Induction of c-fos by an anti-epidermal growth factor receptor monoclonal antibody

The effect of epidermal growth factor (EGF) or a monoclonal antibody to the human EGF receptor on c-fos and c-myc gene expression was examined in KB epidermoid carcinoma cells. EGF increased c-fos transcripts within 30 min and c-myc transcripts within 6-24 hours. The antibody transiently increased c-fos expression within 30 minutes, but did not alter expression of c-myc. Cycloheximide potentiated the c-fos induction by both EGF and antibody. C-fos induction by antibody was less consistent, and was of briefer duration and lesser intensity than the induction by EGF. Nuclear transcription of c-fos decreased in cells treated with EGF or antibody, indicating that c-fos induction by EGF or antibody resulted from post-transcriptional mechanisms.