circUSP34 accelerates osteosarcoma malignant progression by sponging miR‐16‐5p

Osteosarcoma (OS) is a primary and highly malignant mesenchymal tissue tumor. The specific pathological mechanism underlying disease initiation or progression remains unclear. Circular RNAs (circRNAs) are a type of covalently circular RNA with a head‐to‐tail junction site. In this study, we aimed to investigate the sponging mechanism between circRNAs and microRNAs (miRNAs) in OS. Based on the inhibited effect of miR‐16‐5p reported on OS, circUSP34 was analyzed as a sponge of miR‐16‐5p via Starbase. We found that circUSP34 promoted the proliferation, migration, and invasion of OS in vitro and in vivo. circUSP34 increased but miR‐16‐5p decreased in OS by qRT‐PCR. Function assays showed that the malignancy of OS cells, including proliferation, migration, and invasion, was inhibited after knocking out circUSP34. Western blotting results showed that the expression level of vimentin and Ki‐67 decreased. Similarly, miR‐16‐5p mimic compromised the proliferation, migration, and invasion of OS cells. FISH assay results indicated that circUSP34 and miR‐16‐5p were colocalized in the cytoplasm. The sponging mechanism of circUSP34 and miR‐16‐5p was verified by dual‐luciferase reporter assay, RNA immunoprecipitation (RIP), and RNA pull down assays. Interestingly, the miR‐16‐5p inhibitor partly reversed the inhibitory effect of sh‐circUSP34 on the malignancy of OS cells. Further, mice tumors for IHC indicated that vimentin, N‐cadherin, and Ki‐67 protein expression decreased, but E‐cadherin protein expression increased. Collectively, circUSP34 promoted OS malignancy, including proliferation, migration, and invasion, by sponging miR‐16‐5p. It can serve as a potential therapeutic target and biomarker.     

冠状动脉旁路移植术后心房颤动患者ceRNA机制的研究

目的 探讨环状RNA(circRNAs)在冠状动脉旁路移植(CABG)术后心房颤动(POAF)中的调控机制.方法 从基因表达综合数据库(GEO)的数据集基因样本表达集97455(GSE97455)中获得circRNA表达谱,使用GEO2R工具在线分析GSE97455数据集中差异表达的circRNAs(DECs),然后把...     

环状RNA在三阴性乳腺癌中的研究进展

三阴性乳腺癌是乳腺癌中恶性程度最高的亚型，其分子分型标志物雌激素受体、孕激素受体及人表皮生长因子2受体均为阴性。三阴性乳腺癌的治疗方案仍以化疗为主，但患者的预后较差。环状RNA（circRNA）是一类单链闭合的且在真核细胞中广泛表达的非编码RNA。近年来，circRNA逐渐成为肿瘤研究领域的新热点，但大多数circRNA在肿瘤中的作用机制仍不明朗。此外，相关研究显示circRNA在三阴性乳腺癌的发生、发展中发挥着重要作用，可作为三阴性乳腺癌早期诊断及预后的一种新兴的生物标志物。针对circRNA在肺癌发生和发展中的作用机制进行干预，能够使之成为具有潜在临床价值的三阴性乳腺癌治疗新靶点。本文系统回顾circRNA一般特征、形成机制及其功能，并对circRNA在三阴性乳腺癌发生、发展中的研究进展进行综述。本文重点关注circRNA在三阴性乳腺癌中作用机制的研究进展。     

Emerging roles of circular RNAs in cancer: a narrative review

Circular RNAs (circRNAs) constitute a novel class of endogenous noncoding RNAs characterized by a covalently closed structure and involved in multiple biologica...     

Circ_0008285 knockdown represses tumor development by miR-384/RRM2 axis in hepatocellular carcinoma

Introduction and objectivesCircular RNA (circRNA) has attracted extensive attention in studies related to the malignant progression of cancer, including hepatocellular carcinoma (HCC). Therefore, its molecular mechanism in HCC needs to be further explored.Materials and methodsThe expression levels of circ_0008285, microRNA (miR)-384 and ribonucleotide reductase subunit M2 (RRM2) mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was analyzed using cell counting kit-8 assay and 5-ethynyl-2’-deoxyuridine assay, cell apoptosis was analyzed by flow cytometry, and cell migration and invasion were detected by transwell assay. Protein level was detected by western blot. The relationships between miR-384 and circ_0008285 or RRM2 were predicted by bioinformatics software and validated by dual luciferase reporter assay and RNA immunoprecipitation (RIP) assay.ResultsCirc_0008285 expression is elevated to HCC tissues and cell lines. Silencing of circ_0008285 inhibited the proliferation, migration and invasion of HCC cells but accelerated cell apoptosis in vitro and impeded HCC tumorigenesis in vivo. Mechanistically, circ_0008285 directly interacted with miR-384, and miR-384 silencing attenuated the effects of circ_0008285 interference on cell proliferation, migration, invasion, and apoptosis. RRM2 was a direct target of miR-384, and RRM2 overexpression reversed the effects of miR-384 overexpression on cell proliferation, migration, invasion, and apoptosis. In addition, circ_0008285 regulated RRM2 expression by sponging miR-384.ConclusionIn this study, circ_0008285 could promote the malignant biological behaviors of HCC cells through miR-384/RRM2 axis and has the potential to become a therapeutic target for HCC, providing a new idea for targeted therapy of HCC.