miR-638通过靶向调控Notch 4促进神经胶质瘤细胞的侵袭能力

MiR-638 promotes invasion of glioma cells via modulating Notch 4 expression

目的研究微小RNA-638(miR-638)在恶性胶质瘤中的表达,探讨miR-638在胶质瘤细胞侵袭过程中的作用及可能机制。方法实时荧光定量PCR(qRT-PCR)分别检测正常神经组织、胶质瘤组织、正常胶质细胞株、胶质瘤细胞株中miR-638的表达水平;Transwell实验检测分别转染miR-638模拟物和miR-638抑制物后U251细胞侵袭水平的改变;生物信息学预测和验证miR-638对Notch 4的靶向调控关系;构建Notch 4真核表达重组质粒(p CMV-Notch 4 c DNA)过表达U251细胞中的Notch 4表达水平,并检测U251细胞侵袭水平的改变。结果 miR-638在胶质瘤组织和细胞株中表达上调,而Notch 4在胶质瘤细胞中表达下调,两者表达呈负相关性;过表达miR-638使U251细胞的侵袭细胞数上升(P<0.01),而抑制miR-638表达后U251细胞的侵袭细胞数减少(P<0.01);miR-638在U251细胞中能直接靶向抑制Notch 4的表达,提升Notch 4在U251细胞中的表达能使侵袭细胞数减少(P<0.01)。结论 miR-638在胶质瘤中高表达,其可能通过靶向抑制Notch 4的表达促进胶质瘤细胞的侵袭能力。

Objective To investigate the expression of microRNA-638 （miR-638） in gliomas tissues/cells and its role in the invasion of human glioma cells and the potential mechanism. Methods RT-PCR was used to detected expression of miR-638 in normal nerve tissues/cells and glioma tissue/cells. Transwell assay was used to detect the changes of the invasion level of U251 cells transfected with miR- 638 mimic and miR-638 inhibitor. Relationship between miR-638 and Notch 4 was predicted and validated by bioinformatics analysis. Overexpressing Notch 4 by constructing eukaryotic expression plasmid and transfeeted into U251 （ pCMV-Notch 4 eDNA ） , invasion level of U251 cells was detected by Transwell assay. Results Expression of miR-638 in glioma tissues and cells was up- regulated, whereas Notch 4 was down-regulated, the correlation was negative ; In U251 cells, the overexpression of miR-638 increased the number of invasive cells （P 〈 0. 01 ） , and that inhibited the expression of miR-638 can decrease the number of invasive cells（ P 〈 0. 01 ） ; in U251 cells, miR-638 target to inhibit the expression of Notch 4 directly, and enhanced the expression of Notch 4 can decrease the number of invasive cells（ P 〈 0. 01 ）. Conclu- sion MiR-638 is highly expressed in gliomas, which may promote the invasion of glioma ceils by inhibiting the expression of Notch 4.