miR-195通过下调IGF-1R的表达抑制胶质母细胞瘤的增殖和迁移

目的:探讨miR-195对胶质母细胞瘤(Glioblastoma,GBM)增殖和迁移的影响,并阐明其分子调控机制。方法:采用qRT-PCR检测不同级别胶质瘤中miR-195的表达。将miR-195转染至胶质瘤U251细胞后,应用qRT-PCR验证转染效率,MTT及划痕实验检测U251细胞的增殖及迁移能力的改变,qRT-PCR及Western blot检测胰岛素样生长因子1受体(Insulin-like growth factor 1receptor, IGF-1R)的mRNA和蛋白表达;利用质粒转染过表达miR-195后,同时过表达IGF-1R,再应用MTT及划痕实验检测U251细胞的增殖及迁移能力的变化。结果:随着胶质瘤级别的增加,miR-195的表达逐渐降低,各级别胶质瘤中miR-195的表达差异有统计学意义(P0.05)。体外转染miR-195至U251细胞24、48、72 h后,转染组细胞活力和迁移能力均较对照组显著降低(P0.05),细胞中IGF-1R的mRNA和蛋白的表达也明显减少(P0.05);通过转染IGF-1R过表达质粒可显著逆转miR-195过表达对U251细胞增殖及迁移的抑制作用。结论:miR-195可能通过下调IGF-1R的表达,进而抑制胶质母细胞瘤的增殖和迁移。

MiR-195 Inhibits the Proliferation and Migration of Glioblastoma Through Down-regulation the Expression of IGF-1R

ABSTRACT Objective: To investigate the effect of miR-195 on the proliferation and migration of glioblastoma and to elucidate its molecular regulation mechanism. Methods: qRT-PCR was used to detect the expression of miR-195 in gliomas with different grades. After transfecting miR-195 into glioma U251 cells, qRT-PCR was used to verify the transfection efficiency, MTT and Scratch test were used to detect the proliferation and metastasis ability of U251 cells, and qRT-PCR and Western blot were used to detect the mRNA and protein expression of Insulin-like growth factor 1 receptor (IGF-1R). After overexpression of miR-195 by plasmid transfection, IGF-1R was overexpressed simultaneously, then the MTT and Scratch test were applied to detect the proliferation and metastasis ability of U251 cells. Results: The expression of miR-195 was gradually decreased with the increase of glioma grade. The expression of miR-195 was statistically significant between all grades of gliomas (P<0.05); After transfection of miR-195 to U251 cells for 24, 48 and 72 h in vitro, both of the cell viability and migration ability in transfected group were significantly lower than those in control group (P<0.05), and the expression of IGF-1R mRNA and protein were also decreased in transfected group (P<0.05); Transfection of IGF-1R overexpression plasmid significantly reversed the inhibitory effect of miR-195 overexpression on the proliferation and migration of U251 cells. Conclusion: miR-195 might inhibit the proliferation and migration of glioblastoma by down-regulating the expression of IGF-1R.