Dexamethasone and retinyl acetate similarly inhibit and stimulate EGF- or insulin-induced proliferation of prostatic epithelium.
Prostatic epithelium proliferates in a defined medium consisting of basal medium RPMI1640 containing transferring (1 microgram/ml), EGF (10 ng/ml), and insulin (3.7 micrograms/ml or 0.1 IU/ml). Although neither dexamethasone nor retinyl acetate affected the proliferation of prostatic epithelium in RPMI1640 containing transferrin alone, they modify the mitogenic effect of EGF and insulin. Dexamethasone at 10(-10) M or retinyl acetate at about 3 X 10(-9) M inhibits proliferation stimulated by EGF. Higher concentrations of dexamethasone (10(-8) - 10(-6) M) or retinyl acetate (3 X 10(-8) - 10(-7) M) enhance the mitogenic activity of EGF. Dexamethasone had a similar effect in the presence of insulin. However, retinyl acetate stimulated, but did not significantly inhibit, proliferation in the presence of insulin. These results suggest that both dexamethasone and retinyl acetate, and possibly other glucocorticoids and retinoids, may regulate the proliferation of prostate epithelium by a dose-dependent modification of the activity of insulin and EGF.
D000368:Aged; D002455:Cell Division / Q000187:drug effects; D003470:Culture Media; D003907:Dexamethasone / Q000494:pharmacology*; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004848:Epithelium / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D007328:Insulin / Q000494:pharmacology*; D007329:Insulin Antagonists / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000494:pharmacology
D003470:Culture Media; D004224:Diterpenes; D007328:Insulin; D007329:Insulin Antagonists; D000084562:Retinyl Esters; D014801:Vitamin A; C009166:retinol acetate; D004815:Epidermal Growth Factor; D003907:Dexamethasone