1
|
Cho YH, Jang Y, Woo HD, Kim YJ, Kim SY, Christensen S, Cole E, Choi SY, Chung HW. LINE-1 hypomethylation is associated with radiation-induced genomic instability in industrial radiographers. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:174-184. [PMID: 30488609 PMCID: PMC6363886 DOI: 10.1002/em.22237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/15/2018] [Accepted: 08/10/2018] [Indexed: 06/09/2023]
Abstract
Global DNA hypomethylation is proposed as a potential biomarker for cancer risk associated with genomic instability, which is an important factor in radiation-induced cancer. However, the associations among radiation exposure, changes in DNA methylation, and carcinogenesis are unclear. The aims of this study were (1) to examine whether low-level occupational radiation exposure induces genomic DNA hypomethylation; and (2) to determine the relationships between radiation exposure, genomic DNA hypomethylation and radiation-induced genomic instability (RIGI) in industrial radiographers. Genomic DNA methylation levels were measured in blood DNA from 40 radiographers and 28 controls using the LINE-1 pyrosequencing assay and the luminometric methylation assay. Further, the micronucleus-centromere assay was performed to measure aneuploidy of chromosomes 1 and 4 as a marker of delayed RIGI. Genomic DNA methylation levels were significantly lower in radiographers than those in controls. LINE-1 hypomethylation was not significantly correlated with recent 1-year, recent 3-year, or total cumulative radiation doses in radiographers; however, LINE-1 hypomethylation significantly correlated with the cumulative radiation dose without recent 3-year exposure data (D3dose, r = -0.39, P < 0.05). In addition, LINE-1 hypomethylation was a significant contributor to aneuploidy frequency by D3dose (F (2, 34) = 13.85, P < 0.001), in which a total of 45% of the variance in aneuploidy frequency was explained. Our results provide suggestive evidence regarding the delayed effects of low-dose occupational radiation exposure in radiographers and its association with LINE-1 hypomethylation; however, additional studies using more subjects are needed to fully understand the relationship between genomic DNA hypomethylation and RIGI. Environ. Mol. Mutagen. 60: 174-184, 2019. © 2018 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yoon Hee Cho
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Yoonhee Jang
- Departments of Psychology, The University of Montana, Missoula, MT, USA
| | - Hae Dong Woo
- Molecular Epidemiology Branch, Division of Cancer Epidemiology and Prevention, Research Institute, National Cancer Center, Goyang-si, Gyeonggi-do, Korea
| | - Yang Jee Kim
- Da Vinci College of General Education, Chung-Ang University, Seoul, Korea
| | - Su Young Kim
- Departments of Preventive Medicine, School of Medicine, Jeju National University, Jeju-si, Jeju-do, Korea
| | - Sonja Christensen
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Elizabeth Cole
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Soo Yong Choi
- Laboratory of Radiation Effect, Korea Institute of Radiological and Medical Science, Seoul Korea
| | - Hai Won Chung
- School of Public Health, Seoul National University, Seoul, Korea
| |
Collapse
|
2
|
Molecular cytogenetics of the micronucleus: Still surprising. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 836:36-40. [DOI: 10.1016/j.mrgentox.2018.05.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/09/2018] [Accepted: 05/07/2018] [Indexed: 01/12/2023]
|
3
|
Delayed Numerical Chromosome Aberrations in Human Fibroblasts by Low Dose of Radiation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:15162-72. [PMID: 26633443 PMCID: PMC4690915 DOI: 10.3390/ijerph121214979] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 11/16/2022]
Abstract
Radiation-induced genomic instability refers to a type of damage transmitted over many generations following irradiation. This delayed impact of radiation exposure may pose a high risk to human health and increases concern over the dose limit of radiation exposure for both the public and radiation workers. Therefore, the development of additional biomarkers is still needed for the detection of delayed responses following low doses of radiation exposure. In this study, we examined the effect of X-irradiation on delayed induction of numerical chromosomal aberrations in normal human fibroblasts irradiated with 20, 50 and 100 cGy of X-rays using the micronucleus-centromere assay. Frequencies of centromere negative- and positive-micronuclei, and aneuploidy of chromosome 1 and 4 were analyzed in the surviving cells at 28, 88 and 240 h after X-irradiation. X-irradiation increased the frequency of micronuclei (MN) in a dose-dependent manner in the cells at all measured time-points, but no significant differences in MN frequency among cell passages were observed. Aneuploid frequency of chromosomes 1 and 4 increased with radiation doses, and a significantly higher frequency of aneuploidy was observed in the surviving cells analyzed at 240 h compared to 28 h. These results indicate that low-dose of X-irradiation can induce delayed aneuploidy of chromosomes 1 and 4 in normal fibroblasts.
