Onapristone

Onapristone is a progesterone receptor antagonist, with K_ds of 11.6 nM and 11.90 nM for human endometrium and myometrium progesterone receptor in saturation analysis. Onapristone has antitumor activity^[1][2]. IC50 & Target:Kd: 1.6 nM (Human endometrium progesterone receptor), 11.90 nM (Human myometrium progesterone receptor)^[1] In Vitro:Onapristone is a progesterone receptor antagonist, with K_ds of 11.6 nM and 11.90 nM for human endometrium and myometrium progesterone receptor in saturation analysis. In Scatchard analysis, Onapristone shows K_ds of 9.80 nM and 15.42 nM for human endometrium and myometrium progesterone receptor^[1]. Onapristone (16, 64 μM) reduces the viability of ISHIKAWA cells after treatment for 96 h. Onapristone (20 μM) also induces ISHIKAWA cell apoptosis after treatment for 72 h. However, Onapristone shows no inhibition on HEC1A and SKUT2 cells^[2].