Department of Neurology, Huai'an Second People's Hospital and The Affiliated Huai'an Hospital of Xuzhou Medical University, Huai'an, China.
Department of Orthopaedics, The Fifth People's Hospital of Fudan University, Heqing Road No. 801, Minghang District, Shanghai 200240, China.
Gene. 2020 May 25;740:144520. doi: 10.1016/j.gene.2020.144520. Epub 2020 Mar 1.
Osteosarcoma (OS) is the most common primary bone tumor, and mainly occurs in children and early adults. The overall pathogenesis of osteosarcoma remains unclear. Circular RNAs (circRNAs) have been demonstrated to be one of the regulators in tumors as non-coding RNAs. In present study, we identified an elevated expressed circ-0060428 in osteosarcoma cells. The results of CCK-8 and flow cytometry assay showed that circ-0060428 promoted cell proliferation and reduced cell apoptosis of osteosarcoma cells. Bioinformatics analyses predicted the binding site between miR-375 to RPBJ and circ-0060428, and dual luciferase reporter assay verified this prediction. Furthermore, miRNA inhibitor of miR-375 could recover the influence of cell proliferation and apoptosis by knocking down the expression of circ-0060428. Meanwhile, knockdown of both circ-0060428 and RBPJ resulted in a lower apoptosis rate than circ-0060428 alone. Western blot analyses indicated that circ-0060428 regulated the expression of apoptosis related proteins (Bax, Bcl-2, and cleaved-Caspase-3) by upregulating RPBJ expression in osteosarcoma cells. Altogether, we confirmed the up-regulated circ-0060428 could improve the proliferation and survival of osteosarcoma cells by sponging miR-375 to upregulate RBPJ expression. This finding supported a novel clinically biomarker and treatment target for osteosarcoma therapy.
骨肉瘤（OS）是最常见的原发性骨肿瘤，主要发生在儿童和早期成人。骨肉瘤的整体发病机制尚不清楚。环状 RNA（circRNA）已被证明是肿瘤中非编码 RNA 的调节因子之一。在本研究中，我们鉴定出骨肉瘤细胞中circ-0060428 的表达升高。CCK-8 和流式细胞术检测结果表明，circ-0060428 促进骨肉瘤细胞的增殖并减少细胞凋亡。生物信息学分析预测了 miR-375 与 RPBJ 之间的结合位点以及 circ-0060428，双荧光素酶报告基因检测验证了这一预测。此外，miR-375 的 miRNA 抑制剂可以通过敲低 circ-0060428 的表达来恢复细胞增殖和凋亡的影响。同时，circ-0060428 和 RBPJ 的敲低比单独敲低 circ-0060428 导致更低的凋亡率。Western blot 分析表明，circ-0060428 通过上调 RPBJ 的表达来调节骨肉瘤细胞中凋亡相关蛋白（Bax、Bcl-2 和 cleaved-Caspase-3）的表达。总之，我们证实了上调的 circ-0060428 通过海绵吸附 miR-375 来上调 RBPJ 的表达，从而提高骨肉瘤细胞的增殖和存活能力。这一发现为骨肉瘤的治疗提供了一种新的临床生物标志物和治疗靶点。
