Expression of NF-kappaB in prostate cancer lymph node metastases

Abstract

Introduction: Nuclear factor-kappaB (NF-kappaB) is a transcription factor that transactivates genes involved in the regulation of cell growth, apoptosis, angiogenesis, and metastasis. Our aim was to assess NF-kappaB expression in lymph node (LN) metastases of prostate cancer.

Methods: Immunohistochemical staining was performed using the p65 anti-NF-kappaB antibody. Seventy-seven paraffin-embedded LN specimens obtained from 54 prostate cancer patients were analyzed. Of the 54 patients, 32 had positive LN metastases, while 22 showed no evidence of metastasis and were considered as controls. The overall percentage of NF-kappaB-nuclear localization was assessed, as well as the intensity of staining.

Results: Nuclear localization of NF-kappaB was significantly greater in the metastatic LN group compared to controls. In patients with positive-LN metastases, 84.4% showed >10% nuclear staining in tumor cells. Moreover, 64.4% of the malignant LN specimens had >10% nuclear staining in lymphocytes compared to 0% in controls. Intensity of cytoplasmic and nuclear staining was higher in the metastatic LN group than in controls (P < 0.01).

Conclusions: Nuclear localization/activation of NF-kappaB is up-regulated in prostate cancer LN metastasis. Such up-regulation of NF-kappaB activity is observed in the tumor cells as well as in the surrounding lymphocytes.