PMC

(A) Sulforaphane decreased protein levels of β-catenin and cyclin D1 in both SUM159 and MCF7 cell lines. (B) TOP-dGFP reporter lentivirus-infected MCF7 mammospheres were treated with indicated compounds (0.5 μM BIO and 5 μM sulforaphane) either alone or in combination for 2 days. Sulforaphane decreased the percentage of dGFP-positive cells by 30% ~40%. BIO increased this population, while sulforaphane decreased it by over 60% in the presence of BIO. Representative flow cytometry results of TOP-dGFP mammospheres and their pictures under fluorescence microscope(magnification × 100)are shown on the right. (C) Sulforaphane promoted β-catenin phosphorylation at Ser33/37/Thr41, while LiCl suppressed the phosphorylation by inactivating GSK3β (upper panel). Sulforaphane decreased phospho-GSK3β (Ser9)level, whereas total GSK3β remained unchanged(middle panel). LiCl increased protein level of β-catenin by phosphorylating/inactivating GSK3β at Ser9, while sulforaphane attenuated LiCl-induced GSK3β phosphorylation and β-catenin accumulation(bottom panel). SF = sulforaphane; dGFP = destabilized green fluorescent protein.

(A) SUM159 and MCF7 cells growing in log phase were treated with increasing concentrations of sulforaphane for 48 hrs. The anti-proliferation effect of sulforaphane was measured by MTS assay. (B) Sulforaphane enhanced caspase-3 activity in SUM159 cells. Data are presented as mean ± SD(n≥ 3). SF = sulforaphane.

Sulforaphane induces proteasomal degradation of Hsp90 client proteins. (a) Mia Paca-2 and Panc-1 cells were treated with 15 μM sulforaphane for different time periods. Sulforaphane induced a time-dependent down-regulation of Akt, Cdk4, and p53 mutant. Densitometry data are presented as mean ± SD (n = 3, P < 0.05). (b) Cells were treated with 5, 15, 25 μM sulforaphane. Sulforaphane induced a concentration-dependent down-regulation of these proteins. Densitometry data are presented as mean ± SD (n = 3, P < 0.05). (c) Cells were pre-incubated with 10 μM MG132 before sulforaphane treatment. Sulforaphane-induced down-regulation of Hsp90 client proteins were proteasome-mediated. SF, sulforaphane.

(A) Sulforaphane increased Nrf2 expression in untransformed cells. BEAS-2BR cells were treated with sulforaphane at different concentrations (0, 2.5, 5, and 10 µM) for 24 hours. Cells were harvested and whole protein lysates were extracted. Nrf2 expression was examined by immunoblotting. (B) Sulforaphane inhibited Nrf2 and Bcl-2 and restored apoptosis in cadmium-transformed cells. These transformed cells (BEAS-2B-Cd) were treated with sulforaphane (SFN) at different concentrations (0, 2.5, 5, and 10 µM) for 24 h. The whole protein lysates were extracted. Protein levels were examined by immunoblotting.