The expression and function of miR-424 in infantile skin hemangioma and its mechanism.

Infantile hemangioma is the most common benign tumor in infants. Many studies have confirmed that basic fibroblast growth factor (bFGF) and its key receptor FGFR1 are highly expressed in hemangioma. Moreover, several miRNAs can regulate angiogenesis. In this regard, miR-424 often plays a role as tumor suppressor gene. This study was designed to investigate the mechanism of miR-424 in infantile skin hemangioma. Our results showed low expression of miR-424 in infantile skin hemangioma tissues, and that miR-424 overexpression downregulated FGFR1 expression in hemangioma-derived endothelial cells, while miR-424 inhibition upregulated FGFR1 expression. Luciferase reporter analysis confirmed that FGFR1 was a target gene of miR-424. CCK-8, flow cytometry, transwell migration and tube formation assays demonstrated that miR-424 overexpression inhibited cell proliferation, migration and tube formation, at least in part by blocking the bFGF/FGFR1 pathway. In contrast, miR-424 inhibition significantly enhanced these functions. Furthermore, miR-424 overexpression significantly inhibited ERK1/2 phosphorylation, whereas miR-424 inhibition enhanced ERK1/2 phosphorylation. In conclusion, miR-424 could suppress the bFGF/FGFR1 pathway, thereby inhibit ERK1/2 phosphorylation, and thus inhibit cell proliferation, migration and tube formation capabilities and the development of infantile skin hemangioma.