目的 探讨miR-221和miR-222在胶质瘤细胞侵袭过程中的作用及其机制.方法 采用反义寡核苷酸下调miR-221和miR-222表达,Transwell、Western blot、荧光素酶实验及体内实验分别检测细胞侵袭能力、体内肿瘤生长、相关基因蛋白表达变化及靶基因鉴定.结果 下调miR-221和miR-222表达能明显抑制胶质瘤细胞侵袭能力,同时相关侵袭蛋白MMP2和MMP9表达下降.miRNA靶基因预测软件分析、Western blot、荧光素酶实验证实TIMP3是miR-221和miR-222的靶基因.裸鼠皮下肿瘤模型显示下调miR-221和miR-222表达抑制体内肿瘤生长.免疫组化发现TIMP3表达上调,MMP2和MMP9表达下调.结论 在胶质瘤细胞中,侵袭相关蛋白TIMP3是miR-221和miR-222的一个新靶基因.
Objective To investigate the role and mechanism of miR -221 and miR -222 in glioma cell invasion. Method After reduction of miR -221 and miR -222 by antisense oligonucleotides, cell invasion,invasion related - gene expression and target identification were determined by Transwell assay, Western blot analysis and luciferase reporter assay,respectively. Moreover,the effects of miR -221 and miR -222 on xenograft tumors in nude mice were also observed. Results Down - regulation of miR - 221 and miR - 222 decreased glioma cell invasion in vitro, and inhibited glioma growth in a subcutaneous mouse model. Furthermore,down -regulation of miR -221 and miR - 222 resulted in obvious inactivation of MMP2 and MMP9. Western blot analysis and luciferase reporter assay showed that the reduction of miR - 221 and miR -222 repressed TIMP3 protein expression and TIMP3 mRNA 3'UTR existed the biding sites of miR -221 and 222. Conclusions TIMP3 is a novel target of miR -221 and miR -222 in glioma cell invasion.