Tommasino F, Friedrich T, Scholz U, Taucher-Scholz G, Durante M, Scholz M
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany.
Radiat Prot Dosimetry. 2015 Sep;166(1-4):66-70. doi: 10.1093/rpd/ncv164. Epub 2015 Apr 15.
In the recent version of the local effect model (LEM), the biological effects of ionising radiation can be well described trough the consideration of DNA double-strand breaks (DSB) clustering at the micrometre scale. Assuming a giant-loop organisation for the chromatin higher-order structure, two classes of DSB are defined, namely isolated (iDSB) and clustered DSB (cDSB), according to whether exactly one or more than one DSB are induced in a loop, respectively. Here, a DSB kinetic rejoining model based on the LEM is applied to the description of two specific aspects of DSB rejoining, namely the dose dependence of the rejoining capacity after photon radiation and the residual damage observed at late times after ion irradiation. Based on the hypothesis that iDSB and cDSB can be associated to the fast and slow components of rejoining, the model is able to reproduce the experimental data, therefore supporting the relevance of micrometre scale clustering of damage for photon radiation as well as for high-LET radiation.
在最新版本的局部效应模型（LEM）中，通过考虑微米尺度上的DNA双链断裂（DSB）聚类，可以很好地描述电离辐射的生物学效应。假设染色质高阶结构为巨环组织，根据在一个环中是恰好诱导一个DSB还是多个DSB，定义了两类DSB，即孤立DSB（iDSB）和聚类DSB（cDSB）。在此，基于LEM的DSB动力学重新连接模型被应用于描述DSB重新连接的两个特定方面，即光子辐射后重新连接能力的剂量依赖性以及离子辐照后长时间观察到的残余损伤。基于iDSB和cDSB可与重新连接的快速和慢速成分相关联的假设，该模型能够重现实验数据，因此支持了损伤的微米尺度聚类对于光子辐射以及高LET辐射的相关性。
