MicroRNAs in HBV-related hepatocellular carcinoma: functions and potential clinical applications

Hepatitis B virus (HBV) infection is still a relevant problem worldwide and many cases of hepatocellular carcinoma (HCC) are related to HBV. The prognosis of HBV-related HCC is poor, particularly for advanced stage diagnosis. Although follow-up strategies were adopted for patients at risk, there is need for an optimal early biomarker for the screening purpose. MicroRNAs (miRNAs) are small non-coding RNAs, tightly connected to cell type and differentiation status and act as genetic regulator which can be involved in oncogenic processes. The alteration in miRNA expression pattern may represent a new opportunity for HBV-related HCC diagnosis and therapies. Some studies focused on miRNA polymorphism responsible for HCC susceptibility; others found several miRNAs deregulated by HBV X protein as well as miRNAs altered in HBV-related HCC tissue and cells. A high variability among results emerged, probably due to different techniques employed, biological substrates, experimental procedures, criteria of miRNAs selection and ethnic provenience of the included patients. Interestingly, circulating miRNAs have been studied as potential HCC-biomarkers but the reported accuracy is still not convincing, particularly in distinguishing patients with HCC from patients with cirrhosis. Hence, the use of miRNAs remains in an experimental phase and more studies are required to define their role in the clinical practice.