miR-490-3p Modulates Cell Growth and Epithelial to Mesenchymal Transition of Hepatocellular Carcinoma Cells by Targeting Endoplasmic Reticulum-Golgi Intermediate Compartment Protein 3 (ERGIC3)

MicroRNAs (miRNAs) are considered to be regulators of various biological processes in cancers, including the epithelial to mesenchymal transition (EMT), which is a key factor in cancer metastasis. In this study, we aimed to clarify the potential roles of miR-490-3p in hepatocellular carcinoma (HCC) cells. Using real-time quantitative RT-PCR, we discovered that miR-490-3p was up-regulated in HCC tissues and cells compared with the adjacent non-tumor tissues and normal cells. We also found that overexpression of miR-490-3p led to an increase in cell proliferation, migration, and invasion abilities and that it contributed to EMT. The inhibition of miR-490-3p had the opposite effect on the cells. We identified ERGIC3 (endoplasmic reticulum-Golgi intermediate compartment protein 3) as a direct target gene for miR-490-3p . Unlike most miRNA-mRNA interactions, miR-490-3p increased ERGIC3 mRNA and protein levels as well as the intensity of expression of the EGFP reporter gene controlled by the 3′-UTR of ERGIC3 mRNA. The up-regulation by miR-490-3p also required the participation of Ago2. The inhibition of miR-490-3p reduced the expression of ERGIC3 . Overexpression of ERGIC3 led to the same effect on HCC cells as miR-490-3p overexpression, including EMT. Importantly, silencing ERGIC3 reversed the cellular responses mediated by miR-490-3p overexpression. In conclusion, our study indicated for the first time that miR-490-3p functioned like an oncogenic miRNA in HCC cells and that the inhibition of miR-490-3p might provide an potential treatment approach for HCC patients. Background: The role of miR-490-3p in hepatocellular carcinoma (HCC) has not been well clarified. Results: miR-490-3p is up-regulated in HCC and enhances the cell proliferation, migration, invasion abilities, and stimulates the epithelial to mesenchymal transition (EMT) through targeting ERGIC3 . Conclusion: miR-490-3p may play an important role in promoting tumor growth and metastasis in HCC. Significance: miR-490-3p may provide beneficial therapeutic strategy for HCC patients.