p53基因、PTEN基因协同对胶质瘤U251细胞系生长抑制作用的研究

The co-inhibitory effect of p53 gene and PTEN gene on the growth of glioma cell line U251

目的探讨p53基因和PTEN基因在脑胶质瘤细胞系U251发生发展过程中的作用机制。方法用不同MOI的p53腺病毒表达载体pAdCMV-p53及空载体pAdCMV-lacZ分别感染表达野生型PTEN基因和突变型PTEN基因的细胞系,RT-PCR及Westernblot方法检测转染效率;并通过MTT检测生长抑制率、流式细胞仪检测细胞周期及TUNEL检测分析细胞凋亡等指标观察p53基因及PTEN基因对U251细胞生长的影响。结果MOI为100时,p53基因可引起U251细胞G0G1期阻滞、诱导细胞凋亡,生长抑制;MOI为50时,U251-p53+PTEN生长抑制率明显高于U251-p53,并能出现细胞凋亡,而U251-p53仅出现少量细胞凋亡。结论p53基因可以通过细胞周期G0G1期阻滞及诱导细胞凋亡抑制胶质瘤细胞系U251的生长;PTEN基因可以促进p53基因对胶质瘤细胞系U251的生长抑制作用,并能增加U251细胞对p53基因诱导凋亡的敏感性。

Objective To investgate the role of p53 gene and PTEN gene in the growth of glioma cell line U251. Methods We infected U251 and U251-PTEN with recombinant adenovirus encoding wild-type p53 gene and pAdCMV-lacZ in different MOI respectively Expression of exogenous p53 gene was confirmed by RT-PCR and Western blot analysis the suppression effects of these genes were evaluated by MTT and flow cytometric analysis and TUNEL technique. Results Both of the G1 arrest and apoptosis were detected after high efficiency expressed of wild-type p53 gene in U251(MOI 100) comparing the ratio of cell growth inhibition between U251-p53MOI 50+PTEN in which lots of apoptosis signals were detected and U251-p53MOI 50 we found the former is higher than the other. Conclusions The overe xpression of wild type p53 gene and PTEN gene can inhibit the cell growth of U251 and the overexpression of PTEN gene can increase the sensitization of p53-induced apoptosis.