Regulation of epidermal growth factor receptor gene expression

• Published in: Molecular endocrinology (Baltimore, Md.) Vol. 3; no. 2; pp. 400 - 408
• Main Authors: HUDSON, L. G, SANTON, J. B, GILL, G. N
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01.02.1989
• Subjects: Biological and medical sciences; Cell Line; Cells, Cultured; Cyclic AMP - pharmacology; Dexamethasone - pharmacology; Epidermal Growth Factor - pharmacology; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation; Humans; Molecular and cellular biology; Molecular genetics; Placenta - cytology; Placenta - drug effects; Promoter Regions, Genetic; Receptor, Epidermal Growth Factor - genetics; Tetradecanoylphorbol Acetate - pharmacology; Transcription, Genetic; Tretinoin - pharmacology; Proteins; Regulation(control); Epidermal growth factor; Transfection; Luciferase; Restriction map; Gene expression; Hela cell line; Biological receptor
• ISSN: 0888-8809; 1944-9917
• DOI: 10.1210/mend-3-2-400

Synthesis and metabolism of the epidermal growth factor (EGF) receptor are extensively regulated to modulate cellular responses to ligand. To study regulation of EGF receptor gene expression, the 5' region of the gene was isolated from a human placental genomic library. A 5' proximal 1.1-kilobase fragment (-1100 to -19 relative to the ATG translation start site) and subfragments of this were subcloned in both forward and reverse orientations into the luciferase expression vector pSVOAL delta 5' and transfected into human cell lines. Luciferase activity was stimulated by treatment of transfected HeLa cells with EGF, 12-O-tetradecanoylphorbol 13-acetate (TPA), (Bu)2 cAMP, retinoic acid, and dexamethasone. Deletion analysis indicated full retention of activity after removal of the -1100 to -485 region (-485 to -19 fragment), but a 5-fold reduction in activity on removal of the -485 to -153 region (-153 to -19 fragment). Despite a reduction in basal activity, the proximal 134-basepair fragment retained responses to all inducers. Additivity was observed in response to maximal concentrations of TPA plus retinoic acid and of TPA plus (Bu)2 cAMP; the response to a combination of four inducers exceeded that to the RSV-LTR strong promoter. Differences in stimulated responses were observed in various recipients, with hepatoma HepG2 cells lacking responses to (Bu)2 cAMP and glioblastoma T98G cells lacking responses to EGF and TPA. These results indicate that a 134-basepair DNA fragment closely adjacent to the translation start site contains elements responsible for directing basal and stimulated expression of the EGF receptor gene.