The expression and DNA-binding activity of NF-κB nuclear transcription factor in the tumors of patients with breast cancer.

The content and DNA-binding activity of NF-κB nuclear transcription factor subunit p65 (NF-κBp65) were evaluated by quantitative enzyme immunoassay in tumors and histologically intact tissues of 119 patients with breast cancer. DNA-binding activity of NF-κBp65 in the tumors was higher than in adjacent tissue in 97% cases. This elevation was paralleled by an increase in total protein content in the majority of cases. No significant relationship of the parameter with the disease stage, tumor size and histology, and degree of lymph node involvement was detected. However, the content of NF-κBp65 in tumors of malignancy degree III was significantly higher than in tumors of malignancy degree II. An increase in total expression of NF-κBp65 protein was found in HER-2+ tumors. This increase was not related to steroid hormone receptor status and was not paralleled by elevation of DNA-binding activity, which was maximum in tumors with the "triple negative" receptor status (RE-RP-HER-2-).