Cytogenetic effects of chloroquine in human lymphocyte cultures

Addition of chloroquine to a culture of human lymphocytes at the G₁ stage showed that the compound, in a concentration of 15 g/ml, does not affect the level of chromosomal aberrations, but in concentrations of 60 and 100 g/ml it suppresses mitotic activity of the cells virtually completely. By its actions of the G₂ stage chloroquine, in a concentration of 100 g/ml, significantly increases the number of chromosomal aberrations, but in a concentration of 15 g/ml it has no appreciable action.Presented by Academician N. P. Dubinin.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 879–881 (1976).     

Chromosomal aberrations in embryonic liver and bone marrow cells of A/He and C57BL/6 mice induced by thiotepa

Chromosomal aberrations in the first mitosis of embryonic liver and bone marrow cells were studied in A/He and C57Bl/6 mice after injection of the alkylating agent thioTEPA in the g₁-S period of the cell cycle. Chromosomes of A/He mice were shown to be more sensitive to the mutagenic action of the compound.Laboratory of Experimental Genetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. P. Bochkov.) Translated from Byulleten Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 10, pp. 458–460, October, 1979.     

DNA damage and cytotoxcity induced in mammalian cells by a tetramethylfuroquinolinone derivative

1,4,6,8-Tetramethyl-2H-furo[2,3-h]quinolin-2-one (FQ) is an angelicin isoster characterized by a strong photosensitizing activity. FQ shows a significant antiproliferative activity also in the dark, i.e., without UVA activation. The cytotoxic activity of FQ in the dark was detected in HeLa cells and in normal human lymphocytes; FQ showed notable antiproliferative effects, barely lower in comparison with ellipticine, used as a reference. Similar results were obtained studying the FQ's capacity for forming chromosome aberrations. For both FQ and ellipticine, the chromosomal damage correlated closely with cell killing; when compared with ellipticine at the same levels of survival, FQ appeared to be muchless genotoxic. Using alkaline elution we have investigated the ability of FQ to damage DNA. The formation of equivalent amounts of single-strand breaks (SSB) and DNA-protein cross-links (DPC) was observed; in addition, these lesions appeared to be located at the same sites in DNA. Experiments carried out with neutral elution demonstrated the formation of double-strand breaks (DSB). All these data are consistent with an inhibition of topoisomerase II; this hypothesis was confirmed performing an enzymatic test in vitro using topoisomerase II from Drosophila melanogaster embryos. Environ. Mol. Mutagen. 29:256-264, 1997 © 1997 Wiley-Liss, Inc.     

Etoposide (VP-16): Cytogenetic studies in mice

Etoposide (VP 16-213), the epipodophyllotoxin derivative that is widely used in the treatment of cancer, forms complexes with DNA-topoisomerase type llα to exert its cytotoxicity. The drug was evaluated in vivo in Swiss albino mouse bone marrow cells for its ability to induce clastogenicity and sister chromatid exchanges (SCEs). Doses of 5, 10, 15, and 20 mg/kg body weight etoposide given intraperitoneally induced a dose-dependent significant increase of clastogenicity (Trend test, α ≦ 0.05). The aberrations induced were predominanty chromatid types. The drug shows specificity for S-phase cells: cells harvested 6 and 12 hr posttreatment showed a significantly increased number of damaged cells and aberrations per cell. Doses of 0.5, 1.0, 2.5, 5.0, and 10.0 mg etoposide/kg body weight induced a dose-dependent significant induction of SCEs (Trend test, α ≦ 0.05). The minimal effective concentration was 0.5 mg/kg body weight. Etoposide significantly prolonged the cell cycle time at all concentrations tested: 12-13 hr in treated animals vs. 11 hr in control. The results confirm in vivo cell cycle phase specificity of the drug and further designate etoposide as a potent clastogen and a genotoxic agent in mice. © 1994 Wiley-Liss, Inc.     

