Sep. 2021, Presentation Award, Transfection efficiency depending on distance between a double-strand break site and EGFP-gene in plasmid DNA, 日本放射線影響学会第64回大会
小畑結衣;木名瀨暁理;秋光信佳;横谷明徳

Oct. 2020, Presentation Award, Development of a vector DNA system for visualization of intracellular repair dynamics of DNA damage by ionizing radiation, 日本放射線影響学会第63回大会
小畑結衣;平嵜敬志朗;秋光信佳;鈴木雅雄;横谷明徳

Hydroxyl radical scavenging and chemical repair capabilities of positively charged peptides (PCPs): a pulse radiolysis study
Chaozhong Tian; Shinichi Yamashita; Atsushi Kimura; Yui Obata; Hao Yu; Mitsumasa Taguchi, Informa UK Limited
Free Radical Research, 02 Jul. 2024

Expression of an X-Ray Irradiated EGFP-Expressing Plasmid Transfected into Nonirradiated Human Cells.
Yui Obata; Hiroki Nakaue; Keishiro Hirasaki; Nobuyoshi Akimitsu; Akinari Yokoya, To investigate the repairability of X-ray induced DNA damage, particularly non-double-strand breaks in living cells, enhanced green fluorescent protein (EGFP)-expressing plasmids X-ray irradiated and then transfected into nonirradiated human cells, MCF7 and MCF10A. Live-cell imaging of EGFP fluorescence was performed to measure the efficiency of plasmid repair in cells. The number of EGFP-expressing cells significantly decreased with increasing X-ray dose for both cell lines. The obtained kinetic curves of EGFP expression indicating plasmid repair were quantitatively compared against algebraically calculated ones based on the values of the transfected plasmids that had been treated with nicking or restriction enzymes. Then, assuming a Poisson distribution of single-strand breaks (SSBs), the number of cells carrying these nicked plasmids that could express EGFP were estimated. Our experimental results revealed considerably fewer cells expressing EGFP compared to the expected values we had calculated. These results suggest that the lower proportion of cells expressing EGFP as a measure of plasmid repair was due not only to the complex chemical structures of termini created by SSBs compared to those created by enzyme treatments, but also that base lesions or AP sites proximately arising at the strand-break termini might compromise EGFP expression. These results emphasize that radiation-induced DNA breaks are less repairable than enzymatically induced DNA breaks, which is not apparent when using conventional gel electrophoresis assays of plasmid DNA.
Radiation research, 01 Sep. 2021

VISUALIZATION OF THE DNA REPAIR PROCESS IN MAMMALIAN CELLS TRANSFECTED WITH EGFP-EXPRESSING PLASMID DNA AFTER EXPOSURE TO X-RAYS IN VITRO.
Hiroki Nakaue; Yui Obata; Kiichi Kaminaga; Nobuyoshi Akimitsu; Akinari Yokoya, To investigate the repair process of DNA damage induced by ionizing radiation in isolation from various types of cytoplasmic damage, we transfected X-irradiated enhanced green fluorescent protein (EGFP)-expressing plasmid DNA into non-irradiated mammalian cells using lipofectamine. The repair kinetics of the irradiated plasmids in the cells were visualized under microscopy as the EGFP fluorescence emitted by transfected cells. Using an agarose gel electrophoresis method, the yields of single- and double-strand breaks of the plasmids were also quantified. As positive control experiments, plasmid DNA with single- or double-strand breaks induced by a nicking or restriction enzyme were also transfected into the cells. The DNA repair rates for X-ray-irradiated plasmids were significantly lower than those of the enzymatically digested positive control samples. These results indicate that X-rays could induce less repairable damage than that induced by enzymes.
Radiation protection dosimetry, 01 May 2019

In vivo and In vitro rejoining of enzymatically induced double-strand breaks in EGFP expressing plasmid DNA
江田脩真; 伊東裕真; 小畑結衣; 廣瀬エリ; 横谷明徳; 横谷明徳
アイソトープ・放射線研究発表会(Web), 2024

Pulse radiolysis study on reaction of halogenated nucleotides (Br-dUMP) with radiation-induced water decomposition products.　　　　　　　　　　　　　　　
Yui OBATA; Yuma ITO; Akinari YOKOYA; Shinichi YAMASHITA
日本放射線影響学会大会講演要旨集, Nov. 2023

Yields of DNA strand breaks and nucleobase lesions in dilute aqueous solutions of scavenger-free plasmid DNA irradiated with X-ray　　　　　　　　　　　　　　　
Yui OBATA; Shunsuke SHINOHARA; Chaozhong TIAN; Shinichi YAMASHITA
第66回放射線化学討論会, Sep. 2023

EGFP plasmid DNA damage induced by phosphorus K-resonance excitation and its cellular repair
小畑結衣; 木名瀬暁理; 横谷明徳; 横谷明徳
量子ビームサイエンスフェスタ(Web), 2023

ヒト細胞中に導入された線形プラスミドDNAは遺伝子発現をするのか?(Does linear plasmid DNA express genes in it after transfected into human cells)　　　　　　　　　　　　　　　
小畑 結衣; 木名瀬 暁理; 伊東 祐真; 秋光 信佳; 横谷 明徳
日本放射線影響学会大会講演要旨集, Sep. 2022

軟X線を照射したEGFP発現プラスミドDNAの非照射細胞内におけるDNA修復の難易性(DNA repair susceptibility in non-irradiated cells transfected with EGFP expressing plasmid DNA irradiated with various soft X-rays)　　　　　　　　　　　　　　　
木名瀬 暁理; 小畑 結衣; 横谷 明徳
日本放射線影響学会大会講演要旨集, Sep. 2022

