Dysregulated long noncoding RNAs (lncRNAs) in hepatocellular carcinoma: implications for tumorigenesis, disease progression, and liver cancer stem cells

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours with a poor prognosis worldwide. While early stage tumours can be treated with curative approaches such as liver transplantation or surgical resection, these are only suitable for a minority of patients. Those with advanced stage disease are only suitable for supportive approaches and most are resistant to the conventional chemotherapy or radiotherapy. Liver cancer stem cells (LCSCs) are a small subset of cancer cells with unlimited differentiation ability and tumour forming potential. In order to develop novel therapeutic approaches for HCC, we need to understand how the cancer develops and why treatment resistance occurs. Using high-throughput sequencing techniques, a large number of dysregulated long noncoding RNAs (lncRNAs) have been identified, and some of which are closely linked to key aspects of liver cancer pathology, progression, outcomes and for the maintenance of cancer stem cell-like properties. In addition, some lncRNAs are potential biomarkers for HCC diagnosis and may serve as the therapeutic targets. This review summarizes data recently reported lncRNAs that might be critical for the maintenance of the biological properties of LCSCs.