Figure 2.

Comparative effects of curcumin and curcumin-glucuronide on TGFβ-stimulated phosphorylation of receptor-regulated Smad2 in bone-tropic human MDA-1833, human MDA2287 and murine 4T1 breast cancer cells. Cells were pretreated with 30 μM curcumin, curcumin-glucuronide, or vehicle (16h) prior to stimulation for 1 hour with TGFβ−1 (5 ng/ml). Phosphorylated (p)-Smad2 and Smad2 protein levels were determined by western analysis with verification of protein loading by tryptophan labeling (data not shown) and normalization to βactin. Data are representative of 3–5 independent experiments.