Liu Bo, Jiang Hui-Yang, Yuan Tao, Luo Jie, Zhou Wei-Dong, Jiang Qi-Quan, Wu Denglong
Department of Urology, Tongji Hospital, Tongji University of Medicine, Shanghai, China.
Front Oncol. 2021 Jun 30;11:650054. doi: 10.3389/fonc.2021.650054. eCollection 2021.
Our previous studies have demonstrated that Enzalutamide-induced upregulation of long non-coding RNA p21 (lncRNA-p21) facilitates prostate cancer (PCa) neuroendocrine differentiation (NED). Given the important role of lncRNAs in PCa pathogenesis, and given that lots of lncRNAs are dys-regulated in neuroendocrine PCa (NEPC) patients, we next explored the biological function and underlying mechanism of lncRNA-PCAT6 (PCAT6) in mediating Enzalutamide-induced NED. The level of PCAT6 in Enzalutamide-treated PCa cells and NEPC samples were assessed using quantitative RT-PCR (qPCR). The effect of PCAT6 on PCa cell proliferation, invasion, and NED was evaluated through CCK-8, transwell, qPCR, western blot analysis, Xenograft mouse model, and lung metastasis model. We found that PCAT6 was highly expressed in NE-like cells (PC3, DU145, and NCI-H660) compared with androgen-sensitive LNCaP cells. PCAT6 was also highly expressed in NEPC tissues. Enzalutamide treatment resulted in a significant increase of PCAT6 level in a dose- and time-dependent fashion. Functionally, PCAT6 overexpression promoted NED of C4-2 cells, as evidenced by an increased expression of NE markers (NSE, ChgA, and SYP), whereas PCAT6 knockdown in NCI-H661 cells repressed NED. Furthermore, PCAT6 overexpression promoted PCa cell proliferation and invasion and . Mechanistically, PCAT6 functioned as competing endogenous (ce) RNA absorbing miR-326, thus resulting in a de-suppression of target gene. The current results demonstrate that PCAT6 acted as a tumor activator in PCa progression by sponging miR-326 and increasing Hnrnpa2b1 expression and that the PCAT6/miR-326/Hnrnpa2b1 signaling might be a new therapeutic target for PCa.
我们之前的研究表明，恩杂鲁胺诱导的长链非编码RNA p21（lncRNA-p21）上调促进前列腺癌（PCa）神经内分泌分化（NED）。鉴于lncRNAs在PCa发病机制中的重要作用，且许多lncRNAs在神经内分泌PCa（NEPC）患者中表达失调，我们接下来探讨了lncRNA-PCAT6（PCAT6）在介导恩杂鲁胺诱导的NED中的生物学功能及潜在机制。使用定量逆转录PCR（qPCR）评估恩杂鲁胺处理的PCa细胞和NEPC样本中PCAT6的水平。通过CCK-8、Transwell、qPCR、蛋白质免疫印迹分析、异种移植小鼠模型和肺转移模型评估PCAT6对PCa细胞增殖、侵袭和NED的影响。我们发现，与雄激素敏感的LNCaP细胞相比，PCAT6在神经内分泌样细胞（PC3、DU145和NCI-H660）中高表达。PCAT6在NEPC组织中也高表达。恩杂鲁胺处理导致PCAT6水平以剂量和时间依赖性方式显著增加。在功能上，PCAT6过表达促进C4-2细胞的NED，神经内分泌标志物（NSE、ChgA和SYP）表达增加证明了这一点，而在NCI-H661细胞中敲低PCAT6则抑制NED。此外，PCAT6过表达促进PCa细胞增殖和侵袭。从机制上讲，PCAT6作为竞争性内源（ce）RNA发挥作用，吸附miR-326，从而导致靶基因去抑制。目前的结果表明，PCAT6通过结合miR-326和增加Hnrnpa2b1表达在PCa进展中充当肿瘤激活剂，并且PCAT6/miR-326/Hnrnpa2b1信号通路可能是PCa的一个新治疗靶点。
