Li Peihuan, Wang Zhijie, Li Shuai, Wang Liuxing
Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, People's Republic of China.
Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, People's Republic of China.
Onco Targets Ther. 2021 Jan 6;14:83-95. doi: 10.2147/OTT.S277831. eCollection 2021.
Circular RNAs (circRNAs) have been proven to function as pivotal regulators in cancer occurrence and progression. However, the function of circ_0006404 (circRNA Forkhead box O3 (circFOXO3)in prostate cancer (PCa) is poorly understood.
The enrichment of circ_0006404, FOXO3, microRNA-1299 (miR-1299) and cofilin 2 (CFL2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The viability, metastasis and proliferation were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell and colony formation assays, respectively. Flow cytometry was used to assess cell cycle progression and apoptosis. Circ_0006404/miRNAs interactions were explored using Circular RNA Interactome database, while TargetScan software was used for seeking the targets of miR-1299. Dual-luciferase reporter assay, RNA-pull down and RNA immunoprecipitation (RIP) assays were conducted to verify the target interaction between miR-1299 and circ_0006404 or CFL2. CFL2 protein level was analyzed by Western blot assay. Animal experiments were performed to test the role of circ_0006404 in PCa tumor growth in vivo.
Circ_0006404 level was notably elevated in PCa. Circ_0006404 contributed to the viability, metastasis and proliferation and impaired the apoptosis of PCa cells. Circ_0006404 directly targeted miR-1299, and miR-1299 silencing largely reversed circ_0006404 interference-induced influences in PCa cells. CFL2 directly bound to miR-1299, and miR-1299-induced effects in PCa cells were largely attenuated by CFL2 overexpression. CFL2 was regulated by circ_0006404/miR-1299 axis in PCa cells. Circ_0006404 promoted PCa progression via miR-1299/CFL2 axis in vivo.
Circ_0006404 accelerated the survival, motility and proliferation while impeded the apoptosis of PCa cells via miR-1299/CFL2 axis. Circ_0006404 might be a stable potential bio-marker for PCa diagnosis and treatment.
环状RNA（circRNAs）已被证明在癌症发生和发展中起关键调节作用。然而，circ_0006404（环状叉头框O3（circFOXO3））在前列腺癌（PCa）中的功能尚不清楚。
采用定量实时聚合酶链反应（qRT-PCR）检测circ_0006404、叉头框O3（FOXO3）、微小RNA-1299（miR-1299）和丝切蛋白2（CFL2）的表达水平。分别采用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐（MTT）法、Transwell法和集落形成法检测细胞活力、迁移和增殖能力。采用流式细胞术评估细胞周期进程和凋亡情况。利用Circular RNA Interactome数据库探索circ_0006404/微小RNA之间的相互作用，同时使用TargetScan软件寻找miR-1299的靶标。进行双荧光素酶报告基因检测、RNA下拉实验和RNA免疫沉淀（RIP）实验，以验证miR-1299与circ_0006404或CFL2之间的靶标相互作用。通过蛋白质免疫印迹法分析CFL2蛋白水平。进行动物实验，以检测circ_0006404在体内PCa肿瘤生长中的作用。
circ_0006404水平在PCa中显著升高。circ_0006404促进了PCa细胞的活力、迁移和增殖，并损害了其凋亡。circ_0006404直接靶向miR-1299，miR-1299沉默在很大程度上逆转了circ_0006404干扰对PCa细胞的影响。CFL2直接与miR-1299结合，CFL2过表达在很大程度上减弱了miR-1299对PCa细胞的诱导作用。在PCa细胞中，CFL2受circ_0006404/miR-1299轴调控。circ_0006404在体内通过miR-1299/CFL2轴促进PCa进展。
circ_0006404通过miR-1299/CFL2轴加速PCa细胞的存活、迁移和增殖，同时抑制其凋亡。circ_0006404可能是PCa诊断和治疗的一个稳定潜在生物标志物。
