Biochemical characterization of 17 beta-hydroxysteroid dehydrogenase in human meningioma

17 beta-Hydroxysteroid dehydrogenase (E2-DH) activity was characterized on a semipurified microsomal preparation of human meningioma tissue (mean Km of 2 microM and Vmax of 500 pmol/mg protein/10 min) and then assayed in 49 meningioma specimens with high progesterone receptor and low estrogen receptor levels. Of these 49 tumors, 36% contained an E2-DH activity greater than 1,000 pmol/mg protein/10 min and similar to that of uterine myometrium. In this limited series of tumors, no correlation between E2-DH activity and progesterone receptor levels was noted.