Epidermal growth factor increases cortisol production and type II 3 beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(4)-isomerase expression in human adrenocortical carcinoma cells: evidence for a Stat5-dependent mechanism.
We tested the ability of epidermal growth factor (EGF) to regulate a key enzyme in the adrenal synthesis of glucocorticoids: human type II 3beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(4)-isomerase (3 beta HSD). EGF treatment (25 ng/ml) of human adrenocortical carcinoma cells (H295R) resulted in a 5-fold increase in cortisol production and a corresponding 2-fold increase in 3 beta HSD mRNA. Experiments were performed to determine whether EGF is acting through a previously identified signal transducer and activator of transcription 5 (Stat5)-responsive element located from -110 to -118 in the human type II 3 beta HSD promoter. A Stat5 expression construct was cotransfected with a 3 beta HSD-chloramphenol acetyltransferase (CAT) reporter construct comprised of nucleotides -301-->+45 of the human type II 3 beta HSD promoter linked to the CAT reporter gene sequence. The addition of EGF at doses as low as 10 ng/ml resulted in an 11- to 15-fold increase in CAT activity. The introduction of 3-bp point mutations into critical nucleotides in the Stat5 response element obviated the EGF response. Either Stat5a or Stat5b isoforms induced CAT reporter expression upon treatment with EGF. These results demonstrate the ability of EGF to regulate the expression of a critical enzyme (3 beta HSD) in the production of cortisol and suggest a molecular mechanism by which this regulation occurs.
Feltus
F Alex
FA
Department of Obstetrics and Gynecology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
Kovacs
William J
WJ
Nicholson
Wendell
W
Silva
Corrine M
CM
Nagdas
Subir K
SK
Ducharme
Nicole A
NA
Melner
Michael H
MH
D000306:Adrenal Cortex Neoplasms / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000008:administration & dosage / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D006854:Hydrocortisone / Q000096:biosynthesis*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008894:Milk Proteins; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D011375:Progesterone Reductase / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020218:Response Elements / Q000502:physiology; D050799:STAT5 Transcription Factor; D013251:Steroid Isomerases / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D004268:DNA-Binding Proteins; D007527:Isoenzymes; D008894:Milk Proteins; D009097:Multienzyme Complexes; D012333:RNA, Messenger; D050799:STAT5 Transcription Factor; C494092:STAT5A protein, human; C494095:STAT5B protein, human; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D004815:Epidermal Growth Factor; D011375:Progesterone Reductase; D013251:Steroid Isomerases; D006854:Hydrocortisone