Reductase activity of 17beta-hydroxysteroid oxidoreductase in prostatic tumors of different histological structure.

Reductase activity of 17beta-hydroxysteroid oxidoreductase in biopsy specimens of prostatic cancer and benign hyperplasia, and prostatic intraepithelial neoplasia and serum concentrations of testosterone, 5alpha-dihydrotestosterone, 4-androstene-3,17-dione were compared in patients and healthy individuals. Reductase activities of 17beta-hydroxysteroid oxidoreductase in soluble fraction of prostatic biopsy specimens decreased in the following order: prostatic cancer>prostatic intraepithelial neoplasia>>benign prostatic hyperplasia. No differences in serum concentrations of testosterone, 5alpha-dihydrotestosterone, 4-androstene-3,17-dione between these three groups of patients were found, while the mean serum concentration of these androgens in patients with prostatic tumors did not surpass the threshold normal values for men. Hence, high reductase activity of 17beta-hydroxysteroid oxidoreductase can be associated with pathogenetic mechanisms of human malignant prostatic tumors.

[Bone tumors and androgen metabolism]. / Opukholi kostei i metabolizm androgenov.

The paper provides data of comparative assessment of activity of the key enzymes in metabolism of androgens in various morphological variants of sarcomas and benign bone tumors in 46 patients within the age range from 15 to 61, which were under treatment in the ORC named after N. N. Blokhin, RAMS, from 1996 to 1997. On the basis on publications and our own research results we can suggest that malignant human bone tumors of various histogenesis are subject to metabolic processes of testosterone (T), the principal androgen regulator in the bone tissue, as well as formation in bones of 5 alpha-dihydrotestosterone (DHT). One cannot exclude a possibility that metabolism of androgen in bone tissues is directed towards formation of other androgens (in addition to DHT), which may participate in the bone tissue regulation, for instance, 3 alpha- and 3 beta-diols; specific activity of the latter has recently been intensively scrutinized. One can expect that further research shall disclose the clinical significance of metabolism of androgens and of individual androgens in human bone formations.

[Metabolism of androgens in various histological variants of bone tumors]. / Osobennosti metabolizma androgenov v razlichnykh gistologicheskikh variantakh opukholei kostei.

The role of androgens in human normal and neoplastic bone tissues is still unclear. The paper presents data on metabolism of androgens in homogenates of malignant (osteosarcoma, chondrosarcoma, Ewing and giant cell) and benign primary tumors from 46 male and female patients aged 14-58 years. Using two substrates (testosterone and 5 alpha-dihydrotestosterone) for the first time are shown activities of main enzymes of androgen metabolism in all tumor types. 5 alpha-reductase activity was similar in all tumors, 3 alpha-hydroxysteroid dehydrogenase activity was the highest while that of 17 beta-hydroxysteroid dehydrogenase was the lowest. Unknown metabolite(s) of 5 alpha-dehydrotestosterone was discovered which may be hydroxy-metabolites of 5 alpha-androstane-3 beta, 17 beta-diol. A principal scheme of androgen metabolism in human neoplastic tissue is proposed.