Biotransformation of steroid hormones by a spontaneous interstitial cell tumor originating from a BALB/cJ mouse has been studied in vitro. Tumor tissue grown in a female host converted estrone predominantly to estradiol-17β. The same tissue transformed estradiol-17β to estrone to a considerably lesser extent. Incubation of the tumor tissue with androstenedione yielded testosterone as the principal conversion product and several other metabolites with chromatographic characteristics of 11β-hydroxytestosterone, 11β-hydroxyandrostene-dione, and 11-ketotestosterone. Interstitial cell tumors grown in male and female hosts transformed progesterone to testosterone, 20α-hydroxypregn-4-en-3-one, androstenedione, and 11-deoxycorticosterone. The tumor tissue in vitro showed the presence of enzyme systems which are commonly found in testis tissue as well as steroid 11β- and 21-hydroxylases which are normally localized in adrenocortical cells. Testis tissue from animals bearing interstitial cell tumor formed in vitro less testosterone from progesterone than testes from normal animals.
This study was supported by grants from the National Cancer Institute of Canada and the Medical Research Council of Canada.