miR-19a对血肿瘤屏障通透性的影响

Effects of miR-19a on the Blood-Tumor Barrier Permeability

目的研究miR-19a对血肿瘤屏障通透性的影响。方法将miR-19a模拟物转染至人脑微血管内皮细胞hCMEC/D3,应用real-timePCR法检测miR-19a的表达。用过表达miR-19a的hCMEC/D3细胞和人U251胶质瘤细胞建立体外血肿瘤屏障模型,跨内皮电阻测量系统检测血肿瘤屏障跨内皮阻抗值的变化;Western blot和免疫荧光法检测体外血肿瘤屏障hCMEC/D3细胞中,紧密连接相关蛋白ZO-1和occludin的表达。结果经miR-19a模拟物转染后,hCMEC/D3细胞中miR-19a的表达水平显著升高;血肿瘤屏障跨内皮阻抗值显著下降;体外血肿瘤屏障hCMEC/D3细胞中,紧密连接相关蛋白ZO-1和occludin的表达水平显著降低,在细胞膜上呈不连续分布。结论 miR-19a过表达能显著增加血肿瘤屏障的通透性,其机制之一可能与降低紧密连接相关蛋白相关。

Objective To investigate the effect of miR-19a on the blood-tumor barrier （BTB） permeability.Methods After transfecting human cerebral microvascular endothelial cells （hCMEC/D3） with miR-19a mimic,real-time PCR analysis was used to detect the expression of miR-19a.The hCMEC/D3 cells overexpressing miR-19a and human U251 glioma cells were cocultured to establish the BTB model in vitro.Transendothelial electrical resistance （TEER） of BTB was measured and the expressing levels of tight junction associated proteins ZO-1 and occludin were detected by Western blot and immunofluorescence staining.Results After transfection with miR-19a mimic,the expressing level of miR-19a in hCMEC/D3 cells raised up markedly.The TEER of BTB decreased significantly.In the hCMEC/D3 cells of BTB in vitro,the expressing levels of tight junction associated proteins ZO-1 and occludin were reduced significantly.ZO-1 and occludin proteins showed a discontinuous localization on the membrane of hCMEC/D3 cells.Conclusions Overexpressing miR-19a can increase the BTB permeability significantly,and the decreased expression of tight junction associated proteins might be one of the related mechanisms.