Circulating MicroRNA-122 as a Potential Biomarker for Hepatitis C Virus Induced Hepatocellular Carcinoma

Background: The microRNA (miRNA) mediated translational repression can cause various diseases in humans. The liver-specific miRNA (microRNA-122 (miR-122)) is primarily involved in tissue tropism during hepatitis C virus (HCV) infection which ultimately leads to hepatocellular carcinoma (HCC). Objectives: This study focuses on evaluating host serum miR-122 as a prognostic marker in HCV-induced hepatocellular carcinoma. Methods: Evaluation of miR-122 expression was carried out by quantitative real time PCR. Results: Positive expression of miR-122 was observed in patients with chronic hepatitis C (CHC) followed by HCC patients compared to healthy controls. A difference in median levels of the miR-122 expression in CHC and HCC patients (P < 0.000) was found in contrast to cirrhosis patients (P = 0.511). The serum miR-122 expression was found threefold higher in liver cirrhosis patients than chronic hepatitis. Further, the area under the receiver operating characteristic curve (AUROC) analysis of miR-122 expression profile can efficiently distinguish CHC patients (AUROC = 0.978, P = 0.000, 95% confidence interval (CI) = 0.958 to 0.998) and HCC from healthy controls (AUROC = 0.971, P = 0.000, 95% CI = 0.944 to 0.997). Moreover, receiver operating characteristic (ROC) curve analysis significantly distinguished between CHC patients from cirrhosis patients (AUROC = 0.955, P = 0.000, 95% CI = 0.925 to 0.986) but not CHC from HCC patients (AUROC = 0.584, P = 0.104, 95% CI = 0.485 to 0.684). This study revealed a substantial correlation of miR-122 with HCV viral load (r = 0.56, P = 0.000), ALT (r = 0.67, P = 0.000) and AST (r = 0.65, P = 0.000) levels. Conclusions: Serum miR-122 can potentially serve as a promising prognostic tool for HCV induced HCC.