Differential Expression of MicroRNAs in Hepatitis C Virus-Mediated Liver Disease Between African Americans and Caucasians: Implications for Racial Health Disparities.

African Americans (AAs) have higher hepatocellular carcinoma (HCC) mortality rates than Caucasian Americans (CAs). Chronic hepatitis C virus (HCV) infection leads to cirrhosis and HCC. HCV infection is highly prevalent in the AA population compared to other racial groups. AAs are also less likely to naturally clear HCV, potentially contributing to higher prevalence of HCV. However, the explanation for this disparity is currently unknown. Circulating microRNAs (miRNAs) in the blood are emerging as biomarkers for pathological conditions. Expression analysis of miRNAs in major racial groups would be important for optimizing personalized treatment strategies. Here we assessed the differential expression of circulatory miRNAs from HCV-infected AA and CA patients. We identified increased expression of miR-146a, miR-150, and miR-155 in HCV-infected AA patient sera compared to that of CA. Further analysis demonstrated that these miRNAs were significantly elevated in AA patients diagnosed with HCV-mediated HCC. Higher expression of miR-150 was also noted in cirrhosis and HCC in AA patients, which may serve as a predictor of liver disease progression in this population. The differential expression of miRNAs suggests that these miRNAs and their target genes could be useful to gain further mechanistic insight of racial disparity associated with HCV-mediated pathogenesis.