The miR-758/astrocyte elevated gene-1 signaling pathway regulates metastasis of human hepatocellular carcinoma HepG2 cells

Objective To investigate the mechanism of miR-758 in hepatocellular carcinoma cell HepG2, and to investigate the regulatory role of miR-758 on astrocyte elevated gene-1 (AEG-1). Methods Transient transfection of miR-758 into HepG2 cells was performed to study the effect of miR-758 on tumor cell metastasis by transwell migration and invasion experiments. CCK8 assay was used to detect the cell proliferation activity. The cell cycle was analyzed by flow cytometry. The effect of miR-758 on epidermal mesenchymal transition (EMT) was determined by the expression of EMT markers. Transient transfection of miR-758 into human umbilical vein endothelial cells (HUVECs) was performed to explore the effect of miR-758 on luminal formation. AEG-1 3′UTR containing the binding site of miR-758 was constructed into luciferase expression vector. The miR-758 and the vector was co-transfected into HepG2 cells. And then the change in expression level of AEG-1 protein was detected through Western Blot. Results The overexpression of miR-758 inhibited HepG2 cell migration and invasion, as well as the cell proliferation and the cell cycle. The miR-758 was also found to inhibit EMT of HepG2 cells and the lumen formation of HUVEC cells. After the co-transfection of miR-758 with the plasmid containing AEG-1 gene 3′UTR into HepG2 cells, the luciferase expression was decreased. The luciferase expression was restored when the binding site of miR-758 in the 3′UTR was mutated. Further evidence by Western Blot showed the protein level of AEG-1 in HepG2 cells was significantly decreased after transfection of miR-758. Conclusions The miR-758 negatively regulates multiple steps during cancer metastasis, including cell migration, invasion, cell proliferation, EMT, as well as angiogenesis. And AEG-1 has been identified as a downstream target of miR-758. Key words: microR-758; Astrocyte elevated gene-1; Liver cancer; Cancer metastasis