Sakairi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Benjamin J Blyth
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Takamitsu Morioka
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Mutsumi Kaminishi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yi Shang
- Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Mayumi Nishimura
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yoshiya Shimada
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Akira Tachibana
- Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Shizuko Kakinuma
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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Bozzini G, Casellato S, Viganò A, Maruccia S, Picozzi S, Carmignani L. Predicting female ureteral length: a mathematical model. JOURNAL OF CLINICAL UROLOGY 2014. [DOI: 10.1177/2051415814520868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aim: Ureteral double J stent placement is a common urological procedure. A stent placement is performed for multiple conditions but some of them are contraindicated, mainly in pregnant female patients, because of X-rays. This work aims to suggest a mathematical model to predict female ureteral length by finding a link among different physical data. Materials and methods: Between June 2007 and July 2009, 100 female patients who had undergone ureteral stent placement were enrolled in the present study with the exception of those with septic conditions, history or evidence of TCC, congenital and acquired kidney or ureteral malformations, and previous ureteral surgery. The physical data of each patient were collected (mean age 55.8 years, range 18–89 SD 15.27, mean height 173 cm, range 160–182 SD 6.31, mean weight 75.33 kg, range 62–94 SD 8.81). A previous ureteral retrograde pyelography was performed during the procedure to individualise the pyeloureteral junction. Ureteral length was estimated through a graduated ureteral catheter with a final result between 24 and 27 cm. The length was read in cystoscopy examining the ureteral orifice while the catheter tip reached the pyeloureteral junction. The collected data were then analysed. Results: A link between the female patients’ ureteral length and height was observed. The following mathematical model can predict female ureteral length starting from the patient’s height: Result: y = 0.151712487 (height expressed in cm) ± 0.12; correlation coefficient: r = 0,973, residual sum of squares: rss = 5.285. No link was found between ureteral length and patients’ age and weight. Conclusions: A good estimation of the length of the ureter to be cannulated enables us to choose in advance the proper one to use. Female patient height correlates with ureteral length. A cost reduction can also be obtained, avoiding an intra-operative X-ray control. An X-ray-free ureteral stenting procedure can be described simply through an ultrasound control mainly in pregnant women. Further studies are needed to obtain a similar mathematical model for male patients.
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Affiliation(s)
- Giorgio Bozzini
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
| | - Stefano Casellato
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
| | - Alberto Viganò
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
| | - Serena Maruccia
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
| | - Stefano Picozzi
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
| | - Luca Carmignani
- Academic Division of Urology, IRCCS Policlinico San Donato, University of Milan, Italy
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Zhao W, Wu M, Lai Y, Deng W, Liu Y, Zhang Z. Involvement of DNA polymerase β overexpression in the malignant transformation induced by benzo[a]pyrene. Toxicology 2013; 309:73-80. [PMID: 23652152 DOI: 10.1016/j.tox.2013.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/27/2013] [Accepted: 04/27/2013] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To explore the relationship between DNA polymerase β (pol β) overexpression and benzo[a]pyrene (BaP) carcinogenesis. METHODS Firstly, mouse embryonic fibroblasts that express wild-type level of DNA polymerase β (pol β cell) and high level of pol β (pol β oe cell) were treated by various concentrations of BaP to determine genetic instability induced by BaP under differential expression levels of pol β. Secondly, malignant transformation of pol β cells by low concentration of BaP (20 μM) was determined by soft agar colony formation assay and transformation focus assay. Thirdly, the mRNA and protein levels of BaP-transformed pol β cells (named pol β-T cells) was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot, and the genetic instability of these cells were examined by HPRT gene mutation assay and random amplified polymorphic DNA (RAPD) assay. RESULTS Pol β cells were successfully transformed into malignant pol β-T cells by an exposure to low concentration of BaP for 6 months. Pol β-T cells exhibited increased levels of pol β gene expression, HPRT gene mutation frequency and polymorphisms of RAPD products that were comparable to those of pol β oe cells. CONCLUSION Pol β overexpression and its-associated genetic instability may play a key role in BaP carcinogenesis.
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Affiliation(s)
- Wei Zhao
- Department of Environmental Health, West China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China
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7
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Denissova NG, Tereshchenko IV, Cui E, Stambrook PJ, Shao C, Tischfield JA. Ionizing radiation is a potent inducer of mitotic recombination in mouse embryonic stem cells. Mutat Res 2011; 715:1-6. [PMID: 21802432 DOI: 10.1016/j.mrfmmm.2011.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 05/30/2011] [Accepted: 06/29/2011] [Indexed: 12/28/2022]
Abstract
Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the elevated loss of heterozygosity after irradiation is mitotic recombination, with lesser contributions from deletions and gene conversions that span Aprt. Aprt point mutations and epigenetic inactivation are very rare in mESCs compared to fibroblasts. Mouse ESCs, therefore, are distinctive in their response to ionizing radiation and studies of differentiated cells may underestimate the mutagenic effects of ionizing radiation on ESC or other stem cells. Our findings are important to understanding the biological effects of ionizing radiation on early development and carcinogenesis.
