Effect of curcumin on constitutive nuclear NF-κB in multiple myeloma cells.
Curcumin inhibits constitutive nuclear NF-κB in multiple myeloma cells. (A-D) Dose responses of NF-κB to curcumin treatment in U266 (panel A), MM.1 (panel B), MM1R (panel C), and RPMI 8226 (panel D) cells. First, 2 × 106 cells per milliliter were treated with the indicated concentration of curcumin for 4 hours and tested for nuclear NF-κB by EMSA as described. (E-I) The effect of exposure duration on curcumin-induced NF-κB suppression in U266 (panel E), MM.1 (panel F), MM.1R (panel G), and RPMI 8226 (panel H) cells. Cells were treated with curcumin (50 μM) for the indicated times and tested for nuclear NF-κB by EMSA as described. The binding of NF-κB to the DNA is specific and consists of p50 and p65 subunits (panel I). Nuclear extracts were prepared from U266 cells (2 × 106/mL), incubated for 30 minutes with different antibodies or unlabeled NF-κB oligonucleotide probe, and then assayed for NF-κB by EMSA.
