The role of noncoding RNA in hepatocellular carcinoma

Increasing noncoding RNAs (ncRNAs) were found to show abnormal expression patterns in various human cancers. Based on their length, ncRNAs are briefly divided into two categories. Transcripts that are shorter than 200 nucleotides are recognized as short/small noncoding RNAs and greater than 200 nucleotides as long noncoding RNAs (lncRNAs). Short/small noncoding RNAs include microRNAs, piRNAs, snoRNAs, and endogenous siRNAs. Numerous studies have revealed that these short/small ncRNA play important roles in multiple biological processes and tumorigenesis. In contrast to small ncRNAs, long noncoding RNAs are much less known concerning their functions in human cancers especially in hepatocellular carcinoma (HCC). In this review, we highlight recent progress regarding HCC development, tumorigenesis, metastasis, clinical implication, as well as the role in the risk of HBV infection.