MiR-26b通过下调COX-2表达抑制神经胶质瘤的增殖、侵袭和迁移

MiR-26b inhibits proliferation,invasion,and migration of glioma by targeting cyclooxygenase-2

目的:观察不同级别神经胶质瘤中miR-26b和环氧化酶(COX)-2的表达情况,研究miR-26b对于神经胶质瘤细胞增殖、侵袭和迁移的影响。方法:运用Western印迹和实时定量荧光PCR(q RT-PCR)检测不同级别神经胶质瘤中miR-26b和COX-2的表达情况;使用miR-26b mimic转染人神经胶质瘤细胞U87,上调miR-26b的表达;q RT-PCR检测miR-26b mimic转染后miR-26b和COX-2 mRNA的表达变化情况;双荧光素酶报告基因系统检测miR-26b对COX-2转录活性的影响;使用Transwell侵袭实验检测miR-26b对人神经胶质瘤细胞U87侵袭能力的影响;使用划痕实验检测miR-26b对人神经胶质瘤细胞U87迁移能力的影响;使用CCK-8(cell counting kit-8)检测miR-26对人神经胶质瘤细胞U87增殖能力的影响;裸鼠体内成瘤实验检测过表达miR-26b后胶质瘤细胞成瘤能力的变化。结果:随着神经胶质瘤肿瘤级别的增加,miR-26b表达明显降低(P<0.05),而COX-2明显增加,差异有统计学意义(P<0.001);双荧光素酶实验证实miR-26b可以直接靶向调控COX-2的蛋白表达水平;使用miR-26b mimic明显上调miR-26b的表达(P<0.05);上调miR-26b可以显著降低COX-2的表达(P<0.05);上调miR-26b可以抑制神经胶质瘤细胞增殖、侵袭和迁移能力(P<0.05)。实验组和对照组相比肿瘤的质量和体积都变小。结论:随着神经胶质瘤肿瘤级别的增加,miR-26b表达逐渐降低,而COX-2表达逐渐增加。miR-26b可通过抑制COX-2表达从而抑制神经胶质瘤的增殖、侵袭和迁移。

Objective： To explore the expressions ofmiR-26b and cyclooxygenase （COX）-2 in different grades ofgliomas and the effect ofmiR-26b on glioma cell proliferation, invasion and migration. Methods： Western blot and Real-time quantitative PCR （qRT-PCR） were used to detect theexpression levels of miR-26b and COX-2 in different grades of gliomas. Human glioma cells were transfected with miR-26b mimics, qRT-PCR was employed to detect the mRNA expressions of miR-26b and COX-2 after miR-26b mimics transfection, while dual-luciferase reporter assay was used to investigate the regulatory effect of miR-26b on COX-2. Cell counting kit-8 （CCK8）, trans- well invasion assay and scratch assay were used to detect the proliferation, invasion and migration of human U87 glioma cells after miR-26b mimic transfection, respectively. The antitumor effect of miR-26b was verified by evaluating the volume and weight of tumor in nude mice. Results： With the increase in tumor grades, the expression of miR-26b was significantly decreased （P〈0.05）, while COX-2 expression was increased （P〈0.001）. Dual luciferase assay confirmed that miR-26b could directly regulate the protein expression of COX-2. MiR-26b mimics could significantly reduce the expression of COX-2 （P〈0.05） and suppress the proliferation, invasion and migration of glioma cell （P〈0.05）. The volume and weight of tumor in MiR-26b mimics transfection group were smaller than those in the control group. Conclusion： Overexpression of miR-26b may inhibit proliferation, invasion, and migration of glioma by suppressing the expression of COX-2. Therefore, the miR-26b/COX-2 pathway might be a therapeutic target in glioma.