Collapse
|
4
|
Udroiu I, Sgura A, Vignoli L, Bologna MA, D'Amen M, Salvi D, Ruzza A, Antoccia A, Tanzarella C. Micronucleus test on Triturus carnifex as a tool for environmental biomonitoring. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:412-417. [PMID: 25263003 DOI: 10.1002/em.21914] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 09/10/2014] [Accepted: 09/11/2014] [Indexed: 06/03/2023]
Abstract
The amphibian micronucleus test has been widely used during the last 30 years to test the genotoxic properties of several chemicals and as a tool for ecogenotoxic monitoring. The vast majority of these studies were performed on peripheral blood of urodelan larvae and anuran tadpoles and to a lesser extent adults were also used. In this study, we developed protocols for measuring micronuclei in adult shed skin cells and larval gill cells of the Italian crested newt (Triturus carnifex). Amphibians were collected from ponds in two protected areas in Italy that differed in their radon content. Twenty-three adult newts and 31 larvae were captured from the radon-rich pond, while 20 adults and 27 larvae were taken from the radon-free site. The animals were brought to the laboratory and the micronucleus test was performed on peripheral blood and shed skins taken from the adults and on larval gills. Samples from the radon-rich site showed micronucleus frequencies higher than those from the radon-free site and the difference was statistically significant in gill cells (P < 0.00001). Moreover, the larval gills seem to be more sensitive than the adult tissues. This method represents an easy (and noninvasive in the case of the shed skin) application of the micronucleus assay that can be useful for environmental studies in situ.
Collapse
Affiliation(s)
- I Udroiu
- Dipartimento di Scienze, Università "Roma Tre,", Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Fan Y, Zhao HC, Liu J, Tan T, Ding T, Li R, Zhao Y, Yan J, Sun X, Yu Y, Qiao J. Aberrant expression of maternal Plk1 and Dctn3 results in the developmental failure of human in-vivo- and in-vitro-matured oocytes. Sci Rep 2015; 5:8192. [PMID: 25645239 PMCID: PMC4314639 DOI: 10.1038/srep08192] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 01/12/2015] [Indexed: 12/31/2022] Open
Abstract
Fertilisation is the first step in embryonic development, and dynamic changes of key genes may potentially improve assisted reproduction techniques efficiency during this process. Here, we analysed genes that were differentially expressed between oocytes and zygotes and focused on cytokinesis-related genes. Plk1 and Dctn3 were identified as showing dramatic changes in expression during fertilisation and were suggested to play a key role in inducing aneuploidy in zygotes and 8-cell embryos. Moreover, we found that maternal Plk1 and Dctn3 were expressed at lower levels in in vitro matured oocytes, which may have contributed to the high ratio of resulting embryos with abnormal Plk1 and Dctn3 expression levels, thereby reducing the developmental competence of the resulting embryos. Furthermore, the overexpression of Dctn3 can silence Plk1 expression, which suggests a potential regulation mechanism. In conclusion, our present study showed that aberrant expression of Plk1 and Dctn3 increases embryo aneuploidy and developmental failure, particularly in in vitro matured oocytes. Our results facilitate a better understanding of the effects of oocyte maternal gene expression on embryonic development and can be used to improve the outcome of assisted reproduction techniques.
Collapse
Affiliation(s)
- Yong Fan
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
| | - Hong-Cui Zhao
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, 100191, China
| | - Jianqiao Liu
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
| | - Tao Tan
- Yunnan Key Laboratory of Primate Biomedical Research and Kunming Biomed International and National Engineering Research Center of Biomedicine and Animal Science, Kunming, 650500, China
| | - Ting Ding
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
| | - Rong Li
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, 100191, China
| | - Yue Zhao
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, 100191, China
| | - Jie Yan
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
| | - Xiaofang Sun
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
| | - Yang Yu
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, 100191, China
| | - Jie Qiao
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
- Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, 100191, China
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, 100191, China
| |
Collapse
|
6
|
Di Paolo A, Racca C, Calsou P, Larminat F. Loss of BRCA1 impairs centromeric cohesion and triggers chromosomal instability. FASEB J 2014; 28:5250-61. [PMID: 25205741 DOI: 10.1096/fj.14-250266] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In contrast to its well-known role in the DNA damage response during interphase, the function of BRCA1 in the maintenance of chromosomal stability during mitosis remains to be defined. In this study, we uncover a novel role of BRCA1 in preserving centromere integrity in mitotic human cells. Using immunofluorescence and chromatin immunoprecipitation approaches, we report BRCA1 association with centromeric chromatin during mitosis. BRCA1 depletion impairs centromeric cohesion, leading to an increase in interkinetochore distance and in unpaired sister-chromatids frequency during prometaphase. Moreover, BRCA1 loss partially decreased accumulation of the Aurora B kinase at the centromere. We found that proper recruitment of the DNMT3b DNA methyltransferase to satellite sequences is BRCA1-dependent during mitosis, suggesting that DNA hypomethylation contributes to Aurora B mislocalization. BRCA1-deficient cells exhibited decreased ability to correct improper Aurora B-dependent chromosome-spindle attachments and to align chromosomes at metaphase. Finally, we show that BRCA1 disruption promotes merotelic kinetochore attachments that represent a major mechanism of aneuploidy in human cells. In summary, we report here a novel function of BRCA1 in maintaining chromosomal stability through its contribution to the mitotic centromere integrity necessary for faithful segregation of sister-chromatids during cell division.
