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Kweon J, Hwang HY, Ryu H, Jang AH, Kim D, Kim Y. Targeted genomic translocations and inversions generated using a paired prime editing strategy. Mol Ther 2023; 31:249-259. [PMID: 36114670 PMCID: PMC9840113 DOI: 10.1016/j.ymthe.2022.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/12/2022] [Accepted: 09/12/2022] [Indexed: 01/26/2023] Open
Abstract
A variety of cancers have been found to have chromosomal rearrangements, and the genomic abnormalities often induced expression of fusion oncogenes. To date, a pair of engineered nucleases including ZFNs, TALENs, and CRISPR-Cas9 nucleases have been used to generate chromosomal rearrangement in living cells and organisms for disease modeling. However, these methods induce unwanted indel mutations at the DNA break junctions, resulting in incomplete disease modeling. Here, we developed prime editor nuclease-mediated translocation and inversion (PETI), a method for programmable chromosomal translocation and inversion using prime editor 2 nuclease (PE2 nuclease) and paired pegRNA. Using PETI method, we successfully introduced DNA recombination in episomal fluorescence reporters as well as precise chromosomal translocations in human cells. We applied PETI to create cancer-associated translocations and inversions such as NPM1-ALK and EML4-ALK in human cells. Our findings show that PETI generated chromosomal translocation and inversion in a programmable manner with efficiencies comparable of Cas9. PETI methods, we believe, could be used to create disease models or for gene therapy.
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Affiliation(s)
- Jiyeon Kweon
- Department of Biomedical Sciences, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea; Stem Cell Immunomodulation Research Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Hye-Yeon Hwang
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Haesun Ryu
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - An-Hee Jang
- Department of Biomedical Sciences, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea; Stem Cell Immunomodulation Research Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Daesik Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea.
| | - Yongsub Kim
- Department of Biomedical Sciences, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea; Stem Cell Immunomodulation Research Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea.
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2
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Herate C, Sabatier L. Retrospective biodosimetry techniques: Focus on cytogenetics assays for individuals exposed to ionizing radiation. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 783:108287. [PMID: 32192645 DOI: 10.1016/j.mrrev.2019.108287] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/26/2019] [Accepted: 11/01/2019] [Indexed: 01/28/2023]
Abstract
In the absence of physical data, biodosimetry tools are required for fast dose and risk assessment in the event of radiological or nuclear mass accidents or attacks to triage exposed humans and take immediate medical countermeasures. Biodosimetry tools have mostly been developed for retrospective dose assessment and the follow-up of victims of irradiation. Among them, cytogenetics analyses, to reveal chromosome damage, are the most developed and allow the determination of doses from blood samples as low as 100 mGy. Various cytogenetic tests have already allowed retrospective dose assessment of Chernobyl liquidators and military personnel exposed to nuclear tests after decades. In this review, we discuss the properties of various biodosimetry techniques, such as their sensitivity and limitations as a function of the time from exposure, using multiple examples of nuclear catastrophes or working exposure. Among them, chromosome FISH hybridization, which reveals chromosome translocations, is the most reliable due to the persistence of translocations for decades, whereas dicentric chromosome and micronuclei assays allow rapid and accurate dose assessment a short time after exposure. Both need to be adjusted through mathematical algorithms for retrospective analyses, accounting for the time since exposure and the victims' age. The goal for the future will be to better model chromosome damage, reduce the time to result, and develop new complementary biodosimetry approaches, such as mutation signatures.
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Affiliation(s)
- C Herate
- PROCyTox, French Alternative Energies and Atomic Energy Commission (CEA), University Paris-Saclay, Fontenay-aux-Roses, France
| | - L Sabatier
- PROCyTox, French Alternative Energies and Atomic Energy Commission (CEA), University Paris-Saclay, Fontenay-aux-Roses, France.
