CONTRIBUTION OF INDIRECT EFFECTS TO CLUSTERED DAMAGE IN DNA IRRADIATED WITH PROTONS
CONTRIBUTION OF INDIRECT EFFECTS TO CLUSTERED DAMAGE IN DNA IRRADIATED WITH PROTONS
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DOI：
10.1093/rpd/ncv159
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发表时间：
2015-09-01
影响因子：
1
通讯作者：
Sihver, L.
中科院分区：
文献类型：
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作者：
Brabcova, K. Pachnerova;Stepan, V.;Sihver, L.
质子是银河系宇宙射线和太阳粒子事件中的主要粒子，此外，质子辐照越来越多地用于肿瘤治疗。据信，复杂的DNA损伤是导致细胞对辐射反应的决定性因素。用30 MeV质子在U120-M回旋加速器照射DNA质粒pBR322，并用两种大肠杆菌碱基切除修复酶处理。用琼脂糖凝胶电泳分析了SSBs和DSBs的产率。DNA在羟基自由基清除剂（香豆素-3-羧酸）存在下辐照，以区分生物靶标的直接和间接损伤。采用纯清除剂溶液作为探针，测定了诱导OH中心点自由基产率。实验羟基中心点自由基产率动力学与radamol和Geant4-DNA两种理论模型的预测结果进行了比较。两种方法都使用Geant4-DNA来描述辐射作用的物理阶段，然后每种方法都应用不同的模型来描述化学前和化学阶段。
Protons are the dominant particles both in galactic cosmic rays and in solar particle events and, furthermore, proton irradiation becomes increasingly used in tumour treatment. It is believed that complex DNA damage is the determining factor for the consequent cellular response to radiation. DNA plasmid pBR322 was irradiated at U120-M cyclotron with 30 MeV protons and treated with two Escherichia coli base excision repair enzymes. The yields of SSBs and DSBs were analysed using agarose gel electrophoresis. DNA has been irradiated in the presence of hydroxyl radical scavenger (coumarin-3-carboxylic acid) in order to distinguish between direct and indirect damage of the biological target. Pure scavenger solution was used as a probe for measurement of induced OH center dot radical yields. Experimental OH center dot radical yield kinetics was compared with predictions computed by two theoretical models-RADAMOL and Geant4-DNA. Both approaches use Geant4-DNA for description of physical stages of radiation action, and then each of them applies a distinct model for description of the pre-chemical and chemical stage.