Kinashi Yuko, Yokomizo Natsuya, Takahashi Sentaro
Research Reactor Institute, Kyoto University, Kumatori, Japan
Research Reactor Institute, Kyoto University, Kumatori, Japan.
Anticancer Res. 2017 Apr;37(4):1681-1685. doi: 10.21873/anticanres.11499.
To use the 53BP1 foci assay to detect DNA double-strand breaks induced by fractionated neutron beam irradiation of normal cells.
The Kyoto University Research Reactor heavy-water facility and gamma-ray irradiation system were used as experimental radiation sources. After fixation of Chinese Hamster Ovary cells with 3.6% formalin, immunofluorescence staining was performed. Number and size of foci were analyzed using ImageJ software.
Fractionated neutron irradiation induced 25% fewer 53BP1 foci than single irradiation at the same dose. By contrast, gamma irradiation induced 30% fewer 53BP1 foci than single irradiation at the same dose. Fractionated neutron irradiation induced larger foci than gamma irradiation, raising the possibility that persistent unrepaired DNA damage was amplified due to the high linear energy transfer component in the neutron beam.
Unrepaired cluster DNA damage was more prevalent after fractionated neutron irradiation than after gamma irradiation.
使用53BP1灶点检测法检测正常细胞经分次中子束照射诱导产生的DNA双链断裂。
使用京都大学研究堆重水设施和γ射线照射系统作为实验辐射源。用3.6%的福尔马林固定中国仓鼠卵巢细胞后，进行免疫荧光染色。使用ImageJ软件分析灶点的数量和大小。
在相同剂量下，分次中子照射诱导产生的53BP1灶点比单次照射少25%。相比之下，γ射线照射诱导产生的53BP1灶点比单次照射少30%。分次中子照射诱导产生的灶点比γ射线照射诱导产生的灶点更大，这增加了由于中子束中高传能线密度成分导致持续未修复的DNA损伤被放大的可能性。
分次中子照射后未修复的簇状DNA损伤比γ射线照射后更普遍。
