Department of Pathology, Saint Louis University, St. Louis, Missouri, USA.
Department of Internal Medicine, Saint Louis University, St. Louis, Missouri, USA.
J Virol. 2018 Sep 26;92(20). doi: 10.1128/JVI.01215-18. Print 2018 Oct 15.
Chronic hepatitis C virus (HCV) infection may lead to end-stage liver disease, including hepatocellular carcinoma (HCC). We have shown previously that microRNA-373 (miR-373) is upregulated in HCV-infected human liver biopsy specimens. To gain insight into the role of miR-373 in HCV-mediated pathogenesis, we investigated its interacting partner for hepatocyte growth regulation. Transcriptome sequencing (RNA-seq) data revealed that Wee1 is associated with miR-373 and is a direct target. Interestingly, higher expression of Wee1 was noted in HCV-infected hepatocytes than in uninfected hepatocytes, suggesting that other factors may block miR-373-mediated Wee1 inhibition. We subsequently found an association between the long noncoding RNA NORAD (LINC00657) and miR-373, and we demonstrated that NORAD binds to miR-373 and Wee1 independently. However, the high level of Wee1 expression in HCV-infected hepatocytes suggested that miR-373 forms a complex with NORAD. Depletion of miR-373 or the inhibitor Wee1 reduces the growth of Huh7.5 cells harboring the HCV genome as well as reducing Wee1 expression. Taken together, our data demonstrate a novel mechanism of hepatocyte growth promotion during HCV infection involving a miR-373-NORAD-Wee1 axis, which may be a target for future therapy against HCV-associated HCC. The mechanism of HCV-mediated liver pathogenesis is poorly understood. In this study, we observed that HCV infection upregulates miR-373 and Wee1, a pivotal player in the G checkpoint in the cell cycle, although Wee1 is a direct target for miR-373. Subsequent investigation demonstrated that miR-373 forms a complex with the long noncoding RNA NORAD, resulting in the release of their common target, Wee1, in HCV-infected cells, which, in turn, favors uncontrolled cell growth. Our study suggested a previously unknown mechanism for hepatocyte growth promotion following HCV infection, and this pathway can be targeted for future therapy against HCV-mediated liver pathogenesis.
慢性丙型肝炎病毒（HCV）感染可导致终末期肝病，包括肝细胞癌（HCC）。我们之前已经表明，microRNA-373（miR-373）在 HCV 感染的人类肝活检标本中上调。为了深入了解 miR-373 在 HCV 介导的发病机制中的作用，我们研究了其与肝细胞生长调节有关的相互作用伙伴。转录组测序（RNA-seq）数据显示，Wee1 与 miR-373 相关，是其直接靶标。有趣的是，在 HCV 感染的肝细胞中，Wee1 的表达高于未感染的肝细胞，这表明其他因素可能阻止了 miR-373 介导的 Wee1 抑制。随后，我们发现长链非编码 RNA NORAD（LINC00657）与 miR-373 之间存在关联，并且我们证明 NORAD 独立于 miR-373 和 Wee1 结合。然而，在 HCV 感染的肝细胞中高水平的 Wee1 表达表明 miR-373 与 NORAD 形成复合物。miR-373 耗竭或抑制剂 Wee1 减少了携带 HCV 基因组的 Huh7.5 细胞的生长，并降低了 Wee1 的表达。总之，我们的数据表明，在 HCV 感染过程中，miR-373-NORAD-Wee1 轴促进肝细胞生长是一种新的机制，这可能是针对 HCV 相关 HCC 的未来治疗的靶点。HCV 介导的肝发病机制的机制尚不清楚。在这项研究中，我们观察到 HCV 感染上调了 miR-373 和 Wee1，Wee1 是细胞周期 G 检查点中的关键因子，尽管 Wee1 是 miR-373 的直接靶标。随后的研究表明，miR-373 与长链非编码 RNA NORAD 形成复合物，导致其共同靶标 Wee1 在 HCV 感染细胞中释放，进而有利于不受控制的细胞生长。我们的研究提出了一种 HCV 感染后促进肝细胞生长的未知机制，该途径可作为针对 HCV 介导的肝发病机制的未来治疗靶点。
