Department of Biliary Minimally Invasive Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning, P.R. China.
Department of Minimally Invasive Surgery, Tongji University Affiliated Shanghai East Hospital, Shanghai, P.R. China.
Oncol Res. 2018 Jul 5;26(6):879-888. doi: 10.3727/096504017X15024935181289. Epub 2017 Aug 15.
Long noncoding RNAs (lncRNAs) are known to play important roles in cancers. However, little is known about lncRNAs in cholangiocarcinoma (CCA), a cholangiocyte malignancy with poor prognosis. We investigated the role of nuclear paraspeckle assembly transcript 1 (NEAT1) lncRNA in promoting CCA. qRT-PCR analysis of patient samples showed that NEAT1 expression was higher in CCA tumors than in matched adjacent nontumor tissue. NEAT1 levels were also higher in CCA cell lines than in a normal biliary epithelium cell line (HIBEpic). NEAT1 knockdown in CCA cell lines using shNEAT1 reduced cell proliferation and colony formation in CCK-8 and colony formation assays, respectively. CCA cells transfected with shNEAT1 also exhibited reduced metastasis and invasiveness in Transwell assays. NEAT1 knockdown cells produced smaller tumors, demonstrating that NEAT1 promotes tumor growth in vivo. Silencing of NEAT1 increased E-cadherin expression in vitro, and E-cadherin expression was inversely correlated with NEAT1 expression in CCA tissue samples. RIP and ChIP assays suggest that NEAT1 is recruited to the E-cadherin promoter by EZH2 (enhancer of zeste homolog 2), where it represses E-cadherin expression. These findings indicate that NEAT1 exerts oncogenic effects in CCA. We postulate that NEAT1 is a potentially useful diagnostic and therapeutic target for CCA.
长链非编码 RNA（lncRNA）已知在癌症中发挥重要作用。然而，胆管癌（CCA）中的 lncRNA 知之甚少，胆管癌是一种预后不良的胆管细胞恶性肿瘤。我们研究了核斑装配转录本 1（NEAT1）lncRNA 在促进 CCA 中的作用。对患者样本的 qRT-PCR 分析显示，CCA 肿瘤中的 NEAT1 表达高于匹配的相邻非肿瘤组织。CCA 细胞系中的 NEAT1 水平也高于正常胆管上皮细胞系（HIBEpic）。使用 shNEAT1 对 CCA 细胞系进行 NEAT1 敲低，分别在 CCK-8 和集落形成测定中降低了细胞增殖和集落形成。在 Transwell 测定中，转染 shNEAT1 的 CCA 细胞也表现出降低的转移和侵袭性。NEAT1 敲低细胞产生的肿瘤较小，表明 NEAT1 在体内促进肿瘤生长。体外沉默 NEAT1 增加了 E-钙粘蛋白的表达，并且 E-钙粘蛋白的表达与 CCA 组织样本中的 NEAT1 表达呈负相关。RIP 和 ChIP 测定表明，NEAT1 通过 EZH2（增强子结合蛋白 2）被募集到 E-钙粘蛋白启动子，在那里它抑制 E-钙粘蛋白的表达。这些发现表明 NEAT1 在 CCA 中发挥致癌作用。我们假设 NEAT1 是 CCA 潜在有用的诊断和治疗靶标。
