Contribution of apoptosis to responses in the comet assay
| Autor: | Beatrice-L Pool-Zobel, Gerhard Rechkemmer, Silvia Roser |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Methylnitronitrosoguanidine
Cell Survival DNA damage Health Toxicology and Mutagenesis Apoptosis DNA Fragmentation Biology medicine.disease_cause chemistry.chemical_compound Annexin Tumor Cells Cultured Genetics medicine Humans Staurosporine Chromosome Breakage Hydrogen Peroxide Phosphatidylserine Molecular biology Comet assay chemistry DNA fragmentation Comet Assay Genotoxicity DNA Damage Mutagens medicine.drug |
| Zdroj: | Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 497:169-175 |
| ISSN: | 1383-5718 |
| Popis: | Apoptosis, a physiological process of selected cell deletion, leads to DNA fragmentation in typical segments of 180 base pairs. DNA strand breaks are also an effect induced by genotoxic compounds. The aim of this study was to compare these two types of damaging potentials by a known genotoxic substance and an apoptosis-inducing agent in HT-29 colon adenocarcinoma cells. The cells were incubated for 24 h with N -methyl- N ′-nitro- N -nitrosoguanidin (MNNG), a potent DNA damage-inducing agent, staurosporine, an inhibitor of proteine kinase C and apoptosis-inducing agent, and hydrogen peroxide, a source of reactive oxygen species. Apoptosis was measured with the Annexin V affinity assay which detects the translocation of phosphatidylserine (PS) from the inner to the outer leaflet of the cytoplasmic membrane, an early event in the apoptotic process. DNA damage as an end point of genotoxicity was detected by single cell microgel electrophoresis, also called “comet assay”. The results show that apoptosis does not necessarily need to correlate or coincide with DNA damage observed with genotoxic substances in the comet assay. The representative apoptosis-inducing agent (staurosporine) did not induce strand breaks in the tested concentrations (0.5 and 1.0 μM); genotoxic doses of the strand break inducing agent MNNG did not induce apoptosis. Therefore, the comet assay can be used as a specific test for detecting genotoxicity, and the results are not necessarily confounded by concomittant processes leading to apoptosis. |
| Databáze: | OpenAIRE |
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