Phorbol ester or epidermal growth factor (EGF) stimulates the concurrent accumulation of mRNA for the EGF receptor and its ligand transforming growth factor-alpha in a breast cancer cell line.

摘要: We have previously reported that both 12-O-tetradecanoylphorbol-13-acetate (TPA) and epidermal growth factor (EGF) can stimulate the synthesis rate of EGF receptors. now show MDA468 breast cancer cells express mRNA for EGF-like molecule, transforming factor-alpha (TGF-alpha), demonstrate TPA or cause an accumulation receptor TGF-alpha mRNA. The levels paralleled our earlier protein data, with peak accumulations 2-3-fold 10(-9) M 3-5-fold 100 ng/ml seen between 6 8 h. A 7-fold was following 4 h treatment TPA, a 2-fold after EGF. These changes in mRNAs were observed absence any change level alpha-subunit hexosaminidase (a lysosomal enzyme), demonstrating some degree specificity. Detectable quantities immunoreactive accumulated cell culture medium treated blocking anti-EGF monoclonal antibody B1D8 while no detected unblocked concentration used sufficient to block binding exogenously added 125I-EGF undetectable but had only minor effects on effect expression