Collapse
Affiliation(s)
- Aurélie Di Paolo
- Institute of Pharmacology and Structural Biology, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5089, Toulouse, France; University of Toulouse, Université Paul Sabatier, Toulouse, France; and
| | - Carine Racca
- Institute of Pharmacology and Structural Biology, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5089, Toulouse, France; University of Toulouse, Université Paul Sabatier, Toulouse, France; and
| | - Patrick Calsou
- Institute of Pharmacology and Structural Biology, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5089, Toulouse, France; University of Toulouse, Université Paul Sabatier, Toulouse, France; and Equipe Labellisée Ligue Nationale contre le Cancer, Toulouse, France
| | - Florence Larminat
- Institute of Pharmacology and Structural Biology, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5089, Toulouse, France; University of Toulouse, Université Paul Sabatier, Toulouse, France; and
| |
Collapse
|
7
|
Manshian BB, Singh N, Doak SH. The in vitro micronucleus assay and kinetochore staining: methodology and criteria for the accurate assessment of genotoxicity and cytotoxicity. Methods Mol Biol 2014; 1044:269-89. [PMID: 23896882 DOI: 10.1007/978-1-62703-529-3_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The in vitro micronucleus assay is currently one of the most commonly used test systems for the study of genotoxic effects of chemicals. It is considered the preferred method for measuring chromosome damage as it allows the determination of both chromosomal loss and breakage. The type of chromosomal damage induced can be distinguished by using the kinetochore or pan-centromeric staining using molecular probes that label the centromeric regions of chromosomes allowing the determination of aneugenic (chromosome loss) or clastogenic (chromosome breakage) agents. In this chapter, we provide a description of the basic principles and methods of the in vitro micronucleus assay with detailed explanations of the scoring criteria for the genotoxicity and cytotoxicity end-points by manual or automated analysis.
Collapse
Affiliation(s)
- Bella B Manshian
- Institute of Life Science, College of Medicine, Swansea University, Swansea, Wales, UK
| | | | | |
Collapse
|
8
|
Kirkland D, Reeve L, Gatehouse D, Vanparys P. A core in vitro genotoxicity battery comprising the Ames test plus the in vitro micronucleus test is sufficient to detect rodent carcinogens and in vivo genotoxins. Mutat Res 2011; 721:27-73. [PMID: 21238603 DOI: 10.1016/j.mrgentox.2010.12.015] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/12/2010] [Accepted: 12/15/2010] [Indexed: 01/27/2023]
Abstract
In vitro genotoxicity testing needs to include tests in both bacterial and mammalian cells, and be able to detect gene mutations, chromosomal damage and aneuploidy. This may be achieved by a combination of the Ames test (detects gene mutations) and the in vitro micronucleus test (MNvit), since the latter detects both chromosomal aberrations and aneuploidy. In this paper we therefore present an analysis of an existing database of rodent carcinogens and a new database of in vivo genotoxins in terms of the in vitro genotoxicity tests needed to detect their in vivo activity. Published in vitro data from at least one test system (most were from the Ames test) were available for 557 carcinogens and 405 in vivo genotoxins. Because there are fewer publications on the MNvit than for other mammalian cell tests, and because the concordance between the MNvit and the in vitro chromosomal aberration (CAvit) test is so high for clastogenic activity, positive results in the CAvit test were taken as indicative of a positive result in the MNvit where there were no, or only inadequate data for the latter. Also, because Hprt and Tk loci both detect gene-mutation activity, a positive Hprt test was taken as indicative of a mouse-lymphoma Tk assay (MLA)-positive, where there were no data for the latter. Almost all of the 962 rodent carcinogens and in vivo genotoxins were detected by an in vitro battery comprising Ames+MNvit. An additional 11 carcinogens and six in vivo genotoxins would apparently be detected by the MLA, but many of these had not been tested in the MNvit or CAvit tests. Only four chemicals emerge as potentially being more readily detected in MLA than in Ames+MNvit--benzyl acetate, toluene, morphine and thiabendazole--and none of these are convincing cases to argue for the inclusion of the MLA in addition to Ames+MNvit. Thus, there is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.
Collapse
Affiliation(s)
- David Kirkland
- Kirkland Consulting, PO Box 79, Tadcaster LS24 0AS, United Kingdom.
| | | | | | | |
Collapse
|
9
|
Yang Jee Kim, Jun Yeol Choi, Yoon Hee Cho, Hae Dong Woo, Hai Won Chung. Micronucleus-centromere assay in workers occupationally exposed to low level of benzene. Hum Exp Toxicol 2010; 29:343-50. [PMID: 20129955 DOI: 10.1177/0960327110361500] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Benzene is a well-known carcinogen that induces chromosomal instability, including chromosome aberration and aneuploidy. In order to assess aneugenic effect of low-level benzene, micronucleus-centromere assay using specific probes for chromosomes 7 and 9 was performed in workers occupationally exposed to low-dose benzene at a petroleum refinery. A micronucleus-centromere assay using a pan-centromeric probe was also performed to determine the origin of benzene-induced micronucleus (MN). Frequency of aneuploidy of chromosomes 7 and 9 was significantly higher among workers compared to the unexposed control group. Poisson regression analysis revealed that aneuploidy frequency of chromosome 7 or 9 was significantly associated with benzene level after adjusting for confounding variables such as age, smoking, alcohol intake, and duration of work (p = .042). Additionally, frequencies of MN and centromere-negative micronuclei (MNC-) were significantly higher in benzene-exposed workers compared to controls, while frequency of centromere-positive micronuclei (MNC+) was similar in both groups. In conclusion, aneuploidy of chromosomes 7 and 9 could be a useful biomarker to assess the effect of low-level benzene exposure, and benzene-induced MN originates from chromosome breaks rather than chromosome non-disjunction.
