Role, control and expression of estrone sulfatase and 17 beta-hydroxysteroid dehydrogenase activities in human breast cancer

Abstract

Breast cancer tissue contains the enzymes necessary for local synthesis of estradiol (E2) and it was demonstrated that, despite the presence of the sulfatase and its messenger in hormone-dependent and hormone-independent breast cancer cells, this enzyme operates particularly in hormone-dependent cells. Different progestins: Nomegestrol acetate, Promegestone, Tibolone (Org OD14) and its metabolites (Org-OM38, Org 4098 and Org 30126), as well as Danazol, can block the conversion of estrone sulfate to E2 very strongly in hormone-dependent breast cancer cells. The last step in the formation of E2 is the conversion of estrone (E1) to estrogen by the action of 17 beta-hydroxysteroid dehydrogenase. This activity is preferentially in the reductive direction (formation of E2) in hormone-dependent cells, but oxidative (E2-->E1) in hormone-independent cells. Using intact hormone-dependent cells, it was observed that Nomegestrol acetate. Promegestone as well as Danazol, can block the conversion of E1 to E2. Clinical trials of these "anti-enzyme" substances in breast cancer patients could be the next step to investigate new therapeutic possibilities for this disease.