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Affiliation(s)
- Natalia G Denissova
- Department of Genetics, Rutgers University, Piscataway, 145 Bevier Rd, NJ 08854, United States
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8
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Pachkowski BF, Guyton KZ, Sonawane B. DNA repair during in utero development: A review of the current state of knowledge, research needs, and potential application in risk assessment. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2011; 728:35-46. [DOI: 10.1016/j.mrrev.2011.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 05/29/2011] [Accepted: 05/31/2011] [Indexed: 10/18/2022]
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9
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Tichy ED, Liang L, Deng L, Tischfield J, Schwemberger S, Babcock G, Stambrook PJ. Mismatch and base excision repair proficiency in murine embryonic stem cells. DNA Repair (Amst) 2011; 10:445-51. [PMID: 21315663 DOI: 10.1016/j.dnarep.2011.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/20/2010] [Accepted: 01/12/2011] [Indexed: 02/02/2023]
Abstract
Accumulation of mutations in embryonic stem (ES) cells would be detrimental to an embryo derived from these cells, and would adversely affect multiple organ systems and tissue types. ES cells have evolved multiple mechanisms to preserve genomic integrity that extend beyond those found in differentiated cell types. The present study queried whether mismatch repair (MMR) and base-excision repair (BER) may play a role in the maintenance of murine ES cell genomes. The MMR proteins Msh2 and Msh6 are highly elevated in mouse ES cells compared with mouse embryo fibroblasts (MEFs), as are Pms2 and Mlh1, albeit to a lesser extent. Cells transfected with an MMR reporter plasmid showed that MMR repair capacity is low in MEFs, but highly active in wildtype ES cells. As expected, an ES cell line defective in MMR was several-fold less effective in repair level than wildtype ES cells. Like proteins that participate in MMR, the level of proteins involved in BER was elevated in ES cells compared with MEFs. When BER activity was examined biochemically using a uracil-containing oligonucleotide template, repair activity was higher in ES cells compared with MEFs. The data are consistent with the suggestion that ES cells have multiple mechanisms, including highly active MMR and BER that preserve genetic integrity and minimize the accumulation of mutations.
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Affiliation(s)
- Elisia D Tichy
- Department of Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA.
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10
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The bright and the dark sides of DNA repair in stem cells. J Biomed Biotechnol 2010; 2010:845396. [PMID: 20396397 PMCID: PMC2852612 DOI: 10.1155/2010/845396] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 11/16/2009] [Accepted: 02/01/2010] [Indexed: 12/22/2022] Open
Abstract
DNA repair is a double-edged sword in stem cells. It protects normal stem cells in both embryonic and adult tissues from genetic damage, thus allowing perpetuation of intact genomes into new tissues. Fast and efficient DNA repair mechanisms have evolved in normal stem and progenitor cells. Upon differentiation, a certain degree of somatic mutations becomes more acceptable and, consequently, DNA repair dims. DNA repair turns into a problem when stem cells transform and become cancerous. Transformed stem cells drive growth of a number of tumours (e.g., high grade gliomas) and being particularly resistant to chemo- and radiotherapeutic agents often cause relapses. The contribution of DNA repair to resistance of these tumour-driving cells is the subject of intense research, in order to find novel agents that may sensitize them to chemotherapy and radiotherapy.
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11
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Hendricks KEM, Penfold LM, Evenson DP, Kaproth MT, Hansen PJ. Effects of airport screening X-irradiation on bovine sperm chromatin integrity and embryo development. Theriogenology 2010; 73:267-72. [PMID: 19864012 DOI: 10.1016/j.theriogenology.2009.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/25/2009] [Accepted: 09/07/2009] [Indexed: 11/26/2022]
Abstract
Biological samples, including cryopreserved sperm, are routinely X-rayed during air shipment. The goal was to investigate the impact of X-irradiation used for checked and carry-on luggage on bovine sperm chromatin integrity and postfertilization in vitro embryonic development. Frozen domestic bull sperm (Bos taurus) (n=9 bulls) stored in a dry shipper (-160 degrees C) was screened by X-irradiation 0, 1, 2, and 3 times as either carry-on or checked luggage. Duplicate straws were thawed, and sperm were assessed for chromatin damage using the sperm chromatin structure assay (SCSA) and by postfertilization in vitro developmental competence of mature oocytes. Multiple exposure to X-rays did not significantly affect sperm chromatin integrity assessed by SCSA. There were lower proportions of oocytes cleaved (P=0.07; 21.6+/-3.1% vs. 29.4+/-3.1%, 24.9+/-3.1%, and 25.7+/-3.3% for 3 vs. 0, 1, and 2 times, respectively; least-squares means+/-SEM) and that developed to blastocysts (P=0.06; 9.0+/-1.7% vs. 13.8+/-1.7%, 11.5+/-1.7%, and 12.6+/-1.9%, respectively) when fertilization was performed with sperm X-rayed 3 times using checked luggage irradiation; developmental competence (percentage cleaved embryos becoming blastocysts) was unaffected. There were no deleterious effects of other X-irradiation treatments on embryo development. We inferred that screening by X-irradiation may reduce the ability of sperm to activate oocyte cleavage after multiple exposures at the checked luggage dose. However, there was no evidence that competence of embryos to become blastocysts was reduced by X-irradiation (45.4+/-5.7%, 40.4+/-5.7%, 46.4+/-6.1%, and 41.8+/-5.7% for 0, 1, 2, and 3 doses, respectively), but potential long-term epigenetic effects are unknown.