Collapse
Affiliation(s)
- Yang Jee Kim
- School of Public Health, Seoul National University, Seoul 110-460, Korea
| | | | | | | | | |
Collapse
|
10
|
Jiang W, Lu Y, Chen Z, Chen S, Zhang M, Jin L, Lou J, He J. Studying the genotoxicity of vincristine on human lymphocytes using comet assay, micronucleus assay and TCR gene mutation test in vitro. Toxicology 2008; 252:113-7. [PMID: 18722497 DOI: 10.1016/j.tox.2008.07.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 07/22/2008] [Accepted: 07/22/2008] [Indexed: 11/12/2022]
Abstract
The results of our previous investigation for workers occupationally exposed to vincristine (VCR) indicated that the genetic damage was detectable with comet assay, cytokinesis-block micronucleus (CBMN) assay and housekeeping gene mutation tests. In order to determine the results of above investigation and to inquire further the characteristics of genotoxicity of VCR, the cytogenetic effects of VCR on human lymphocytes were assessed with comet assay, CBMN assay and T-cell receptor (TCR) gene mutation test in vitro. The lymphocytes from two healthy donors were incubated for 24h at doses of 0.00, 0.01, 0.02, 0.04, and 0.08microgml(-1) VCR. The results of the present experiment showed that VCR not only could induce DNA damage, increase significantly micronucleus frequencies and the apoptotic cell ratios and decrease the nuclear division index (NDI) with dose-response relationship, but also could produce nucleoplasmic bridges (NPBs), a biomarker of DNA misrepair and/or telomere end-fusions and nuclear buds (NBUDs), a biomarker of elimination of amplified DNA and/or DNA repair complexes. Moreover, VCR could enhance TCR gene mutation frequency (Mf-TCR) of human lymphocytes. There was good correlation between the parameters (mean tail length, mean tail moment, micronucleus frequency, micronucleated frequency and Mf-TCR). The results of present study supported the results of our previous investigation for workers occupationally exposed to VCR, and the genotoxicity of VCR was determined at the different genetic end-points in vitro.
Collapse
Affiliation(s)
- Wei Jiang
- Zhejiang University, Medical College, Institute of Environmental Medicine, Hangzhou 310058, Zhejiang, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Kayani M, Parry JM. The detection and assessment of the aneugenic potential of selected oestrogens, progestins and androgens using the in vitro cytokinesis blocked micronucleus assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 651:40-5. [DOI: 10.1016/j.mrgentox.2007.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 10/28/2007] [Indexed: 10/22/2022]
|
12
|
Cho YH, Jeon HK, Chung HW. Effects of extremely low-frequency electromagnetic fields on delayed chromosomal instability induced by bleomycin in normal human fibroblast cells. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1252-8. [PMID: 17654242 DOI: 10.1080/15287390701429281] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This study was carried out to examine the interaction of extremely low-frequency electromagnetic fields (ELF-EMF) on delayed chromosomal instability by bleomycin (BLM) in human fibroblast cells. A micronucleus-centromere assay using DNA probes for chromosomes 1 and 4 was performed and a 60-Hz ELF-EMF of 0.8 mT field strength was applied either alone or with BLM throughout the culture period. The frequencies of micronuclei (MN) and aneuploidy were analyzed at 28, 88, and 240 h after treatment with BLM. The coexposure of cells to BLM and ELF-EMF led to a significant increase in the frequencies of MN and aneuploidy compared to the cells treated with BLM alone. No difference was observed between field-exposed and sham-exposed control cells. The frequency of MN induced by BLM was increased at 28 h, and further analysis showed a persistent increase up to 240 h, but the new levels were not significantly different from the level at 28 h. BLM increased the frequencies of aneuploidy at 28, 88, and 240 h, and significantly higher frequency of aneuploidy was observed in the cells analyzed at 240 h compared to the cells examined at 28 h. No interaction of ELF-EMF on delayed chromosomal instability by BLM was observed. Our results suggest that ELF-EMF enhances the cytotoxicity of BLM. BLM might induce delayed chromosomal instability, but no effect of ELF-EMF was observed on the BLM-induced delayed chromosomal instability in fibroblast cells.
Collapse
Affiliation(s)
- Yoon Hee Cho
- School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea
| | | | | |
Collapse
|
13
|
Hongping D, Jianlin L, Meibian Z, Wei W, Lifen J, Shijie C, Wei Z, Baohong W, Jiliang H. Detecting the cytogenetic effects in workers occupationally exposed to vincristine with four genetic tests. Mutat Res 2006; 599:152-9. [PMID: 16580025 DOI: 10.1016/j.mrfmmm.2006.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2005] [Revised: 02/10/2006] [Accepted: 02/15/2006] [Indexed: 05/08/2023]
Abstract
To study the human genetic damage induced by vincristine (VCR), the cytogenetic effects in workers occupationally exposed to vincristine were studied with micronucleus (MN) test, comet assay, hypoxantinepho-guanine phosphoribosyl-transferase (hprt) gene mutation assay and T-cells receptor (TCR) gene mutation assay. Fresh peripheral blood samples were collected from the workers and controls. Fifteen workers from a plant producing antineoplastic drug (vincristine) and 15 controls were matched according to age, gender and smoking. The results of MN test showed that the mean micronuclei rate (MNR) and mean micronucleated cells rate (MCR) in 15 workers were 17.80+/-1.88 per thousand and 13.67+/-1.56 per thousand, respectively, which were significantly higher than those (3.73+/-0.80 per thousand and 3.13+/-0.59 per thousand) in controls (P<0.01). It was found in the comet assay that the mean tail length (MTL) of 15 workers and 15 controls were 1.72+/-0.15 microm and 0.71+/-0.01 microm, respectively, there was significant difference between workers and controls for MTL (P<0.05), but the difference between the mean tail moment (MTM, 0.29+/-0.03) of 15 workers and MTM (0.17+/-0.05) of 15 controls was not significant (P>0.05). The results of hprt gene mutation assay showed that the average mutation frequency of hprt (Mf-hprt) in workers was 1.03+/-0.02 per thousand, which was significantly higher than that (0.87+/-0.01 per thousand) in controls (P<0.05). Meanwhile, the results of TCR gene mutation assay indicated that Mfs-TCR of workers and controls were 2.52+/-0.34 x 10(-4) and 1.51+/-0.11 x 10(-4), respectively, there was a significant difference between workers and controls (P<0.01). It is found in the results of our study that the genetic damage is detectable in 15 workers occupationally exposed to vincristine.
Collapse
Affiliation(s)
- Deng Hongping
- Zhejiang University, Medical College, Institute of Occupational and Environmental Health, Hangzhou 310006, Zhejiang, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Timoshevsky VA, Nazarenko SA. Interphase cytogenetics in estimation of genomic mutations in somatic cells. RUSS J GENET+ 2005. [DOI: 10.1007/s11177-005-0051-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
15
|
Chung HW, Kang SJ, Kim SY. A combination of the micronucleus assay and a FISH technique for evaluation of the genotoxicity of 1,2,4-benzenetriol. Mutat Res 2002; 516:49-56. [PMID: 11943610 DOI: 10.1016/s1383-5718(02)00018-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cytokinesis-block micronucleus (CBMN) assay has emerged as one of the preferred methods for assessing chromosome damage. Micronuclei (MN) are small, extranuclear bodies that are formed in mitosis from acentric chromosomal fragments or chromosomes that are not included in each daughter nucleus. Thus, MN contain either chromosomal fragments or whole chromosomes. The CBMN assay, together with a fluorescence in situ hybridization (FISH) technique using specific centromeric probes for chromosomes 7 and 8, were employed in mitogen-stimulated human lymphocytes pretreated with the benzene metabolite, 1,2,4-benzenetriol (BT). Treatment of human lymphocytes resulted in the induction of MN in a dose-dependent manner. The frequency of MN in control lymphocytes was 4.5 per 1000 binucleated (BN) cells and this increased to 9.5, 14, 28 and 40 per 1000 BN cells at 10, 25, 50 and 100 microM BT, respectively. The frequency of aneuploidy 7 and 8 in BN cells also increased at each concentration. Aneuploidy 8 was more frequent than aneuploidy 7, suggesting that chromosome 8 is more sensitive to aneuploidy induction by BT. The frequency of MN containing centromere positive signals for chromosomes 7 and 8 increased with the concentration of BT. The frequency of MN with centromere positive signals was higher for chromosome 8 than for chromosome 7, also suggesting a greater sensitivity of chromosome 8 to this agent. These results suggest that combined application of the CBMN assay with a FISH technique, using chromosome-specific centromeric probes, would allow the detection of aneuploidy in human lymphocytes and identify the mechanistic origin of MN induced by a clastogen or aneugen.
Collapse
Affiliation(s)
- Hai Won Chung
- School of Public Health, Seoul National University, 28 Yunkeun-dong, Chongno-ku, 110-460, South Korea.
| | | | | |
Collapse
|
16
|
Müller P, Stock T, Bauer S, Wolff I. Genotoxicological characterisation of complex mixtures. Genotoxic effects of a complex mixture of perhalogenated hydrocarbons. Mutat Res 2002; 515:99-109. [PMID: 11909758 DOI: 10.1016/s1383-5718(02)00005-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Toxicological and genotoxicological investigation of complex mixtures is one of the main focus of the recent research in toxicology. Testing complex mixtures present a formidable scientific problem since most recently available toxicological data has been obtained from single substance studies and is not simply transferable to mixtures of chemicals. Although there are no special strategies and standard protocols available for determining toxic and genotoxic effects of complex mixtures, the fundamental concepts of evaluation are the same as those for single substances. The focus of interest of the submitted paper is the genotoxicological characterisation of a complex mixture of mostly perhalogenated hydrocarbons which is generated as a waste product from the plasma etching process in the semiconductor industry. By use of several in vitro test systems (comet assay and micronucleus test), the clastogenic potency of the mixture was tested in various human cell types (lymphocytes and normal bronchial epithelial cells) and in rat hepatocytes. Results demonstrated that the complex perhalogenated hydrocarbons mixture causes DNA single-strand breaks and micronuclei formation, and direct concentration-to-effect correlations were proved in all experiments. The presence of an external metabolising system (S9 mix from rat hepatocytes) in human cell culture systems did not cause any change of the observed effects when compared to experiments performed in the absence of the S9 mix. Therefore, we conclude that the mixture acts as direct genotoxicant and that there is no detoxification by the external enzyme system.Further, convincing and reproducible results of the in vitro comet assay and the micronucleus assay in primary human cell cultures indicated these tests may be utilized for the genotoxicological analyses of complex mixtures with concern to human health hazard.
