中文摘要：

目的研究miRNA-451过表达后通过靶标钙结合蛋白39（CAB39）调控人脑胶质瘤细胞上皮-间质转化发生的机制，以及miRNA-451过表达对胶质瘤细胞侵袭和迁移能力的影响。方法培养U251胶质瘤细胞，将其分为空白对照组、无义序列组以及miRNA-451 mimics处理组（简称miRNA-451组）。采用实时定量PCR检测转染后U251细胞miRNA-451的表达；以Western blot法检测CAB39、E-钙黏素、N-钙黏素、波形蛋白、TWIST、人基质金属蛋白酶2（MMP-2）、人基质金属蛋白酶9（MMP-9）、Snail、蛋白激酶B（AKT）、磷酸化蛋白激酶B（P—AKT）的表达水平；通过细胞免疫荧光实验进一步验证N-钙黏素、波形蛋白的表达水平；采用划痕实验和Transwell实验检测细胞侵袭和迁移能力的变化。结果与空白对照组及无义序列组相比，miRNA-451组的miRNA-451相对表达水平明显升高（均P〈0．05）。Western blot结果显示，与空白对照组及无义序列组相比，miRNA-451组CAB39、N-钙黏素、波形蛋白、TWIST、MMP-2、MMP-9、Snail、P-AKT的表达水平降低（均P〈0．05），而E-钙黏素的表达水平升高（均P〈0．05）。细胞免疫荧光实验结果显示，miRNA-451组的N-钙黏素、波形蛋白的表达水平相对于空白对照组明显降低（均P〈0．05）。划痕操作后24h、48h miRNA-451组的划痕修复率与空白对照组及无义序列组相比均明显降低（均P〈0．05）。转染48h后miRNA-451组穿过滤膜的细胞数目与空白对照组及无义序列组相比显著减少（均P〈0．05）。结论miRNA-451可能通过降低靶标CAB39的表达调控P13K／AKT通路，抑制人脑胶质瘤细胞中上皮-间质转化现象的发生，从而抑制人脑胶质瘤细胞的侵袭和迁移能力。

英文摘要：

Objective To investigate the mechanism of miRNA-451 overexpression in the regulation of epithelial-mesenchymal transition（EMT） in human glioma cells through target calcium binding protein 39 （CAB39） and to explore the effects of milRNA-451 overexpression on invasion and migration of glioma cells. Methods The U251 glioma cells were cultured and divided into 3 groups including control group, nonsense sequence group and miRNA-451 mimics treatment group （briefly miRNA-451 group）. The expression of miRNA-451 was detected by RT-PCR in glioma cells after transfection. The expression proteins of CAB39, E-cadherin, N-cadherin, Vimentin, TWIST, MMP-2, MMP-9, Snail, AKT, P-AKT were detected by Western blot. Cell immunofluorescence assay was used to further validate the expression levels of N-cadherin and Vimentin. The wound healing and transwell experiments were performed to detect changes in cell invasion and migration abilities. Results The miRNA-451 expression level in the miRNA-451 group was significantly higher compared with those in the control and nonsense sequence groups （ both P 〈 0.05 ）. The results of Western blot revealed that the expression levels of CAB39, N-cadherin, Vimentin, TWIST, MMP- 2, MMP-9, Snail, P-AKT in miRNA-451 group were decreased （all P 〈0.05） and the expression level of E-cadherin was increased as compared with those in the control and nonsense sequence groups （ all P 〈 0.05）. Cell immunofluorescence assay showed that the relative expressions of N-cadherin and Vimentin in miRNA-451 group were significantly lower than those in control group （both P 〈 0. 05 ）. The results of the wound healing showed that the scar repair rate of miRNA451 group was significantly lower than those in the control and nonsense groups at 24 hrs or 48 hrs post would healing（ all P 〈 0.05）. The number of cells in the miRNA451 group was significantly decreased as compared with the other two groups at 48 hrs post transfection （both P 〈 0.05）. Conclusion The regulation of PI3K