Department of Neurosurgery, the First Hospital of China Medical University, NO.155, North Nanjing Street, Heping District, Shenyang City, 110001, China.
Department of Neurosurgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, People's Republic of China.
J Exp Clin Cancer Res. 2021 Apr 15;40(1):134. doi: 10.1186/s13046-021-01931-9.
Glioma is the most common and malignant tumor of central nervous system. The tumor initiation, self-renewal, and multi-lineage differentiation abilities of glioma stem cells (GSCs) are responsible for glioma proliferation and recurrence. Although circular RNAs (circRNAs) play vital roles in the progression of glioma, the detailed mechanisms remain unknown.
qRT-PCR, western blotting, immunohistochemistry, and bioinformatic analysis were performed to detect the expression of circATP5B, miR-185-5p, HOXB5, and SRSF1. Patient-derived GSCs were established, and MTS, EDU, neurosphere formation, and limiting dilution assays were used to detect the proliferation of GSCs. RNA-binding protein immunoprecipitation, RNA pull-down, luciferase reporter assays, and chromatin immunoprecipitation assays were used to detect these molecules' regulation mechanisms.
We found circATP5B expression was significantly upregulated in GSCs and promoted the proliferation of GSCs. Mechanistically, circATP5B acted as miR-185-5p sponge to upregulate HOXB5 expression. HOXB5 was overexpressed in glioma and transcriptionally regulated IL6 expression and promoted the proliferation of GSCs via JAK2/STAT3 signaling. Moreover, RNA binding protein SRSF1 could bind to and promote circATP5B expression and regulate the proliferation of GSCs, while HOXB5 also transcriptionally regulated SRSF1 expression.
Our study identified the SRSF1/circATP5B/miR-185-5p/HOXB5 feedback loop in GSCs. This provides an effective biomarker for glioma diagnosis and prognostic evaluation.
神经胶质瘤是中枢神经系统最常见和最恶性的肿瘤。神经胶质瘤干细胞（GSCs）的肿瘤起始、自我更新和多谱系分化能力是神经胶质瘤增殖和复发的原因。尽管环状 RNA（circRNA）在神经胶质瘤的进展中发挥着重要作用，但详细的机制尚不清楚。
采用 qRT-PCR、western blot、免疫组织化学和生物信息学分析检测 circATP5B、miR-185-5p、HOXB5 和 SRSF1 的表达。建立患者来源的 GSCs，并采用 MTS、EDU、神经球形成和有限稀释测定法检测 GSCs 的增殖。采用 RNA 结合蛋白免疫沉淀、RNA 下拉、荧光素酶报告基因测定和染色质免疫沉淀测定法检测这些分子的调节机制。
我们发现 circATP5B 在 GSCs 中表达显著上调，并促进 GSCs 的增殖。机制上，circATP5B 作为 miR-185-5p 的海绵体，上调 HOXB5 的表达。HOXB5 在神经胶质瘤中过度表达，并通过 JAK2/STAT3 信号转导转录调控 IL6 的表达，促进 GSCs 的增殖。此外，RNA 结合蛋白 SRSF1 可以结合并促进 circATP5B 的表达，调节 GSCs 的增殖，而 HOXB5 也可以转录调控 SRSF1 的表达。
本研究在 GSCs 中鉴定了 SRSF1/circATP5B/miR-185-5p/HOXB5 反馈环。这为神经胶质瘤的诊断和预后评估提供了有效的生物标志物。