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3
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Walker VE, Degner A, Carter EW, Nicklas JA, Walker DM, Tretyakova N, Albertini RJ. 1,3-Butadiene metabolite 1,2,3,4 diepoxybutane induces DNA adducts and micronuclei but not t(9;22) translocations in human cells. Chem Biol Interact 2019; 312:108797. [PMID: 31422076 DOI: 10.1016/j.cbi.2019.108797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/26/2019] [Accepted: 08/14/2019] [Indexed: 11/26/2022]
Abstract
Epidemiological studies of 1,3-butadiene (BD) exposures have reported a possible association with chronic myelogenous leukemia (CML), which is defined by the presence of the t(9;22) translocation (Philadelphia chromosome) creating an oncogenic BCR-ABL fusion gene. Butadiene diepoxide (DEB), the most mutagenic of three epoxides resulting from BD, forms DNA-DNA crosslink adducts that can lead to DNA double-strand breaks (DSBs). Thus, a study was designed to determine if (±)-DEB exposure of HL60 cells, a promyelocytic leukemia cell line lacking the Philadelphia chromosome, can produce t(9;22) translocations. In HL60 cells exposed for 3 h to 0-10 μM DEB, overlapping dose-response curves suggested a direct relationship between 1,4-bis-(guan-7-yl)-2,3-butanediol crosslink adduct formation (R = 0.977, P = 0.03) and cytotoxicity (R = 0.961, P = 0.002). Experiments to define the relationships between cytotoxicity and the induction of micronuclei (MN), a dosimeter of DNA DSBs, showed that 24 h exposures of HL60 cells to 0-5.0 μM DEB caused significant positive correlations between the concentration and (i) the degree of cytotoxicity (R = 0.998, p = 0.002) and (ii) the frequency of MN (R = 0.984, p = 0.016) at 48 h post exposure. To determine the relative induction of MN and t(9;22) translocations following exposures to DEB, or x-rays as a positive control for formation of t(9;22) translocations, HL60 cells were exposed for 24 h to 0, 1, 2.5, or 5 μM DEB or to 0, 2.0, 3.5, or 5.0 Gy x-rays, or treatments demonstrated to yield 0, 20%, 50%, or 80% cytotoxicity. Treatments between 0 and 3.5 Gy x-rays caused significant dose-related increases in both MN (p < 0.001) and t(9;22) translocations (p = 0.01), whereas DEB exposures causing similar cytotoxicity levels did not increase translocations over background. These data indicate that, while DEB induces DNA DSBs required for formation of MN and translocations, acute DEB exposures of HL60 cells did not produce the Philadelphia chromosome obligatory for CML.
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Affiliation(s)
- Vernon E Walker
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, VT, United States.
| | - Amanda Degner
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States.
| | - Elizabeth W Carter
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, VT, United States.
| | - Janice A Nicklas
- Department of Pediatrics, University of Vermont, Burlington, VT, United States.
| | - Dale M Walker
- The Burlington HC Research Group, Inc., Jericho, VT, United States.
| | - Natalia Tretyakova
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States.
| | - Richard J Albertini
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, VT, United States.
