Hydroxysteroid 17-beta dehydrogenase 2 (HSD17B2)

Hydroxysteroid 17-beta dehydrogenase 2 (HSD17B2) is a membrane-associated **enzyme** of the short chain dehydrogenase/reductase (SDR) family, encoded by the HSD17B2 gene in humans[1][2][3]. It catalyzes the **NAD-dependent oxidation of potent 17β-hydroxysteroids**, such as estradiol (E2), testosterone, and dihydrotestosterone (DHT), converting them into their less active 17-keto forms (estrone, androstenedione, and 5α-androstan-3,17-dione, respectively)[1][2]. HSD17B2 also has 20α-hydroxysteroid dehydrogenase activity, modulating progestogen activity[1]. By controlling the local and systemic levels of active estrogens and an`drogens, HSD17B2 plays a critical role in **steroid hormone inactivation** in diverse tissues, including placenta, liver, intestines, endometrium, kidney, pancreas, breast, prostate, and bone[1][2][5]. Altered expression or activity of this enzyme has significant implications for hormone-dependent diseases, especially **breast and prostate cancers, lung cancer, endometriosis, and osteoporosis**[4][5].

Other names

17-beta-hydroxysteroid dehydrogenase type 217β-HSD2EDH17B2SDR9C217β-HSD 220-alpha-HSDHSD1720 alpha-hydroxysteroid dehydrogenaseE2DHEstradiol 17-beta-dehydrogenase 2Microsomal 17-beta-hydroxysteroid dehydrogenaseShort chain dehydrogenase/reductase family 9C member 2Testosterone 17-beta-dehydrogenase

Inhibition of HSD17B2 leads to **increased intracellular concentrations of active estrogens and androgens** (estradiol, testosterone), possibly enhancing estrogenic or androgenic signaling[1][2]. Pharmacological modulation could be useful for **reducing inactivation of sex steroids** in hormone-responsive diseases.