Chromosome Aberrations In Cells Research Articles

Radiation Leukemogenesis in Mice: Loss ofPU.1on Chromosome 2 in CBA and C57BL/6 Mice after Irradiation with 1 GeV/nucleon56Fe Ions, X Rays or γ Rays. Part II. Theoretical Considerations Based on Microdosimetry and the Initial Induction of Chromosome Aberrations

Chromosome aberrations in mitotic bone marrow cells of CBA/Ca and C57BL/6 mice were measured 1 day after exposure to 1 Gy of 1 GeV/nucleon 56Fe ions or 3 Gy of gamma rays. The proportion that have lost a region of chromosome 2 containing the PU.1 gene could be explained by a model based on these measurements. The distribution of aberrations among cells was close to the expected Poisson for the gamma-irradiated cells, but for the HZE 56Fe ions the distribution was highly dispersed. The observations were consistent with the results of an analysis similar to that of Edwards and co-workers in 1980 after ex vivo irradiation of human blood with alpha particles. The analysis used to fit the current data was based on a compound Poisson process, also used previously by others, but in addition included the random nature of parameters involved such as cell nuclear diameter, particle traversal lengths through cell nuclei, production of aberrations, and cell cycle arrest per traversal. From the measured numbers of acentric fragments produced, the relative size of chromosome 2 and the region associated with PU.1 deletions, an independent prediction of PU.1 loss agreed well with measurements described in the accompanying paper.

Cytogenetic investigation of chromosomal aberrations in cells treated with plantamajoside from Plantago asiatica

Plantago asiatica is a member of the Plantaginaceae family, and is widely distributed in East Asia. In our previous work, a single active compound, plantamajoside was isolated and confirmed to have glycation inhibitory activity, and did not possess toxicity during a 90 day repeated oral toxicity test in rats. In the present study, a chromosomal aberration test was performed to investigate the genotoxicity of plantamajoside. From the results of the cytotoxicity test, plantamajoside proved to be less toxic when it was treated combined with S9 cell fractions. However, there was a significant increase in structural aberrations during the short-term treatment of plantamajoside at its highest dose (5000 microg/mL) even when combined with S9. This seems to have been a natural phenomenon due to the very high dose of plantamajoside that was used. However, to confirm the safety of plantamajoside for its potential use as a phytochemical agent in health products, additional mutagenicity tests are necessary.

Micronuclei and chromosome aberrations in bone marrow cells and lymphocytes of humans exposed mainly to petroleum vapors.

Several cytogenetic parameters, i.e. chromosome aberrations in bone marrow cells and in peripheral lymphocytes as well as micronuclei in erythropoietic bone marrow cells, were studied in 16 tank cleaners exposed to organic solvents and other petroleum products and sediments containing heavy metals, such as lead, mercury, arsenic and cadmium. Micronuclei and chromosome breaks in peripheral blood lymphocytes proved significantly more common in tank cleaners than in controls. The data indicated an exposure-connected relationship, suggesting that assessment of micronuclei in bone marrow cells might be a useful method for detecting cytogenetic effects in humans chronically exposed to chemical agents. In this respect both erythroblasts and polychromatic erythrocytes could be studied.

Effect of superoxide dismutase and catalase on spontaneously occurring chromosome breaks in patients with Fanconi's anemia.

The effect of the two enzymes, superoxide dismutase (SOD) and catalase on spontaneously occurring chromosome breaks in 2 patients with Fanconi's anemia (FA) was studied. Cells, cultured in the presence of SOD and catalase, separately and combined, showed a significant decrease in the frequency of gaps and chromatid breaks (P < 0.01). There was also a decrease in the frequency of chromosome aberrations in cells cultured in the presence of both SOD and catalase (P <0.05). Since both enzymes are known to interfere with biological oxidation-reduction processes, involving the production of different radicals, it is suggested that the decreased frequency of chromosome breaks is due to radical-scavenging.

Clustering of aberrations to specific chromosomes in human neoplasms. III. Incidence and geographic distribution of chromosome aberrations in 856 cases.

