中文摘要：

目的探讨敲低miRNA-221／222表达上调p27^kip1抑制U251人脑胶质瘤细胞株生长的效果及机制。方法脂质体共转染反义miRNA-221／222下调U251人脑胶质瘤细胞株miRNA-221、miRNA-222的表达。使用Northern blot方法鉴定转染后U251细胞miRNA-221、miRNA-222表达水平下调；MTT法评价反义miRNA-221／222抑制U251细胞生长效果；流式细胞术检测转染后U251细胞周期分布；Westernblot分析p27^kip1蛋白的表达变化。结果Northernblot显示反义miRNA-221／222共转染组使miRNA-221、miRNA-222的表达水平明显下降。反义miRNA-221转染组仅使miRNA-221的表达水平明显下降，反义miRNA：222转染组仅使miRNA-222的表达水平明显下降。转染无意序列组及对照组的miRNA-221、miRNA-222表达水平没有改变。MTT结果显示反义miRNA-221／222共转染组肿瘤细胞生长速度小于对照组、转染无意序列组、转染反义miRNA-221组、转染反义miRNA-222组。流式细胞术检测可见反义miRNA-221／222共转染组细胞周期存在G0／G1期阻滞且明显高于其他各组。Western blot显示反义miRNA-221／222共转染组的p27^kip1蛋白表达明显上调。结论反义miRNA-221／222通过上调p27^kip1蛋白表达来抑制胶质瘤细胞U251的生长。

英文摘要：

Objective To study the suppressive effect of enhancing p27^kip1 by knocking down of miRNA-221/222 on the U251 human glioma cell line growth and the possible mechanism. Methods Oligofectamine was used to transfect miRNA-221/222 antisense oligonucleotides to knock down the miRNA-221/221 expression level of U251 human glioma cell line in vitro. Northern blot was conducted to detect the miRNA expression of miRNA-221/222 among different treated groups. The proliferation ability of anti-miRNA-221/222 treated U251 glioma cell was determined by MTT. The cell cycle distribution was detected by cell flow cytometry. Western blot assay was used for p27^kip1 expression. Results The expression level of miRNA-221/222 in the anti-miRNA-221/222 group was significantly knocked down than in the other group was determined by northern blot. During the MTr observation, the tumor cell growth was slower in anti-miRNA-221/222 treated group than that in the other treated group. Cell cycle was blocked in G0/G1 phase in the anti-miRNA-221/222 group than in the other group. The expression of p27^kip1 was upregulated in the anti-miRNA-221/222 group by western blot. Conclusion By up-regulateing p27^kip1, antimiRNA-221/222 suppresses growth of U251 human glioma cell line.