Inhibitory Effects Of Quercetin On Tumor Angiogenesis And Its Molecular Mechanisms

AIM: To observe the inhibitory effects of Quercetin on tumor angiogenesis and its molecular mechanisms.METHODS: The effects of Quercetin on tumor angiogenesis and angiogenesis induced by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were detected in vivo by transplantation of sarcoma S180 in mice and CAM test respectively. The expression of MVD in the tumor tissue was determined by Immunohistochemistry (IHC). The effect of Quercetin on proliferation of vascular endothelial cells ECV304 was assessed by MTT viability assay and flow cytometer (FCM). The expression of cyclin mRNA and bFGF mRNA and protein was observed by RT-PCR and Western blotting.RESULTS: Growth of S180 was significantly inhib ted by Quercetin. Expression of MVD in tumor tissue was also inhibited by Quercetin Angiogenesis induced by VEGF and bFGF in CAM was strongly inhibited by Quercetin in a dose-dependent manner. Quercetin markedly inhibited the proliferation of ECV3 04 and resulted in S, G2 arrest of cells. Quercetin decreased expression of cyclin A and cyclin B mRNA and bFGF mRNAand proteins.CONCLUSIONS: Quercetin can act against the tumor angiogenesis, which can be attributed to multiple signaling mechanisms, including inhibition of angiogenesis induced by VEGF and bFGF, downregulation of expression of bFGF, downregulation of expression of cyclin A and cyclin B.