Collapse
Affiliation(s)
- Peggy Müller
- Centre of Applied Medical and Human Biological Research, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Street 1, D-06097, Saale, Halle, Germany
| | | | | | | |
Collapse
|
17
|
Acar H, Calişkan U, Demirel S, Largaespada DA. Micronucleus incidence and their chromosomal origin related to therapy in acute lymphoblastic leukemia (ALL) patients: detection by micronucleus and FISH techniques. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 2002; 21:341-7. [PMID: 11746248 DOI: 10.1002/tcm.1022] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Micronucleus assay and dual color-fluorescence in situ hybridization (DC-FISH), using centromere-specific and whole chromosome-specific painting probes, are considered a useful screening test to determine the incidence of micronucleus, their origin and contents. The patients with acute lymphoblastic leukemia (ALL), who had undergone chemotherapy, were analysed before and after treatment with vincristine, methotrexate, daunomycin, prednisone, and asparaginase. The incidence of micronuclei after the antileukemic agent treatment was significantly higher than before the treatment. Application of DC-FISH using a combination of whole chromosome-specific painting probes and the same chromosome-specific alpha-satellite centromeric probe showed that there were no significant differences in the micronucleus incidence for any specific chromosome (chromosomes 7, 8, 11, 17, X, and Y). There were no significant differences between the incidence of centromere-positive micronuclei and the incidence of centromere-negative micronucleus. We concluded that antileukemic agents induced the somatic genetic damage but this damage is not related to any specific chromosome studied.
Collapse
Affiliation(s)
- H Acar
- Department of Medical Genetics, Selçuk University, Medical Faculty, Konya, Turkey.
| | | | | | | |
Collapse
|
18
|
Sgura A, Antoccia A, Cherubini R, Tanzarella C. Chromosome nondisjunction and loss induced by protons and X rays in primary human fibroblasts: role of centromeres in aneuploidy. Radiat Res 2001; 156:225-31. [PMID: 11500131 DOI: 10.1667/0033-7587(2001)156[0225:cnalib]2.0.co;2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To study the origin of micronuclei induced in human primary fibroblasts by low-energy protons (7.7 and 28.5 keV/microm) and X rays, we have developed a combined antikinetochore-antibody (CREST) and FISH staining with pancentromeric probes. This technique allowed us to analyze the integrity of the kinetochore and centromeric DNA structures and to assess their role in induced aneuploidy. The effect of LET on radiation-induced chromosome nondisjunction was studied in binucleated cells with centromeric-specific DNA probes for chromosomes 7 and 11. Our results indicate that, though more than 90% of radiation-induced micronuclei were CREST(-)/FISH(-), 28.5 keV/microm protons and X rays were also able to induce statistically significant increases in the number of micronuclei that were CREST(-)/FISH(+) and CREST(+)/FISH(+), respectively. One interpretation of these results could be that the protons induced chromosome loss by kinetochore detachment or by breakage in the centromeric DNA region, whereas X rays induced aneuploidy through a non-DNA damage mechanism. Nondisjunction appears to be a far more important mechanism leading to radiation-induced aneuploidy. Irrespective of the higher frequency of micronuclei induced by 28.5 keV/microm protons, the frequency of chromosome loss was markedly higher for X rays than for 28.5 keV/microm protons, strengthening the hypothesis that non-DNA targets, such as components of the mitotic spindle apparatus, may be involved in aberrations in chromosome segregation after X irradiation.
