MDA-MB-231 and 4T1 cells were treated with 0, 0.25, and 0.50 µM of casticin for 24 h, respectively. Nuclear and cytosolic protein extracts were subjected to Western blot analysis. (A) Representative results of Western blotting for NF-κB, c-Jun, and c-Fos in the nuclear fractions and cytosolic extracts, respectively. Lamin B and β-actin served as an internal control for nuclear and cytosolic fractions, respectively. (B) The protein levels of NF-κB, c-Jun, and c-Fos in the nuclear fractions and cytosolic extracts were respectively quantitated against the densitometric signal of Lamin B or β-actin bands. Data are expressed as the mean ± S.D. of three independent experiments. *P<0.05 and **P<0.01 compared with the control.