Gastric cancer (GC) is a malignant tumor with high morbidity and mortality in the world. Circular RNA hsa_circHN1_005 (circ_HN1), also termed as hsa_circ_0045602, is reported as an oncogene in GC. However, the molecular mechanism of circ_HN1 in GC development has not been fully explored. Here, we surveyed the regulatory mechanism of circ_HN1 in GC progression. The levels of circ_HN1, miR-302b-3p, and rho-associated coiled-coil containing protein kinase 2 (ROCK2) mRNA were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, colony formation, cell cycle progresion, migration, and invasion were determined by using cell counting, flow cytometry, colony formation, or transwell assays. Protein levels were detected with Western blotting. The relationship between circ_HN1 or ROCK2 and miR-302b-3p was verified via dual luciferase reporter or RNA immunoprecipitation (RIP) assays. The role of circ_HN1 in vivo was confirmed by xenograft assay. We observed that circ_HN1 and ROCK2 were upregulated while miR-302b-3p was downregulated in GC tissues and cells. Circ_HN1 silencing slowed tumor growth in vivo and impeded cell proliferation migration, invasion, and facilitated cell apoptosis in GC cells in vitro. Circ_HN1 sponged miR-302b-3p to regulate ROCK2 expression. MiR-302b-3p inhibitor reversed circ_HN1 silencing-mediated influence on the malignant behaviors of GC cells. Furthermore, ROCK2 overexpression restored miR-302b-3p mimic-mediated impacts on cell malignant behaviors in GC cells. In conclusion, circ_HN1 exerted an oncogenic role in GC through upregulating ROCK2 via sponging miR-302b-3p, offering evidence that circ_HN1 is a potential target for GC therapy.

中文翻译：

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环状RNA circ_HN1通过调节miR-302b-3p/ROCK2轴促进胃癌进展。

胃癌（GC）是世界上发病率和死亡率都很高的恶性肿瘤。环状 RNA hsa_circHN1_005 (circ_HN1)，也称为 hsa_circ_0045602，据报道是 GC 中的致癌基因。然而，circ_HN1在GC发展中的分子机制尚未得到充分探索。在这里，我们调查了 circ_HN1 在 GC 进展中的调控机制。通过定量实时聚合酶链反应 (qRT-PCR) 测量 circ_HN1、miR-302b-3p 和含有 rho 相关卷曲螺旋的蛋白激酶 2 (ROCK2) mRNA 的水平。细胞增殖、凋亡、集落形成、细胞周期进展、迁移和侵袭通过使用细胞计数、流式细胞术、集落形成或 transwell 测定来确定。蛋白质水平用蛋白质印迹检测。circ_HN1 或 ROCK2 与 miR-302b-3p 之间的关系通过双荧光素酶报告基因或 RNA 免疫沉淀 (RIP) 分析得到验证。circ_HN1 在体内的作用通过异种移植试验得到证实。我们观察到 circ_HN1 和 ROCK2 上调，而 miR-302b-3p 在 GC 组织和细胞中下调。Circ_HN1 沉默减缓了体内肿瘤的生长，阻碍了细胞增殖迁移、侵袭，并促进了体外 GC 细胞的细胞凋亡。Circ_HN1 海绵 miR-302b-3p 以调节 ROCK2 表达。MiR-302b-3p 抑制剂逆转了 circ_HN1 沉默介导的对 GC 细胞恶性行为的影响。此外，ROCK2 过表达恢复了 miR-302b-3p 模拟物介导的对 GC 细胞中细胞恶性行为的影响。综上所述，