Department of Neurosurgery, Second Affiliated Hospital, 223527Xinjiang Medical University, Urumqi, Xinjiang, China.
Technol Cancer Res Treat. 2020 Jan-Dec;19:1533033820957026. doi: 10.1177/1533033820957026.
In recent years, accumulating studies have found that circular RNA (circRNA) exerts a great effect on tumor progression. Circ_0000215, a novel circRNA, remains largely unknown in terms of its effect and mechanism in glioma.
Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to detect the expressions of circ_0000215, miR-495-3p and CXCR2 in human glial cell line HEB and glioma cell lines (A172, U251, U87, SHG-44, LN-18), human glioma tissues and adjacent healthy tissues. Gain- and loss-assays of circ_0000215 were conducted. Cell proliferation ability was detected via the CCK8 assay, and cell invasion ability was examined by Transwell assay. CXCR2 expression was evaluated via RT-PCR and Western blot. Moreover, bioinformatics was applied to analyze the targeting molecules of circ_0000215 and CXCR2. Verification of the relationship between these molecules were supported through the dual-luciferase reporter gene and RNA immunocoprecipitation (RIP) assay.
Circ_0000215 and CXCR2 were remarkably upregulated in glioma tissues and cells. Overexpression of circ_0000215 notably promoted the proliferation, invasion and epithelial-mesenchymal transition (EMT) but inhibited apoptosis of glioma cells, while knocking down circ_0000215 had the opposite effects. Additionally, miR-495-3p, a sponge RNA of circ_0000215, inhibited the growth, invasion and EMT of glioma cells. Mechanistically, miR-495-3p targeted CXCR2 and negatively regulated CXCR2/PI3K/Akt pathway. However, the effects of miR-495-3p were all dampened by overexpression of circ_0000215.
These data demonstrated that circ_0000215 functions as a competitive endogenous RNA by sponging miR-495-3p, thus accelerating glioma progression through CXCR2 axis.
近年来，越来越多的研究发现环状 RNA（circRNA）对肿瘤进展有很大的影响。环状 RNA_0000215 是一种新型环状 RNA，其在神经胶质瘤中的作用和机制仍知之甚少。
采用实时定量聚合酶链反应（qRT-PCR）检测人神经胶质细胞系 HEB 和神经胶质瘤细胞系（A172、U251、U87、SHG-44、LN-18）、人神经胶质瘤组织和相邻正常组织中 circ_0000215、miR-495-3p 和 CXCR2 的表达。进行 circ_0000215 的增益和缺失实验。通过 CCK8 检测细胞增殖能力，通过 Transwell 检测细胞侵袭能力。通过 RT-PCR 和 Western blot 检测 CXCR2 表达。此外，还应用生物信息学分析 circ_0000215 和 CXCR2 的靶向分子。通过双荧光素酶报告基因和 RNA 免疫沉淀（RIP）实验验证这些分子之间的关系。
circ_0000215 和 CXCR2 在神经胶质瘤组织和细胞中显著上调。circ_0000215 的过表达显著促进了神经胶质瘤细胞的增殖、侵袭和上皮间质转化（EMT），但抑制了细胞凋亡，而敲低 circ_0000215 则产生相反的效果。此外，circ_0000215 的海绵 RNA miR-495-3p 抑制了神经胶质瘤细胞的生长、侵袭和 EMT。机制上，miR-495-3p 靶向 CXCR2 并负调控 CXCR2/PI3K/Akt 通路。然而，过表达 circ_0000215 均减弱了 miR-495-3p 的作用。
这些数据表明，circ_0000215 通过海绵吸附 miR-495-3p 发挥竞争性内源 RNA 的作用，从而通过 CXCR2 轴加速神经胶质瘤的进展。
