目的 探讨应用RNA干涉(RNAi)技术抑制U251恶性胶质瘤细胞丝/苏氨酸蛋向激酶1(AKT1)和3-羧基磷脂酰肌醇激酶的85000催化亚基(P13KP85)表达后对U251胶质瘤细胞侵袭的抑制作用.方法 实验设正常对照组(未做任何处理);阴性对照组(rAd-HK组):用无义序列重组腺病毒感染U251胶质瘤细胞;基凶治疗组(rAd-A+P组):用靶向AKT1和P13KP85的重组腺病毒感染U251胶质瘤细胞.应用实时PCR检测AKT1和P13KP85 mRNA水平的变化;应用Western blot方法 检测AKT1和P13KP85蛋白水平的变化,并对肿瘤细胞中相关功能蛋白的表达进行分析;应用酶联免疫分析法(ELISA)检测细胞外基质金属蛋白酶2(MMP2)和基质金属蛋白酶9(MMP9)浓度的变化;应用划痕和Transwell实验评价肿瘤细胞侵袭能力的变化.结果tAd-A+P 可显著抑制U251胶质瘤细胞AKT1和P13KP85的表达.与正常对照组和rAd-HK组比较.rAd-A+P组MMP2、MMP9表达下降,而基质金属蛋白酶抑制因子(TMP2)表达上调,差异有统计学意义(P〈0.05).划痕和Transwell实验显示rAd-A+P组细胞体外侵袭能力明显减弱.结论 靶向AKT1和P13KP85的RNAi技术可以显著抑制U251胶质瘤细胞AKT1和PDKP85表达,对U251胶质瘤细胞的侵袭能力产生明显抑制作用.
Objective To investigate the suppressing effects of RNA interference (RNAi)targeting AKT1 and phosphatidylinositol 3-kinase p85 (PI3KP85) on the invasion ability of malignant glioma U251 cells in vitro.Methods Normal control group,negative control group (U251 cells being transfected by nonsense sequence of adenovirus) and gene treatment group were chosen in the experiment.A recombinant rctrovims expressing short interference RNA (siRNA) sequence targeting AKTi and PI3KP85 genes was established and transfected into the U251 cells in the gene treatment group.The silencing effect of RNAi on AKTI and PI3KP85 expressions was identified by real time PCR and Westem blotting,respectively.Western blotting was also employed to analyze the expression of some functional proteins.Enzyme-linked immuno sorbent assay (ELISA) was used to detect the changes of concentration of ectocytic matrix metalloproteinases 2 (MMP2) and MMPg.The invasion ability of U251 cells in the 3 groups was evaluated by scarification and Transwell assay.Results The expressions of AKT1 and PI3KP85 in U251 cells in the gene treatment group were dramatically down-regulated.As compared with the normal control and negative control groups,the gene treatment group showed significantly lower expression level of MMP2 and MMP9(P〈0.05);meanwhile tissue inhibitor of matrix metalloproteinase-2(TIMP2)in the gene treatment group was significantly up-regulated.ELISA also indicated obvious changes of concentration of ectocytic MMP2 and MMP9.The scarification and Transwell assay showed that the invasion ability in the gene treatment group was significantly decreased as compared with that in the other 2 groups (P〈0.05).Conclusion RNAi targeting AKT1 and PI3KP85 can significantly down-regulate the expressions of AKT1 and PI3KP85 and decrease the invasion ability of U251 cells in vitro.