MicroRNAs (miRNAs/miRs) have been identified as important post-transcriptional regulators in healthy liver physiology and liver diseases. However, the clinical significance of miR-638 in hepatocellular carcinoma (HCC) remains unclear. The aim of the present study was to investigate the status of miR-638 expression in HCC and to determine its clinical significance. The expression of miR-638 was evaluated in 60 HCC tissues samples and HCC SMMC-7721, HepG2 and Hep3B cell lines using reverse transcription-quantitative polymerase chain reaction. The association between the expression of miR-638 and the clinicopathological characteristics of patients with HCC was analyzed. The proportion of HCC patients with low miR-638 expression was identified as 68.3% (41/60). Furthermore, significantly lower miR-638 expression was identified in HCC tissue samples compared with the healthy control group (P=0.031). miR-638 expression was significantly lower in SMMC-7721 (P=0.021), HepG2 (P=0.005) and Hep3B (P=0.003) cells compared with the healthy human hepatic HL-7702 cell line. In addition, miR-638 expression was correlated with α-fetoprotein levels (P=0.042) and portal vein invasion (P=0.025). The area under curve was identified as 0.71 (95% confidence interval=0.63-0.79; P=0.001). The cut-off value for miR-638 was the median 2-Δ∆Cq=0.125. In conclusion, miR-638 may be involved in the progression of HCC and act as a potential biomarker for the prediction of HCC.
Keywords: clinicopathological characteristics; formalin-fixed paraffin-embedded tissue; hepatocellular carcinoma; miR-638; reverse transcription-quantitative polymerase chain reaction.