RNAi下调PIK3 CB表达抑制U251胶质瘤细胞生长的体内外研究

目的 探讨应用RNAi技术靶向磷酸肌醇酯-3-激酶β催化亚单位(PIK3CB)抑制恶性胶质瘤细胞系U251的PIK3CB表达后在体内外对U251细胞生长抑制作用.方法 将短发夹RNA(shRNA)表达载体psiRNA-PIK3CB进行脂质体介导的U251人脑恶性胶质瘤细胞系表达,检测细胞转染前后的细胞增殖能力和凋亡的变化.应用裸鼠皮下荷瘤模型观察脂质体介导shRNA基因治疗对U251细胞生长抑制作用,对肿瘤组织应用免疫荧光双染色和免疫组化的方法分析结果.结果 靶向PIK3CB的shRNA转染后U251细胞生长受到抑制,细胞周期出现G2/M阻滞,细胞明显凋亡.裸鼠皮下荷瘤模型实验显示psiRNA-PIK3CB显著抑制皮下肿瘤生长(P＜0.01).结论 靶向PIK3CB的shRNA基因治疗可以成为胶质瘤治疗的新策略.

Downregulation of PIK3CB by RNAi suppresses malignant glioma cell growth in vitro and in vivo

Objective To investigate the growth inhibition effect on tumor growth of U251 glioma cells with overexpressing the catalytic beta polypeptide of phosphatidylinositol 3-kinase(PIK3 CB)by small hairpin RNA targeting PIK3CB.Methods A short hairpin RNA(shRNA)expression construct,psiRNA-PIK3 CB was transfected into human malignant glioma U251 cells as mediated by Lipofectamine.The proliferative activities and cell apoptosis were evaluated.For in vivo study,lipofectamine-mediated psiRNA-PIK3 CB plasmid was injected intratumorally into established subcutaneous U251 glioma,tumor samples were further examined by immunofluorescence staining and immunohistochemistry.Results Cell growth was inhibited and cell cycle induced at G2/M phase arrest in vitro,meanwhile with significant apoptosis.The tumor volume of psiRNA-PIK3 CB treated group was smaller than that of the control(psiRNA-scr)and empty plasmid treated group(P＜0.01).Conclusion Gene therapy targeting PIK3CB would be a new strategy in targeting molecular therapy of gliomas.