title: Hormone-sensitive cholesterol ester hydrolase in adrenal tumor cells: activation by corticotropin and tetradecanoyl phorbol acetate.
abstract: The effects of corticotropin (ACTH) and tetradecanoyl phorbol acetate (TPA) on cholesterol ester hydrolase, intracellular cholesteryl ester concentration and steroid hormone formation were studied in mouse adrenal tumor cells (Y-1) in monolayer culture. Cholesterol ester hydrolase activity increased about 2-fold during 7 min incubation with ACTH, dibutyryl 3',5'-cyclic AMP (dbcAMP) and TPA at maximally effective concentrations; whereas, incubation with phorbol monoacetate had no effect. Long-term exposure to ACTH and dbcAMP markedly lowered intracellular cholesteryl [3H]-oleate concentration and highly increased steroid hormone output, while TPA treatment resulted in lowering cholesteryl [3H]-oleate content without affecting steroid hormone formation. Calcium activated phospholipid-dependent protein kinase C was detected in Y-1 cell cytosol. It is concluded that the mouse adrenal tumor cells in monolayer culture respond to ACTH in a fashion similar to normal adrenocortical cells; whereas, the response to the phorbol ester TPA (possibly mediated through protein kinase C) involves activation of cholesterol ester hydrolase and cholesteryl ester depletion, however, without affecting steroid hormone secretion.
authors.affiliation: Institut fur Physiologische Chemie, Ruhr Universitat, Bochum, Federal Republic of Germany.
authors.forename: C
authors.initials: C
authors.lastname: Balkow
authors.forename: W H
authors.initials: WH
authors.lastname: Trzeciak
authors.forename: W H
authors.initials: WH
authors.lastname: Kunau
mesh_terms: D000302:Adrenal Cortex / Q000201:enzymology*; D000310:Adrenal Gland Neoplasms / Q000201:enzymology*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002788:Cholesterol Esters / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D007700:Kinetics; D051379:Mice; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D002787:Sterol Esterase / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D002788:Cholesterol Esters; C014409:cholesteryl oleate; D003994:Bucladesine; D000324:Adrenocorticotropic Hormone; D011493:Protein Kinase C; D002265:Carboxylic Ester Hydrolases; D002787:Sterol Esterase; D013755:Tetradecanoylphorbol Acetate