Chromatin- and temperature-dependent modulation of radiation-induced double-strand breaks
2003 (English)In: International Journal of Radiation Biology, ISSN 0955-3002, E-ISSN 1362-3095, Vol. 79, no 10, 809-816 p.Article in journal (Refereed) Published
Purpose: To investigate the influence of chromatin organization and scavenging capacity in relation to irradiation temperature on the induction of double-strand breaks (DSB) in structures derived from human diploid fibroblasts. Materials and methods: Agarose plugs with different chromatin structures (intact cells±wortmannin, permeabilized cells with condensed chromatin, nucleoids and DNA) were prepared and irradiated with X-rays at 2 or 37°C and lysed using two different lysis protocols (new ice-cold lysis or standard lysis at 37°C). Induction of DSB was determined by constant-field gel electrophoresis. Results: The dose-modifying factor (DMFtemp) for irradiation at 37 compared with 2°C was 0.92 in intact cells (i.e. more DSB induced at 2°C), but gradually increased to 1.5 in permeabilized cells, 2.2 in nucleoids and 2.6 in naked DNA, suggesting a role of chromatin organization for temperature modulation of DNA damage. In addition, DMFtemp was influenced by the presence of 0.1 M DMSO or 30 mM glutathione, but not by post-irradiation temperature. Conclusion: The protective effect of low temperature was correlated to the indirect effects of ionizing radiation and was not dependent on post-irradiation temperature. Reasons for a dose modifying factor <1 in intact cells are discussed.
Place, publisher, year, edition, pages
2003. Vol. 79, no 10, 809-816 p.
dimethyl sulfoxide, glutathione, naked DNA, wortmannin, article, chromatin, controlled study, correlation analysis, diploidy, DNA damage, DNA strand breakage, fibroblast, gel electrophoresis, human, human cell, lysis, priority journal, radiation exposure, regulatory mechanism, temperature dependence, X ray, Androstadienes, Cell Line, Cryopreservation, DNA, Dose-Response Relationship, Radiation, Fibroblasts, Humans, Radiation Dosage, Radiation Protection, Relative Biological Effectiveness, Temperature
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:sh:diva-23267DOI: 10.1080/09553000310001610204ISI: 000186683400006PubMedID: 14630540ScopusID: 2-s2.0-0344553303OAI: oai:DiVA.org:sh-23267DiVA: diva2:713643