Objective: To investigate the regulatory role of miR-26b-3p in proliferation, migration and invasion of glioma.
Methods: The expressions of miR-26b-3p and cAMP-responsive element binding protein 1 (CREB1) in gliomas of different pathological grades were detected with RT-qPCR and Western blotting. Bioinformatic methods were used to analyze the target sequence of miRNA-26b-3p binding to CREB1, and dual luciferase gene reporter experiment was performed to explore the mechanism for targeted regulation of CREB1 by miR-26b-3p. Glioma U251 cells were treated with miR-26b-3p mimic or inhibitor, and the changes in CREB1 expression and cell proliferation, migration, invasion and apoptosis were determined with Western blotting, CCK-8 assay, wound healing assay, Transwell assay, and flow cytometry.
Results: The expression of miR-26b-3p decreased while CREB1 expression increased significantly as the pathological grade of gliomas increased (P < 0.05). Dual luciferase gene reporter experiment confirmed that CREB1 was a downstream target of miR-26b-3p. Inhibition of miR-26b-3p significantly upregulated the expression of CERB1, suppressed apoptosis and promoted proliferation and invasion of glioma cells, and overexpression of miR-26b-3p produced the opposite effects (P < 0.05).
Conclusion: MiR-26b-3p regulates CREB1 expression to modulate apoptosis, proliferation, migration and invasion of glioma cells, thereby participating in tumorigenesis and progression of glioma.
目的: 探讨miR-26b-3p靶向调控环磷酸腺苷效应元件结合蛋白1（CREB1）表达水平影响胶质瘤细胞增殖、迁移和侵袭能力的分子机制。
方法: 运用RT-qPCR和Western blotting检测不同级别胶质瘤中miR-26b-3p和CREB1的表达情况；生物信息学方法分析miR-26b-3p与CREB1结合的靶向序列。采用双荧光素酶报告基因检测miR-26b-3p对CREB1的靶向调控机制；将胶质瘤U251细胞分为对照组、miR-26b-3p mimic组及miR-26b-3p inhibitor组，采用Western blotting检测CREB1的表达变化，采用CCK-8法检测各组细胞增殖能力的影响，采用划痕实验检测各组细胞迁移能力的影响，采用Transwell检测各组细胞侵袭能力的影响，采用流式细胞术检测各组细胞凋亡的影响。
结果: miR-26b-3p的表达随着胶质瘤级别的增加而降低（P < 0.05），而CREB1的表达则逐渐增加，差异有统计学意义（P < 0.05）；双荧光素酶报告基因结果显示miR-26b-3p可显著影响CREB1 3′UTR表达载体的荧光素酶活性，CREB1是miR-26b-3p下游靶基因。抑制miR-26b-3p表达可上调CERB1的表达，进而抑制细胞凋亡，促进胶质瘤细胞的增殖和侵袭。过表达miR-26b-3p可下调CERB1的表达，促进细胞凋亡，抑制胶质瘤细胞的增殖和侵袭（P < 0.05）。
结论: miR-26b-3p可靶向调控CREB1的表达调节胶质瘤细胞的凋亡、增殖、迁移和侵袭，进而参与胶质瘤的发生发展。
Keywords: cAMP-responsive element binding protein 1; glioma; invasion; miR-26b-3p; migration; proliferation.