Zhu Xi, Liu Changhao, Shi Jiandang, Zhou Zhanwen, Chen Suoli, Jami Sayed Abdulla
Department of Spinal Surgery, General Hospital of Ningxia Medical University, Ningxia, China.
Department of Spinal Surgery, Ningxia Medical University, Ningxia, China.
J Bone Oncol. 2021 Jan 14;27:100347. doi: 10.1016/j.jbo.2021.100347. eCollection 2021 Apr.
Circular RNAs (circRNAs) have been discovered to exert essential roles in human cancers, including osteosarcoma (OS). The aim of this study was to investigate the exact roles and regulatory mechanism of circRNA ankyrin repeat and IBR domain containing 1 (circANKIB1) in OS.
Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of circANKIB1, microRNA-217 (miR-217) and paired box 3 (PAX3). Cell proliferation was assessed by colony formation assay. Cell cycle distribution and apoptosis rate were determined by flow cytometry analysis. Wound healing assay and transwell assay were employed to evaluate cell migration and invasion abilities. Western blot assay was used to analyze the protein levels of PAX3, E-cadherin and Vimentin. Targeting relationship between miR-217 and circANKIB1 or PAX3 was predicted by Circular RNA Interactome or TargetScan and demonstrated by dual-luciferase reporter assay. The mice xenograft model was established to confirm the role of circANKIB1 .
CircANKIB1 and PAX3 were high-expressed, whereas miR-217 was low-expressed in OS tissues and cells. Knockdown of circANKIB1 inhibited the progression of OS by reducing cell proliferation, migration, invasion, and tumor growth (), and inducing apoptosis. MiR-217 was a direct target of circANKIB1, and its inhibition reversed the inhibitory effect of circANKIB1 knockdown on the progression of OS cells. Moreover, PAX3 was a direct target of miR-217, and miR-217 exerted the anti-tumor role in OS cells by targeting PAX3. Furthermore, circANKIB1 positively regulated PAX3 expression by sponging miR-217.
Knockdown of circANKIB1 suppressed OS progression by upregulating miR-217 and downregulating PAX3, which might provide a novel insight into the pathogenesis of OS.
环状RNA（circRNAs）已被发现可在包括骨肉瘤（OS）在内的人类癌症中发挥重要作用。本研究旨在探讨环状锚蛋白重复序列和IBR结构域包含蛋白1（circANKIB1）在骨肉瘤中的具体作用及调控机制。
采用定量实时聚合酶链反应（qRT-PCR）检测circANKIB1、微小RNA-217（miR-217）和配对盒3（PAX3）的表达水平。通过集落形成试验评估细胞增殖。采用流式细胞术分析确定细胞周期分布和凋亡率。采用伤口愈合试验和Transwell试验评估细胞迁移和侵袭能力。采用蛋白质印迹法分析PAX3、E-钙黏蛋白和波形蛋白的蛋白质水平。通过Circular RNA Interactome或TargetScan预测miR-217与circANKIB1或PAX3之间的靶向关系，并通过双荧光素酶报告基因试验进行验证。建立小鼠异种移植模型以证实circANKIB1的作用。
circANKIB1和PAX3在骨肉瘤组织和细胞中高表达，而miR-217低表达。敲低circANKIB1可通过降低细胞增殖、迁移、侵袭和肿瘤生长，并诱导凋亡来抑制骨肉瘤的进展。MiR-217是circANKIB1的直接靶点，其抑制作用可逆转circANKIB1敲低对骨肉瘤细胞进展的抑制作用。此外，PAX3是miR-217的直接靶点，miR-217通过靶向PAX3在骨肉瘤细胞中发挥抗肿瘤作用。此外，circANKIB1通过吸附miR-217正向调节PAX3表达。
敲低circANKIB1可通过上调miR-217和下调PAX3来抑制骨肉瘤进展，这可能为骨肉瘤的发病机制提供新的见解。
