Background

Circular RNA (circRNA) is a newly-discovered endogenous transcript that has been reported to participate in osteosarcoma (OS) progression. However, the underlying mechanism of circ_0051079 modulating OS development remains unclear.

Methods

RNA expressions of circ_0051079, miR-625-5p and tripartite motif containing 66 (TRIM66) were detected by quantitative real-time polymerase chain reaction. Protein expression was checked by Western blot analysis. The functional effects of circ_0051079 on OS cell malignancy were investigated by cell counting kit-8, clonogenicity, transwell, tube formation and flow cytometry assays. The interactions among circ_0051079, miR-625-5p and TRIM66 were identified by dual-luciferase reporter and RNA immunoprecipitation assays. Mouse xenograft model assay was performed to elucidate the effects of circ_0051079 knockdown on tumor formation in vivo.

Results

Circ_0051079 and TRIM66 expressions were significantly upregulated, but miR-625-5p was downregulated in OS tissues and cells compared with control groups. Circ_0051079 expression was significantly associated with tumor-node-metastasis stage and tumor size of OS patients. Circ_0051079 knockdown inhibited OS cell proliferation, migration and invasion, repressed angiogenesis but induced cell apoptosis, accompanied by the decreases of PCNA and Bcl-2 production and an increase of Bax production. MiR-625-5p, a target miRNA of circ_0051079, participated in regulating circ_0051079-induced effects. Also, TRIM66 was identified as a target mRNA of miR-625-5p, and partially attenuated the inhibitory effects of miR-625-5p in OS cells. Circ_0051079 modulated the Wnt/β-catenin pathway through TRIM66 in vitro. Importantly, circ_0051079 silencing reduced TRIM66 expression by interacting with miR-625-5p. Further, circ_0051079 depletion inhibited tumor formation in vivo.

Conclusion

Circ_0051079 regulated OS development by the miR-625-5p/TRIM66/Wnt/β-catenin pathway, providing a novel therapeutic target for OS.

中文翻译：

---

Circ_0051079 沉默通过 TRIM66/Wnt/β-catenin 通路以 miR-625-5p 依赖性方式抑制骨肉瘤细胞的恶性表型

背景

环状 RNA (circRNA) 是一种新发现的内源性转录物，据报道它参与骨肉瘤 (OS) 的进展。然而，circ_0051079 调节操作系统开发的潜在机制仍不清楚。

方法

通过定量实时聚合酶链反应检测circ_0051079、miR-625-5p和含有66的三联基序（TRIM66）的RNA表达。通过蛋白质印迹分析检查蛋白质表达。circ_0051079 对 OS 细胞恶性肿瘤的功能影响通过细胞计数 kit-8、克隆形成、transwell、管形成和流式细胞术测定进行研究。circ_0051079、miR-625-5p 和 TRIM66 之间的相互作用通过双荧光素酶报告基因和 RNA 免疫沉淀测定进行鉴定。进行小鼠异种移植模型试验以阐明 circ_0051079 敲低对体内肿瘤形成的影响。

结果

与对照组相比，Circ_0051079 和 TRIM66 表达显着上调，但 miR-625-5p 在 OS 组织和细胞中下调。Circ_0051079 的表达与 OS 患者的肿瘤淋巴结转移分期和肿瘤大小显着相关。Circ_0051079 敲低可抑制 OS 细胞增殖、迁移和侵袭，抑制血管生成但诱导细胞凋亡，同时 PCNA 和 Bcl-2 的产生减少，Bax 的产生增加。MiR-625-5p 是 circ_0051079 的靶 miRNA，参与调节 circ_0051079 诱导的效应。此外，TRIM66 被鉴定为 miR-625-5p 的靶 mRNA，并部分减弱了 miR-625-5p 在 OS 细胞中的抑制作用。Circ_0051079在体外通过 TRIM66 调节 Wnt/β-catenin 通路. 重要的是，circ_0051079 沉默通过与 miR-625-5p 相互作用降低了 TRIM66 的表达。此外，circ_0051079 的消耗抑制了体内肿瘤的形成。

结论

Circ_0051079 通过 miR-625-5p/TRIM66/Wnt/β-catenin 通路调节 OS 的发展，为 OS 提供了一个新的治疗靶点。