Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiao-Tong University, No.227, Yanta west Road, Xi'an, 710061, Shaanxi province, China.
, Xi'an, China.
Metab Brain Dis. 2022 Apr;37(4):1231-1245. doi: 10.1007/s11011-022-00965-y. Epub 2022 Mar 25.
Recent studies revealed the key role of circular RNA (circRNA) in glioma progression. However, the effect of circ_0000520, also named as circRNA ribonuclease P RNA component H1 (circ_RPPH1), in glioma development was unknown. The study aimed to reveal the role of circ_RPPH1 in glioma cell malignancy.
Human astrocytes (NHA) and glioma cell lines (A172 and U251) were employed in this study. Quantitative real-time polymerase chain reaction and western blot were used to check the expression of circ_RPPH1, microRNA-627-5p (miR-627-5p), miR-663a and syndecan 1 (SDC1). Immunohistochemistry assay was conducted to assess the protein expression of nuclear proliferation marker ki67 and matrix metalloprotein 9 (MMP9). Cell viability was assessed by 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell proliferation and apoptosis were investigated by flow cytometry analysis, 5-Ethynyl-29-deoxyuridine, or cell colony formation assay. Cell migration and invasion were evaluated by transwell assays. The interaction between miRNAs (miR-627-5p and miR-663a) and circ_RPPH1 or SDC1 was identified by a dual-luciferase reporter assay. A mouse model assay was performed to reveal the impact of circ_RPPH1 knockdown on glioma cell malignancy in vivo by analyzing neoplasm volume and weight.
Circ_RPPH1 and SDC1 expression were significantly increased, whereas miR-627-5p and miR-663a expression were decreased in glioma tissues and cells in comparison with healthy brain tissues or human astrocytes. Circ_RPPH1 depletion led to the decreased cell proliferation, migration and invasion, and the increased cell apoptosis. Additionally, circ_RPPH1 bound to miR-627-5p/miR-663a and mediated glioma cell processes by interacting with them. SDC1 overexpression attenuated miR-627-5p/miR-663a-mediated actions. Moreover, circ_RPPH1 regulated SDC1 expression through interaction with miR-627-5p and/or miR-663a. Furthermore, circ_RPPH1 knockdown inhibited glioma cell malignancy in vivo, accompanied by the decreases of ki67 and MMP9 expression.
Circ_RPPH1 knockdown inhibited glioma tumorigenesis by downregulating SDC1 by binding to miR-627-5p/miR-663a, showing that circ_RPPH1 might be an effective therapeutic target for glioma.
最近的研究揭示了环状 RNA（circRNA）在神经胶质瘤进展中的关键作用。然而，circ_0000520（也称为环状 RNA 核糖核酸酶 P RNA 成分 H1（circ_RPPH1））在神经胶质瘤发展中的作用尚不清楚。本研究旨在揭示 circ_RPPH1 在神经胶质瘤细胞恶性中的作用。
本研究采用人星形胶质细胞（NHA）和神经胶质瘤细胞系（A172 和 U251）。采用实时定量聚合酶链反应和 Western blot 检测 circ_RPPH1、微小 RNA-627-5p（miR-627-5p）、miR-663a 和 syndecan 1（SDC1）的表达。免疫组织化学检测核增殖标志物 ki67 和基质金属蛋白酶 9（MMP9）的蛋白表达。通过 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）测定评估细胞活力。通过流式细胞术分析、5-乙炔基-29-脱氧尿苷或细胞集落形成测定法研究细胞增殖和凋亡。通过 Transwell 测定评估细胞迁移和侵袭。通过双荧光素酶报告基因测定鉴定 miRNA（miR-627-5p 和 miR-663a）与 circ_RPPH1 或 SDC1 之间的相互作用。通过分析肿瘤体积和重量，在体内进行小鼠模型实验，以揭示 circ_RPPH1 敲低对神经胶质瘤细胞恶性的影响。
与健康脑组织或人星形胶质细胞相比，神经胶质瘤组织和细胞中 circ_RPPH1 和 SDC1 的表达显著增加，而 miR-627-5p 和 miR-663a 的表达降低。circ_RPPH1 耗竭导致细胞增殖、迁移和侵袭减少，细胞凋亡增加。此外，circ_RPPH1 与 miR-627-5p/miR-663a 结合并通过与它们相互作用介导神经胶质瘤细胞过程。SDC1 的过表达减弱了 miR-627-5p/miR-663a 介导的作用。此外，circ_RPPH1 通过与 miR-627-5p 和/或 miR-663a 的相互作用调节 SDC1 的表达。此外，circ_RPPH1 敲低抑制了体内神经胶质瘤细胞的恶性肿瘤形成，同时降低了 ki67 和 MMP9 的表达。
circ_RPPH1 通过与 miR-627-5p/miR-663a 结合抑制 SDC1 的表达来抑制神经胶质瘤肿瘤发生，表明 circ_RPPH1 可能是神经胶质瘤的有效治疗靶点。