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Petibone DM, Mustafa T, Bourdo SE, Lafont A, Ding W, Karmakar A, Nima ZA, Watanabe F, Casciano D, Morris SM, Dobrovolsky VN, Biris AS. p53
-competent cells and p53
-deficient cells display different susceptibility to oxygen functionalized graphene cytotoxicity and genotoxicity. J Appl Toxicol 2017; 37:1333-1345. [DOI: 10.1002/jat.3472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Dayton M. Petibone
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Thikra Mustafa
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
- Department of Medical Bioscience; College of Veterinary Medicine, University of Kirkuk; Kirkuk Iraq
| | - Shawn E. Bourdo
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Andersen Lafont
- Nanotechnology Core Facility, Office of Scientific Coordination, National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Wei Ding
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Alokita Karmakar
- Nanotechnology Core Facility, Office of Scientific Coordination, National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Zeid A. Nima
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Fumiya Watanabe
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Daniel Casciano
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Suzanne M. Morris
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Vasily N. Dobrovolsky
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Alexandru S. Biris
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
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Ulsh BA, Dolling J, Lavoie J, Mitchel REJ, Boreham DR. Chromosome Damage Caused by Accidental Chronic Whole-Body Gamma Radiation Exposure in Thailand. Dose Response 2015; 13:1559325815614302. [PMID: 26740811 PMCID: PMC4674019 DOI: 10.1177/1559325815614302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In February 2000, a radiation incident involving a medical 60Co source occurred in a metal scrapyard in Thailand. Several individuals were suspected to have received chronic or fractionated exposures ranging from a few mGy to a several Gy. Using fluorescence in situ hybridization to paint chromosomes, we determined the frequencies of chromosome aberrations in peripheral blood lymphocytes of 13 people who entered the scrapyard, 3 people who involved in recovering the source, and 9 nearby residents. Aberration frequencies greater than controls were observed in 13 of the donors at 3 months postexposure. The predominant form of aberration observed was simple, complete, symmetrical translocations. An approximate 50% decrease in these aberrations and in total color junctions was observed in 7 donors resampled at 16 months postexposure. Although high, acute exposures are known to have detrimental effects, the biological consequences of chronic, low dose-rate radiation exposures are unclear. Thirteen of the donors had elevated aberration frequencies, and 6 also had symptoms of acute radiation syndrome. If there are any long-term health consequences of this incident, it will most likely occur among this group of individuals. The consequences for the remaining donors, who presumably received lower total doses delivered at lower dose rates, are less clear.
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Affiliation(s)
- B A Ulsh
- McMaster University Institute of Applied Radiation Sciences, Hamilton, Ontario, Canada; M. H. Chew & Associates, Cincinnati, OH, USA
| | - J Dolling
- McMaster University Institute of Applied Radiation Sciences, Hamilton, Ontario, Canada
| | - J Lavoie
- McMaster University Institute of Applied Radiation Sciences, Hamilton, Ontario, Canada
| | - R E J Mitchel
- Chalk River Laboratories, Atomic Energy of Canada, Ltd, Chalk River, Ontario, Canada
| | - D R Boreham
- McMaster University Institute of Applied Radiation Sciences, Hamilton, Ontario, Canada
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Little MP, Kwon D, Doi K, Simon SL, Preston DL, Doody MM, Lee T, Miller JS, Kampa DM, Bhatti P, Tucker JD, Linet MS, Sigurdson AJ. Association of chromosome translocation rate with low dose occupational radiation exposures in U.S. radiologic technologists. Radiat Res 2014; 182:1-17. [PMID: 24932535 DOI: 10.1667/rr13413.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chromosome translocations are a well-recognized biological marker of radiation exposure and cancer risk. However, there is uncertainty about the lowest dose at which excess translocations can be detected, and whether there is temporal decay of induced translocations in radiation-exposed populations. Dosimetric uncertainties can substantially alter the shape of dose-response relationships; although regression-calibration methods have been used in some datasets, these have not been applied in radio-occupational studies, where there are also complex patterns of shared and unshared errors that these methods do not account for. In this article we evaluated the relationship between estimated occupational ionizing radiation doses and chromosome translocation rates using fluorescent in situ hybridization in 238 U.S. radiologic technologists selected from a large cohort. Estimated cumulative red bone marrow doses (mean 29.3 mGy, range 0-135.7 mGy) were based on available badge-dose measurement data and on questionnaire-reported work history factors. Dosimetric assessment uncertainties were evaluated using regression calibration, Bayesian and Monte Carlo maximum likelihood methods, taking account of shared and unshared error and adjusted for overdispersion. There was a significant dose response for estimated occupational radiation exposure, adjusted for questionnaire-based personal diagnostic radiation, age, sex and study group (5.7 translocations per 100 whole genome cell equivalents per Gy, 95% CI 0.2, 11.3, P = 0.0440). A significant increasing trend with dose continued to be observed for individuals with estimated doses <100 mGy. For combined estimated occupational and personal-diagnostic-medical radiation exposures, there was a borderline-significant modifying effect of age (P = 0.0704), but little evidence (P > 0.5) of temporal decay of induced translocations. The three methods of analysis to adjust for dose uncertainty gave similar results. In summary, chromosome translocation dose-response slopes were detectable down to <100 mGy and were compatible with those observed in other radiation-exposed populations. However, there are substantial uncertainties in both occupational and other (personal-diagnostic-medical) doses that may be imperfectly taken into account in our analysis.
