Belli M, Cherubini R, Dalla Vecchia M, Dini V, Esposito G, Moschini G, Sapora O, Simone G, Tabocchini M A
Physics Laboratory, Istituto Superiore di Sanità, Rome, Italy.
Int J Radiat Biol. 2002 Jun;78(6):475-82. doi: 10.1080/09553000210123676.
To compare the results on DNA fragmentation induced in Chinese hamster V79 cells by various doses of gamma-rays and low-energy protons and helium-4 ions.
V79 cells were irradiated as monolayers with monoenergetic protons and helium-4 ions; gamma-rays were used as the reference radiation. DNA double-strand breaks were evaluated by calibrated pulsed-field gel electrophoresis using conditions covering the range 5.7 Mbp-23.1 kbp.
The fragment-counting method gave double-strand breaks yields and the relative biological effectiveness higher than those obtained by the fraction of activity released method. The frequency distribution of fragments showed that protons and helium ions induced more fragments below the Mbp region than did gamma-rays at the same dose. The distributions for both the irradiated and non-irradiated samples clearly appeared to be non-random.
Differences were observed in the yield and spatial correlation, at a molecular size scale characteristic of loop dimensions, of the double-strand breaks induced by gamma-rays and by light ions. These effects may have a role in the observed different cell response to these radiations.
比较不同剂量的γ射线、低能质子和氦 - 4离子对中国仓鼠V79细胞诱导的DNA片段化结果。
将V79细胞单层培养物用单能质子和氦 - 4离子进行辐照；γ射线用作参考辐射。使用覆盖5.7 Mbp至23.1 kbp范围的条件，通过校准的脉冲场凝胶电泳评估DNA双链断裂。
片段计数法得到的双链断裂产率和相对生物效能高于活性释放分数法得到的结果。片段的频率分布表明，在相同剂量下，质子和氦离子在Mbp区域以下诱导的片段比γ射线更多。辐照和未辐照样品的分布明显呈现非随机。
在γ射线和轻离子诱导的双链断裂的产率和空间相关性方面，在环尺寸特征的分子大小尺度上观察到差异。这些效应可能在观察到的细胞对这些辐射的不同反应中起作用。
