REGULATION OF LOW-DENSITY-LIPOPROTEIN RECEPTOR ACTIVITY IN CHINESE-HAMSTER OVARY CELLS TRANSFECTED WITH THE C-FMS GENE

Chinese hamster ovary (CHO) cells were transfected with the human c-fi ns gene, which encodes the receptor for macrophage colony-stimulating factor, to examine the effects on the low density lipoprotein (LDL) re ceptor activity. Degradation of[I-125]LDL was significantly reduced in the transfected CHO cells as compared to non-transfected cells when i ncubated in lipoprotein-deficient serum. Quantitative analysis of LDL receptor mRNA using a competitive PCR method demonstrated that LDL rec eptor suppression occurred at transcription. These findings suggest th at expression of the c-fms gene is involved in the regulation of LDL r eceptors on macrophages.