Transforming growth factor activity of bovine brain-derived growth factor.

Bovine brain-derived growth factor (BDGF), whose biochemical properties resemble those of endothelial cell growth factor (ECGF) and brain-derived acidic fibroblast growth factor (acidic FGF), is able to promote colony formation of normal rat kidney fibroblasts (NRK cells) in soft agar. As in the case of transforming growth factor beta (TGF beta), EGF potentiates the anchorage-independent growth promoting activity of BDGF. In the presence of EGF (5 ng/ml), the optimal concentration of BDGF for stimulation of anchorage-independent of NRK cells is approximately 0.5 ng/ml. At higher concentrations, BDGF becomes inhibitory. The anchorage-independent cell growth promoting activity of BDGF differs from that of TGF beta in acid and reducing agent stability.