Endothelial growth factor production in cultures of human glioma cells

Human glioma cells derived from biopsied material were grown in tissue culture for periods of up to 2 weeks. Supernatants from these cultures were harvested at various intervals and their ability to enhance proliferation of cultured umbilical vein human endothelial cells was assessed. All of the supernatants tested contained some degree of endothelial cell mitogenic factor activity. The activity in the supernatants reached a maximum from cultures which were 4-8 days old and gradually decreased thereafter. Supernatants from the fibroblast monolayer were not significantly stimulatory for this endothelial cell model. On the other hand, supernatants from the glioma cultures did not increase the growth of human skin fibroblast or peripheral blood lymphocytes in culture. Extracts from bovine cartilage inhibited the mitogenic activity of the supernatants from glioma cultures.