Methyltransferase like 3 (METTL3) has been reported to be dysregulated in glioma. However, its role in aerobic glycolysis of glioma remains unknown. This study was conducted to explore the molecular mechanism by which METTL3 regulates aerobic glycolysis of glioma and provide novel targets for the treatment of glioma. The expression levels of METTL3, microRNA (miR)-27b-3p, and pyruvate dehydrogenase kinase 1 (PDK1) were determined in glioma cell lines and normal human astrocytes. Cell proliferation and aerobic glycolysis were evaluated by cell counting kit-8 and colony formation assays and measurements of glucose uptake, lactate production, adenosine triphosphate, Hexokinase activity, oxygen consumption rate, and extracellular acidification rate. After m6A quantification analysis, methylated RNA immunoprecipitation, and the dual-luciferase assay, the rescue experiments were performed using miR-27b-3p inhibitor or pcDNA3.1-PDK1 with pcDNA3.1-METTL3. METTL3 was lower in glioma cells and METTL3 overexpression reduced aerobic glycolysis. METTL3 increased m6A modification to promote the processing of pri-miR-27b by DGCR8 and the expression of mature miR-27b-3p, and miR-27b-3p targeted and inhibited PDK1 expression. miR-27b-3p inhibition or PDK1 overexpression both neutralized the inhibitory role of METTL3 overexpression in aerobic glycolysis. Overall, METTL3 overexpression increased the expression of mature miR-27b-3p via m6A modification and inhibited PDK1 expression, thus suppressing aerobic glycolysis of glioma.

中文翻译：

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METTL3 通过调节 m6A/miR-27b-3p/PDK1 在胶质瘤有氧糖酵解中的作用

据报道，甲基转移酶样 3 (METTL3) 在神经胶质瘤中失调。然而，其在神经胶质瘤有氧糖酵解中的作用仍不清楚。本研究旨在探讨METTL3调节胶质瘤有氧糖酵解的分子机制，为胶质瘤的治疗提供新的靶点。在神经胶质瘤细胞系和正常人星形胶质细胞中测定 METTL3、microRNA (miR)-27b-3p 和丙酮酸脱氢酶激酶 1 (PDK1) 的表达水平。通过细胞计数试剂盒8和集落形成测定以及葡萄糖摄取、乳酸产生、三磷酸腺苷、己糖激酶活性、耗氧率和细胞外酸化率的测量来评估细胞增殖和有氧糖酵解。经过 m6A 定量分析、甲基化 RNA 免疫沉淀和双荧光素酶测定后，使用 miR-27b-3p 抑制剂或 pcDNA3.1-PDK1 与 pcDNA3.1-METTL3 进行救援实验。METTL3 在神经胶质瘤细胞中较低，METTL3 过度表达减少了有氧糖酵解。METTL3增加m6A修饰促进DGCR8对pri-miR-27b的加工以及成熟miR-27b-3p的表达，并且miR-27b-3p靶向并抑制PDK1表达。miR-27b-3p 抑制或 PDK1 过表达均可中和 METTL3 过表达在有氧糖酵解中的抑制作用。总体而言，METTL3过表达通过m6A修饰增加成熟miR-27b-3p的表达并抑制PDK1表达，从而抑制胶质瘤的有氧糖酵解。