Metformin inhibited VEGF-induced proliferation of HUVECs and reduced Flk1 expression and pFlk1 levels.

<p>(A) VEGF-treatment increased the proliferation of HUVECs compared to non-treated control cells (CTL), and metformin inhibited VEGF-induced proliferation. (n = 10, CTL; control HUVECs, VEGF; VEGF-treated HUVECs, +Met; VEGF plus metformin treated HUVECs, Met; metformin-treated HUVECs) (B) RT-PCR data showed that Flk1 mRNA level was not significantly changed in HUVECs treated with VEGF or VEGF plus metformin (n = 3). (C) Western blotting for pFlk1 and Flk1 in HUVECs after exposed to VEGF or VEGF plus metformin (n = 4). (D, E and F) Densitometric analysis of Western blots showed that VEGF increased the levels of pFlk1 and Flk1 in HUVECs, and demonstrated that metformin inhibited these increases. *P < 0.05, **P < 0.01, ^#P < 0.005 and ^##P < 0.001.