The present survey comprises 856 cases of human neoplasms in which 1 or more chromosome aberrations have been identified by banding techniques. Of these, 704 cases had been published by the end of 1977, and 152 cases have not yet been published. The material is divided into 15 groups of malignant or premalignant disorders belonging to myeloproliferative disorders, lymphoproliferative disorders and solid tumors with 571, 160 and 125 cases, respectively. Most of the material (774 cases) is presented in tables, in which the chromosomes involved in aberrations are listed separately for each country. The main conclusion of the survey is that the different chromosome types are involved in aberrations to a strikingly different extent. The selective involvement, combined from all groups of diseases, clusters to 12 of the 24 human chromosome types, and 8 chromosome types are involved in 3–9 diseases each. There are suggestive indications that geographic differences in chromosome aberrations may exist. Agent dependence and tissue specificity of chromosome aberrations in neoplastic cells are discussed tentatively, and a working hypothesis is outlined concerning the possible role of chromosomal aberrations in oncogenesis.

Location of chromosome aberrations in bone marrow cells of individuals exposed mainly to petroleum vapors.

Structural chromosome aberrations were analysed in bone marrow cells from 15 tank cleaners exposed to organic solvents and other petroleum products, and sediments containing heavy metals, such as lead, mercury, arsenic and cadmium. Break points were identified by Giemsa banding in a total of 28 structural aberrations, 6 of which affected chromosome No. 9.

Genotoxic Effects of Herbicide Illoxan (Diclofop-Methyl) on Allium cepa L.

The genotoxic potential of the commercial herbicide Illoxan (containing 284 g/L diclofop-methyl) was determined by using chromosome aberrations in Allium cepa root tip cells. The EC_{50} value was determined as 150.00 mg/L using a root growth inhibition test and then the roots were treated with 37.50, 75.00, and 150.00 mg/L concentrations for 12, 24, and 48 h. The results indicated that Illoxan significantly increased the abnormal cell frequency at all concentrations and treatment periods when compared with their controls, and this increase was dose-dependent for the 24 and 48 h treatments. On the other hand, Illoxan significantly decreased the mitotic index (MI) in all treatments when compared with their controls. The decrease in the mitotic index was slightly dose-dependent for the 24 and 48 h treatments. Illoxan did not affect the percentage of mitotic stages. For the pretreated root tips, Illoxan (except 37.50 mg/L at 12 and 24 h) significantly increased the frequency of abnormal cells in a dose-dependent manner. This study indicates that Illoxan decreased the mitotic index and produced clastogenic and aneugenic types of abnormalities in Allium cepa root tip cells. The data obtained in this study showed that plant bioassays can be used as an important test battery to detect possible genotoxicity of chemicals.

Investigation of cytotoxic genotoxic effects of Ecballium elaterium juice based on allium test

The genus Ecballium only comprises the Ecballium elaterium (EE) (L.) A.Rich species which is a wild medicinal plant found in the Mediterranean region. EE fruit juice is widely used in Turkish folk medicine for the relief of sinusitis and for several illnesses. Up to date, there has been no report on the genotoxicity of EE fruit juice. Thus, the aim of this study was to investigate the potential genotoxic effects of EE fruit juice using the Allium test system. Allium cepa (A. cepa) bulbs were treated with four concentrations (10 ml/L, 20 ml/L, 50 ml/L and undiluted) of EE fruit juice for 72 h and tap water (pH 7.3) was used as a control. The results showed significant dose-dependent (P < 0.05) inhibition of root growth and mitodepressive effects on cell division in A. cepa root tip cells after the EE fruit juice treatments. Also, EE fruit juice significantly increased the dose-dependent frequency of chromosome aberrations (breaks, stickiness and pole deviations) in root tip cells and micronucleus formations. There was no dividing cell in the undiluted EE fruit juice treated group, but there were pyknotic/apoptotic cells with varying frequency.

