MicroRNA-139-5p negatively regulates NME1 expression in hepatocellular carcinoma cells

Background. High expression of NME1 is associated with hepatocellular carcinoma (HCC) progression and poor prognosis. However, there are few reports on the association between NME1 and microRNAs (miRNAs) in HCC progression. Objectives. To explore miRNAs that regulate NME1 expression in HCC. Materials and methods. Data from the Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA), Tar-getScan, starBase, and mirDIP were used to analyze the expression pattern of NME1 in HCC tissues, the rela-tionship between NME1 level and the progression of HCC or patient prognosis, miRNAs targeting NME1, and the biological processes that may be regulated by NME1. The regulation of miRNAs to NME1 was assessed using the dual-luciferase reporter assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. The cell cycle and cell proliferation were detected using propidium iodide (PI) staining and EdU assay, respectively. Results. Highly expressed NME1 in HCC was associated with HCC progression and prognosis. The miR-139-5p and miR-335-5p were weakly expressed in HCC samples and negatively correlated with NME1. The down-regulation of miR-139-5p in HCC patients resulted in worse overall survival (OS) and disease-free interval (DFI); however, the level of miR-335-5p was not significantly correlated with OS and DFI in patients with HCC. In vitro experiments verified that the level of miR-139-5p was lower and NME1 expression was higher in HCC cell lines compared to L-02. Moreover, miR-139-5p negatively regulates the expression of NME1 in HCC cell lines. The NME1 may regulate cell cycle, DNA replication, oxidative phosphorylation, and the pentose phosphate pathway. The miR-139-5p inhibited cell proliferation by negatively regulating NME1 expression. Conclusions. The upregulation of NME1 in HCC indicates a poor prognosis. The NME1 is negatively regulated by miR-139-5p to inhibit cell proliferation.