HCV-E2 inhibits hepatocellular carcinoma metastasis by stimulating mast cells to secrete exosomal shuttle microRNAs

Exosomal miRNAs are emerging as mediators of the interaction between mast cells (MCs) and tumor cells. The exosomal miRNAs can be internalized by liver cancer cells to inhibit cell metastasis. We explored the interaction between MCs and hepatocellular carcinoma (HCC) cells. We used hepatitis C virus E2 envelope glycoprotein (HCV-E2) to stimulate MCs and harvest MCs-derived exosomes to detect the miRNAs and changes of exosomal miRNAs before and after stimulation. Through miRNA microarray analysis, we identified 19 differentially expressed miRNAs in exosomes derived from MCs with or without HCV-E2 treatment. HCV-E2 not only increased the level of miRNA-490 in MCs and their secreted exosomes but also increased the levels of miRNA-490 in recipient HepG2 cells, which ultimately inhibited the ERK1/2 pathway. The transfection of antagomiR-490 significantly decreased the levels of miR-490 in MCs, MCs-derived exosomes, and recipient HepG2 cells and increased migration of HepG2, indicating that miR-490 is involved in the regulation of HepG2 cell migration. The present study suggests that MCs can inhibit HCC cell metastasis by inhibiting the ERK1/2 pathway by transferring the exosomal shuttle microRNAs into HCC cells, which provides new insights for the biological therapy of HCC induced by hepatitis C.