Long non-coding RNAs era in liver cancer

Hepatocellular carcinoma (HCC) is one of the most common malignancies leading to high mortality rates in the general population and the sixth most common cancer worldwide. HCC is characterized by deregulation of multiple genes and signalling pathways. These genetic effects can involve both protein coding genes as well as non-coding RNA genes. Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nt, constituting a subpopulation of ncRNAs. Their biological effects are not well understood compared to small non-coding RNA (microRNAs), but they have been recently recognized to exert a crucial role in the regulation of gene expression and modulation of signalling pathways. Notably, several studies indicated that lncRNAs contribute to the pathogenesis and progression of HCC. Investigating the molecular mechanisms underlying lncRNAs expression opens potential applications in diagnosis and treatment of liver disease. This editorial provides three examples (MALAT-1 metastasis associated lung adenocarcinoma transcript, HULC highly upregulated in liver cancer and HOTAIR HOX transcript antisense intergenic RNA) of well-known lncRNAs upregulated in HCC, whose mechanisms of action are known, and for which therapeutic applications are delineated. Targeting of lncRNAs using several approaches (siRNA-mediated silencing or changing their secondary structure) offers new possibility to treat HCC.