PTEN基因敲除降低辐射敏感性及其机制

目的 探讨PTEN基因敲除对辐射敏感性的影响及机制。方法 采用流式细胞术检测MEF1和MEF1/PTEN^－/－细胞内ROS水平;采用Western blot方法,检测H₂O₂和DPI预处理后AKT激酶的表达变化;采用细胞克隆形成率试验分析细胞对⁶⁰Co γ射线的敏感性。结果 PTEN基因敲除后细胞ROS水平增加,辐射敏感性降低。H₂O₂和DPI预处理后影响MEF1细胞AKT激酶活性,但对MEF1/Pten^－/－细胞无影响。 结论 PTEN基因敲除阻断了ROS对AKT的介导,AKT激酶持续活化,可能是辐射敏感性降低的重要原因。

PTEN gene knock-out effect of radiosensitivity and its mechanism

Objective To analyze the effect of PTEN gene on radiosensitivity and its mechanism.Methods The reactive oxygen species levels of MEF1 and MEF1/PTEN-/- cell were determined with flow cytometry.The AKT activity pretreated with diphenyleneiodonium chloride or hydrogen peroxide(H2O2)was detected by Westem blot.Cell cloning efficiency test was used to detect the radiosensitivity.Results Deletion of PTEN increased the level of basal reactive oxygen species and decreased the radiosensitivity.Pretreatment with diphenyleneiodonium chloride or hydrogen peroxide influenced the AKT activity of control MEF1 cells but not MEF1/Pten-/- cells.Conclusions Knock-out of PTEN gene could make AKT constitutively active and block H2O2 mediated PI3K/AKT signal transduction pathway,which should be the most reason of radioresistance.