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Affiliation(s)
- Mark P Little
- a Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland 20892
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Bakhmutsky MV, Joiner MC, Jones TB, Tucker JD. Differences in cytogenetic sensitivity to ionizing radiation in newborns and adults. Radiat Res 2014; 181:605-16. [PMID: 24828110 DOI: 10.1667/rr13598.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Radiation exposure causes DNA breaks leading to structural chromosome aberrations that can be carcinogenic. Lifetime cancer risks are elevated in irradiated children compared to similarly exposed adults. To determine the extent to which age influences the frequency and types of chromosome damage in response to ionizing radiation, peripheral blood samples were collected from 20 adults (aged 22-78 years) and from the umbilical cords of 10 newborns and acutely exposed to 0 (control), 1, 2, 3 or 4 Gy of cobalt-60 gamma rays. Cells were cultured in the presence of the mitogen phytohemagglutinin, harvested at 48 h and then evaluated for structural chromosome aberrations by fluorescence in situ hybridization whole chromosome painting. Regression analyses were used to evaluate radiation-induced translocated chromosomes, dicentrics, acentric fragments, color junctions and aberrant cells to determine whether the frequencies of these events was dependent upon age. Peripheral blood lymphocytes from newborns showed statistically significant increases in the induced frequencies of translocated chromosomes, dicentrics, acentric fragments, color junctions and abnormal cells at several radiation doses when compared to blood from adults. No significant changes in sensitivity with age were observed when adults were evaluated separately. We conclude that peripheral lymphocytes from newborns are significantly more prone to radiation-induced chromosome aberrations than peripheral lymphocytes from adults. The increased sensitivity of newborns in this study relative to adults was found to be 37(±9)%, 18(±4)%, 12(±2)% and 4(±5)% at doses of 1, 2, 3 and 4 Gy, respectively. These data may be relevant when making radiation exposure risk assessments.
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8
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Tucker JD, Joiner MC, Thomas RA, Grever WE, Bakhmutsky MV, Chinkhota CN, Smolinski JM, Divine GW, Auner GW. Accurate Gene Expression-Based Biodosimetry Using a Minimal Set of Human Gene Transcripts. Int J Radiat Oncol Biol Phys 2014; 88:933-9. [DOI: 10.1016/j.ijrobp.2013.11.248] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 11/26/2013] [Accepted: 11/30/2013] [Indexed: 10/25/2022]
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9
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Tucker JD, Divine GW, Grever WE, Thomas RA, Joiner MC, Smolinski JM, Auner GW. Gene expression-based dosimetry by dose and time in mice following acute radiation exposure. PLoS One 2013; 8:e83390. [PMID: 24358280 PMCID: PMC3865163 DOI: 10.1371/journal.pone.0083390] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 11/04/2013] [Indexed: 11/19/2022] Open
Abstract
Rapid and reliable methods for performing biological dosimetry are of paramount importance in the event of a large-scale nuclear event. Traditional dosimetry approaches lack the requisite rapid assessment capability, ease of use, portability and low cost, which are factors needed for triaging a large number of victims. Here we describe the results of experiments in which mice were acutely exposed to 60Co gamma rays at doses of 0 (control) to 10 Gy. Blood was obtained from irradiated mice 0.5, 1, 2, 3, 5, and 7 days after exposure. mRNA expression levels of 106 selected genes were obtained by reverse-transcription real time PCR. Stepwise regression of dose received against individual gene transcript expression levels provided optimal dosimetry at each time point. The results indicate that only 4–7 different gene transcripts are needed to explain ≥ 0.69 of the variance (R2), and that receiver-operator characteristics, a measure of sensitivity and specificity, of ≥ 0.93 for these statistical models were achieved at each time point. These models provide an excellent description of the relationship between the actual and predicted doses up to 6 Gy. At doses of 8 and 10 Gy there appears to be saturation of the radiation-response signals with a corresponding diminution of accuracy. These results suggest that similar analyses in humans may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations.
