Cancer-related microRNAs and their role as tumor suppressors and oncogenes in hepatocellular carcinoma.

MicroRNAs (miRNAs) have emerged as key factors involved in several biological processes, including development, differentiation, cell proliferation, and tumorigenesis. In hepatocellular carcinoma (HCC), miRNAs frequently present aberrant expression profiles, which make them potentially attractive for diagnostic or prognostic applications. Currently, accumulating evidence is indicating the role of miRNAs as tumor suppressors or oncogenes in hepatic malignancies. In particular, comprehensive studies have made possible a better understanding of HCC behavior, such as tumor growth, response to therapies, metastatic potential, or recurrence, regarding the altered expression of cancer-related miRNAs. Based on these findings, efforts are under way to define new markers for liver cancer in both invasive (hepatic biopsy or tumor resection) and non-invasive (circulating miRNAs in blood serum) ways. Due to their implication in the control of various cell processes altered in HCC, cancer-related miRNAs also offer encouraging perspectives for the development of innovative cancer therapies. In this article, we review the importance of miRNA deregulation in HCC progression and the role of these small non-coding RNAs as tumor suppressors and oncogenes. The significance of miRNAs in HCC diagnosis and miRNA-based therapeutic strategies is then discussed.