Combination of exosomes and circulating microRNAs may serve as a promising tumor marker complementary to alpha-fetoprotein for early-stage hepatocellular carcinoma diagnosis in rats

Due to unsatisfying prognosis of AFP for hepatocellular carcinoma (HCC), we aim to evaluate the prognostic value of combination of exosomes and miRNAs in detecting HCC. HCC was induced with diethylnitrosamine in rats and using a scoring system based on histological examination six different stages (normal liver, degeneration, fibrosis, cirrhosis, early HCC and late HCC) were identified in the development of HCC. The expression levels of AFP, exosomes and miRNAs (miRNA-10b, miRNA-21, miRNA-122 and miRNA-200a) were detected in both tissue and blood samples from those six stages. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the power of each parameter and their different combinations in diagnosing HCC or cirrhosis. A change in the expression of both exosomes and miRNAs was observed during cirrhosis, which in contrast with AFP starts showing up until the early HCC stage. Interestingly, the expressions of exosomes and the selected four miRNAs at early HCC stage obtained more remarkably alterations than the level of AFP (P < 0.05). On correlation analysis, four selected miRNAs had a significant closer relationship with exosomes when compared with AFP. The different combinations of AFP, exosomes, serous miRNAs and exosomal miRNAs had stronger power in predicting HCC than AFP (area under the curve of ROC, 0.943 vs 0.826). To conclude, the combination of circulating miRNAs and exosomes might serve as promising biomarkers for non-virus infected HCC screening and cirrhosis discrimination.