Cytogenetic effects of phosphine inhalation by rodents. I: Acute 6-hour exposure of mice

Phosphine (PH₃) is a highly toxic grain fumigant that can be produced from the reaction of metal phosphides with water. To determine the in vivo cytogenetic effects of inhalation of PH₃, male CD-1 mice were exposed to either 0, 5, 10, or 15 ppm target concentrations of PH₃ for 6 hr. Twenty hours after the termination of exposure, the spleens of the mice were removed, macerated, and the splenocytes cultured for analyses of sister chromatid exchanges, chromosome aberrations, and micronuclei in cytochalasin B-in-duced binucleated cells. In addition, bone marrow smears were made for the analysis of micronuclei in polychromatic erythrocytes. No increase in any of the cytogenetic endpoints was found at any of the concentrations examined. The only statistically significant response was a concentration-related slowing of the cell cycle in the splenocytes. © 1994 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Types of chromosomal aberrations induced by seed aging in crepis capillaris

The types of chromosomal aberrations during the aging of Crepis capillaris (Hawksbeard; fam. Asteraceae) seeds were investigated. Seeds were stored at 22°C for 2, 4, 6, and 8 years. Chromosomal aberrations were analyzed in metaphase chromosomes at the first and second mitotic cycles. A colchicine block was used for the differentiation of individual mitotic cycles. The frequency of chromosomal aberrations induced during seed aging gradually increased with the increase in the time of aging, reaching its maximal value after 8 years of aging. Both chromatid and chromosome types of aberrations were observed in first mitosis. At all times of aging, the frequency of chromosome-type aberrations considerably surpassed the frequency of the chromatid type. At the different times of aging, the frequency of chromosome-type aberrations was 3–4.5 times higher than that of chromatid-type aberrations. In the second mitosis, the frequency of both aberration types was low. The frequency and type of derived chromosomal aberrations observed in second mitosis corresponded to those observed in first mitosis. These results are discussed in relation to the factors inducing chromosome lesions during seed aging and the mechanism of formation of chromosomal aberrations. © 1994 Wiley-Liss, Inc.     

Specificity of arsenite in potentiating cytogenetic damage induced by the DNA crosslinking agent diepoxybutane.

In the present study, the induction of sister chromatid exchanges (SCEs) and chromosomal aberrations were measured in normal human lymphocytes treated with low concentrations of arsenite alone (0.5-2.0 microM) and arsenite in combination with the potent DNA crosslinking agent diepoxybutane (DEB). Experiments were carried out with lymphocytes from blood donors with different sensitivities to SCE induction by DEB. Arsenite, beginning at concentrations as low as 1 microM, increased SCE frequencies; chromosomal aberration frequencies were increased at 2 microM of arsenite. DEB treatments alone increased SCE frequencies and chromosomal aberrations. The yields of chromatid deletions and exchanges in lymphocytes exposed to both arsenite and DEB were markedly increased above the levels expected if the effects of the two agents had been simply additive. The frequencies of chromatid deletions were 4- to 8-fold greater than expected and chromatid exchanges were increased 7- to 40-fold. Chromatid exchanges detected in cells treated with arsenite and DEB were predominately incomplete exchanges. The most dramatic increases in chromatid aberrations were observed in lymphocytes from an individual sensitive to SCE induction by DEB, indicating that individuals may vary in their sensitivity to the co-clastogenic effects of arsenite. At concentrations that dramatically affect aberrations, arsenite had no effect on the induction of SCEs by DEB. These studies suggest a specific interaction of arsenite with the induction or repair of DNA damage produced by DEB that leads to chromosomal aberrations but not to SCEs. Based on the selective chemical reactivity of low concentrations of arsenite with proteins containing vicinal dithiols and the occurrence of these groups within DNA repair proteins, it is proposed that the specific co-clastogenic effects of arsenite may be mediated by its interference with DNA repair activities.     

