Silence of lncRNA UCA1 Represses the Growth and Tube Formation of Human Microvascular Endothelial Cells Through miR-195

Background/Aims: Recent studies have suggested that several lncRNAs contribute to the angiogenic function of endothelial cells. Herein, we set out to reveal whether lncRNA UCA1 has functions in endothelial angiogenesis. Methods: The expression levels of lncRNA UCA1, miR-195 and CCND1 in human microvascular endothelial HMEC-1 cells were altered by transfection. Subsequently, cell viability, migration, tube formation and apoptosis of HMEC-1 cells were respectively assessed. The cross-talk between lncRNA UCA1, miR-195, CCND1, and MEK/ERK and mTOR signaling pathways were investigated by performing qRT-PCR and Western blotting. Results: Silence of lncRNA UCA1 repressed HMEC-1 cells viability, migration, tube formation, and induced apoptosis. Meanwhile, silence of lncRNA UCA1 significantly up-regulated miR-195 expression. These alterations induced by lncRNA UCA1 were further enhanced by miR-195 overexpression, while were attenuated by miR-195 suppression. Moreover, silence of lncRNA UCA1 deactivated MEK/ERK and mTOR signaling pathways via a miR-195-dependent regulation. And the deactivation of MEK/ERK and mTOR signaling pathways led to a down-regulation of CCND1. Conclusion: This study demonstrates that silence of lncRNA UCA1 largely represses microvascular endothelial cells growth and tube formation. Silence of lncRNA UCA1 exerts its function possibly via up-regulation of miR-195, which in turn inactivates MEK/ERK and mTOR signaling pathways, and ultimately represses CCND1 expression