Zibotentan

Zibotentan (ZD4054) is a potent, selective and orally active endothelin A (ET_A) receptor antagonist with a K_i of 13 nM. Zibotentan has no inhibitory effect on ETB. Zibotentan has anticancer effects and can be used for castration-resistant prostate cancer (CRPC) research^[1][2]. In Vitro: Zibotentan potently inhibits the binding of ¹²⁵iodine-ET-1 to cloned human ETA expressed in mouse erythroleukaemic cells, with a pIC₅₀ (concentration to inhibit 50% of binding) value of 22 nM^[1].
Zibotentan (48 hours) treatment increases the number of early apoptotic cells in serum-starved A2780 WT cells^[2].
Zibotentan (ZD4054; 1 μM; 24 hours) treatment shows significant inhibition of cell proliferation in serum-starved HEY, OVCA 433, SKOV-3, and A-2780 cells^[3].
Zibotentan (ZD4054; 1 μM; 48 hours) treatment induces an increase in apoptotic cells. Zibotentan inhibits bcl-2 and activates caspase-3 and poly(ADP-ribose) polymerase proteins.^[3].
Zibotentan (ZD4054; 1 μM) decreases the endogenous ET-1-induced phosphorylation/activation of both kinases (AKT and p42/44MAPK) in HEY cells^[3].
Zibotentan treatment also results in a reduction of ETAR-driven angiogenesis and invasive mediators, such as vascular endothelial growth factor, cyclooxygenase-1/2, and matrix metalloproteinase (MMP)^[3]. In Vivo: Zibotentan (10 mg/kg; intraperitoneal injection; daily; for 21 days) treatment significantly inhibits tumor growth in mice. And Zibotentan treatment increases E-cadherin expression^[2].