Assessment of the contribution of thiophosphamide-induced chromosomal aberrations to preimplantation embryonic mortality in mice

A cytological analysis was made of thio-TEPA-induced preimplantation embryonic mortality in mice and the contribution of induced chromosomal aberrations was examined. Under the influence of thio-TEPA in a dose of 1.25 mg/kg cleavage was arrested in late spermatids in 27% of cases at the 2–16-cell stage and in 11.9% at the 17–22-cell stage, making a total of 38.9% compared with 6% in the control. Cytogenetic analysis of embryos consisting of 2–16 cells revealed gross structural chromosomal aberrations in 75% of metaphases suitable for analysis.Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. P. Bochkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 9, pp. 353–355, September, 1979.     

Cytogenetic effects of shale-derived oils in murine bone marrow

The cytogenetic effects of exposure of mice to shale-derived oils by either skin painting or intraperitoneal injection were examined. Skin painting with 40 mg crude oil every other day for five weeks had no effect on the frequency of chromosomal aberrations observed in the bone marrow. Three daily intraperitoneal injections of 0.5–2.0 ml/kg per day of a crude shale oil from an aboveground retort induced a dose-related increase in the frequency of aberrations observed. A hydrotreated sample of this oil produced a similar pattern of aberration induction, but at lower frequencies. Crude shale oil from a modified in situ retort induced the highest frequency of chromosomal aberrations at the 0.5 ml/kg dose; lower frequencies were induced at the 1.0 ml and 2.0 ml/kg doses. Of the three shale oils tested, only the crude oil from the aboveground retort induced increased frequencies of sister chromatid exchanges and only at doses that also induced structural aberrations. These studies indicate that structural aberration analysis is a more sensitive test than sister chromatid exchange analysis for the type of DNA damage induced by shale-derived oils in murine bone marrow cells.     

Interstitial telomeric sequences are not preferentially involved in the chromosome damage induced by the methylating compound streptozotocin in chinese hamster cells

The effect of the methylating compound streptozotocin (STZ) on interstitial telomeric sequences (ITSs) was investigated in Chinese hamster ovary (CHO) cells by using peptide nucleic acid‐fluorescence in situ hybridization with a pantelomeric probe. Cells were exposed to increasing concentrations of STZ, and chromosomal aberrations were analyzed at the first mitosis after treatment. The frequency of chromosomal aberrations directly involving ITSs increased in STZ‐treated cells by a factor of 2.6 (2 mM) and 3.6 (4 mM) when compared with the frequency of these aberrations in control cells (P < 0.05). However, no significant differences were found between control and exposed cells in the percentage of aberrations directly involving ITSs, demonstrating that these repeat regions were not preferentially involved in the chromosome damage induced by STZ. In addition, STZ did not alter telomerase activity, suggesting that this enzyme may not be involved in the induction of chromosomal aberrations by this compound. Environ. Mol. Mutagen., 2013. © 2012 Wiley Periodicals, Inc.     

Induction of latent liver damage by cyclophosphamide

Department of General Biology, P. J. afarik University, Koice, Czechoslovakia. (Presented by Academician of the Academy of Medical Sciences of the USSR, D. S. Sarkisov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 107, No. 6, pp. 756–758, June, 1989.     

Quantitative estimation of chromosome aberration frequency in cancer patients induced by endogenous and exogenous factors

In patients with skin melanoma and colon cancer, cell distribution by the number of chromosome aberrations cannot be described by Poisson distribution, but corresponds to a bipopulation model combining the Poisson and geometric distributions. In contrast to the control, in patients with malignant tumors, cells with geometric distribution possess the majority of chromosomal aberrations.     

Acrylamide: Induction of heritable translocations in male mice

Acrylamide (AA), known to induce dominant lethals in male rodents, was studied in the mouse heritable translocation test by using intraperitoneal injections on 5 consecutive days. Matings on days 7-10 following the last injection yielded a high frequency of translocation carriers in the F₁ male population, which demonstrated that acrylamide is an effective inducer of translocations in postmeiotic germ cells. As an inducer of both dominant lethals and heritable translocations in late spermatids and early spermatozoa, AA is similar to alkylating agents such as ethylmethanesulfonate and ethylene oxide. However, AA′s chemical structure, the nature of adducts formed with DNA, and its lack of mutagenicity in bacteria suggest a different mechanism as the basis for AA′s germ cell mutagenicity.     

