Figure 4

THL inhibits the migration and invasion ability of endothelial cells and inhibits the secretion of MMP-2 and uPA in endothelial cells. A) The Boyden chamber transwell assay indicates that THL can dose-dependently inhibit the migration of HMEC-1 and HUVEC endothelial cells. Upper panel, images of migrated HMEC-1 endothelial cells in the presence of various concentrations of THL (× 200 magnification). Lower panel, quantitation of migrated HMEC-1 and HUVEC endothelial cells in the presence of various concentrations of THL at 6 h post-seeding. The migrated cells were counted in six randomly selected microscopic fields (× 200 magnification). The relative migrated cell number was obtained by comparing the migrated cell number in the presence of THL with that in the absence of THL. Values represent means ± SD, n = 2. *P < 0.05 versus untreated control. B) The Matrigel-coated Boyden chamber transwell assay indicates that THL can dose-dependently inhibit the invasion ability of HMEC-1 endothelial cells. The cells that invaded and migrated to the lower chamber were counted in six randomly selected microscopic fields (× 200 magnification). The relative invaded cell number was obtained by comparing the invaded cell number in the presence of THL with that in the absence of THL. Values represent means ± SD, n = 2. *P < 0.05; **P < 0.001 versus untreated control. C) Gelatin zymogram of concentrated conditioned medium from HMEC-1 endothelial cells treated with various concentrations of THL during 6-h incubation period. D) Casein zymogram of concentrated conditioned medium from HMEC-1 endothelial cells treated with various concentrations of THL during 6-h incubation period. E) Gelatin zymography indicates that THL can inhibit VEGF-induced MMP-2 expression in HMEC-1 endothelial cells. The cells were cultured in serum-free medium without or with VEGF (50 ng/ml) plus various concentrations of THL for 6 h.