Clustered DNA damage induced by heavy ion particles

Terato, Hiroaki; Ide, Hiroshi

doi:10.2187/bss.18.206

Cited by 55 publications

(38 citation statements)

References 62 publications

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“…A common method to study these damages is to observe the conformational changes of the plasmid DNA. While an intact plasmid is supercoiled, conformational changes to relaxed circular or to linear fragments occur for a SSB or DSB, respectively (Boudaiffa et al, 2000;Terato and Ide, 2004). If more than one DSB is induced, fragmentation of the plasmid into short pieces takes place.…”

Section: Introductionmentioning

confidence: 99%

SFM studies of carbon ion induced damages in plasmid DNA

Brezeanu

Taucher-Scholz²,

Psonka³

et al. 2007

J of Molecular Recognition

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In this study we present for the first time detailed scanning force microscopy (SFM) investigations of carbon ion induced damages in plasmid DNA in order to obtain information about the biological effectiveness of particle radiation. For this purpose, we have combined SFM and gel electrophoresis measurements in a dose range between D = 0 Gy and 5000 Gy. After irradiation with C ions, the percentage of double-strand breaks (DSBs) increases drastically, i.e. from initially 0% for D = 0 Gy to 38% for D = 5000 Gy. Increasing the dose over the total range is accompanied by a shortening of the average fragment length from L = 1100 nm to L = 575 nm. In addition to our experiments, the average numbers of induced DSBs per irradiated plasmid and per broken plasmid have been calculated from the SFM measurements. The most important among the numerous results is that a significant amount of plasmids has suffered more than two DSBs for all applied doses, indicating multiple DSBs. The number of DSBs per broken plasmid increases from approximately 1.7 after irradiation with a dose of D = 250 Gy to 3.2 after exposure to the highest dose of D = 5000 Gy. The results provide experimental data for the spatially correlated production of DSBs after carbon irradiation, that are relevant to the understanding of its biological effectiveness.

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Section: Introductionmentioning

confidence: 99%

SFM studies of carbon ion induced damages in plasmid DNA

Brezeanu

Taucher-Scholz²,

Psonka³

et al. 2007

J of Molecular Recognition

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“…It was shown in a recent review article by Terato [37], that Â varies from around Â = 0.006 DSBs/(MbpGy) [3,38,39] to Â = 0.14 DSBs/(MbpGy) [40] for X-ray irradiation.…”

Section: Experimental Data and Discussionmentioning

confidence: 99%

Scanning force microscopy studies of X-ray-induced double-strand breaks in plasmid DNA

2009

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We present an analysis of X-ray-induced damage in X174 plasmid DNA, applying doses between D = 250 and 1,500 Gy. To analyse this damage in detail, the distribution of plasmid fragments after irradiation have been determined by scanning force microscopy. The results show that even for the lowest dose of D = 250 Gy, a significant amount of double-strand breaks are observed. For increasing dose, the percentage of small fragments increases and is accompanied by a shortening of the average fragment length from < L >= 1,400 nm for a dose of D = 250 Gy to < L >= 1,080 nm after irradiation with D = 1,500 Gy. The most crucial parameter, the average number of double-strand breaks per broken plasmid () has been determined for the first time for the applied doses. The results show that the average number of DSBs per broken plasmid increases almost linearly from a value of = 1.3 after irradiation with D = 250 Gy to = 1.7 after exposure to D = 1,500 Gy. The presented results show that the amount of DSBs induced by X-ray radiation in plasmid DNA can be calculated with high accuracy by means of scanning force microscopy, providing relevant information regarding the interaction of X-rays with DNA molecules.

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“…It is well established that the level of clustering of DNA damage and their complexity increase with increasing LET of radiation (Terato and Ide, 2004;Sage and Harrison, 2011). For low-LET IR, this clustering occurs mainly on small sites of DNA and nucleosomes in the chromatin.…”

Section: Introductionmentioning

confidence: 99%

“…High-LET radiation, such as α-rays, yields more than 90% of DSB with ends carrying additional single lesions (Terato and Ide, 2004;Hada and Georgakilas, 2008). It was shown that in the case of irradiation of cells with protons (LET 9.2 keV/m), 45% of the resulting SSB in the DNA are accompanied by additional damage of bases in close proximity to these breaks, and this value increases to 78% after exposure of these cells to α-particles (LET 129 keV/m) (Terato and Ide, 2004). Other studies have also shown the formation of more complex DNA lesions after exposure of cells to high-LET radiation (Semenenko and Stewart, 2004).…”

Section: Introductionmentioning

confidence: 99%