Transforming growth factor (TGF) activity in human urine: Synergism between TFG-beta and urogastrone

Abstract

Human urine contains an acid and heat stable peptide with an apparent molecular weight of 8,000–10,000 that, in the presence of urogastrone (EGF), induces the anchorage‐independent growth of nontransformed cells in semisolid media. This nonmitogenic growth‐modulating activity does not compete with EGF for binding to EGF membrane receptor sites and can be resolved from EGF by high‐performance liquid chromatography. The urine‐derived growth factor has been purified more than 10,000‐fold and shares many biochemical properties with and is functionally related to the B class of TGFs isolated from transformed cells and nonneoplastic tissues. The low molecular weight anchorage‐independent growth‐, stimulating activity universally present in human urine is a result of the synergistic interaction of this urine‐derived TGF‐beta and urogastrone.