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Affiliation(s)
- James D. Tucker
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America
- * E-mail:
| | - George W. Divine
- Department of Public Health Sciences, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - William E. Grever
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America
| | - Robert A. Thomas
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America
| | - Michael C. Joiner
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan, United States of America
| | - Joseph M. Smolinski
- Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan, United States of America
| | - Gregory W. Auner
- Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan, United States of America
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Tucker JD, Vadapalli M, Joiner MC, Ceppi M, Fenech M, Bonassi S. Estimating the Lowest Detectable Dose of Ionizing Radiation by the Cytokinesis-Block Micronucleus Assay. Radiat Res 2013; 180:284-91. [DOI: 10.1667/rr3346.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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11
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Long-term exposure to depleted uranium in Gulf-War veterans does not induce chromosome aberrations in peripheral blood lymphocytes. Mutat Res 2013; 757:132-9. [PMID: 23933231 DOI: 10.1016/j.mrgentox.2013.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 07/29/2013] [Accepted: 07/29/2013] [Indexed: 11/23/2022]
Abstract
Depleted uranium (DU) is a high-density heavy metal that has been used in munitions since the 1991 Gulf War. DU is weakly radioactive and chemically toxic, and long-term exposure may cause adverse health effects. This study evaluates genotoxic effects of exposure to DU by measuring chromosome damage in peripheral blood lymphocytes with fluorescence in situ hybridization whole-chromosome painting. Study participants are Gulf War-I Veterans with embedded DU fragments and/or inhalation exposure due to involvement in friendly-fire incidents; they are enrolled in a long-term health surveillance program at the Baltimore Veterans Administration Medical Center. Blood was drawn from 35 exposed male veterans aged 39 to 62 years. Chromosomes 1, 2, and 4 were painted red and chromosomes 3, 5, and 6 were simultaneously labeled green. At least 1800 metaphase cells per subject were scored. Univariate regression analyses were performed to evaluate the effects of log(urine uranium), age at time of blood draw, log(lifetime X-rays), pack-years smoked and alcohol use, against frequencies of cells with translocated chromosomes, dicentrics, acentric fragments, color junctions and abnormal cells. No significant relationships were observed between any cytogenetic endpoint and log(urine uranium) levels, smoking, or log(lifetime X-rays). Age at the time of blood draw showed significant relationships with all endpoints except for cells with acentric fragments. Translocation frequencies in these Veterans were all well within the normal range of published values for healthy control subjects from around the world. These results indicate that chronic exposure to DU does not induce significant levels of chromosome damage in these Veterans.
