MicroRNAs (miRs) are endogenously expressed small noncoding RNAs that regulate gene expression at the posttranscriptional level. Previous works indicated that the miR-17-92 cluster could regulate endothelial cell (EC) functions involved in angiogenesis. miR-17-3p, a component of the miR-17-92 cluster, could control the angiogenic activity of human umbilical vein ECs in a cell-autonomous manner in vitro. A 21-bp fragment from the Flk-1 3′-untranslated region containing miR-17-3p targeting sites was required for the rapid downregulation of Flk-1 expression by in silico and experimental analysis. Subsequently, the downstream cell growth pathway was inhibited by forced upregulation of miR-17-3p. Based on these data, we conclude that miR-17-3p is a negative regulator of the angiogenic phenotype of ECs through its ability to modulate the expression of Flk-1, which is implicated in the pleiotropic effects of miR-17-92 in angiogenesis.

Keywords:
Angiogenesis, Endothelial cells, Flk-1, MicroRNA, miR-17-3p
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2012
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