Circ?0080229结合蛋白的筛选及其在胶质瘤调控中的意义

［摘要］ 目的 鉴定EGFR基因来源的环状RNA circ?0080229在胶质瘤中所结合的蛋白，并分析其在胶质瘤调控中所发挥的作用。方法 通过PCR技术验证circ?0080229在胶质瘤中高表达，再应用RNA结合蛋白纯化实验及蛋白质谱技术，分析circ?0080229所结合的蛋白质。利用TCGA数据库进行circ?0080229结合蛋白的差异表达分析及生存分析，筛选出最有价值的circ?0080229结合蛋白ANXA2，并进行细胞功能实验的验证。结果 共有33个蛋白可与circ?0080229结合，其中以ANXA2和SIL1为代表的蛋白与胶质瘤病理分级和预后相关。在胶质瘤U251细胞系中，下调ANXA2的表达可显著抑制细胞的增殖、迁移及侵袭能力。结论 环状RNA circ?0080229可特异性结合ANXA2等RNA结合蛋白，同时circ?0080229结合蛋白ANXA2可促进胶质瘤的增殖能力、迁移能力与侵袭能力。

Screening of circ?0080229 binding proteins and their pivotal role in regulating glioma

［Abstract］ Objectives Glioma was the most common primary brain tumor whose molecular mechanism was unclear. In this study， we tried to assess the role of a circular RNA circ?0080229， derived from EGFR， as a critical biomarker in glioma， through the analysis of RNA binding proteins of circ?0080229. Methods At the beginning， qPCR analysis was carried out to verify the expression of circ?0080229 in glioma. Then， the tagged RNA affinity purification assay and the mass spectrum analysis were performed which figured out RNA binding proteins of circ?0080229. Moreover， we analyzed the differential expression of the genes of the RNA binding proteins and carried out the survival analysis based on TCGA data. Finally， the most valuable biomarker among all the RNA binding proteins was screened out， which was identified to regulate proliferation， migration and invasion in vitro in U251 glioma cell line. Results The expression of circ?0080229 was significantly increased in glioma compared to normal brain tissue. Circ?0080229 would physically bind to 33 RNA binding proteins and the bioinformatics analysis among the 33 genes indicated that two of the RNA binding proteins called ANXA2 and SIL1 were the most significant biomarkers in glioma. We further proved that ANXA2 could promote proliferation， migration and invasion in glioma cell line U251 in vitro. Conclusion The circ?0080229 would physically bind to ANXA2， which might promote the proliferation， migration and invasion in glioma.