Manifestations and mechanisms of radiation-induced genomic instability in V-79 Chinese hamster cells

Purpose: The relationship between different forms of persistent radiation damage in irradiated cells was investigated in order to identify a common underlying mechanism. Material and methods: V-79 Chinese hamster cells were irradiated with different doses of X-rays, neutrons and a-particles. In the progeny of surviving cells, up to 4 weeks after irradiation, delayed reproductive death, delayed micronuclei, delayed appearance of dicentric chromosomes and delayed apoptosis were investigated in parallel. Results: A similar dose-response relationship was found for all endpoints, with a steep rise at low doses to a plateau at doses > 3 Gy. The target for inducing genomic instability by alpha-particles is larger than the nucleus. All chromosomes are equally involved in delayed breakage reunion events. Conclusion: The results indicate that non-lethal radiation damage to an extranuclear target leads to a persistent increase in clastogenic activity in the surviving irradiated cells.