Pretreatment of Balb c-3T3 cells with platelet-derived growth factor (PDGF) has been shown to decrease binding sites for 125I-labelled epidermal growth factor (EGF) (1,2,3). Agents which elevate cellular cyclic AMP concentrations enhance this ability, and the change in EGF binding is inversely proportional to the elevation of cyclic AMP. In quiescent density arrested cells, the sensitivity of cells to down regulation of EGF receptors by PDGF is proportional to the cyclic AMP content of the cultures in three different cell lines. Agents which elevate cyclic AMP and which potentiate PDGF mediated heterologous down regulation of EGF receptors are able, like cholera toxin (3), to stimulate cells to synthesize DNA in defined medium in the absence of EGF. Down regulation of EGF receptors by PDGF in combination with agents elevating cyclic AMP effectively mimics the action of EGF.
|Original language||English (US)|
|Number of pages||9|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Nov 16 1982|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology