转录因子Sp1介导的miR-181b对胶质瘤细胞糖代谢过程的调控机制

Metabolism has become a hotspot of cancer research, and how to inhibit malignant tumor cell metabolism is the development direction of tumor biological treatment. MicroRNAs (miRNAs) are small highly conserved noncoding RNA molecules of approximately 18-25 nucleotides in length, regulate gene expression at the post-transcriptional level by binding complimentary sequences in the 3'-untranslated regions (UTRs) of target mRNAs. Increasing evidences have linked dysregulation of miRNA with glioma. Our data have verified that miR-181b is downregulted in glioma tissues, enhanced miR-181b could effectively inhibit glioma glycolysis and tumor growth; Bioinformatics analysis found that PKM2 and GLUT-1 are downstream factors of Sp1; Sp1 is the direct target of miR-181b.Base on these results, we propose a signaling pathway in glioma cell glucose metabolism, in which miR-181b inhibit the expression of PKM2 or GLUT-1 by targeting Sp1. Therefor, we intend to establish miR-181b→Sp1→PKM2/GLUT-1 diverse expression of cell model, and take a serial of cell function experiments combined with the tests of miRNA target gene validation and transcriptional regulation to deeply explore the interactive effect of miR-181b→Sp1→PKM2/GLUT-1 and the mechanism involved in glioma cell glucose metabolism. Taken together, we will provide a new miRNA functional model regulating glioma cell glucose metabolism, explore and develop optimization strategy ofglioma biological therapy dependent on the studies.

目前，肿瘤细胞代谢（特别是糖代谢）研究已成为当今肿瘤研究领域的热点，而有关胶质瘤发生发展过程与糖代谢关系的机制研究尚不全面。我们预实验发现：下调PKM2、GLUT-1或上调miR-181b能有效抑制胶质瘤糖酵解和生长；上调miR-181b可抑制靶基因Sp1的表达；生物信息学分析PKM2及GLUT-1为Sp1下游。据此提出假说：胶质瘤糖代谢与生长过程中存在miR-181b→Sp1→PKM2/GLUT-1调控通路。本课题拟以不同胶质瘤细胞为模型，以转录调控、转录后调控、基因回复等为手段，全面分析miR-181b→SP1→PKM2/GLUT-1调控网络及其对胶质瘤细胞糖代谢与生长的影响，分析网络关键节点在胶质瘤分子诊断、预后判断及靶向治疗中的作用，为寻找胶质瘤新的治疗靶点奠定基础。

目前，肿瘤细胞代谢（特别是糖代谢） 研究已成为当今肿瘤研究领域的热点，而有关胶质瘤发生发展过程与糖代谢关系的机制研究尚不全面。本项目中，我们通过应用胶质瘤U87及U251细胞系，发现上调 miR-181b能影响 PKM2 及 GLUT1 的蛋白表达，并能够抑制胶质瘤的糖代谢；下调 Sp1 的表达能下调 PKM2 及 GLUT1 的蛋白表达，同时发现胶质瘤细胞糖酵解水平下降，细胞增殖能力显著降低；Sp1为miR-181的直接靶基因； Sp1能通过转录调控直接调控 PKM2 并影响GLUT1的表达并影响胶质瘤细胞糖代谢过程；体内实验验证 了miR-181b/Sp1/PKM2、 GLUT1调控通路对胶质瘤生长的抑制现象，提出了miR-181b→SP1→PKM2/GLUT-1调控网络的概念。本课题以不同胶质瘤细胞为模型，以转录调控、转录后调控、基因回复等为手段，全面分析miR-181b→SP1→PKM2/GLUT-1调控网络及其对胶质瘤细胞糖代谢与生长的影响，分析网络关键节点在胶质瘤分子诊断、预后判断及靶向治疗中的作用，为寻找胶质瘤新的治疗靶点奠定基础。