Objective: To investigate the effect of human umbilical cord mesenchymal stem cell culture supernatant medium (hUCMSC-CM) on the angiogenesis of human umbilical vein endothelial cell (HUVEC) induced by papillary thyroid carcinoma cell line TPC-1.  Methods: TPC-1 cells were treated with hUCMSC-CM at different concentrations. And then the effect of hUCMSC-CM-treated TPC-1 cells on the angiogenesis of human umbilical vein endothelial cells were detected by the endothelial tube formation assay. The proliferation of TPC-1 cells was detected by CCK-8 assay. RT-PCR and Western blotting were used to detect the expression of vascular endothelial growth factor (VEGF) mRNA and protein in hUCMSC-CM-treated TPC-1 cells; and the concentration of VEGF in the culture supernatant medium of hUCMSC-CM-treated TPC-1 cells was measured by ELISA. Results: Compared with the control group, hUCMSC-CM significantly inhibited the proliferation of TPC-1 cells(P<0.05 and P<0.01). hUCMSC-CM-treated TPC-1 cells significantly down-regulated angiogenesis of HUVEC(P<0.001). At the same time, the expressions of VEGF mRNA and protein in hUCMSC-CM-treated TPC-1 cells were significantly reduced (P<0.001). The concentration of VEGF in the culture supernatant of hUCMSC-CM-treated TPC-1 cells was also decreased (P<0.05). Conclusion: hUCMSC-CM down-regulated the expression and secretion of VEGF in TPC-1 cells and suppressed the angiogenesis of HUVEC induced by TPC-1.

［Key words］human umbilical cord mesenchymal stem cells; papillary thyroid carcinoma; VEGF; angiogenesis；human umbilical vein endothelial cells