A Laser-plasma-produced soft X-ray laser at 89 eV generates DNA double-strand breaks in human cancer cells

Sato, Katsutoshi*; Nishikino, Masaharu; Kawachi, Tetsuya; Shimokawa, Takashi*; Imai, Takashi*; Teshima, Teruki*; Nishimura, Hiroaki*; Kando, Masaki

Journal of Radiation Research, 56(4), p.633 - 638, 2015/07

https://doi.org/10.1093/jrr/rrv015

While X-ray laser is expected to be widely applied to biomedical studies, this has not been achieved to date and its biological effects such as DNA damage have not been evaluated. As a first step for its biological application, we developed a culture cell irradiation system using laser-plasma soft X-ray laser and investigated whether the soft X-ray laser is able to induce the DNA double strand breaks (DSBs) in living cells or not. The human adenocarcimona cell line A549 was irradiated with the soft X-ray laser at a photon energy of 89 eV and then the repair focus formation of the DSBs was assessed by immunofluorescence staining with anti-phosphorylated DNA-PKcs antibody. As a result, the phosphorylated DNA-PKcs foci were clearly identified even with just a single shot of the soft X-ray laser. In this study, we successfully demonstrated for the first time that soft X-ray laser at 89 eV induced the DNA double strand breaks in living cells.

Measurement of DNA double-strand break yield in human cancer cells by high-current, short-duration bunches of laser-accelerated protons

Yogo, Akifumi; Sato, Katsutoshi; Nishikino, Masaharu; Maeda, Takuya*; Sakaki, Hironao; Hori, Toshihiko*; Ogura, Koichi; Nishiuchi, Mamiko; Teshima, Teruki*; Nishimura, Hiroaki*; et al.

Japanese Journal of Applied Physics, 50(10), p.106401_1 - 106401_7, 2011/10

https://doi.org/10.1143/JJAP.50.106401

-H2AX and phosphorylated ATM focus formation in cancer cells after laser plasma X irradiation

Sato, Katsutoshi; Nishikino, Masaharu; Okano, Yasuaki*; Oshima, Shinsuke*; Hasegawa, Noboru; Ishino, Masahiko; Kawachi, Tetsuya; Numasaki, Hodaka*; Teshima, Teruki*; Nishimura, Hiroaki*

Radiation Research, 174(4), p.436 - 445, 2010/10

https://doi.org/10.1667/RR2178.1

Usefulness of laser-plasma X-ray pulse for medical and radiation biological studies was investigated and compared with that of conventional sources such as those obtained from a linear accelerator. A cell irradiation system was developed which uses Copper-K (8 keV) lines from an ultra-short high intensity laser to produce plasma. The absorbed dose of the 8 keV laser-plasma X-ray pulse was accurately estimated with Gafchromic EBT film. When the cells were irradiated with approximately 2 Gy of laser plasma X-ray, the circular regions on -H2AX positive cells could be clearly identified. Moreover, the number of -H2AX and phosphorylated ataxia telangiectasia mutated (ATM) foci induced by 8 keV laser plasma X-ray were comparable to those induced by 4MV X-ray. These results indicate that the laser plasma X-ray source can be useful for radiation biological studies.

Application of laser produced plasma K X-ray probe in radiation biology

Nishikino, Masaharu; Sato, Katsutoshi; Hasegawa, Noboru; Ishino, Masahiko; Oshima, Shinsuke*; Okano, Yasuaki*; Kawachi, Tetsuya; Numasaki, Hodaka*; Teshima, Teruki*; Nishimura, Hiroaki*

Review of Scientific Instruments, 81(2), p.026107_1 - 026107_3, 2010/02

https://doi.org/10.1063/1.3302827

An X-ray generation and exposure system dedicated for radiation biology is developed. An X-ray pulse of 8.0 keV in energy as short as 1 ps is generated with a fs-laser pulse, and sample cells are irradiated through a specially designed cell dish with a silicon nitride membrane. DNA double-strand breaks in a nucleus of a human caner cell are caused by X-ray irradiation, and similar DNA breaks are obtained to those with the conventional X-ray source. This result demonstrates feasibility of radiobiological study with a single burst of X-rays shining on a single cell specimen.

Development of focused laser plasma X-ray beam for radiobiological applications

Nishikino, Masaharu; Okano, Yasuaki*; Sato, Katsutoshi*; Hasegawa, Noboru; Ishino, Masahiko; Oshima, Shinsuke*; Kawachi, Tetsuya; Numasaki, Hodaka*; Teshima, Teruki*; Nishimura, Hiroaki*

no journal, , 

Recently, high energy, monochromatic X-rays emanating from laser-produced plasma (LPP) are attracting much attention as a new radiation source indispensable for high energy density physics, bioscience, and material sciences. Aiming at these applications, we have been improving performances of Ka lines emitted from and soft X-ray lasers. The monochromaticity is particularly important when X-rays are handled with a narrow-band optics or used to selectively excite a specific material involved in matters. In addition, time-duration of such sources is typically an order of pico-second, and it could be comparable or even shorter than recovery time of radiatively-damaged biological cell, so that the LPP source can be a new source for investigating the mechanisms of irradiation survival and death of biological cells. We propose to develop an ultrashort, intense X-ray microbeam system to study the radiobiological effect and the bystander effect.

Laser-driven proton beam irradiation on in-vitro human cancer cells

Yogo, Akifumi; Sato, Katsutoshi*; Nishikino, Masaharu; Mori, Michiaki; Teshima, Teruki*; Numasaki, Hodaka*; Murakami, Masao*; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; et al.

no journal, , 

In this work, we demonstrate the irradiation effect of laser accelerated protons induced on human lung cancer cells. In-vitro A549 cells are irradiated with a proton dose of 20 Gy, resulting in a distinct formation of -H2AX foci as an indicator of DNA double-strand breaks. This is the first result showing that laser-driven ion beams can generate a lethal effect on cancer cells.

Development of focused laser plasma X-ray beam for radiobiological applications

Nishikino, Masaharu; Sato, Katsutoshi*; Oshima, Shinsuke*; Hasegawa, Noboru; Ishino, Masahiko; Kawachi, Tetsuya; Okano, Yasuaki*; Numasaki, Hodaka*; Teshima, Teruki*; Nishimura, Hiroaki*

no journal, , 

https://www.osapublishing.org/abstract.cfm?uri=CLEOPR-2009-TuA2_4

We have started to develop a laser plasma X-ray microbeam irradiation system, and demonstrated a preliminary study of the cell survival and -H2AX focus formation in the culture cells irradiated with laser-produced plasma X-ray.

Induction of DNA double strand breaks by laser-plasma quantum beam

Sato, Katsutoshi; Numasaki, Hodaka*; Nishikino, Masaharu; Yogo, Akifumi; Kawachi, Tetsuya; Teshima, Teruki*; Daido, Hiroyuki

no journal, , 

no abstracts in English

Development of laser plasma X-ray beam for radiation biology

Nishikino, Masaharu; Sato, Katsutoshi; Ishino, Masahiko; Hasegawa, Noboru; Kawachi, Tetsuya; Numasaki, Hodaka*; Teshima, Teruki*; Oshima, Shinsuke*; Nishimura, Hiroaki*

no journal, , 

no abstracts in English

Application of laser produced plasma X-ray probe in radiation biology

Nishikino, Masaharu; Sato, Katsutoshi; Ishino, Masahiko; Hasegawa, Noboru; Kado, Masataka; Kawachi, Tetsuya; Numasaki, Hodaka*; Teshima, Teruki*; Okano, Yasuaki*; Oshima, Shinsuke*; et al.

no journal, , 

A dedicated radiation biologyn X-ray generation and exposure system has been dedicated for radiation biology is developed. An X-ray pulse of 8.0 keV in energy X-ray pulses is generated with an fs-laser pulse were used to irradiate, and sample cells are irradiated through a custom-made culture dish with a silicon nitride membrane. The X-ray irradiation resulted in DNA double-strand breaks in thea nucleus of a culture cell are caused by X-ray irradiation that were, and similar DNA breaks are obtained to those obtained with athe conventional X-ray source, thus. This result demonstrating thees feasibility of radiobiological studiesy utilizing with a single burst of X-rays focused shining on a single cell specimens.