Collapse
Affiliation(s)
- A Sgura
- Department of Biology, University of Rome "Roma Tre," Rome, Italy
| | | | | | | |
Collapse
|
19
|
Ponsa I, Barquinero JF, Miró R, Egozcue J, Genescà A. Non-disjunction and chromosome loss in gamma-irradiated human lymphocytes: a fluorescence in situ hybridization analysis using centromere-specific probes. Radiat Res 2001; 155:424-31. [PMID: 11182793 DOI: 10.1667/0033-7587(2001)155[0424:ndacli]2.0.co;2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Centromere-specific DNA probes for chromosomes 4, 7 and 18 were used to simultaneously analyze chromosome loss, non-disjunction, breaks within the labeled region, and nucleoplasmic bridges induced by gamma rays in binucleated human lymphocytes. The doses used were 0, 1, 2 and 4 Gy, and approximately 1000 cells were scored per dose. Micronucleus frequency increased in a linear-quadratic fashion. For chromosome loss, significant increases were observed at 2 and 4 Gy, whereas for non-disjunction significant increases were observed at 1 Gy; thus non-disjunction allowed us to detect the effects of radiation at a lower dose than chromosome loss. The use of centromere-specific probes allowed discrimination between the clastogenic and aneugenic effects of ionizing radiation. The analysis of chromosome loss, not taking fragmented signals into account, ensures the detection of an aneugenic effect, which was not possible using pancentromeric probes. The frequency of chromosome breakage within the labeled regions was higher in nuclei than in micronuclei, suggesting an increase in the engulfment of chromosomal material by nuclei as a consequence of the presence of cytochalasin B in the cultures. Chromatin filaments connecting main nuclei, the so-called nucleoplasmic bridges, were observed in irradiated samples, and are a manifestation of rearranged chromosomes producing anaphase bridges.
Collapse
Affiliation(s)
- I Ponsa
- Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Spain
| | | | | | | | | |
Collapse
|
20
|
Humpage AR, Fenech M, Thomas P, Falconer IR. Micronucleus induction and chromosome loss in transformed human white cells indicate clastogenic and aneugenic action of the cyanobacterial toxin, cylindrospermopsin. Mutat Res 2000; 472:155-61. [PMID: 11113708 DOI: 10.1016/s1383-5718(00)00144-3] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cylindrospermopsin (CYN) is a potent inhibitor of protein synthesis produced by a number of cyanobacterial species, the most common being Cylindrospermopsis raciborskii. CYN contains a uracil moiety attached to a sulphated guanidino moiety, suggesting that it may have carcinogenic activity. This report describes the use of the WIL2-NS lymphoblastoid cell-line in the well-validated cytokinesis-block micronucleus (CBMN) assay to test this hypothesis. Centromeres (CENs) were identified in micronuclei (MNi) of binucleated cells (BNCs) by fluorescent in situ hybridisation of alpha centromeric DNA sequence repeats. The results indicate that CYN induced a significant increase in the frequency of MNi in BNCs exposed to 6 and 10microg/ml, and a significant increase in CEN-positive MNi at all concentrations of CYN tested (1, 3, 6, and 10microg/ml). However, despite this apparently greater sensitivity of WIL2-NS cells to induction of CEN-positive MNi at low CYN concentrations, at the higher concentrations the magnitude of the increase in CEN-positive MNi did not account for the greater increase in MNi in BNCs, indicating that both CEN-positive and CEN-negative MNi were induced. This suggests that CYN acts to induce cytogenetic damage via two mechanisms, one at the level of the DNA to induce strand breaks, the other at the level of kinetochore/spindle function to induce loss of whole chromosomes (aneuploidy). C. raciborskii occurs in a number of human drinking water sources worldwide and so these findings may have important public health implications.
Collapse
Affiliation(s)
- A R Humpage
- Department of Clinical and Experimental Pharmacology, University of Adelaide Medical School, SA 5005, Adelaide, Australia.
| | | | | | | |
Collapse
|
21
|
Cimini D, Tanzarella C, Degrassi F. Differences in malsegregation rates obtained by scoring ana-telophases or binucleate cells. Mutagenesis 1999; 14:563-8. [PMID: 10567031 DOI: 10.1093/mutage/14.6.563] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In this work we have applied in situ hybridization with alphoid centromeric probes specific to chromosomes 7 and 11 to ana-telophase cells from human primary fibroblasts. The aim was to visualize the events leading to aneuploidy directly during anaphase, analyse the induction of aneuploidy during this mitotic stage and compare the frequencies of chromosome malsegregation observed in ana-telophases with the estimated malsegregation obtained in binucleate cells after a short cytochalasin B treatment. Significantly higher frequencies of chromosome loss and chromosome non-disjunction were observed in fibroblasts undergoing ana-telophase during recovery from a nocodazole-induced mitotic arrest compared with binucleate cells obtained by a further 30 min incubation with cytochalasin B. Using the same experimental schedule, analysis of hybridization signals in mononucleate cells showed higher frequencies of polyploid nuclei in cytochalasin B-treated cultures, indicating that part of the ana-telophases observed after release from the nocodazole-induced mitotic arrest may give rise to polyploid mononucleate cells instead of binucleate ones. A reduced distance between spindle poles was also measured in cells undergoing ana-telophase in the presence of cytochalasin B. Our study suggests that in nocodazole and cytochalasin B-treated cultures the shorter pole-to-pole distance may favour the reformation of a single membrane around telophase chromosomes, especially when several lagging chromosomes lie between the two future daughter nuclei. This would give rise to polyploid mononucleate cells at the ensuing interphase.