Mitochondrial oxidative stress elicits chromosomal instability after exposure to isocyanates in human kidney epithelial cells

The role of oxidative stress is often attributed in environmental renal diseases. Isocyanates, a ubiquitous chemical group with diverse industrial applications, are known to undergo bio-transformation reactions upon accidental and occupational exposure. This study delineates the role of isocyanate-mediated mitochondrial oxidative stress in eliciting chromosomal instability in cultured human kidney epithelial cells. Cells treated with 0.005 µM concentration of methyl isocyanate displayed morphological transformation and stress-induced senescence. Along the time course, an increase in DCF fluorescence indicative of oxidative stress, depletion of superoxide dismutase (SOD) and glutathione reductase (GR) and consistent accumulation of 8-oxo-dG were noticed. Thus, endogenous oxidative stress resulted in aberrant expression of p53, p21, cyclin E and CDK2 proteins, suggestive of deregulated cell cycle, chromosomal aberrations, centromeric amplification, aneuploidy and genomic instability.

Adverse reactions to cosmetics and methods of testing

Untoward reactions to cosmetics, toiletries, and topical applications are the commonest single reason for hospital referrals with allergic contact dermatitis. In most cases, these are only mild or transient and most reactions being irritant rather than allergic in nature. Various adverse effects may occur in the form of acute toxicity, percutaneous absorption, skin irritation, eye irritation, skin sensitization and photosensitization, subchronic toxicity, mutagenicity/genotoxicity, and phototoxicity/photoirritation. The safety assessment of a cosmetic product clearly depends upon how it is used, since it determines the amount of substance which may be ingested, inhaled, or absorbed through the skin or mucous membranes. Concentration of ingredients used in the different products is also important. Various test procedures include in vivo animal models and in vitro models, such as open or closed patch test, in vivo skin irritation test, skin corrosivity potential tests (rat skin transcutaneous electrical resistance test, Episkin test), eye irritation tests (in vivo eye irritancy test and Draize eye irritancy test), mutagenicity/genotoxicity tests (in vitro bacterial reverse mutation test and in vitro mammalian cell chromosome aberration test), and phototoxicity/photoirritation test (3T3 neutral red uptake phototoxicity test). Finished cosmetic products are usually tested in small populations to confirm the skin and mucous membrane compatibility, and to assess their cosmetic acceptability.

Retinyl palmitate is non-genotoxic in Chinese hamster ovary cells in the dark or after pre-irradiation or simultaneous irradiation with UV light

Retinyl palmitate (RP), an ingredient of cosmetic and medical skin-care preparations, has been reported to be photo-genotoxic/photo-clastogenic in mouse lymphoma cells ( Tk locus) as well as in human Jurkat T-cells, as measured by use of the comet assay. Given that these results were obtained under exploratory conditions, we re-investigated the photo-genotoxicity of RP following a protocol consistent with current recommendations for photo-genotoxicity testing of drugs and chemicals. We tested RP in Chinese hamster ovary (CHO) cells in the dark (standard chromosome aberration test), under pre-irradiation (UVA irradiation of cells and subsequent treatment with RP) or simultaneous irradiation (irradiation of cells and RP together, standard photo-genotoxicity protocol) conditions. UVA irradiation was applied at 350 and 700 mJ/cm 2 with the high UV dose targeted to produce a small increase in the incidence of structural chromosome aberrations (CA) in cells not treated with RP. RP was tested up to and above its limit of solubility in the culture medium (20–40 μg/mL). There was no overt cytotoxicity under dark or different irradiation conditions. Treatment of cells with RP in the dark, as well as treatment under pre- or simultaneous irradiation conditions failed to produce biologically significant increases in the incidence of CA, whereas the positive control substances 4-nitroquinolone and 8-methoxypsoralene produced significantly positive effects in the dark or under simultaneous irradiation, respectively. Overall, our results failed to confirm the reported positive photo-genotoxic effects, and suggest that they may have been due to the test conditions, i.e. high irradiation doses, high cytotoxicity or re-irradiation of photo-products. In conclusion, our data suggest that, under standard conditions for testing photo-genotoxicity, RP had no in vitro genotoxic or photo-genotoxic potential and is therefore unlikely to pose a local or systemic genotoxic or photo-genotoxic risk.

