In Vitro: Conobufagin (30-300 nM, 7 days) exerts potent antitumor activity in a dose-dependent manner in uveal melanoma OCM1 cells. Conobufagin (30-300 nM, 24 hours) arrests the cell cycle in the G1 phase in a concentrationdependent manner and induces cell apoptosis and alterations of apoptosis-related proteins in OCM1 cells. Conobufagin (0.01-1 μM, 6 hours) blocks EGFR phosphorylation and induces cell apoptosis and cytotoxicity in glioblastoma multiforme U87MG-EGFR and U87MG-PTEN cells. Cinobufagin (0.4,0.7,1.0 μM, 24-48 hours) induces cell cycle arrest at the G2/M phase and cell apoptosis, leading to inhibition of malignant melanoma A375/B16 cell proliferation.
In Vivo: Cinobufagin (5 mg/kg for i.p., once a day for 10 days) inhibits xenograft growth by inducing cell apoptosis in tumor xenograft mice model. Cinobufagin (5 mg/kg for i.p., once a day for 10 days) suppresses tumor growth in both subcutaneous and intracranial U87MG-EGFR xenograft mouse models and increases the median survival of nude mice bearing intracranial U87MGEGFR tumors.