Steroidal lactones as inhibitors of 17beta-hydroxysteroid dehydrogenase type 5: chemical synthesis, enzyme inhibitory activity, and assessment of estrogenic and androgenic activities.
Androgens are well known to play a predominant role in prostate cancer and other androgen-dependent diseases. To decrease the level of androgen testosterone in the prostate, we are interested in developing inhibitors of 17beta-hydroxysteroid dehydrogenase type 5 (17beta-HSD5). This enzyme expressed in the prostate is one of the two enzymes able to convert 4-androstene-3,17-dione into testosterone. From a screening study, it was found that a series of steroid derivatives bearing a lactone on D-ring demonstrated potent inhibition of 17beta-HSD5 over-expressed in HEK-293 cells. The results of enzymatic assays using intact cells indicated that a C18-steroid (estradiol or 3-deoxyestradiol) backbone and a spiro-delta-lactone (six-member ring) are important for a strong inhibitory activity. Moreover, the presence of a dimethyl group at the alpha-position of the lactone carbonyl increases the selectivity of the inhibitor toward 17beta-HSD5. Compound 26, a 3-deoxyestradiol derivative with a dimethylated spiro-delta-lactone at position 17, possesses the most potent inhibitory activity for 17beta-HSD5 (IC(50)=2.9 nM). It showed no binding affinity for estrogen, androgen, progestin and glucocorticoid receptors (ER, AR, PR and GR). A weak proliferative effect was, however, observed on ZR-75-1 (ER+) cells in culture at high concentration (1 microM), but not at 0.03 microM. Interestingly, no significant proliferative effect was detected on Shionogi (AR+) cells in culture in the presence of 0.1 and 1 microM of lactone 26.
Bydal
Patrick
P
Medicinal Chemistry Division, Oncology and Molecular Endocrinology Research Center, CHUL Research Center and University Laval, 2705 Laurier Boulevard, Québec, Québec G1V 4G2, Canada.
Luu-The
Van
V
Labrie
Fernand
F
Poirier
Donald
D
D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007783:Lactones / Q000138:chemical synthesis* / Q000494:pharmacology; D008297:Male; D011469:Prostatic Diseases / Q000188:drug therapy; D011944:Receptors, Androgen / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D013256:Steroids / Q000138:chemical synthesis* / Q000494:pharmacology; D013329:Structure-Activity Relationship
D004791:Enzyme Inhibitors; D007783:Lactones; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D011980:Receptors, Progesterone; D013256:Steroids; D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase