X刀放射对U251细胞端粒酶活性影响的实验研究

目的观察U251细胞转染PTEN基因前后端粒酶活性的改变及X刀照射前后不同PTEN基因状态的U251细胞端粒酶活性变化,探索X刀对于不同PTEN基因状态的U251细胞端粒酶的影响。方法构建携带正常PTEN基因的pcDNA3.1/Hygro(-)真核质粒载体,并用之转染PTEN失活的U251细胞系,半定量端粒重复序列扩增(TRAP)银染法检测转染前后端粒酶活性改变,用48小时的半数致死剂量对于不同PTEN基因状态的U251细胞进行X刀照射,检测照射前后端粒酶活性水平变化。结果PTEN基因转染的U251细胞在生长过程中其端粒酶活性下降。X刀照射后的U251细胞的端粒酶活性上升,携带外源性PTEN基因的U251细胞照射后则表现为下降。结论携带外源性PTEN基因的U251细胞对于X刀照射的敏感性增加,可能与其抑制细胞的端粒酶活性有关。

Experimental study on the activity of telomerase of U251 gliomas cells treated by X knife

Objective To observe the different telomerase activity of U_(251) gliomas cells tansfected by wild type PTEN gene,and the different activity of telomerase ofthe cells(including transfected and untransfected) treated by linear accelerator radiosurgery X knife.Explore the effects of X knife on the telomerase of the U_(251) and the effects of PTEN gene on the telomerase of the U_(251).Methods Construct a pcDNA3.1/Hygro(-) recombinant plasmid containing PTEN gene.U_(251) cells which express no PTEN were transfected with wild-type PTEN plasmid vector and stable transfected clones were selected.Then,the transfected cells,untransfected cells and the cells transfected with empty vector was treated by X knife,the different activity telomerase of of U_(251) gliomas cells were detected by semi-quantitative telomeric repeat and plification protocol(TRAP),and were compared with the cells which were not treated by X knife.Results The telomerase activity of the transfected cells were obviously lower.The telomerase activity of untransfected cells treated by X knife were highly.But in the transfected cells the telomerase activity were lower.Conclusion Wild-type PTEN could have a positive impact on the Xknife therapy of gliomas cell.