[Heparin-bound growth factors produced by the established RH-PA cell line]

Two types of heparin-bound growth factors (HBGF) are isolated from serum-free culture media of RH-PA cells, which are effective producers of urokinase type plasminogen activator, and from a lysate of these cells. According to affinity to heparin, molecular weight and cells proliferation stimulation, these HBGF are similar to basic and acidic fibroblast growth factors. It is shown that the obtained preparations, produced by RH-PA cells at 2 pg/ml concentration and more, exert mitogenic effect towards RH-PA and NIH 3T3 cells. This effect is additive to the bovine serum factors. It is established that urokinase at the 0.5-25 micrograms/ml concentration also exerts mitogenic effect. The addition of HBGF in concentration of more than 0.05 micrograms/ml significantly stimulates urokinase production. It is suggested that both the factors--HBGF and urokinase--may be elements of the common mechanism of autocrine regulation of the RH-PA cell line proliferation and urokinase production.