Lack of an inhibitory effect of sulfasalazine on NF-κB/Rel DNA binding in CLL lymphocytes.

Electrophoretic mobility shift assays were performed with nuclear extracts from B cells of patients with B-CLL and the labeled H2TF1 binding site as a probe. B-CLL lymphocytes were incubated with sulfasalazine at the indicated concentrations and times before extraction of nuclear proteins. The specific NF-κB/Rel binding complexes are indicated by an arrow. NS corresponds to nonspecific binding. Extracts from neoplastic lymphocytes of 11 patients incubated for 1 hour to 17 hours consistently failed to indicate an inhibitory effect of sulfasalazine.