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Affiliation(s)
- K E M Hendricks
- Department of Animal Sciences, University of Florida, Gainesville, Florida, USA
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12
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Turker MS, Connolly L, Dan C, Lasarev M, Gauny S, Kwoh E, Kronenberg A. Comparison of Autosomal Mutations in Mouse Kidney Epithelial Cells Exposed to Iron IonsIn Situor in Culture. Radiat Res 2009; 172:558-66. [DOI: 10.1667/rr1805.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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13
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Shao C, Liang L, Zhao X, Chen Y, Zheng B, Chen J, Luo M, Tischfield JA. Mutagenesis in vivo in T cells of p21-deficient mice. Mutat Res 2009; 670:103-6. [PMID: 19744501 DOI: 10.1016/j.mrfmmm.2009.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 08/18/2009] [Accepted: 09/01/2009] [Indexed: 01/20/2023]
Abstract
Mice that are deficient in p53 exhibit an early onset of multiple types of tumors, especially thymic lymphoma. However, it remains unclear to what extent each of the p53-regulated pathways exerts its tumor suppressor activity. p21(Cip1/Waf1), acting down stream of p53, is a major G1/S checkpoint protein that restricts cell cycle progression into S phase in the presence of DNA damage. While at old ages p21-/- mice have a higher incidence of many types of tumors than p21+/+ mice, they are more resistant to thymic lymphomagenesis. In this study, we characterized mutagenesis in vivo in T cells of p21-deficient mice, using loss of heterozygosity (LOH) at Aprt locus as an indicator. We found that the spontaneous Aprt mutant frequency in T cells of p21-/- mice is lower than that in p21+/+ mice. The mutational spectra, however, are similar, with mitotic recombination being the predominant pathway. In contrast to the remarkable induction of LOH events in T cells of p53-/- mice exposed to X-rays, LOH in T cells of p21-/- mice is not significantly induced by X-rays. Correspondingly, lymphoid cells of p21-/- mice are more sensitive to IR-induced apoptosis than those of p21+/+ mice, in contrast to the radioresistance of p53-deficient lymphocytes. Reduction in mutation load in T cell lineages may contribute to the suppression of thymic lymphomagenesis in p21-/- mice.
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Affiliation(s)
- Changshun Shao
- Department of Genetics, Rutgers University, Piscataway, NJ 08854, USA.
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14
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Barber RC, Hardwick RJ, Shanks ME, Glen CD, Mughal SK, Voutounou M, Dubrova YE. The effects of in utero irradiation on mutation induction and transgenerational instability in mice. Mutat Res 2009; 664:6-12. [PMID: 19428375 DOI: 10.1016/j.mrfmmm.2009.01.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 12/22/2008] [Accepted: 01/27/2009] [Indexed: 10/21/2022]
Abstract
Epidemiological evidence suggests that the deleterious effects of prenatal irradiation can manifest during childhood, resulting in an increased risk of leukaemia and solid cancers after birth. However, the mechanisms underlying the long-term effects of foetal irradiation remain poorly understood. This study was designed to analyse the impact of in utero irradiation on mutation rates at expanded simple tandem repeat (ESTR) DNA loci in directly exposed mice and their first-generation (F(1)) offspring. ESTR mutation frequencies in the germline and somatic tissues of male and female mice irradiated at 12 days of gestation remained highly elevated during adulthood, which was mainly attributed to a significant increase in the frequency of singleton mutations. The prevalence of singleton mutations in directly exposed mice suggests that foetal irradiation results in genomic instability manifested both in utero and during adulthood. The frequency of ESTR mutation in the F(1) offspring of prenatally irradiated male mice was equally elevated across all tissues, which suggests that foetal exposure results in transgenerational genomic instability. In contrast, maternal in utero exposure did not affect the F(1) stability. Our data imply that the passive erasure of epigenetic marks in the maternal genome can diminish the transgenerational effects of foetal irradiation and therefore provide important clues to the still unknown mechanisms of radiation-induced genomic instability. The results of this study offer a plausible explanation for the effects of in utero irradiation on the risk of leukaemia and solid cancers after birth.
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Affiliation(s)
- Ruth C Barber
- Department of Genetics, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
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