Cariveaua Mickael J, Kalmus Gerhard W, Johnke Roberta M, Allison Ron R, Evans Mark, Holbert Donald
Department of Physics, East Carolina University, Greenville, North Carolina, USA.
Anticancer Res. 2006 Sep-Oct;26(5A):3311-6.
To better understand the relationship between the formation of radiation-induced DNA double strand breaks (DSB) and cell cycle checkpoint activation, studies were conducted in the NIH/3T3 fibroblast cell line in order to establish correlations between the temporal appearance of gamma-H2AX foci (a DSB) and the expression of the cell cycle regulatory proteins, the cyclins, and their cyclin kinase inhibitor, p21.
Immunocytochemistry was used to determine the expression of cyclin E, A, B1, p21, and the generation of DSB in NIH/3T3 cells exposed to 2 or 4 Gy X-irradiation.
The data suggest that the G1/S- and S-phase delay (cyclin E and cyclin A protein levels) are dependent on the dose of radiation while the G2/M (cyclin B1 protein levels) delay is dependent on the quantity of DSB sustained by the irradiated cell.
为了更好地理解辐射诱导的DNA双链断裂（DSB）形成与细胞周期检查点激活之间的关系，我们在NIH/3T3成纤维细胞系中开展了研究，以建立γ-H2AX焦点（一种DSB）的瞬时出现与细胞周期调节蛋白、细胞周期蛋白及其细胞周期蛋白激酶抑制剂p21表达之间的相关性。
采用免疫细胞化学方法测定暴露于2或4 Gy X射线照射的NIH/3T3细胞中细胞周期蛋白E、A、B1、p21的表达以及DSB的产生。
数据表明，G1/S期和S期延迟（细胞周期蛋白E和细胞周期蛋白A蛋白水平）取决于辐射剂量，而G2/M期延迟（细胞周期蛋白B1蛋白水平）取决于受照射细胞承受的DSB数量。
