In Vitro: PQ401 (1, 5, 10, 25, and 50 μM; 3 days) inhibits proliferation of cultured MCF-7 cells grown in serum or IGF-I in MCF-7 cells. Twenty-four hours of treatment with 15 μM PQ401 induces caspase-mediated apoptosis. PQ401 inhibits autophosphorylation of the IGF-IR kinase domain at concentrations <100 nM, with an IC50 <1 μM.
In Vivo: PQ401 (50 or 100 mg/kg; i.p.; thrice a week) results in a significant dose-dependent reduction in tumor growth over the course of the study. PQ401 reduces the growth rate of MCNeuA cells implanted into mice.