title: The role of tissue steroids in regulating aromatase and oestradiol 17 beta-hydroxysteroid dehydrogenase activities in breast and endometrial cancer.
abstract: We have observed that oestradiol concentrations in breast and endometrial tumours are relatively higher than oestrone, in contrast to peripheral tissues. Infusion of radiolabelled oestrogen also suggested there was a difference in metabolism between normal and tumour tissue. We have therefore looked for factors which could modulate tissue steroid metabolism and conclude that progesterone may influence aromatase, and that the adrenal androgens can inhibit oestradiol dehydrogenase activity. The latter mechanism, in particular, may be important in increasing tissue exposure to oestradiol.
mesh_terms: D001141:Aromatase / Q000378:metabolism*; D001940:Breast / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism*; D004970:Estrone / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D012016:Reference Values; D014594:Uterine Neoplasms / Q000378:metabolism*
chemical_list: D004970:Estrone; D004958:Estradiol; D001141:Aromatase