Department of Gastrointestinal Surgery, 47861Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang city, Jiangxi Province, China.
Department of Radiation Oncology, Jilin Provincial Cancer Hospital, Changchun City, Jilin Province, China.
Cell Transplant. 2021 Jan-Dec;30:963689720975390. doi: 10.1177/0963689720975390.
Gastric cancer (GC) is a big threat to human life and health. Circular RNAs (circRNAs), a subclass of noncoding RNAs, were reported to play a critical role in GC progression. Here, we investigated the role of a novel circRNA named hsa_circ_0023409 in GC and its mechanism. Hsa_circ_0023409 expression in GC and adjacent tissues was examined by quantitative real-time polymerase chain reaction and in situ hybridization. The functions of hsa_circ_0023409 in GC cells were assessed both in vitro and in vivo. Immunofluorescence staining was performed for the localization of hsa_circ_0023409 and miR-542-3p in cells. The interaction between hsa_circ_0023409 and miR-542-3p, and miR-542-3p and insulin receptor substrate 4 (IRS4) was detected by dual-luciferase reporter assay. The effect of hsa_circ_0023409, miR-542-3p, and IRS4 on IRS4/phosphatidylinositol 3-kinase (PI3K)/AKT pathway was detected by western blot. The results showed that hsa_circ_0023409 was mainly located in cytoplasm and highly expressed in GC tissues and cells. Moreover, hsa_circ_0023409 showed positive correlation with tumor size, histological grade, and tumor-node-metastasis staging of GC patients. Functional studies showed that hsa_circ_0023409 promoted cell viability, proliferation, migration, and invasion and suppressed apoptosis in GC. Mechanism studies demonstrated that hsa_circ_0023409 upregulated IRS4 via sponging miR-542-3p in GC cells. Furthermore, IRS4 overexpression activated the PI3K/AKT pathway and reversed the inhibitory effect of hsa_circ_0023409 knockdown on the PI3K/AKT pathway. Taken together, we prove that hsa_circ_0023409 activates IRS4/PI3K/AKT pathway by acting as a sponge for miR-542-3p, thus promoting GC progression, indicating that hsa_circ_0023409 may serve as a potential target for treatment of GC and prognosis of GC patients.
胃癌（GC）是严重威胁人类生命健康的疾病。环状 RNA（circRNA）是一类非编码 RNA，研究表明其在 GC 进展中发挥关键作用。本研究旨在探讨一种新型环状 RNA hsa_circ_0023409 在 GC 中的作用及其机制。采用实时定量聚合酶链反应和原位杂交检测 GC 及相邻组织中 hsa_circ_0023409 的表达。在体外和体内评估 hsa_circ_0023409 在 GC 细胞中的功能。免疫荧光染色用于细胞内 hsa_circ_0023409 和 miR-542-3p 的定位。双荧光素酶报告基因检测 hsa_circ_0023409 与 miR-542-3p、miR-542-3p 与胰岛素受体底物 4（IRS4）之间的相互作用。Western blot 检测 hsa_circ_0023409、miR-542-3p 和 IRS4 对 IRS4/磷脂酰肌醇 3-激酶（PI3K）/蛋白激酶 B（AKT）通路的影响。结果显示，hsa_circ_0023409 主要位于细胞质中，在 GC 组织和细胞中高表达。此外，hsa_circ_0023409 与 GC 患者的肿瘤大小、组织学分级和肿瘤-淋巴结-转移分期呈正相关。功能研究表明，hsa_circ_0023409 可促进 GC 细胞活力、增殖、迁移和侵袭，并抑制细胞凋亡。机制研究表明，hsa_circ_0023409 通过海绵吸附 miR-542-3p 上调 IRS4。此外，IRS4 过表达激活 PI3K/AKT 通路，并逆转 hsa_circ_0023409 敲低对 PI3K/AKT 通路的抑制作用。综上所述，hsa_circ_0023409 通过作为 miR-542-3p 的海绵吸附物激活 IRS4/PI3K/AKT 通路，从而促进 GC 进展，表明 hsa_circ_0023409 可能成为治疗 GC 和 GC 患者预后的潜在靶点。
