Modulation of oncogene expression by epidermal growth factor and gamma-interferon in A431 squamous carcinoma cells.
Epidermal growth factor (EGF) acts, in a dose dependent manner, as both a mitogen and an inhibitor of growth of the A431 squamous carcinoma cell line. gamma-interferon (IFN) also inhibits A431 cell growth. The dual effects of EGF on A431 growth and expression of the oncogenes, EGF receptor (EGFR) and Ha-ras, were evaluated with or without gamma-IFN. A mitogenic level (10pM) of EGF had no effect on expression of EGFR 10 kb mRNA or protein. gamma-IFN combined with 10pM EGF caused an initial drop in EGFR mRNA not reflected at the protein level; at 72 hours, the level of EGFR 10kb mRNA rose and inhibition of cell growth was observed. Treatment with a cytostatic amount (10nM) of EGF resulted in decreased expression of EGFR 10kb mRNA and protein within 24 hours; combined treatment with gamma-IFN caused rapid cell death. Expression of Ha-ras mRNA paralleled that of EGFR mRNA upon treatment with 10pM EGF and/or gamma-IFN, but differed with 10nM EGF.
D015152:Blotting, Northern; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000628:therapy; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000032:analysis; D009857:Oncogenes / Q000187:drug effects*; D011401:Promoter Regions, Genetic; D012334:RNA, Neoplasm / Q000032:analysis; D014407:Tumor Cells, Cultured; D014846:Vulvar Neoplasms / Q000235:genetics* / Q000628:therapy
D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D004815:Epidermal Growth Factor; D007371:Interferon-gamma