Detection of DNA damages and repair in human culture cells with simulated space radiation

DNA damages and its repair of cultured WI38 human fibroblast cells and T98G human glioblastoma cells were studied by exposing to carbon ion beams of H IMAC accelerator. The exposed cells were incubated at 37 degrees C for appr opriate intervals and the damages were analyzed by alkaline comet assay and quantitative RT-PCR with p53 mRNA. Highly inhomogeneous DNA damages were o bserved among the electrophoretic cell images of the comet assay. The degre e of the damages was analyzed semi-quantitatively by using the Comet Index. The damaged fraction of W138 cells was 85% immediately after 4 Gy (100 keV /mu m) irradiation and decreased to 50% after 120 min. incubation indicatin g a repair of cell DNA Time dependent p53 gene expression was also analyzed by the quantitative RT-PCR method. (C) 1998 International Astronautical Fe deration Published by Elsevier Science Ltd. AII rights reserved.