Figure 7

The synergism between 5-FU and curcumin is observed in various breast cancer cells of different receptor status. (a) Curcumin-mediated downregulation of 5-FU induced TS activation in SK-BR-3 and MCF7 cells. Cells were pre-treated with curcumin and subsequently exposed to 5-FU for 48 h and subjected to western blotting using TS antibody. (b) Kinetics of 5-FU-induced NF-κB activation in SK-BR-3 and MCF7 cells. Nuclear lysates were prepared after exposing the cells to 10 μM 5-FU for different time periods and electrophoretic mobility shift assay (EMSA) was performed. (c) Effect of curcumin in 5-FU-induced NF-κB DNA-binding activity in SK-BR-3 and MCF7 cells. EMSA was performed using nuclear lysates prepared after exposing the cells to 5-FU and/curcumin for 30 min. (d) Effect of 5-FU and curcumin, alone or in combination, on TS- and NF-κB-silenced SK-BR-3 and MCF7 cells. A total of 5000 cells in triplicates were exposed to the indicated concentrations of the drugs for 48 h and subjected to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data represent three independent sets of experiments and results are shown as the mean±S.D. ***, * and ^Φ represents P-values ⩽0.0001, ⩽0.05 and >0.05 respectively