Steroid biosynthesis in vitro and in tissue culture by adrenal tumours of mice of the CE strain

SUMMARY Incubation in vitro of homogenates of spontaneous adrenocortical tumours from gonadectomized female mice of the CE strain showed the presence of Δ5-3β-hydroxysteroid dehydrogenase systems, capable of metabolizing 3β-hydroxypregn-5-en-20-one, 3β, 17α-dihydroxypregn-5-en-20-one and 3β-hydroxyandrost-5-en-17-one. 17α-, 11β- and 21-hydroxylation of C21-Δ4-3-ketosteroids was also detected as were the enzyme systems required to form 3β-hydroxyandrost-5-ene-7,17-dione from 3β-hydroxyandrost-5-en-17-one. After tissue culture of the tumour cells for 19 days, histochemical and incubation techniques demonstrated that the cells retained Δ5-3β-hydroxysteroid dehydrogenase, 17α-, 11β- and 21-hydroxylase activity. Autoradiography localized radioactivity in the original and newly formed cells of the tissue culture.