microRNA-93-5p在肝细胞癌中正调控MAP3K2的机制研究

miRNA的非经典正调控作用方式是近年来的研究热点：miRNA结合靶基因启动子、增强子、5’ UTR和3’ UTR等序列部位，以RNA激活的调控方式在转录和转录后水平促进靶基因表达。而在肝癌中，RNA激活的调控模式尚缺乏研究。我们前期研究发现，miR-93-5p通过直接作用于靶点MAP3K2 mRNA 3’ UTR，以RNA激活的方式促进MAP3K2的表达，从而激活下游JNK信号通路，继而抑制p21，促进肝癌生长。本项目拟利用双荧光素酶报告基因实验、核糖核苷交联和免疫共沉淀实验和RNA免疫共沉淀实验等方法，发掘miR-93-5p依赖ARE或非依赖ARE的正调控作用方式，进一步探究miR-93-5p作用于MAP3K2 mRNA 3’ UTR的具体机制，发现肝癌中新的miRNA非经典正调控作用方式，为制定有效的抗肿瘤诊治策略提供新的理论基础。

Cumulative evidence suggests that microRNAs (miRNAs) transcriptionally or post-transcriptionally increase gene expression by binding to the sequences in the promoter, enhancer, 5′ -untranslated region (UTR), or 3′ -UTR of target genes, which remains unknown in hepatocellular carcinoma (HCC). Our previous study revealed that miR-93-5p directly activate mitogen-activated protein kinase kinase kinase 2 (MAP3K2) expression through binding to the 3′ -UTR of MAP3K2 mRNA, thereby leading to c-Jun N-terminal kinase (JNK) pathway activation and cell cycle progression in HCC. In this study, we aim to explore the exact mechanism of the 3′ -UTR-induced activation in an AU-rich elements (ARE)-dependent/independent manner via experiments, such as luciferase reporter assay, CLIP and RIP. We believe that this study will lead to a better understanding of the mechanisms involved in miR-93-5p-mediated development and progression of this deadly disease, and offers the implications for designing novel therapeutic interventions.