Abstract
The aim of this study was to investigate if irradiation with X-rays in different cell cycle phases resulted in a different response as measured with the micronucleus technique. In addition, the influence of irradiation temperature was investigated. Materials and Methods: Cells from a non-transformed human fibroblast cell line, HS2429, and a human breast cancer cell line, MCF-7, were synchronized by thymidine block and irradiated at either 2°C or 37°C in the G1-, S- and G2/M-phases. After cytokinesis-block by cytochalasin B, the frequency of micronuclei was determined. Results: Clear dose-response relationships were found. More micronuclei were detected in fibroblast cells irradiated in G1 and S than in G2/M, while the differences were not as prominent in MCF-7 cells. The irradiation temperature had no significant influence on the formation of micronuclei in either of the cell lines. Conclusion: The formation of micronuclei varies with the cell cycle stage at the time of irradiation.
Footnotes
- Received November 9, 2006.
- Revision received January 12, 2007.
- Accepted January 31, 2007.
- Copyright© 2007 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved