An 18,000 molecular weight polypeptide induces early events and stimulates DNA synthesis in cultured cells.

Abstract

Extracts of serum-free medium, conditioned by contact with SV40-transformed BHK cells, stimulate DNA synthesis in cultured fibroblasts. A homogeneous basic protein of MW 18,000, termed fibroblast derived growth factor was purified from this source. In submicrogram quantities, fibroblast derived growth factor stimulates DNA synthesis in mouse 3T3 cells, in the absence of added serum. Prior to the onset of DNA synthesis, both serum and fibroblast derived growth factor induce an array of nearly simultaneous biochemical changes in the membrane of 3T3 cells that include stimulation of the uptake of nucleosides, 2-deoxyglucose and 86Rb+. The early events are probably integral components of the proliferative response, rather than coincidental effects of nonmitogenic molecules present in serum.