Wei Yongbao, Peng Junming, He Shuyun, Huang Haijian, Lin Le, Zhu Qingguo, Ye Liefu, Li Tao, Zhang Xing, Gao Yunliang, Zheng Xiaochun
Shengli Clinical Medical College of Fujian Medical University, Fuzhou 350001, China.
Department of Urology, Fujian Provincial Hospital, Fuzhou 350001, China.
J Cancer. 2020 May 18;11(15):4453-4463. doi: 10.7150/jca.44441. eCollection 2020.
Ectopic expression of miR-223-5p, the lagging strand of miR-223 duplex, has been reported acting as anti-tumor miRNA in many cancers. How miR-223-5p influencing prostate cancer (PCa) remains obscure and worth of experimental investigation. In this study, the expressions of miR-223-5p and ERG in common PCa cell lines were detected and compared to RWPE-1, respectively. Then luciferase reporter assay was performed to verify whether miR-223-5p could specifically target and regulate ERG. Further discovery ERG's role in the PCa oncogenesis was also conducted by up or down regulating miR-223-3p expression. We found miR-223-5p was significantly down-regulated in DU145, while it was only up-regulated in LNCaP. Similarly, ERG expression remarkably decreased in both PC-3 and DU145 than that in RWPE-1, but significantly increasing in LNCaP. Luciferase assay demonstrated slightly decreased ERG expression after miR-223-5p-mimics but significantly increased ERG expression after miR-223-5p-inhibtor. Using gene interference, we further confirmed that both ERG mRNA and protein expressions were decreased in all PCa lines transfected ERG siRNA, but increasing in both DU145 and LNCaP cells with miR-223-5p antisense oligonucleotides. MTT assay, Transwell invasion and migration assay supported the function of ERG in PCa oncogenesis. We revealed tumor suppressive abilities of miR-223-5p in PCa by negatively targeting ERG gene. It could serve as a fundamental supplement and extension of our previous study about miR-223-3p in PCa, revealing the coordinative regulation between miR-223-5p and miR-223-3p in PCa cell biological behaviors. Exploration of miR-233-duplex orientated pathway networks may help us develop novel potential therapeutic options for PCa.
据报道，miR-223双链体的后随链miR-223-5p的异位表达在许多癌症中作为抗肿瘤miRNA发挥作用。miR-223-5p如何影响前列腺癌（PCa）仍不清楚，值得进行实验研究。在本研究中，检测并比较了常见PCa细胞系中miR-223-5p和ERG的表达，并分别与RWPE-1进行比较。然后进行荧光素酶报告基因检测，以验证miR-223-5p是否能特异性靶向并调节ERG。通过上调或下调miR-223-3p的表达，进一步探究ERG在PCa发生中的作用。我们发现，miR-223-5p在DU145中显著下调，而在LNCaP中仅上调。同样，与RWPE-1相比，ERG在PC-3和DU145中的表达均显著降低，但在LNCaP中显著升高。荧光素酶检测表明，miR-223-5p模拟物处理后ERG表达略有下降，而miR-223-5p抑制剂处理后ERG表达显著增加。通过基因干扰，我们进一步证实，在所有转染ERG siRNA的PCa细胞系中，ERG mRNA和蛋白表达均降低，但在转染miR-223-5p反义寡核苷酸的DU145和LNCaP细胞中均升高。MTT检测、Transwell侵袭和迁移检测支持ERG在PCa发生中的作用。我们通过负向靶向ERG基因揭示了miR-223-5p在PCa中的肿瘤抑制能力。它可以作为我们之前关于PCa中miR-223-3p研究的基本补充和扩展，揭示miR-223-5p和miR-223-3p在PCa细胞生物学行为中的协同调节作用。探索miR-233双链体定向的信号通路网络可能有助于我们开发针对PCa的新型潜在治疗方案。
