Activated nuclear factor-kappa B and cytokine profiles in the esophagus parallel tumor regression following neoadjuvant chemoradiotherapy

Abstract

Esophageal adenocarcinoma is increasing in incidence; it relates to chronic gastroesophageal reflux, it is difficult to cure, and treatment modalities increasingly use chemotherapy and radiation therapy prior to resectional surgery. Nuclear factor-kappa B (NF-κB) is a pleiotropic transcription factor that regulates several genes for cytokines and enzymes involved in inflammation and immunity, and we have previously described sequential expression of NF-κB from the normal esophagus through Barrett's metaplasia to adenocarcinoma. The aim of this exploratory study was to assess the NF-κB status and cytokine profiles pre- and post-chemoradiotherapy for esophageal adenocarcinoma. Fresh biopsy specimens obtained from 20 patients with esophageal adenocarcinoma and normal adjacent squamous epithelium were obtained pre-, during and post-chemoradiotherapy, and NF-κB expression was analyzed by electrophoretic mobility shift assay. The cytokine protein content of interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) of tissue homogenates was measured using the ELISA technique. NF-κB was constitutively activated in tumor tissues from esophageal adenocarcinoma but was not detected in adjacent normal esophageal mucosa. Elevated levels of IL-1β and IL-8 were significantly (P < 0.05) higher in tumor tissues compared to control tissues. Patients with a major or complete pathological response (responders) were associated with absence of activated NF-κB from nuclear extracts after treatment. Moreover, IL-1β and IL-8 levels were significantly (P < 0.05) down-regulated in tumor tissues from patients who demonstrated a complete pathological response. No differences in NF-κB, IL-1β and IL-8 levels were detected pre- and post-treatment in patients who did not have a major or complete pathological response (non-responders). The study suggests that monitoring of molecular and cytokine patterns in patients undergoing this neoadjuvant regimen may help subselect the cohort that derives most benefit from the multimodal approach. © 2005 ISDE.