Pan Feng, Zhang Jun, Tang Benseng, Jing Li, Qiu Bing, Zha Zhengang
Department of Bone and Joint Surgery, Institute of Orthopedic Diseases, The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong China.
Department of Bone and Joint Surgery, Gui Zhou Orthopedic Hospital, Gui Zhou, China.
Cancer Cell Int. 2020 Oct 6;20:484. doi: 10.1186/s12935-020-01562-8. eCollection 2020.
Recently, it has been demonstrated that circular RNA (circRNA) contributes to the production and progression in human cancer. However, the specific function and underlying mechanism of circ_0028171 in osteosarcoma (OS) still remain largely unclear and require to be investigated.
In our study, we confirmed differentially expressed circRNAs by microarray analysis in normal bone cells vs. OS cell lines. The expression of circ-0028171 in OS was measured by qRT-PCR. Nuclear-cytoplasmic fractionation was employed to identify the localization of circ-0028171, and RNase R and actinomycin D treatment were used to prove its circular characteristic. In vitro experiments, such as CCK-8 method, cell count, cell colony formation, transwell migration and invasion assays, and in vivo tumor models were adopted to evaluate the effect of circ_0028171. Further, luciferase reporter, RIP and RNA pull-down assays were conducted to confirm the binding sites of circ_0028171 with miR-218-5p.
We found that circ_0028171 displayed a remarkably higher expression in both OS tissues and cell lines. Circ_0028171 mainly located in the cytoplasm as a stable cyclic transcript. Knockdown of circ_0028171 suppressed OS tumor growth in vitro and in vivo, while up-regulated circ_0028171 remarkably enhanced cell proliferation, migration and invasion abilities in OS. Several mechanistic experiments revealed that circ_0028171 served as a sponge of miR-218-5p to increase IKBKB expression.
our research reveals that circ_0028171 might promote the malignant behavior of OS tissues through miR-218-5p/IKBKB axis, which could be a potential novel marker for early diagnosis of OS.
最近，有研究表明环状RNA（circRNA）在人类癌症的发生和发展过程中发挥作用。然而，circ_0028171在骨肉瘤（OS）中的具体功能和潜在机制仍不清楚，有待进一步研究。
在本研究中，我们通过基因芯片分析确定了正常骨细胞与骨肉瘤细胞系中差异表达的circRNA。采用qRT-PCR检测circ-0028171在骨肉瘤中的表达情况。利用核质分离实验确定circ-0028171的定位，并通过RNase R和放线菌素D处理证明其环状特征。采用CCK-8法、细胞计数、细胞集落形成、Transwell迁移和侵袭实验等体外实验以及体内肿瘤模型评估circ_0028171的作用。此外，进行荧光素酶报告基因实验、RIP实验和RNA下拉实验，以证实circ_0028171与miR-218-5p的结合位点。
我们发现circ_0028171在骨肉瘤组织和细胞系中均显著高表达。circ_0028171主要定位于细胞质中，是一种稳定的环状转录本。敲低circ_0028171可抑制骨肉瘤在体外和体内的肿瘤生长，而circ_0028171过表达则显著增强骨肉瘤细胞的增殖、迁移和侵袭能力。多项机制研究表明，circ_0028171作为miR-218-5p的海绵，上调IKBKB的表达。
我们的研究表明，circ_0028171可能通过miR-218-5p/IKBKB轴促进骨肉瘤组织的恶性行为，这可能是骨肉瘤早期诊断的潜在新标志物。
