@misc{oai:repo.qst.go.jp:00077419,
 author = {Hirasaki, Keishiro and Obata, Yui and Yokoya, Akinari and Hirasaki, Keishiro and Obata, Yui and Yokoya, Akinari},
 month = {Nov},
 note = {Clustered DNA damage is defined as two or more
lesions (base lesions, single strand breaks or abasic
(AP) sites ) localized within one or two helical turn(s).
Although repair susceptibility of a synthesized base
lesion (or AP) cluster in oligonucleotides have been
investigated, those induced actually by irradiation is not
clarified yet. To elucidate the repair susceptibility of radiation-
induced clustered damage, in the present study,
fully hydrated DNA films containing 35 water molecules
per nucleotide, as well as DNA solutions (1×TE, 1μg/
μl) were used as samples. In the hydrated DNA films,
diffusible water radicals are hardly generated by ionizing
radiation. Thus, the major process of radiation action
is direct ionization or impact of secondary electrons to
DNA. The EGFP-expressing plasmids were exposed
to X-rays with a 1/e dose for each sample, and then
transfected into non-irradiated human cells (MCF-7).
Those cells were observed for 48h with fluorescence microscope.
DNA repair efficiencies were obtained as the
number of fluorescence expression cells. The efficiency
for the hydrated DNA film was significantly lower than
that for the solution sample. These results indicate that
DNA damage induced in the hydrated DNA would be
clustered lesions and difficult to be repaired., 日本放射線影響学会第62回大会},
 title = {Repair susceptibility of hydrated EGFP-expressing plasmid DNA transfected into human cells after exposure to X-rays},
 year = {2019}
}