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Shiraishi, Iyo; Suzuki, Masao*; Shikazono, Naoya; Fujii, Kentaro; Yokoya, Akinari
Journal of Radiation Research, 55(Suppl.1), p.i92 - i93, 2014/03
Shiina, Takuya; Watanabe, Ritsuko; Shiraishi, Iyo; Suzuki, Masao*; Sugaya, Yuki; Fujii, Kentaro; Yokoya, Akinari
Radiation and Environmental Biophysics, 52(1), p.99 - 112, 2013/03
Times Cited Count：18 Percentile：59.02(Biology)Shiina, Takuya; Sugaya, Yuki; Shiraishi, Iyo; Watanabe, Ritsuko; Yokoya, Akinari
no journal, ,
Many studies using synthetic AP clusters reported that AP clusters retard base excision repair processes. Sutherland et al. (2002) showed that AP clusters are induced efficiently in human cells by low LET X-irradiation with the similar yields with those for the pyrimidine or purine base lesion clusters. There, however, has been very little knowledge of AP sites and AP clusters induced by high LET radiation. In order to clarify the relation between track structure of C ions or X-rays and the induction processes of an AP or AP clusters, we measure the yield of AP sites visualized by the treatment of irradiated pUC18 plasmid DNA with the AP endoclease (Nfo), which converts an AP site to detectable single strand break. Several scavenging capacities of the samples are tested to estimate the effect of indirect action of diffusible OH radicals. These experimental data will be discussed with theoretical radiation track structure in the respect of repair susceptibility of the AP cluster.
Sugaya, Yuki; Shiraishi, Iyo; Shiina, Takuya; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
no abstracts in English
Yokoya, Akinari; Shiraishi, Iyo; Shikazono, Naoya
no journal, ,
In the present study, we investigate how the initial enzymatic repair affects the activity of the latter repair enzyme. Plasmid DNA (pUC18) irradiated with C
ion is treated with two base excision repair enzymes, Nth and Fpg, which convert pyrimidine and purine lesions to a SSB. The enzymatic activities are quantified by measuring the conformational changes of the plasmid using agarose gel electrophoresis. Obtained results show that the amount of enzymatically induced SSB is slightly (about 5%) less in DNA sample treated with Nth first and then Fpg than that in the sample treated with Fpg first and then Nth, or with both enzymes simultaneously. The repairability of clustered damage induced by high-LET ions will be discussed.
Shiina, Takuya; Sugaya, Yuki; Shiraishi, Iyo; Watanabe, Ritsuko; Yokoya, Akinari; Tsuruoka, Chizuru*; Suzuki, Masao*
no journal, ,
There has been very little knowledge of AP sites and AP clusters induced by heavy ion beam irradiation. In order to clarify the relation between track structure of C ions (290MeV/nucleon, LET 13, 60keV/
m) or X-rays and the induction processes of an AP or AP clusters, we measure the yield of AP sites visualized by the treatment of irradiated pUC18 plasmid DNA with the AP endoclease (Nfo), which converts an AP site to detectable single strand break. Several scavenging capacities of the samples are tested to estimate the effect of indirect action of diffusible OH radicals in the induction of AP site. These experimental data will be discussed with theoretical radiation track structure in the respect of repair susceptibility of the AP cluster.
Shiraishi, Iyo; Shiina, Takuya; Sugaya, Yuki; Shikazono, Naoya; Yokoya, Akinari
no journal, ,
Cellular response to cluster DNA damage might depend on the order of repair processes because the configuration of the lesions will be modified by the reaction of the initial repair protein, affecting the DNA-binding or lesion-excision activities of the latter repair protein. In the present study, we investigate how the initial enzymatic repair affects the activity of the latter repair enzyme. Plasmid DNA (pUC18) irradiated with C6+ ion is treated with two base excision repair enzymes, Nth and Fpg, which convert pyrimidine and purine lesions to a SSB. The enzymatic activities are quantified by measuring the conformational changes of the plasmid using agarose gel electrophoresis. Obtained results show that the amount of enzymatically induced SSB is slightly (about 5%) less in DNA sample treated with Nth first and then Fpg than that in the sample treated with Fpg first and then Nth. The repairability of clustered damage induced by high-LET ions will be discussed.
Sugaya, Yuki; Shiina, Takuya; Shiraishi, Iyo; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
In this study, we aim to reveal the role of direct ionization at the energy region of oxygen K-edge in the selective DNA damage. We measure the yields of single strand breaks (SSBs), base lesions, and AP sites produced in thin film of pUC18 plasmid DNA by irradiation of several soft X-rays which excite a1s electron to anti-bonding energy states or a vacuum level. The yields of base lesions and AP sites are determined by post-irradiation-treatment of the DNA with enzymatic probes, which excise (Nth and Fpg for pyrimidine and purine base lesion, respectively, and Nfo for AP site) and convert the lesions into detectable SSBs. The obtained data will be compared with our previous data obtained by soft X-ray irradiation around carbon and nitrogen K-edge region.
Shiina, Takuya; Sugaya, Yuki; Shiraishi, Iyo; Watanabe, Ritsuko; Suzuki, Masao*; Yokoya, Akinari
no journal, ,
no abstracts in English
Sugaya, Yuki; Shiina, Takuya; Shiraishi, Iyo; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
no abstracts in English
Shiraishi, Iyo; Shiina, Takuya; Sugaya, Yuki; Shikazono, Naoya; Yokoya, Akinari
no journal, ,
Shiraishi, Iyo; Shiina, Takuya; Sugaya, Yuki; Shikazono, Naoya; Yokoya, Akinari
no journal, ,
no abstracts in English
Shiina, Takuya; Shiraishi, Iyo; Sugaya, Yuki; Watanabe, Ritsuko; Suzuki, Masao*; Yokoya, Akinari
no journal, ,
no abstracts in English
Sugaya, Yuki; Shiina, Takuya; Shiraishi, Iyo; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
no abstracts in English
Sugaya, Yuki; Narita, Ayumi; Shiina, Takuya; Shiraishi, Iyo; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
no abstracts in English