Automated four-color interphase fluorescence in situ hybridization approach for the simultaneous detection of specific aneuploidies of diagnostic and prognostic significance in high hyperdiploid acute lymphoblastic leukemia

In high hyperdiploid acute lymphoblastic leukemia (ALL), the concurrence of specific trisomies confers a more favorable outcome than hyperdiploidy alone. Interphase fluorescence in situ hybridization (FISH) complements conventional cytogenetics (CC) through its sensitivity and ability to detect chromosome aberrations in nondividing cells. To overcome the limits of manual I-FISH, we developed an automated four-color I-FISH approach and assessed its ability to detect concurrent aneuploidies in ALL. I-FISH was performed using centromeric probes for chromosomes 4, 6, 10, and 17. Parameters established for nucleus selection and signal detection were evaluated. Cutoff values were determined. Combinations of aneuploidies were considered relevant when each aneuploidy was individually significant. Results obtained in 10 patient samples were compared with those obtained with CC. Various combinations of aneuploidies were identified. All clones detected by CC were observed also by I-FISH, and I-FISH revealed numerous additional abnormal clones in all patients, ranging from ≤1% to 31.6% of cells analyzed. We conclude that four-color automated I-FISH permits the identification of concurrent aneuploidies of potential prognostic significance. Large numbers of cells can be analyzed rapidly. The large number of nuclei scored revealed a high level of chromosome variability both at diagnosis and relapse, the prognostic significance of which is of considerable clinical interest and merits further evaluation.

Genotoxic studies in hypertensive and normotensive rats treated with amiodarone

Amiodarone, a benzofuran derivative, is a very effective antiarrhythmic medication, but has potential to cause side effects. Although its cytotoxicity potential is very well-known, there are few reports about its genotoxicity effects. Since amiodarone has not been investigated in genotoxicity studies, and the spontaneously hypertensive rat (SHR) is a well-characterized model for hypertension, the aim of the present study was to perform cytogenetic analysis on chromosome aberrations in bone marrow cells of SHRs and normotensive Wistar-Kyoto rats (WKYs) that received oral amiodarone treatment for 4 weeks. Amiodarone activity was also monitored using electrocardiograms. The presence of bradycardia in amiodarone-treated rats confirmed that this drug was really active. Metaphase analysis on bone marrow cells showed that there were significant differences in total chromosomal damage and percentage abnormal metaphase between WKY and SHR negative controls. In the SHR negative control, the frequencies of basal chromosomal aberrations and abnormal metaphases were significantly higher ( p < 0.05). There were high numbers of chromosomal aberrations in all amiodarone-treated groups, compared with negative controls. In amiodarone-treated groups, the most frequent chromosomal aberration was chromatid breaks. More chromosomal aberrations were found in WKYs that received amiodarone, with a statistically significant difference in comparison with negative controls ( p < 0.05). However, in SHR rats there was no significant difference between the amiodarone and negative groups regarding chromosomal damage induction. These results showed that treatment with amiodarone was genotoxic in WKYs, but not in SHRs. Further studies are needed to confirm whether amiodarone is genotoxic or efficient and harmless, among humans undergoing therapy.