Collapse
Affiliation(s)
- D Cimini
- Centro Genetica Evoluzionistica CNR, c/o Dipartimento Genetica e Biologia Molecolare, Università 'La Sapienza', Via degli Apuli, 4-00185 Rome, Italy
| | | | | |
Collapse
|
22
|
Minissi S, Degrassi F, Tanzarella C, Gustavino B. Direct and indirect non-disjunction in the origin of trisomy in cultured human lymphocytes. Mutagenesis 1999; 14:557-62. [PMID: 10567030 DOI: 10.1093/mutage/14.6.557] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of the present work was to investigate the processes involved in the origin of trisomic karyotypes, i.e. co-migration of sister chromatids (mitotic non-disjunction, MND) and recovery of micronuclei (MN) originating from lagging chromosomes/chromatids at anaphase (mitotic indirect non-disjunction, MIND), and to evaluate their relative contribution to aneuploidy in human lymphocytes mitotically activated in vitro. Therefore, phytohaemagglutinin-stimulated human lymphocytes from one donor were treated with 10 and 25 nM colchicine and analysed through two cell cycles by means of both molecular (FISH with centromeric DNA probes specific for chromosomes 7 and 11) and classical cytogenetic techniques. The following events were analysed: (i) chromosome/chromatid loss (a MN-generating event) in M(1) bipolar ana-telophases; (ii) MN recovery in M(2+) prophases; (iii) non-disjunction and loss of chromosomes 7 and 11 by FISH analysis in cytochalasin B-induced binucleate cells; (iv) spontaneous frequency of trisomic cells by chromosome counting and FISH analysis in M(1) c-metaphases; (v) induced frequency of trisomic cells by chromosome counting and FISH analysis in M(2) c-metaphases. Our results indicate that MND plays a major role compared with MIND in the origin of trisomic karyotypes, being approximately 4- to 5-fold higher in colchicine-treated cells. Moreover, remarkable reductions in the observed frequencies of trisomic cells were recorded in comparison with the expected ones, with an observed/expected frequency ratio of trisomic M(2) c-metaphases ranging between 1/3 and 1/6.
Collapse
MESH Headings
- Adult
- Aneuploidy
- Cell Cycle/drug effects
- Cells, Cultured
- Chromatids/genetics
- Chromatids/metabolism
- Chromosomes, Human, Pair 11/genetics
- Chromosomes, Human, Pair 11/metabolism
- Chromosomes, Human, Pair 7/genetics
- Chromosomes, Human, Pair 7/metabolism
- Colchicine/pharmacology
- Cytochalasin B/pharmacology
- Female
- Humans
- In Situ Hybridization, Fluorescence
- Lymphocytes/drug effects
- Lymphocytes/metabolism
- Micronuclei, Chromosome-Defective/drug effects
- Micronuclei, Chromosome-Defective/genetics
- Mitosis/drug effects
- Mitosis/genetics
- Nondisjunction, Genetic
- Phytohemagglutinins/metabolism
- Trisomy/genetics
Collapse
Affiliation(s)
- S Minissi
- Dipartimento Biologia, Università di Roma 'Tor Vergata', Viale della Ricerca Scientifica, 00133 Roma, Italy
| | | | | | | |
Collapse
|
23
|
Digue L, Orsière T, De Méo M, Mattéi MG, Depetris D, Duffaud F, Favre R, Botta A. Evaluation of the genotoxic activity of paclitaxel by the in vitro micronucleus test in combination with fluorescent in situ hybridization of a DNA centromeric probe and the alkaline single cell gel electrophoresis technique (comet assay) in human T-lymphocytes. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 1999; 34:269-278. [PMID: 10618175 DOI: 10.1002/(sici)1098-2280(1999)34:4<269::aid-em7>3.0.co;2-d] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Paclitaxel is a recent chemotherapeutic agent that inhibits tubulin depolymerization in tumoral cells. Despite its increasing use against various human cancers, the genotoxicity of paclitaxel has never been studied on normal human cells. The in vitro genotoxic effects of the drug were evaluated with two complementary mutagenesis tests on human T-lymphocytes: (1) the cytokinesis-blocked micronuclei assay (CBMN) in combination with fluorescent in situ hybridization (FISH) of nonspecific centromeric probes and (2) the comet assay performed in three ways: on stimulated lymphocytes as in the CBMN, and on freshly isolated lymphocytes at both 4 and 37 degrees C. A slight cytotoxicity of 2.5 to 10 nM paclitaxel was found in the CBMN and a significant increase in the binucleated micronucleated cell rates was observed, with a concentration-dependent manner. In the FISH analysis, more than 85% of the micronuclei (MN) were centromere positive, and a ratio of 72. 2 to 78.6% of these MN contained more than one centromere. Moreover, at 10 nM of paclitaxel, 35.6% of the cells are multimicronucleated lymphocytes. Unexpectedly, paclitaxel induced single-strand breaks on proliferating lymphocytes at 5 and 7.5 nM but not in resting cells, even at 5 to 15 microM. These in vitro results showed that (1) paclitaxel does not present any direct DNA action in resting cells, (2) DNA damage detected in stimulated lymphocytes may be linked either to a high frequency of cells in the S-phase cell cycle or to a direct DNA damaging effect on replicating cells, and (3) paclitaxel is a strong in vitro aneugenic drug on human normal cells, at clinically relevant concentrations.
Collapse
Affiliation(s)
- L Digue
- Laboratoire de Biogénotoxicologie et Mutagenèse Environnementale (EA 1784), Faculté de Médecine, Université de la Méditerranée, Marseille, France
| | | | | | | | | | | | | | | |
Collapse
|