抄録
We have been investigating effects of heavy-ion beams on immortal human cells established by introducing the hTERT gene. G0/GI phase arrested normal and AT cells were irradiated with carbon ions, iron ions and X-ray. In normal cells, the survival after irradiated with iron ions was significantly lower than those after irradiation with carbon ions and the induction of micronuclei was significantly higher after iron ions than carbon ions. In contrast, significant difference between carbon and iron ions was not observed in AT cells. In normal and AT cells after irradiation with heavy-ion beams, induction of micronuclei was significantly high compared with those irradiated with X-ray. Almost similar number of γH2AX foci formation was observed in both normal and AT cells after irradiation with carbon or iron ions. After 40 hours in AT cells significant number of γH2AX foci were observed. In normal cells, DSBs induced by iron ions repaired significantly slower than those induced by carbon ions, while after 40 hours most of γH2AX foci disappeared induced by both carbon and iron ions. These results suggest that AT cells might not be able to repair the DSB induced by heavy-ion beams and severely affected by them.
