Effect of NBD peptide on human multiple myeloma cells.
NEMO-binding domain (NBD) peptide inhibits constitutive NF-κB and induces cytotoxicity in human multiple myeloma cells. (A) U266 cells (2 × 106/mL) were treated with the indicated concentrations of NEMO control or NBD peptide (100 μM) for the indicated times. Nuclear extracts were checked for the presence of NF-κB DNA-binding activity by EMSA. (B) Untreated or NBD peptide–treated (100 μM; 12 hours) U266 cells were cytospun, and p65 immunocytochemistry was performed as described in “Materials and methods.” Red stain indicates the localization of p65, and blue stain indicates nucleus. Original magnification, × 200). (C) U266 cells (2 × 106/mL) were treated with the indicated concentrations of NEMO control or NBD peptide (100 μM) for the indicated times, and cell viability was monitored by the trypan blue dye-exclusion method. The percentage of cell killing was determined as follows: Percentage killing = (number of trypan blue stained cells/total cells) × 100.
