Ruiz de Almodóvar J M, Núñez M I, McMillan T J, Olea N, Mort C, Villalobos M, Pedraza V, Steel G G
Departamento de Radiologia, Hospital Universitario, Facultad de Medicina, Granada, Spain.
Br J Cancer. 1994 Mar;69(3):457-62. doi: 10.1038/bjc.1994.83.
The role of the initial DNA double-strand breaks (dsb) as a determinant of cellular radiosensitivity was studied in human breast and bladder cancer cell lines. Cell survival was measured by monolayer colony-forming assay as appropriate and differences in radiosensitivity were seen (alpha-values ranged from 0.12 to 0.54). After pulsed-field gel electrophoresis (PFGE) the initial slopes of dose-response curves were biphasic with a flattening of the curves above 30 Gy. When the frequency of DNA dsb induction was assessed using a mathematical model based on the DNA fragment size distribution into the gel lane, we found a statistically significant relationship between the number of DNA dsb induced and the corresponding alpha-values and fraction surviving after 2Gy (P = 0.0049 and P = 0.0031 respectively). These results support the view that initial damage is a major determinant of cell radiosensitivity.
在人乳腺癌和膀胱癌细胞系中研究了初始DNA双链断裂（dsb）作为细胞放射敏感性决定因素的作用。通过适当的单层集落形成试验测量细胞存活率，观察到放射敏感性存在差异（α值范围为0.12至0.54）。脉冲场凝胶电泳（PFGE）后，剂量反应曲线的初始斜率呈双相，曲线在30 Gy以上变平。当使用基于DNA片段在凝胶泳道中大小分布的数学模型评估DNA dsb诱导频率时，我们发现诱导的DNA dsb数量与相应的α值以及2 Gy后存活分数之间存在统计学上的显著关系（分别为P = 0.0049和P = 0.0031）。这些结果支持初始损伤是细胞放射敏感性主要决定因素的观点。
