Growth Factors in Mammalian Cell Culture

Inhibition of protein breakdown in cultured cells is a consistent response to growth factors

“…Mitogenic effects in fibroblasts have been described after addition of EGF [ 1 ,S], FGF [2,7], IGF-I and IGF-II [6] as well as high concentrations of insulin [7]. Measurements with IMR-90, a human diploid fibroblast line [ 121, show inhibition of protein breakdown by all these growth factors ( fig.2).…”

Serum stimulation of phospholipase A2 and prostaglandin release in 3T3 cells is associated with platelet-derived growth-promoting activity.

“…Cells that have been rendered "competent ' are at the Go/GC interface in the cell cycle and they may then progress through the cell cycle, provided that adequate nutrients and additional growth factors such as somatomedin C (10) are present. The detailed biochemical mechanisms of action for the stimulation of cell proliferation have not been determined for any of these growth factors (25). Although the results presented above indicate that a PLase activator in serum is the platelet-derived growth factor, additional studies are required to determine if platelet-derived growth factor induces competence to proliferate (5) in 3T3 cells by a mechanism involving the stimulation of PLase or PG synthesis.…”

Primary structure of ovine pituitary basic fibroblast growth factor

“…bFGF has been shown in vitro to be a very potent mitogen for vascular endothelial cells and a wide variety of mesodermal or neuroectodermalderived cells [2,3]. Although structural studies on bovine bFGF reveal that it is a single-chain polypeptide of 146 amino acids [4], the recent characterization of cDNA clones that encode human [5] and bovine [6] bFGF suggests that both growth factors are synthesized with aminoterminal 9-residue extensions that are not found in the isolated forms of bovine [4,7] and human [8,9] bFGFs.…”