Enhanced sensitivity to neoplastic transformation by 137Cs gamma-rays of cells in the G2-/M-phase age interval.
Enhanced sensitivity to neoplastic transformation by 137Cs gamma-rays of cells in the G2-/M-phase age interval.
复制标题
G2/M 期年龄区间细胞对 137Cs 伽马射线导致的肿瘤转化的敏感性增强。
DOI：
10.1080/09553009214552011
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发表时间：
1992
影响因子：
2.6
通讯作者：
Elkind,MM
中科院分区：
文献类型：
--
作者：
Cao,J;Wells,RL;Elkind,MM
暴露于低剂量裂变谱中子的C3 H小鼠10 T1/2细胞，如果使用长期暴露，则肿瘤转化的频率增加（Hillet等人，1982，1984 a，1985）。为了解释这一异常现象，有人提出了一个生物物理模型（Elkind 1991 a，B），具有以下基本特征：（1）在10 T1/2细胞的生长周期中存在窄的年龄间隔，其中细胞对转化具有高敏感性;（2）在后一年龄间隔中，细胞对杀伤也敏感;（3）随着剂量的增加，生长周期早期的细胞逐渐延迟进入敏感年龄窗口;（4）随着剂量的增加，由于杀伤增加，敏感窗口中细胞的转化敏感性不表达。低剂量的普罗维汀会导致频率升高，因为杀伤较少，并且细胞进展延迟减少。有丝分裂中和周围细胞的独特形状和放射生物学性质导致了有丝分裂和可能的细胞正好在M期之前或之后的敏感窗口的提议（Elkind 1991 a，B）。由于敏感窗口中的细胞特性可能只有在使用裂变谱中子时才不明显，因此这项研究使用137 Cs γ射线进行。我们发现G_2晚期至M期的10T_1/2细胞对肿瘤转化和~（137）Cs γ射线杀伤的敏感性最高。
C3H mouse 10T1/2 cells, exposed to low doses of fission-spectrum neutrons, have an enhanced frequency of neoplastic transformation if protracted exposures are used (Hillet al.1982, 1984a, 1985). To explain this anomaly, a biophysical model was proposed (Elkind 1991a,b) having the following essential features: (1) a narrow age interval exists in the growth cycle of 10T1/2 cells in which cells have high sensitivities to transformation; (2) in the latter age interval, cells are also sensitive to killing; (3) with increasing dose, cells at ages earlier in the growth cycle are progressively delayed from entering the sensitive age window; and (4) with increasing dose, the transformation sensitivity of cells in the sensitive window is not expressed due to increased killing. Protracted low doses result in elevated frequencies because of less killing, and reductions in delays in cell progression. Therefore, transformation-sensitive cells can progress into the sensitive interval to replace those that have progressed out of it. The unique shape and radiobiological properties of cells in and around mitosis, led to the proposal that the sensitive window is mitosis and possible cells just preceding or just following M phase (Elkind 1991a,b). Because of the likelihood that the properties of the cells in a sensitive window would not be evident only when fission-spectrum neutrons are used, this study was undertaken using137Cs γ-rays. We have found that late G2- to M-phase 10T1/2 cells have a maximal sensitivity to neoplastic transformation as well as to killing by137Cs γ-rays.