SFN inhibits protein synthesis in human breast cancer cells. MDA MB 231, MCF-7, MDA MB 468 were treated with various concentrations of SFN for 3 h in the presence of a protein precursor, [3H] –leucine. Cells were harvested, and radioactivity of TCA-precipitable material was estimated as described in “Materials and methods”. Results shown are mean ± SE of two independent experiments performed in duplicate (MDA MB 231 and MCF-7) or in triplicate (MDA MB 468), *significantly different (P < 0.01) compared with DMSO-treated control by one-way ANOVA followed by Dunnett’s multiple comparison test