Elevated growth factor levels in transformed mouse embryo cells treated with N,N-dimethylformamide

The transformed mouse embryo fibroblast cell line AKR-MCA, produces several transforming growth factor (TGF) activities which can be identified in cell extracts and serum-free conditioned medium. Treatment of these transformed cells with 1% N,N-dimethylformamide resulted in a more normal phenotype and an increased level of TGFs in cell extracts and conditioned medium. In addition, an 11-fold increase in an epidermal growth factor receptor-competing activity was observed in cell extracts and conditioned medium compared to control untreated cells. Fractionation of the conditioned medium on Bio-Gel P-100 showed that the same size classes of TGFs were present in N,N-dimethylformamide-treated as well as untreated cells. The increased EGF-receptor-competing activity was eluted in two peaks at Mr 6500 and Mr 4000. The Mr 6500 peak did not coelute with a TGF peak in the N,N-dimethylformamide-treated cells.