FXR1 通过稳定 MIR17HG 促进神经胶质瘤细胞的恶性生物学行为。

FXR1 promotes the malignant biological behavior of glioma cells via stabilizing MIR17HG.

机构信息

Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China.

Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, China.

出版信息

J Exp Clin Cancer Res. 2019 Jan 28;38(1):37. doi: 10.1186/s13046-018-0991-0.

DOI:10.1186/s13046-018-0991-0

PMID:30691465

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6348679/

Abstract

BACKGROUND

Accumulating evidence has highlighted the potential role of RNA binding proteins (RBPs) in the biological behaviors of glioblastoma cells. Herein, the expression and function of RNA binding proteins FXR1 were investigated in human glioma cells.

METHODS

Quantitative real-time PCR were conducted to evaluate the expression of MIR17HG and miR-346, miRNA-425-5p in glioma tissues and cells. Western blot were used to explore the expression of FXR1, TAL1 and DEC1 in glioma tissues and cells. Stable knockdown of FXR1 and MIR17HG in glioma cells were established to explore the function of FXR1, MIR17HG in glioma cells. Further, RIP and RNA pull-down assays were used to investigate the correlation between FXR1 and MIR17HG. Cell Counting Kit-8, transwell assays, and flow cytometry were used to investigate the function of FXR1 and MIR17HG in malignant biological behaviors of glioma cells. ChIP assays were employed to ascertain the correlations between TAL1 and MIR17HG.

RESULTS

FXR1and MIR17HG were upregulated in glioma tissues and cell lines. Downregulation of FXR1 or MIR17HG resulted in inhibition of glioma cells progression. We also found that FXR1 regulates the biological behavior of glioma cells via stabilizing MIR17HG. In addition, downregulated MIR17HG increased miR-346/miR-425-5p expression and MIR17HG acted as ceRNA to sponge miR-346/miR-425-5p. TAL1 was a direct target of miR-346/miR-425-5p, and played oncogenic role in glioma cells. More importantly, TAL1 activated MIR17HG promoter and upregulated its expression, forming a feedback loop. Remarkably, FXR1 knockdown combined with inhibition of MIR17HG resulted in the smallest tumor volumes and the longest survivals of nude mice in vivo.

CONCLUSIONS

FXR1/MIR17HG/miR-346(miR-425-5p)/TAL1/DEC1 axis plays a novel role in regulating the malignant behavior of glioma cells, which may be a new potential therapeutic strategy for glioma therapy.

摘要

背景

越来越多的证据表明 RNA 结合蛋白（RBPs）在神经胶质瘤细胞的生物学行为中具有潜在作用。在此，研究了 RNA 结合蛋白 FXR1 在人类神经胶质瘤细胞中的表达和功能。

方法

采用实时定量 PCR 检测神经胶质瘤组织和细胞中 MIR17HG 和 miR-346、miR-425-5p 的表达。Western blot 检测神经胶质瘤组织和细胞中 FXR1、TAL1 和 DEC1 的表达。建立稳定敲低神经胶质瘤细胞中 FXR1 和 MIR17HG 的细胞系，以探讨 FXR1、MIR17HG 在神经胶质瘤细胞中的功能。进一步采用 RIP 和 RNA 下拉实验研究 FXR1 与 MIR17HG 之间的相关性。采用细胞计数试剂盒-8、Transwell 实验和流式细胞术研究 FXR1 和 MIR17HG 在神经胶质瘤细胞恶性生物学行为中的功能。采用 ChIP 实验确定 TAL1 与 MIR17HG 之间的相关性。

结果

FXR1 和 MIR17HG 在神经胶质瘤组织和细胞系中上调。下调 FXR1 或 MIR17HG 导致神经胶质瘤细胞的进展受到抑制。我们还发现，FXR1 通过稳定 MIR17HG 来调节神经胶质瘤细胞的生物学行为。此外，下调 MIR17HG 增加了 miR-346/miR-425-5p 的表达，并且 MIR17HG 作为 ceRNA 来海绵吸附 miR-346/miR-425-5p。TAL1 是 miR-346/miR-425-5p 的直接靶标，在神经胶质瘤细胞中发挥致癌作用。更重要的是，TAL1 激活 MIR17HG 启动子并上调其表达，形成一个反馈环。值得注意的是，FXR1 敲低与抑制 MIR17HG 联合作用导致体内裸鼠的肿瘤体积最小，存活时间最长。