In vitro activity: Flutamide (Eulexin) is an antiandrogen drug. Flutamide-OH, the active metabolite of flutamide, directly binds at rat anterior pituitary androgen receptor with Ki values of 55 nM. Flutamide does not affect the proliferation of an androgen-sensitive clone of the mouse mammary carcinoma Shionogi SC-l 15 cells in culture, shows only antiandrogenic effect, but not androgenic effect. Flutamide provides treatment for prostate cancer when used along with leuprolide.

Kinase Assay: Aliquots of 100 μl cytosol are incubated at 0-4°C for 18 h with 100 μl of the indicated saturating concentration of [3H]T in the presence or absence of increasing concentrations of nonlabeled T, DHT, flutamide (FLU) or flutamide-OH (FLU-OH). At the end of the incubation, free and bound T are separated by the addition of 200 μl dextran-coated charcoal (1 % charcoal, 0.1% dextran T-70, 0.1% gelatin, 1.5 mM EDTA and 50 mM Tris (pH 7.4)) for 15 min before centrifugation at 2300 × g for another 15 min at 0-4°C. Aliquots (350 μl) of the supernatant are transferred to scintillation vials with 10 ml of an aqueous counting solution before counting in a Beckman LS 330 counter.

Cell Assay: Effect of flutamide on the growth of an androgen-sensitive clone (SEM-l) of mouse mammary carcinoma Shionogi cells in culture. The cells are incubated up to 40 days in medium (MEM + 2% dextran-coated charcoal extracted fetal calf serum) containing the compounds at a concentration of 1 μM. Media are changed every second day.

Mol Cell Endocrinol. 1986 Mar;44(3):261-70; J Steroid Biochem. 1988 Jun;29(6):691-8.