rAd-p53 gene induces apoptosis and radiosensitizing effects of human glioma cell line U251

Objective To evaluate the effects of domestic recombinant adenovirus-p53 (rAd-p53) on growth and radiosensitivity of human brain glioma cell line.Methods Human brain glioma cell line U251 was treated with rAd-p53 and rAd-p53 plus radiotherapy,respectively.Expression of p53 protein was detected by immunocytochemistry.The cell growth inhibition was assessed by MTT and clone forming assay,and cell cycle and apoptosis were detected by flow cytometry. ResultsOverexpression of p53 protein was found in rAd-p53 infected U251.There were time dependence in a certain period and dose dependence in the inhibition of cell proliferation by rAd-p53. rAd-p53 induced phase-G2/M block with an apoptotic rate of (27.39±2.89)% in rAd-p53 plus radiotherapy group,which was significantly higher than (11.31±1.99)% in rAd-p53 group,and (5.49±0.84)% in radiotherapy group(P0.01).The survival rate of the cells in rAd-p53 plus radiotherapy group was lower than that in single radiotherapy group at the same radiation doses. Conclusion p53 protein can be expressed in the U251 cells after using rAd-p53 and may induce the apoptosis of human glioma cell lines. rAd-p53 can enhance the sensitivity of radiotherapy.