ASP 9521

ASP-9521 is a potent, selective and orally available AKR1C3 inhibitor with an IC50 of 11 nM for human AKR1C3.

Signaling Pathways >> Others >> Others

Research Areas >> Cancer

IC50:11 nM (human AKR1C3), 49 nM (monkey AKR1C3)[1]

AKR1C3 is a promising therapeutic target in castrationresistant prostate cancer, as combination of an AKR1C3 inhibitor and a gonadotropin-releasing hormone analogue may lead to complete androgen blockade.ASP-9521 inhibits conversion of androstenedione (AD) into androstenediol and testosterone (T) by recombinant human or cynomolgus monkey AKR1C3 in a concentrationdependent manner (IC50, human: 11 nM; IC50,monkey: 49 nM). ASP-9521 shows more than 100-fold selectivity for AKR1C3 over the isoform AKR1C2. In LNCaP-AKR1C3 cells, ASP-9521 suppresses AD-dependent PSA production and cell proliferation[1].

In CWR22R xenografts, single oral administration of ASP-9521 (3 mg/kg) inhibits AD-induced intratumoural T production and this inhibitory effect is maintained for 24 h. After oral administration, ASP-9521is rapidly eliminated from plasma, while its intratumoural concentration remained high. The bioavailability of ASP-9521 after oral administration (1 mg/kg) is 35 %, 78 % and 58 % in rats, dogs and monkeys, respectively[1].

LNCaP-AKR1C3 cells stably expressing human AKR1C3 are seeded in 96-well plates at 10000 cells/100 μL/well in RPMI-1640 medium supplemented with heat-inactivated charcoal-dextran-stripped FBS (1 % for the PSA expression assay and T measurement and 5 % for the cell proliferation assay). After 24 h incubation, AD is added to each well with or without ASP-9521 (0.3-100 nM). The cell culture media are collected 24 h after administration of AD to measure T concentration and 6 days after administration of AD to measure cell proliferation using Cell-Titer Glo assay[1].

Mice carrying HEK293 or HEK293-AKR1C3 tumours with similar sizes are selected and randomly divided into 5 groups (N=3 for each group). All groups are treated with ASP-9521 (single oral administration; 3 mg/kg). Plasma (from the central vein) and tumour tissues are collected at 0.25, 0.5, 1, 2 and 4 h after administration of ASP-9521, and ASP-9521 concentrations are determined using the HPLCMS/MS method[1].

[1]. Kikuchi A, et al. In vitro and in vivo characterisation of ASP9521: a novel, selective, orally bioavailable inhibitor of 17β-hydroxysteroid dehydrogenase type 5 (17βHSD5; AKR1C3).Invest New Drugs. 2014 Oct;32(5):860-70.

Captisol | Cyclosporin A | H2DCFDA | 0MPTP hydrochloride | GW4869 | Etomoxir | TD139 | Mitoquinone mesylate | GSK2795039 | JC-1 | BAPTA-AM | AP 20187 | Setanaxib (GKT137831) | D-Luciferin | Crotaline