Zhao Yongsheng, Ma Xiaocha, Shi Weihua
Department of Oncology, The First People's Hospital of Yinchuan, No. 2 Liqun West Street Xingqing District, Yinchuan, 750001, China.
Mamm Genome. 2021 Dec;32(6):517-529. doi: 10.1007/s00335-021-09923-y. Epub 2021 Oct 10.
Researches indicate that circular RNAs are dysregulated in breast cancer (BC) and play a critical role in regulating the malignant phenotype of cancer cells. Herein, the goal of this work was to investigate the role and mechanism of circ_0069718 in BC development. Levels of genes and proteins were detected by quantitative real-time polymerase chain reaction and western blot. In vitro experiments were performed using cell counting kit-8 assay, colony formation assay, EdU (5-ethynyl-2'-deoxyuridine) assay, flow cytometry, western blot, and transwell assay, respectively. The dual-luciferase reporter and RNA immunoprecipitation assays were used to identify the target relationship between miR-590-5p and circ_0069718 or nuclear factor I/B (NFIB). In vivo experiments were conducted using Xenograft model in mice. Circ_0069718 was up-regulated in BC tissues and cells. Knockdown of circ_0069718 suppressed BC cell apoptosis, migration, and invasion in vitro effectively. Mechanistically, circ_0069718 directly targeted miR-590-5p to up-regulate its target NFIB. Rescue experiments showed that miR-590-5p inhibition reversed the inhibitory effects of circ_0069718 knockdown on BC cell-aggressive oncogenic phenotypes; moreover, miR-590-5p re-expression restrained BC cell proliferation and mobility, which were abolished by NFIB up-regulation. Besides that, circ_0069718 silencing hindered tumor growth via miR-590-5p/NFIB axis in vivo. Circ_0069718 promotes BC progression by up-regulating NFIB through sequestering miR-590-5p, suggesting a potential therapeutic strategy in BC.
研究表明，环状RNA在乳腺癌（BC）中表达失调，并在调节癌细胞的恶性表型中起关键作用。在此，本研究旨在探讨circ_0069718在BC发生发展中的作用及机制。通过定量实时聚合酶链反应和蛋白质印迹法检测基因和蛋白质水平。分别使用细胞计数试剂盒-8法、集落形成试验、EdU（5-乙炔基-2'-脱氧尿苷）试验、流式细胞术、蛋白质印迹法和Transwell试验进行体外实验。采用双荧光素酶报告基因和RNA免疫沉淀试验鉴定miR-590-5p与circ_0069718或核因子I/B（NFIB）之间的靶向关系。在小鼠体内使用异种移植模型进行体内实验。Circ_0069718在BC组织和细胞中上调。敲低circ_0069718可有效抑制体外BC细胞的凋亡、迁移和侵袭。机制上，circ_0069718直接靶向miR-590-5p以上调其靶标NFIB。挽救实验表明，抑制miR-590-5p可逆转circ_0069718敲低对BC细胞侵袭性致癌表型的抑制作用；此外，miR-590-5p的重新表达抑制了BC细胞的增殖和迁移能力，而NFIB的上调则消除了这种抑制作用。除此之外，circ_0069718沉默通过体内miR-590-5p/NFIB轴阻碍肿瘤生长。Circ_0069718通过隔离miR-590-5p上调NFIB来促进BC进展，提示其在BC中具有潜在的治疗策略。
