Stimulation of growth of human breast cancer cells (T47D) by platelet derived growth factor

The human breast cancer cell lines T47D and MCF-7, respond to the mitogenic action of exogenously added PDGF with a 2-3-fold increase in cell number. The maximal response was obtained at a concentration of 1.25 half maximal units/ml (125 ng/ml). PDGF-AA was even more effective than PDGF-AB while PDGF-BB was without effect. The growth-enhancing activity of PDGF was completely abolished by Fab fragments of anti PDGF. Within 7 min of addition of PDGF to cultures of T47D cells, specific phosphorylation of a 65-kDa protein was observed. T47D cells contain specific receptors for PDGF with approximately 4-7 x 10(4) sites (kDa of 3-4 x 10(-10) M) per cell.