Circular RNAs (circRNAs) are endogenous non-coding RNAs, which are associated with various biological processes, including microRNA (miRNA) interaction, protein binding and regulatory splicing. circRNA_0005529 (circ_0005529) is derived from vacuolar protein sorting 33 homologue B (VPS33B), and its biological role in gastric cancer (GC) has not been examined. In this study, the expression and location of circ_0005529 and microRNA-527 (miR-527) were determined by qRT-PCR and fluorescence in situ hybridization (FISH). Cell proliferation and cell migration were determined by MTT, EdU incorporation, colony formation, wound scratch and transwell assays. In addition, immunohistochemistry and western blotting were performed to determine the expressions of specificity protein 1 (Sp1), PCNA, c-myc, E-cadherin and N-cadherin. Western blotting and luciferase reporter assay were performed to study the interaction between circ_0005529 and miR-527 or miR-527 and Sp1. The functional effects of circ_0005529 on GC through regulating Sp1 were further evaluated using xenograft and metastatic mouse models in vivo. Our results showed that circ_0005529 was upregulated in GC tissues and cells, and had promoting effects on cell proliferation and cell migration. Mechanism analysis suggested that circ_0005529 could bind to microRNA-527 (miR-527) and reduce its expression. The interaction between miR-527 and Sp1 in GC was systematically studied. In addition, the results indicated that Sp1 upregulation could rescue the effects on cell proliferation and migration caused by circ_0005529. Moreover, the inhibitory effects of circ_0005529 downregulation on GC growth and metastasis were evaluated in mouse models. These findings suggested that the axis of circ_0005529/miR-527/Sp1 may serve as a promising treatment target for GC diagnosis and treatment. These findings suggested that the signal axis of circ_0005529/miR-527/Sp1 may has the potential to be explored as a novel therapeutic target for GC diagnosis and treatment. Mechanism diagram: During GC development, overexpressed circ_0005529 sponged miR-527 and then upregulated the expression of Sp1. Subsequently, epithelial-mesenchymal transition (EMT), cell proliferation and cell migration were promoted, which ultimately facilitated the tumor metastasis

中文翻译：

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circRNA_0005529通过调节miR-527/Sp1轴促进胃癌生长和转移


环状RNA（circRNA）是内源性非编码RNA，与多种生物过程相关，包括微小RNA（miRNA）相互作用、蛋白质结合和调节剪接。 circRNA_0005529 (circ_0005529) 源自液泡蛋白分选 33 同源物 B (VPS33B)，其在胃癌 (GC) 中的生物学作用尚未得到研究。在本研究中，通过qRT-PCR和荧​​光原位杂交（FISH）测定了circ_0005529和microRNA-527（miR-527）的表达和位置。通过 MTT、EdU 掺入、集落形成、伤口划痕和 Transwell 测定来测定细胞增殖和细胞迁移。此外，还进行免疫组化和蛋白质印迹法测定特异性蛋白1（Sp1）、PCNA、c-myc、E-cadherin和N-cadherin的表达。进行蛋白质印迹和荧光素酶报告基因测定以研究 circ_0005529 与 miR-527 或 miR-527 与 Sp1 之间的相互作用。使用异种移植和体内转移小鼠模型进一步评估了 circ_0005529 通过调节 Sp1 对 GC 的功能影响。我们的结果表明，circ_0005529在GC组织和细胞中表达上调，并且对细胞增殖和细胞迁移具有促进作用。机制分析表明，circ_0005529可以与microRNA-527（miR-527）结合并降低其表达。系统研究了GC中miR-527和Sp1之间的相互作用。此外，结果表明Sp1上调可以挽救circ_0005529对细胞增殖和迁移的影响。此外，在小鼠模型中评估了circ_0005529下调对GC生长和转移的抑制作用。 这些发现表明，circ_0005529/miR-527/Sp1轴可能作为GC诊断和治疗的一个有前景的治疗靶点。这些发现表明，circ_0005529/miR-527/Sp1的信号轴可能有潜力被探索作为GC诊断和治疗的新治疗靶点。机制图：在GC发育过程中，过表达的circ_0005529吸收miR-527，然后上调Sp1的表达。随后，促进上皮间质转化（EMT）、细胞增殖和细胞迁移，最终促进肿瘤转移