Effects of triptolide and TNF-alpha on the expression of VEGF in Raji cells and on angiogenesis in ECV304 cells.

In order to study the relation of antitumour mechanisms of triptolide with neovascularization, the effect of triptolide and tumour necrosis factor (TNF)-alpha on the expression of vascular endothelial growth factor (VEGF) in Raji cell lines and their effect on angiogenesis in human umbilical vein endothelial cells (HUVECs)-derived cell line ECV304 were investigated. The inhibitory rate of cells treated by triptolide detected by MTT; the ELISA was employed to study the VEGF content secreted by Raji cell lines; angiogenesis was tested by network formation of endothelial cells on Matrigel, and the mRNA level of VEGF was measured by RT-PCR. The results showed that treatment of Raji cells with triptolide resulted in significantly enhanced antiproliferative effects in dose- and time-dependent manner. The content of VEGF secreted by Raji cells was increased by TNF-alpha and was suppressed by triptolide (P < 0.01). The mRNA expressions of VEGF(165) and VEGF(121) (containing 165 and 121 amino acid residues, respectively) could be detected in all fractions. TNF-alpha augmented the expression of VEGF(165) and VEGF(121) mRNA when triptolide reduced the expression (P < 0.01). No network and cord were formed in control and triptolide group. There was tube formation on matrigel in the supernatants of Raji culture group and the supernatants groups treated by VEGF and TNF-alpha in Raji cell. It is concluded that the expressions of VEGF in Raji cells are increased by TNF-alpha and suppressed by triptolide. VEGF and TNF-alpha induce angiogenesis and triptolide inhibits angiogenesis in ECV304 cells.