Du Shuangkuan, Zhang Pengjie, Ren Wei, Yang Fan, Du Chun
Department of Urology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China.
The Center of Kidney Diseases and Hemodialysis, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China.
Cancer Manag Res. 2020 Aug 20;12:7487-7499. doi: 10.2147/CMAR.S257441. eCollection 2020.
The development of radioresistance remains the obstacle for prostate cancer (PCa) treatment. Here, we explored the role and potential mechanism of circular RNA zinc finger protein 609 (circ-ZNF609) in the radioresistance of PCa cells.
Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ-ZNF609, microRNA-501-3p (miR-501-3p) and hexokinase 2 (HK2) messenger RNA (mRNA). The viability, apoptosis, metastasis and radioresistance of PCa cells were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, transwell assays and colony formation assay. The glycolytic rate was assessed through measuring the glucose consumption and lactate production using fluorescence-based glucose and lactate assay kits. The target interaction between miR-501-3p and circ-ZNF609 or HK2 was predicted by StarBase software and confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The protein level of HK2 was detected by Western blot assay. In vivo tumor growth assay was used to explore the role of circ-ZNF609 in the radioresistance of PCa in vivo.
Circ-ZNF609 was abnormally up-regulated in PCa tissues and cell lines. Circ-ZNF609 silencing hampered the viability, metastasis, radioresistance and promoted the apoptosis through suppressing cell glycolysis. MiR-501-3p was a direct target of circ-ZNF609, and si-circ-ZNF609-induced influence in PCa cells was partly alleviated by the addition of anti-miR-501-3p. MiR-501-3p functioned through directly interacting with and down-regulating HK2. HK2 was modulated by circ-ZNF609/miR-501-3p axis in PCa cells. Circ-ZNF609 silencing enhanced the radiosensitivity of PCa cells in vivo.
Circ-ZNF609 promoted the progression and radioresistance of PCa cells through accelerating the glycolysis via miR-501-3p/HK2 axis, providing promising targets for improving the prognosis of PCa patients.
放射抗性的产生仍然是前列腺癌（PCa）治疗的障碍。在此，我们探讨了环状RNA锌指蛋白609（circ-ZNF609）在PCa细胞放射抗性中的作用及潜在机制。
采用定量实时聚合酶链反应（qRT-PCR）检测circ-ZNF609、微小RNA-501-3p（miR-501-3p）和己糖激酶2（HK2）信使核糖核酸（mRNA）的表达。通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法、流式细胞术、Transwell实验和集落形成实验评估PCa细胞的活力、凋亡、转移和放射抗性。使用基于荧光的葡萄糖和乳酸检测试剂盒通过测量葡萄糖消耗和乳酸产生来评估糖酵解速率。通过StarBase软件预测miR-501-3p与circ-ZNF609或HK2之间的靶向相互作用，并通过双荧光素酶报告基因实验和RNA免疫沉淀（RIP）实验进行验证。通过蛋白质免疫印迹法检测HK2的蛋白水平。采用体内肿瘤生长实验探讨circ-ZNF609在PCa体内放射抗性中的作用。
Circ-ZNF609在PCa组织和细胞系中异常上调。Circ-ZNF609沉默通过抑制细胞糖酵解阻碍了细胞活力、转移、放射抗性并促进了细胞凋亡。MiR-501-3p是circ-ZNF609的直接靶点，添加抗miR-501-3p可部分缓解si-circ-ZNF609对PCa细胞的影响。MiR-501-3p通过直接与HK2相互作用并下调HK2发挥作用。在PCa细胞中，HK2受circ-ZNF609/miR-501-3p轴调控。Circ-ZNF609沉默增强了PCa细胞在体内的放射敏感性。
Circ-ZNF609通过miR-501-3p/HK2轴加速糖酵解，促进了PCa细胞的进展和放射抗性，为改善PCa患者的预后提供了有前景的靶点。
