Hepatocellular carcinoma (HCC) is a leading lethal malignancy worldwide. However, the molecular mechanisms underlying liver carcinogenesis remain poorly understood. Over the past two decades, overwhelming evidence has demonstrated the regulatory roles of different classes of non-coding RNAs (ncRNAs) in liver carcinogenesis related to a number of aetiologies, including HBV, HCV and NAFLD. Among the ncRNAs, microRNAs, which belong to a distinct class of small ncRNAs, have been proven to play a crucial role in the post-transcriptional regulation of gene expression. Deregulation of microRNAs has been broadly implicated in the inactivation of tumour-suppressor genes and activation of oncogenes in HCC. Modern high-throughput sequencing analyses have unprecedentedly identified a very large number of non-coding transcripts. Divergent groups of long ncRNAs have been implicated in liver carcinogenesis through interactions with DNA, RNA or proteins. Overall, ncRNAs represent a burgeoning field of cancer research, and we are only beginning to understand the importance and complicity of the ncRNAs in liver carcinogenesis. In this Review, we summarize the common deregulation of small and long ncRNAs in human HCC. We also comprehensively review the pathological roles of ncRNAs in liver carcinogenesis, epithelial-to-mesenchymal transition and HCC metastasis and discuss the potential applications of ncRNAs as diagnostic tools and therapeutic targets in human HCC.

肝细胞癌（HCC）是全球领先的致死性恶性肿瘤。但是，肝癌发生的分子机制仍知之甚少。在过去的二十年中，大量证据证明了不同类别的非编码RNA（ncRNA）在肝癌发生中与许多病因有关的调节作用，包括HBV，HCV和NAFLD。在ncRNA中，已证实属于小ncRNA独特类别的microRNA在转录后的基因表达调控中起着至关重要的作用。microRNA的失调与HCC中肿瘤抑制基因的失活和癌基因的激活广泛相关。现代高通量测序分析已前所未有地鉴定出大量非编码转录本。通过与DNA，RNA或蛋白质的相互作用，长的ncRNA的不同种类参与了肝癌的发生。总体而言，ncRNA代表了癌症研究的新兴领域，我们才刚刚开始了解ncRNA在肝癌发生中的重要性和共谋性。在这篇综述中，我们总结了人类肝癌中小而长的ncRNA的常见失调。我们还全面审查了ncRNA在肝癌发生，上皮向间充质转化和HCC转移中的病理作用，并讨论了ncRNA在人类HCC中作为诊断工具和治疗靶标的潜在应用。并且我们才刚刚开始了解ncRNA在肝癌发生中的重要性和共谋性。在这篇综述中，我们总结了人类肝癌中小而长的ncRNA的常见失调。我们还全面审查了ncRNA在肝癌发生，上皮向间充质转化和HCC转移中的病理作用，并讨论了ncRNA在人类HCC中作为诊断工具和治疗靶标的潜在应用。并且我们才刚刚开始了解ncRNA在肝癌发生中的重要性和共谋性。在这篇综述中，我们总结了人类肝癌中小而长的ncRNA的常见失调。我们还全面审查了ncRNA在肝癌发生，上皮向间充质转化和HCC转移中的病理作用，并讨论了ncRNA在人类HCC中作为诊断工具和治疗靶标的潜在应用。