Bryant P E
Department of Biology and Preclinical Medicine, University of St Andrews, Fife, U.K.
Int J Radiat Biol. 1988 Dec;54(6):869-90. doi: 10.1080/09553008814552291.
Some of the cellular effects of radiation, such as mutations, chromosomal aberrations and cell killing, can be mimicked by inducing 'pure' double-strand breaks (dsb) in DNA of cells with restriction endonucleases (RE), although the chemical structure of the ends of dsb induced by RE are likely to differ from those induced by X-rays. Chromosomal aberrations are induced by treatment of cells with a variety of RE at all stages of the cell cycle. The frequency with which RE induce dsb in the DNA may be one factor determining the number of aberrations induced. However, the structure of the dsb generated may also determine the frequencies of aberrations induced. RE which generate 'cohesive-ended' dsb in the DNA have been shown to induce lower frequencies of aberrations than those causing 'blunt-ended' dsb, when inactivated Sendai virus is used to permeabilize cells. Other methods, involving a hypertonic shock to the treated cells, have led to results in which there is little or no difference in the effectiveness between the two types of dsb. It is argued here that the use of treatments which cause a hypertonic shock may influence the frequencies of aberrations induced.
辐射的一些细胞效应，如突变、染色体畸变和细胞杀伤，可用限制性内切酶（RE）在细胞DNA中诱导“纯”双链断裂（dsb）来模拟，尽管RE诱导的dsb末端的化学结构可能与X射线诱导的不同。在细胞周期的所有阶段，用多种RE处理细胞均可诱导染色体畸变。RE在DNA中诱导dsb的频率可能是决定所诱导畸变数量的一个因素。然而，所产生的dsb的结构也可能决定所诱导畸变的频率。当使用灭活仙台病毒使细胞通透时，已表明在DNA中产生“粘性末端”dsb的RE比产生“平端”dsb的RE诱导的畸变频率更低。其他涉及对处理过的细胞进行高渗休克的方法，所得结果表明两种类型的dsb在有效性方面几乎没有差异或没有差异。本文认为，使用引起高渗休克的处理方法可能会影响所诱导畸变的频率。
