RESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) is the sixth most common cancer in the world. Having a very poor prognosis, it currently ranks as the third most common cause of cancer-related deaths. MiRNAs are a set of small, single-stranded, non-coding RNA molecules that negatively regulate gene expression at the post-transcriptional level. Several miRNAs were found to be frequently deregulated in HCC. OBJECTIVE: To investigate whether miRNA-122, miRNA-199a, and miRNA-16 are altered in sera of hepatitis C virus (HCV)-induced HCC patients compared with chronic HCV patients without HCC, and to assess their diagnostic value to differentiate between HCC and chronic HCV in order to develop a non-invasive diagnostic and prognostic tool for HCC. METHODS: We analysed the expression of mature miRNA-122, miRNA-199a, and miRNA-16 in serum by a singleplex TaqMan two-step stem loop quantitative real-time reverse-transcription PCR (qRT-PCR) in 40 newly diagnosed HCC patients and 40 chronic HCV liver cirrhosis patients, as well as 20 apparently healthy individuals as a control group, using RNU48 as a normalisation control. RESULTS: Serum miR-16 was significantly lower in HCC than in HCV patients (P = 0.033). The serum level of miR-199a in chronic HCV patients was significantly lower than in healthy controls (P = 0.001). Receiver operating curve (ROC) analysis for serum miRNA-16 for discriminating HCC from HCV patients showed that at the cut-off value of 0.904, the sensitivity and specificity for this marker were 57.5 and 70 %, respectively. The combination of serum miR-16 with serum alpha fetoprotein (AFP) resulted in improved sensitivity to 85% and increased diagnostic accuracy to 87.5 %. Serum miR-199a and miR-16 were significantly associated with several parameters of HCC such as tumour size and number. CONCLUSION: The combination of serum miR-16 and serum AFP is a significant improvement on the current best practice of serum AFP for HCC in HCVpositive patients. Serum miR-199a and miR-16 could be used as potential indicators of the progress of HCC.