Genotoxic potential of cyfluthrin

Cyfluthrin (CAS no. 68359-37-5), a synthetic fluorinated pyrethroid insecticide, is widely used in the home environment and in agriculture because of its high activity against a broad spectrum of insect pests and its low animal toxicity. There are no adequate data on genotoxic effects of cyfluthrin. The aim of this study was to analyze the potential genotoxic effects of cyfluthrin. The genotoxicity of cyfluthrin was evaluated, in vitro, by assessing the ability of the insecticide to induce gene mutation (evaluated using the Ames/microsome test), chromosomal aberrations (CA), sister chromatid exchange (SCE) and micronucleus (MN) formation in cultured human peripheral blood lymphocytes. Additionally, CAs and cytotoxicity induced by cyfluthrin were investigated in rat ( Rattus norvegicus var. Albinos) bone-marrow cells to assess in vivo genotoxicity of cyfluthrin. The counts of reverse mutations in Salmonella typhimurium were not significantly increased ( P > 0.05). The frequency of CAs in human lymphocytes, treated with any concentration of cyfluthrin (500, 1000 or 2000 μg/ml) for a 24-h period, was not significantly increased ( P > 0.05). In contrast, CA was significantly increased for the highest two concentrations (1000 and 2000 μg/ml) in the 48-h treatment group compared with the control group (dimethyl sulfoxide, DMSO). Micronucleus formation was significantly ( P < 0.05) increased for all doses after the 48-h treatment, although the frequency of SCE did not increase significantly ( P > 0.05). Mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) decreased significantly ( P < 0.05) due to the potential cytotoxicity of cyfluthrin, especially after the 48-h treatment period. The frequency of chromosome aberrations in bone-marrow cells of rats treated with the test substance increased significantly ( P < 0.05) for all doses (250, 500 and 1000 mg/kg body weight) for the two treatment periods (12 and 24 h) and the two administration routes, viz. intraperitoneal injection (i.p.) and oral gavage (gvg). In vivo cytotoxicity of cyfluthrin was detected only after administration by gavage for the 24-h treatment period. All these findings were not dose-dependent.

Chromosome aberrations as indicator of technogenic impact on conifer stands

The level of chromosome aberrations at different stages of mitosis has been studied in the seed sprout meristem of four conifer species growing in the Southern Urals in areas differing in the kind and degree of industrial pollution. The results provide evidence for the adverse effect of pollution on the chromosomal machinery of these species. With respect to environmental quality assessment, the Scots pine is the most sensitive indicator species among conifers growing in the Southern Urals and analysis of chromosome aberrations in anaphase-telophase cells is most effective among the cytogenetic methods tested.

Individual and combined effects of ochratoxin A and citrinin on viability and DNA fragmentation in cultured Vero cells and on chromosome aberrations in mice bone marrow cells

Ochratoxin A (OTA) and citrinin (CTN) are two common contaminant mycotoxins which can occur jointly in a wide range of food commodities. Both mycotoxins have several toxic effects but share a significant nephrotoxic and carcinogenic potential since OTA and CTN were reported to be responsible for naturally occurring human and animal kidney diseases and tumors. Considering the concomitant production of OTA and CTN, it is very likely that humans and animals are always exposed to the mixture rather than to individual compounds. Therefore, the aim of the present study was to investigate, in vivo and in vitro, whether DNA damage is enhanced by combination of both mycotoxins as compared to their effect separately. To this end, we have assessed their effects individually or combined on cell proliferation and DNA fragmentation in cultured Vero cells and in vivo by monitoring the induction of chromosome aberrations. Our results clearly showed that cultured renal cells respond to OTA and CTN exposure by a moderate and weak inhibition of cell proliferation, respectively. However, when combined, they exert a significant increase in inhibition of cell viability. Similar results were found for the investigated genotoxicity endpoints (DNA fragmentation and chromosome aberrations). Altogether, our study showed that OTA and CTN combination effects are clearly synergistic. The synergistic induction of DNA damage observed with OTA and CTN taken concomitantly could be relevant to explain the molecular basis of the renal diseases and tumorogenesis induced by naturally occurring mycotoxins.

Cell survival and chromosomal aberrations in CHO-K1 cells irradiated by carbon ions

Chinese hamster ovary CHO-K1 cells were exposed to high LET 12C-beam (LET: 830 keV/μm) in the dose range of 0–6 Gy and to 60Co irradiation and the RBE value was obtained. Effects of 12C-beam exposure on cell survival and chromosomal aberrations were calculated. The chromosomal aberration data were fitted with linear equation. The distribution of aberration in cells was examined with a standard u-test and used to evaluate the data according to Poisson probabilities. The variance to the mean ratio σ 2/ Y and the dispersion index ( u) were determined. Overdispersion was significant ( p<0.05) when the value of u exceeded 1.96.

