Downregulation of miR-126 induces angiogenesis and lymphangiogenesis by activation of VEGF-A in oral cancer

Background: MicroRNA (miRNA)-126 ( miR-126 ) is an endothelial-specific miRNA located within intron 7 of epidermal growth factor-like domain 7 ( EGFL7 ). However, the role of miR-126 in cancer is controversial. Methods: We examined the function of miR-126 in oral squamous cell carcinoma (OSCC) cells. Furthermore, a series of 118 cases with OSCC were evaluated for the expression levels of miR-126. Results: MicroRNA-126 ( miR-126 ) was associated with cell growth and regulation of vascular endothelial growth factor-A activity, and demethylation treatment increased expression levels of miR-126 and EGFL7 in OSCC cells. A significant association was found between miR-126 expression and tumour progression, nodal metastasis, vessel density, or poor prognosis in OSCC cases. In the multivariate analysis, decreased miR-126 expression was strongly correlated with disease-free survival. Conclusion: The present results suggest that miR-126 might be a useful diagnostic and therapeutic target in OSCC.