Abstract
One of the unique biological effects caused by ionizing radiation is the persistent occurrence of pleiotypic endopoints, including mutagenesis, chromosomal aberration and cancer predisposition. To search factors associated with the persistent property, the behavior of DNA binding proteins as possible candidates were assessed in human cells, which had overcome DNA disorders and restored proliferous status. Interestingly, we found that irradiation to cells introduces inheritable changes into a higher order protein-DNA interaction, which is accompanied by DNA-dependent protein kinase components, DNA-PKcs and Ku heterodimer. Notably, this response maintained over several decades of cellular generation without quantitative changes of the factors. The altered state of the protein-DNA interaction may heritably affect somewhat nuclear processes linked to DNA organization, resulting in the persistent degradation of genetic integrity.