Resveratrol Reduces Radiation-Induced Chromosome Aberration Frequencies in Mouse Bone Marrow Cells

Resveratrol, a polyphenol compound with reported antioxidant and anticarcinogenic effects, a wide range of molecular targets, and toxicity only at extreme doses, has received considerable attention. We evaluated the radioprotective effect of orally administered resveratrol on the frequencies of chromosome aberrations in irradiated mouse bone marrow cells. CBA/CaJ mice were divided into four groups: (1) no treatment, (2) resveratrol only, (3) radiation only, and (4) resveratrol and radiation. Resveratrol treatment (100 mg/kg daily) was initiated 2 days prior to irradiation. Bone marrow was then harvested at 1 and 30 days after a single dose of 3 Gy whole-body gamma radiation. A statistically significant (P < 0.05) reduction in the mean total chromosome aberration frequency per metaphase at both times postirradiation in the resveratrol and radiation group compared to the radiation-only group was observed. This study is the first to demonstrate that resveratrol has radioprotective effects in vivo. These results support the use of resveratrol as a radioprotector with the potential for widespread application.

Chromosome aberrations and telomere length modulation in bone marrow and spleen cells of melphalan‐treated p53+/− mice

The p53 gene regulates cell cycle and apoptotic pathways after induction of DNA damage. Telomeres, capping chromosome ends, are involved in maintaining chromosome stability; alterations of their length have been related to increased levels of chromosomal aberrations. To study a possible interaction between chromosome aberrations, telomere dysfunction, and p53, we investigated via painting analysis the induction and persistence of chromosome aberrations in bone marrow and spleen cells of p53+/- (and wild type) mice exposed for 4, 13, or 26 weeks to 2 mg/kg melphalan (MLP), a chemotherapeutic agent with carcinogenic potential. In addition, telomere length was evaluated in bone marrow cells by quantitative fluorescence in situ hybridization (Q-FISH). Chromosome aberrations were significantly increased in both tissues after MLP treatment. The p53 genotype did not influence the response of spleen cells, whereas a slight but significant increase of the aberration frequency was measured in the bone marrow of p53+/- mice exposed to MLP for 13 weeks with respect to the level detected in the matched wild-type group. The main finding of our still preliminary results on telomere length modulation was again a difference between the two genotypes. In bone marrow cells of wild-type mice, MLP treatment was associated with telomere shortening, while in p53+/- mice telomere elongation was the prevalent response to MLP exposure. In agreement with previous literature data, our in vivo study suggests that even the lack of a single functional copy of the p53 gene might have an impact on the quantity and quality of chromosome alterations induced in cycling cells by a clastogenic exposure.

Acute and subchronic toxicity and genotoxicity of SE5-OH, an equol-rich product produced by Lactococcus garvieae

The consumption of soy-based products is associated with a number of health benefits and much of these benefits are proposed to be due to the soy isoflavones daidzein, genistein, glycitein, their glycosides, and equol, an isoflavone naturally produced from daidzein. Equol is a naturally bacterially-derived metabolite of daidzein and is produced by bacteria in the gut of those humans capable of hosting the particular organism. To allow all humans to enjoy the health benefits of equol, a new functional food ingredient has been developed that relies on bacterial conversion of daidzein to equol under strictly controlled conditions. This new food substance, termed SE5-OH, has been studied extensively for its acute and subchronic toxicity in Sprague–Dawley rats, as well as for its potential genotoxicity. The oral LD 50 is >4000 mg/kg. In a 91-day, subchronic study, the no-observed-adverse-effect-level (NOAEL) was 2000 mg/kg/day, the highest dose tested. SE5-OH was negative in Salmonella typhimurium tester strains TA98, TA100, TA1535 and TA1537 and in Escherichia coli tester strain WP2 uvrA with and without metabolic activation. SE5-OH was negative for chromosome aberrations in Chinese hamster lung cells up to 3000 μg/ml with and without metabolic activation and did not induce increases in micronucleated polychromatic erythrocytes taken from Sprague–Dawley rats administered ( via gavage) up to 4000 mg/kg SE5-OH twice daily for two consecutive days.