Objective   To investigate the effect and underlying mechanism of micro ribonucleic acid (miR)-101 on the epithelial-mesenchymal transition in human hepatocellular carcinoma MHCC97H cells.

  Methods   MHCC97H cell lines were transfected with miR-101 mimics (M101 group) and negative control mimic (NCM group), and the cell lines without transfection were used as the control group. The expression levels of miR-101 in cells of 3 groups were quantitatively measured using reverse transcription polymerase chain reaction (RT-PCR). Transwell assay was performed to evaluate the cell migration and invasion ability of 3 groups. The expression levels of vimentin, -catenin, E-cadherin and USP22 proteins in cells of 3 groups were measured by Western blot. The relationship between miR-101 and USP22 was analyzed by dual-luciferase assay.

  Results   In the M101 group, the expression level of miR-101 was significantly up-regulated, which was approximately 761 times of that in the control group (P < 0.05). In the M101 group, the quantity of migrating cells was 15.7±1.6, significantly lower than 94.1±1.8 in the control group (P < 0.05). In the M101 group, the quantity of invasive cells was 9.1±0.4, significantly lower compared with 51.6±0.9 in the control group (P < 0.05). In the M101 group, the expression levels of vimentin and USP22 protein were significantly down-regulated, whereas the expression levels of -catenin and E-cadherin protein were significantly up-regulated. Dual-luciferase assay revealed that USP22 was the target gene of the downstream miR-101 signaling pathway.

  Conclusion   miR-101 regulates the expression of epithelial-mesenchymal transition-related proteins and suppresses the epithelial-mesenchymal transition of hepatocellular carcinoma MHCC97H cells probably through down-regulating the expression level of USP22.