MicroRNA let‐7a regulates angiogenesis by targeting TGFBR3 mRNA

Angiogenesis has a great impact on human health, owing to its participation in development, wound healing and the pathogenesis of several diseases. It has been reported that let‐7a is a tumour suppressor, but whether it plays a role in angiogenesis is unclear. Here we showed that let‐7a, a microRNA conserved in vertebrates, regulated angiogenesis by concomitantly down‐regulating TGFBR3. Overexpression of let‐7a or knockdown of TGFBR3 in cell culture inhibited the tube formation and reduced migration rate. Moreover, xenograft experiments showed that overexpression of let‐7a or knockdown of TGFBR3 had smaller tumour size. Downstream genes, such as VEGFC and MMP9, were also down‐regulated in let‐7a overexpression or TGFBR3 knockdown groups. Therefore, our results revealed a novel mechanism that let‐7a regulate angiogenesis through post‐transcriptional regulation of TGFBR3.