Brから放出される低エネルギー二次電子がプラスミドDNAの鎖切断に与える効果(Effect of low-energy secondary electrons emitted from bromine atoms on the strand breaks of plasmid DNA)　　　　　　　　　　　　　　　
伊東 祐真; 小畑 結衣; 木名瀬 暁理; 横谷 明徳
日本放射線影響学会大会講演要旨集, Sep. 2022

Core level ionization or excitation and Auger relaxation induce clustered DNA damage.
Akinari Yokoya; Yui Obata
The Enzymes, 2022

放射線損傷DNAの細胞内修復ダイナミクス可視化のための新たなベクターDNA系の開発(Development of a vector DNA system for visualization of intracellular repair dynamics of DNA damage by ionizing radiation)　　　　　　　　　　　　　　　
小畑 結衣; 平嵜 敬志朗; 秋光 信佳; 鈴木 雅雄; 横谷 明徳
日本放射線影響学会大会講演要旨集, Oct. 2020

放射線損傷DNAの細胞内修復ダイナミクス可視化のための新たなベクターDNA系の開発(Development of a vector DNA system for visualization of intracellular repair dynamics of DNA damage by ionizing radiation)　　　　　　　　　　　　　　　
小畑 結衣; 平嵜 敬志朗; 秋光 信佳; 鈴木 雅雄; 横谷 明徳
日本放射線影響学会大会講演要旨集, Oct. 2020

水和水に対するX線エネルギー付与により誘発されたEGFPプラスミドDNA損傷の修復のライブセルイメージング(Live cell imaging of repair of EGFP plasmid DNA damage induced by X-ray energy deposition on hydrated waters)　　　　　　　　　　　　　　　
平嵜 敬志朗; 小畑 結衣; 横谷 明徳
日本放射線影響学会大会講演要旨集, Oct. 2020

非照射ヒト細胞におけるin vitro X線照射プラスミドDNAのEGFP発現のライブセル観察(Live cell observation of EGFP expression of in vitro X-irradiated plasmid DNA in non-irradiated human cells)　　　　　　　　　　　　　　　
小畑 結衣; 平嵜 敬志朗; 横谷 明徳
日本放射線影響学会大会講演要旨集, Nov. 2019

ヒト細胞中に移入されたX線照射水和EGFP発現プラスミドDNAの修復感受性(Repair susceptibility of hydrated EGFP-expressing plasmid DNA transfected into human cells after exposure to X-rays)　　　　　　　　　　　　　　　
平嵜 敬志朗; 小畑 結衣; 横谷 明徳
日本放射線影響学会大会講演要旨集, Nov. 2019

DNA repair response of mammary gland cells to EGFP plasmid DNA exposed to various ionizing radiations or treated with restriction enzymes　　　　　　　　　　　　　　　
Obata Y; Kinase A; Hirasaki K; Akimitsu N; Yokoya A
The Radiation Research Society's 68th Annual Meeting, 17 Oct. 2022
20221016, 20221019

Measurement of irradiation plasmid DNA repair rate in non-irradiated human cells.　　　　　　　　　　　　　　　
Obata Y; Hirasaki K; Akimitsu N; Yokoya A
University Training program to Australian Nuclear Science and Technology Organisation,, 12 Mar. 2020

Live cell observation of DNA repair using EGFP plasmid exposed to X-rays in various conditions.　　　　　　　　　　　　　　　
Hirasaki K; Obata Y; Yokoya A
3th QST International Symposium Quantum Life Science, 04 Dec. 2019
20191204, 20191205

Repair susceptibility of X-irradiated EGFP plasmid DNA transfected into non-irradiated cells.　　　　　　　　　　　　　　　
Obata Y; Hirasaki K; Akimitsu N; Suzuki M; Yokoya A
3th QST International Symposium Quantum Life Science, 04 Dec. 2019
20191204, 20191205

Live cell observation of expression of X-irradiated EGFP-plasmid DNA in non-irradiated human cells.　　　　　　　　　　　　　　　
Obata Y; Hirasaki K; Akimitsu N; Yokoya A
The 16th International Congress of Radiation Research (ICRR 2019), 27 Aug. 2019
20190825, 20190829

A. Live cell observation of repair of EGFP-plasmid DNA damage induced by X-irradiation　　　　　　　　　　　　　　　
Obata Y; Nakaue H; Hirasaki K; Akimitsu N; Suzuki M; Yokoya, A
Ibaraki University Training program to Australian Nuclear Science and Technology Organisation, 30 Jan. 2019
20190129, 20190131

A novel method to visualize DNA repair process in mammalian cells transformed by plasmid DNA exposed to various quantum beams.　　　　　　　　　　　　　　　
Nakaue H; Obata Y; Kaminaga K; Yokoya A
1st QST International Symposium Quantum Life Science
20170725, 20170726

Visualization of DNA repair process in mammalian cells transformed by plasmid DNA exposed to X-ray in vitro　　　　　　　　　　　　　　　
Nakaue H; Obata Y; Kaminaga K; Yokoya A
17th International Symposium on Microdosimetry on MICROS 2017
20170705, 20170710

Oct. 2024 - Present, プラズマ・核融合学会

Sep. 2023 - Present, Japanese Society of Radiation Chemistry

Sep. 2018 - Present, The Japanese Radiation Research Society