Application of cytogenetic endpoints and Comet assay on human lymphocytes treated with vincristine in vitro.
ABSTRACT The genotoxic potential of vincristine is assessed on human peripheral blood lymphocytes following administration of the drug at a dose 0.0875 microg/ml by use of single cell gel electrophoresis - Comet assay (SCGE), analysis of structural chromosome aberrations (CA), micronucleus assay (MN) and sister chromatid exchange (SCE) analysis. In vitro treatment of human lymphocytes with vincristine was performed on cells in G0 phase, as well on lymphocyte cultures 24 hours after stimulation with mitogen phytohemagglutinine. For the Comet assay at 24, 48 and 72 h the treated cells were embedded in agarose on slides, lysed with alkaline lysis solution and exposed to an electric field. DNA migrated within the agarose and formed comets whose length depends on the amount of DNA damage. For the analysis of structural CA cells were grown on F-10 medium for 48 hours, and for MN and SCE analysis for 72 hours. The results on SCGE showed an increase in tail length compared to control both in cells treated in G0 and in cells treated 24 h after mitogen stimulation. The amount of DNA damage was higher in cells treated with vincristine 24 h after mitogen stimulation. Administered concentration of drug caused total inhibition of lymphocytes growth in 72-h cultures for MN and SCE analysis indicating strong microtubule distruptive effects of vincristine. Analysis of structural CA reveals chromatid breaks and acentric fragments as the main aberration types both in cells treated in G0 and in cells treated 24 h after mitogen stimulation. Number of these aberrations was higher in cells treated in G0 phase. Results obtained in this study by use of different cytogenetic endpoints confirmed that vincristine exhibits both aneugenic and clastogenic effects on human lymphocytes.
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ABSTRACT: The alkaline comet assay was employed to assess the pre- and post-treatment levels of in vivo DNA damage in peripheral blood leukocytes of cancer patients. During the study all patients were given antineoplastic drugs, mainly as polychemotherapy. To quantify the DNA damage, two different comet parameters were evaluated: the tail length and the tail moment. Our results indicate marked interindividual variations between baseline DNA damage in peripheral blood leukocytes recorded among cancer patients prior to the chemotherapy. After intravenous administration of various antineoplastic drugs, a significantly increased level of DNA damage in all cancer patients compared to their pre-treatment values was recorded The highest level of DNA damage was seen following administration of 5-fluorouracil, adriamycin, and cisplatin (FAP protocol). The results indicate that administration of antineoplastic drugs in standard protocols is accompanied by significant DNA damage in peripheral blood leukocytes. In order to diminish the potential risks of developing second neoplasms, a continuous biomonitoring of cancer patients after the ending of chemotherapy becomes important. Despite their limitations, present results confirm the usefulness of the alkaline comet assay as a sensitive biomarker of exposure that enables rapid and simple detection of primary DNA damage in peripheral blood leukocytes of cancer patients. Together with standard cytogenetic endpoints, the comet assay provides a powerful technique for the routine detection of critical DNA lesions produced after administration of antineoplastic drugs in the clinical settings.Teratogenesis Carcinogenesis and Mutagenesis 02/2002; 22(1):13-30.
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ABSTRACT: Several studies have reported radioprotective, antimutagenic, anti-inflammatory, antinociceptive, and anticancer effects of bee venom both in the cell and the whole organism. The aim of this study was to assess the effects of a single high dose of 100 microg mL(-1) of whole bee venom in human lymphocytes in vitro over a variety of time spans (from 10 min to 24 h). After the treatment, we used the comet assay and micronucleus test to see the effect of bee venom on the cell. The comet assay confirmed that the venom damaged the DNA molecule. Tail length, tail intensity, tail moment showed a significant increase (P < 0.05). The percentage of long-tailed nuclei (LTN) with the tail length exceeding the 95th percentile also increased in a time-dependent manner. The micronucleus parameters (number of micronuclei, nucleoplasmic bridges, and nuclear buds) also showed a significant time-dependent increase (P < 0.05). This research indicates that high concentrations of bee venom can lead to cellular instability. Further research is needed to understand the mechanism of action of bee venom and its components in human cells and to see if this natural product may find application in medicine.Archives of Industrial Hygiene and Toxicology 04/2009; 60(1):27-34. · 0.67 Impact Factor