Tang Yanhui, Liu Junxiang, Li Xilan, Wang Wenbin
Department of Clinical Laboratory, Shandong Jinan Jiyang Public Hospital, Jinan, Shandong, China.
J Biosci. 2021;46.
Prostate cancer (PCa) is the second frequent malignancy among men in the world. Exosomal circular RNAs (circRNAs) have been reported to function in PCa progression. The current study aimed to investigate the role of exosomal circRNA homeodomain-interacting protein kinase 3 (circHIPK3) in PCa development. Exosomes were extracted from serum and cells utilizing commercial kit, and identified by transmission electron microscopy (TEM), Western blot assay and nanoparticle tracking analyzer. Relative expression of circHIPK3, microRNA (miR)-212 and B-cell specific MMLV insertion site-1 (BMI-1) was examined by quantitative realtime PCR or Western blot assay. Receiver Operating Characteristic (ROC) analysis was conducted to assess the diagnostic potential of exosomal miR-212. Cell viability, and metastasis including migration and invasion, were detected by Methyl thiazolyl tetrazolium (MTT) assay and Transwell assay, respectively. Cell apoptosis was monitored using flow cytometry. The interaction between miR-212 and circHIPK3 or BMI-1 was validated by dual-luciferase reporter assay. Xenograft tumor assay was employed to explore the role of exosomal circHIPK3 . Exosomal circHIPK3 was increased in serum of PCa patients, and could discriminate PCa patients from normal volunteers. Depletion of exosomal circHIPK3 or overexpression of exosomal miR-212 reduced viability, migration and invasion, but promoted cell apoptosis in PCa cells, which was attenuated by miR-212 inhibition or BMI-1, respectively. MiR-212 targeted BMI-1, and downregulated BMI-1 expression. Exosomal circHIPK3 knockdown also suppressed tumor growth . Exosomal circHIPK3 knockdown inhibited PCa progression by regulating miR-212/BMI-1 axis, at least in part, offering a new insight into the molecular mechanism of PCa.
前列腺癌（PCa）是全球男性中第二常见的恶性肿瘤。据报道，外泌体环状RNA（circRNAs）在PCa进展中发挥作用。本研究旨在探讨外泌体环状同源结构域相互作用蛋白激酶3（circHIPK3）在PCa发展中的作用。利用商业试剂盒从血清和细胞中提取外泌体，并通过透射电子显微镜（TEM）、蛋白质免疫印迹分析和纳米颗粒跟踪分析仪进行鉴定。通过定量实时PCR或蛋白质免疫印迹分析检测circHIPK3、微小RNA（miR）-212和B细胞特异性MMLV插入位点1（BMI-1）的相对表达。进行受试者工作特征（ROC）分析以评估外泌体miR-212的诊断潜力。分别通过甲基噻唑基四氮唑（MTT）法和Transwell法检测细胞活力以及包括迁移和侵袭在内的转移情况。使用流式细胞术监测细胞凋亡。通过双荧光素酶报告基因检测验证miR-212与circHIPK3或BMI-1之间的相互作用。采用异种移植瘤实验来探究外泌体circHIPK3的作用。PCa患者血清中外泌体circHIPK3增加，并且可以将PCa患者与正常志愿者区分开来。外泌体circHIPK3的缺失或外泌体miR-212的过表达降低了PCa细胞的活力、迁移和侵袭能力，但促进了细胞凋亡，而miR-212抑制或BMI-1分别减弱了这种作用。miR-212靶向BMI-1，并下调BMI-1的表达。外泌体circHIPK3的敲低也抑制了肿瘤生长。外泌体circHIPK3的敲低至少部分通过调节miR-212/BMI-1轴抑制了PCa进展，为PCa的分子机制提供了新的见解。
