Roles of long noncoding RNAs in Hepatocellular Carcinoma

Long noncoding RNAs (lncRNAs) are nonprotein coding transcripts longer than 200 nucleotides. Aberrant expression of lncRNAs has been found to be associated with hepatocellular carcinoma, one of the most malignant tumors. In this paper, we give a systematic and comprehensive review of existing literature about the involvement of lncRNAs in hepatocellular carcinoma. To date, evidence suggests that a number of lncRNAs, including HEIH, H19, HOTAIR, MALAT1, and PVT1, may regulate the transcription of target genes by recruiting histone-modifying complexes. Under certain circumstances, lncRNAs form RNA-dsDNA triplexes. Certain lncRNAs, such as HULC, HOTAIR, H19, HOTTIP and PTENP1, exhibit their biological roles by associating with microRNAs (miRNAs). In addition, by complementary base pairing with mRNAs or forming complexes with RNA binding proteins (RBPs), lncRNA-ATB, MALAT1 and PCNA-AS1 may mediate mRNA stability and splicing. In conclusion, interactions with DNA, RNA and proteins appears to be involved in lncRNAs' participation in tumorigenesis and developmental processes related to hepatocellular carcinoma.