Cytogenetic effects of cis-platinum(II)diamminedichloride in vivo

The chemotherapeutic agent cis-platinum(II)diamminedichloride (cis-PDD) has been shown to be mutagenic, teratogenic, and carcinogenic. We determined the cytogenetic effects of cis-PDD on human and rabbit lymphocytes in vitro and on rabbit marrow cells, lymph node cells, and lymphocytes in vivo. Lymphocyte cultures from two humans and one rabbit were treated in vitro with cis-PDD. For in vivo studies, five New Zealand white rabbits were given iv injections of cis-PDD. Posttreatment blood samples were withdrawn for analysis and rabbits were sacrificed at either 6 or 24 hr for cytogenetic analysis of marrow and node cells. Sister chromatid exchange (SCE) analysis of human and rabbit metaphases from lymphocytes treated in vitro showed that rabbit lymphocytes are more sensitive to SCE induction by cis-PDD. Significant increases in SCE were observed in lymphocyte cultures obtained as early as 1 hr post treatment from injected rabbits. Analysis of node, marrow, and lymphocyte metaphases from injected rabbits showed a high number of chromosome aberrations in these cells with bone marrow showing a delayed response to treatment. These results indicate that cis-PDD is clastogenic in hematopoietic tissues in vivo and that SCE methodology may be useful in monitoring patients receiving cis-PDD therapy.     

Determination of genetic damage and urinary metabolites in fuel filling station attendants

Fuel (diesel and petrol) constitutes a complex mixture of volatile flammable liquid hydrocarbons among them benzene (BZ), toluene (TOL), and xylene (XYL) are considered to be the most hazardous, predominantly BZ because of its carcinogenic potency. Exposure to these compounds may have an impact on the health of the exposed subjects. Hence, genotoxicity and quantitative analysis of these compounds was performed in blood and urine samples of 200 workers exposed to fuel in filling stations and compared to controls. The level of genetic damage was determined by micronucleus test (MNT) in buccal epithelial cells (BEC) and chromosomal aberrations (CA) assay in peripheral blood lymphocytes (PBL) of fuel filling station attendants (FFSA) and compared to a matched control group. Urine analysis for BZ and its metabolites, phenol (Ph), trans, trans‐Muconic Acid (t, t‐MA), and S‐Phenyl Mercapturic Acid (S‐PMA) was done in all the study subjects. The results of our study revealed that exposure to BTX in petrol vapors induced a statistically significant increase in the frequency of micronuclei (MN) and CA in the exposed subjects than in controls (P < 0.05). There was a significant rise in the levels of urinary BZ, Ph, t, t‐MA, and S‐PMA in the exposed subjects. Our study highlights the significance of MNT, CA, and urinary metabolites as potential biological exposure indices of genetic damage in FFSA. This study suggests the need for regular monitoring of FFSA for possible exposure to BTX as a precautionary and preventive step to minimize exposure and reduce the associated health risks. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.     

Immunotoxicity induced in mice by subacute exposure to berberine

The immunotoxic effects of the isoquinoline alkaloid berberine (BBR) were investigated in Balb/c mice. Here, BBR was administered daily by intraperitoneal injection at doses of 5 and 10?mg/kg for 14 days. Following the exposure, host spleen weight, cellularity and histopathology, as well as delayed-type hypersensitivity (DTH) responses, hemagglutination titers (HA), spleen cell subtype profiles, splenocyte cytokine production and lymphocyte proliferation were studied in all of the test groups of animals. The results showed that the high dose of BBR (10?mg/kg) could suppress both cellular and humoral immune functions in the treated hosts. BBR at 5?mg/kg only appeared to impact on DTH responses and lymphoproliferation. Based on the finding here, it would seem that BBR has effective immunosuppressive properties. Mechanistic studies are required to determine exactly how this material is acting to impart many of the immunotoxic effects demonstrated here. At the same time, further research should also be performed on BBR to further develop its potential use as an effective immunosuppressant or co-adjuvant for the treatment of diseases caused by an exaggerated or unwanted immune response.