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Guruprasad KP, Subramanian A, Singh VJ, Sharma RSK, Gopinath PM, Sewram V, Varier PM, Satyamoorthy K. Brahmarasayana protects against Ethyl methanesulfonate or Methyl methanesulfonate induced chromosomal aberrations in mouse bone marrow cells. Altern Ther Health Med 2012; 12:113. [PMID: 22853637 PMCID: PMC3457898 DOI: 10.1186/1472-6882-12-113] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 06/28/2012] [Indexed: 01/24/2023]
Abstract
Background Ayurveda, the traditional Indian system of medicine has given great emphasis to the promotion of health. Rasayana is one of the eight branches of Ayurveda which refers to rejuvenant therapy. It has been reported that rasayanas have immuno-modulatory, antioxidant and antitumor functions, however, the genotoxic potential and modulation of DNA repair of many rasayanas have not been evaluated. Methods The present study assessed the role of Brahmarasayana (BR) on Ethyl methanesulfonate (EMS)-and Methyl methanesulfonate (MMS)-induced genotoxicity and DNA repair in in vivo mouse test system. The mice were orally fed with BR (5 g or 8 mg / day) for two months and 24 h later EMS or MMS was given intraperitoneally. The genotoxicity was analyzed by chromosomal aberrations, sperm count, and sperm abnormalities. Results The results have revealed that BR did not induce significant chromosomal aberrations when compared to that of the control animals (p >0.05). On the other hand, the frequencies of chromosomal aberrations induced by EMS (240 mg / kg body weight) or MMS (125 mg / kg body weight) were significantly higher (p<0.05) to that of the control group. The treatment of BR for 60 days and single dose of EMS or MMS on day 61, resulted in significant (p <0.05) reduction in the frequency of chromosomal aberrations in comparison to EMS or MMS treatment alone, indicating a protective effect of BR. Constitutive base excision repair capacity was also increased in BR treated animals. Conclusion The effect of BR, as it relates to antioxidant activity was not evident in liver tissue however rasayana treatment was observed to increase constitutive DNA base excision repair and reduce clastogenicity. Whilst, the molecular mechanisms of such repair need further exploration, this is the first report to demonstrate these effects and provides further evidence for the role of brahmarasayana in the possible improvement of quality of life.
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13
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Radivoyevitch T, Hlatky L, Landaw J, Sachs RK. Quantitative modeling of chronic myeloid leukemia: insights from radiobiology. Blood 2012; 119:4363-71. [PMID: 22353999 PMCID: PMC3362357 DOI: 10.1182/blood-2011-09-381855] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 02/13/2012] [Indexed: 11/20/2022] Open
Abstract
Mathematical models of chronic myeloid leukemia (CML) cell population dynamics are being developed to improve CML understanding and treatment. We review such models in light of relevant findings from radiobiology, emphasizing 3 points. First, the CML models almost all assert that the latency time, from CML initiation to diagnosis, is at most ∼10 years. Meanwhile, current radiobiologic estimates, based on Japanese atomic bomb survivor data, indicate a substantially higher maximum, suggesting longer-term relapses and extra resistance mutations. Second, different CML models assume different numbers, between 400 and 10(6), of normal HSCs. Radiobiologic estimates favor values>10(6) for the number of normal cells (often assumed to be the HSCs) that are at risk for a CML-initiating BCR-ABL translocation. Moreover, there is some evidence for an HSC dead-band hypothesis, consistent with HSC numbers being very different across different healthy adults. Third, radiobiologists have found that sporadic (background, age-driven) chromosome translocation incidence increases with age during adulthood. BCR-ABL translocation incidence increasing with age would provide a hitherto underanalyzed contribution to observed background adult-onset CML incidence acceleration with age, and would cast some doubt on stage-number inferences from multistage carcinogenesis models in general.
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MESH Headings
- Adult
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/epidemiology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/etiology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy
- Models, Biological
- Models, Theoretical
- Nuclear Weapons
- Radiation, Ionizing
- Radiobiology/methods
- Recurrence
- Survivors/statistics & numerical data
- Time Factors
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Affiliation(s)
- Tomas Radivoyevitch
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH, USA
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14
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Tucker JD, Luckinbill LS. Estimating the Lowest Detectable Dose of Ionizing Radiation by FISH Whole-Chromosome Painting. Radiat Res 2011; 175:631-7. [DOI: 10.1667/rr2506.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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