Background

It has been known for decades that circRNAs are deregulated in cancer. Here, we characterized the role and underlying mechanism of circ_0088212 in osteosarcoma.

Methods

The expression levels of circ_0088212, miR-520 h, and APOA1 were determined by RT-qPCR. RNase R digestion was performed to verify the circular structure of circ_0088212. CCK8 and transwell invasion assays were conducted to examine the in vitro malignancy of osteosarcoma. Caspase-3 activity was also measured.

An in vivo model of osteosarcoma was constructed to examine the in vivo effect of circ_0088212 on osteosarcoma. Luciferase reporter, RNA RIP, and RNA pull-down assays were performed to verify the interaction between miR-520 h and APOA1 or circ_0088212.

Results

Circ_0088212 and APOA1 were expressed at low levels in osteosarcoma tissues and cells, while miR-520 h was highly expressed. Overexpression of circ_0088212 was found to inhibit the in vitro and in vivo growth of osteosarcoma. Mechanistically, miR-520 h was the target of circ_0088212 and APOA1 was the target of miR-520 h. Circ_0088212 downregulated miR-520 h expression, while miR-520 h overexpression abolished the inhibitory effect of circ_0088212 on osteosarcoma cell proliferation and migration. Furthermore, miR-520 h overexpression led to reduced APOA1 expression, while APOA1 overexpression counteracted the oncogenic effect of miR-520 h in osteosarcoma cells.

Conclusion

Our findings demonstrated that circ_0088212 might exert a tumor-suppressive activity in osteosarcoma by sponging and sequestering miR-520 h away from APOA1. This suggests that the circ_0088212/miR-520 h/APOA1 axis may be a promising therapeutic target for osteosarcoma intervention.

中文翻译：

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Hsa_circ_0088212 介导的 miR-520 h/APOA1 轴抑制骨肉瘤进展

背景

数十年来，人们都知道 circRNA 在癌症中失调。在这里，我们描述了 circ_0088212 在骨肉瘤中的作用和潜在机制。

方法

通过 RT-qPCR 确定 circ_0088212、miR-520 h 和 APOA1 的表达水平。进行RNase R消化以验证circ_0088212的环状结构。进行 CCK8 和 transwell 侵袭试验以检查骨肉瘤的体外恶性程度。还测量了 Caspase-3 活性。

构建了骨肉瘤的体内模型以检查 circ_0088212 对骨肉瘤的体内作用。进行荧光素酶报告基因、RNA RIP 和 RNA 下拉测定以验证 miR-520 h 与 APOA1 或 circ_0088212 之间的相互作用。

结果

Circ_0088212和APOA1在骨肉瘤组织和细胞中低表达，而miR-520h高表达。发现circ_0088212的过表达抑制骨肉瘤的体外和体内生长。从机制上讲，miR-520 h 是 circ_0088212 的靶标，APOA1 是 miR-520 h 的靶标。Circ_0088212下调miR-520 h表达，而miR-520 h过表达消除了circ_0088212对骨肉瘤细胞增殖和迁移的抑制作用。此外，miR-520 h 过表达导致 APOA1 表达降低，而 APOA1 过表达抵消了 miR-520 h 在骨肉瘤细胞中的致癌作用。

结论

我们的研究结果表明，circ_0088212 可能通过海绵和隔离 miR-520 h 与 APOA1 来在骨肉瘤中发挥肿瘤抑制活性。这表明 circ_0088212/miR-520 h/APOA1 轴可能是骨肉瘤干预的有希望的治疗靶点。