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.