Molecular changes in the esophageal epithelium after a subchronic exposure to cigarette smoke in the presence of bile-acid reflux.

Background: Gastroesophageal reflux of bile acids plays an important role in the development of Barrett’s esophagus (BE)–associated esophageal adenocarcinoma (EAC). Cigarette smoke has been demonstrated to exacerbate the effects of reflux and thus the initial stages of EAC carcinogenesis. To date, no in vivo studies have been conducted to look at the concomitant effects of cigarette smoke and bile acids on EAC incidence.Methods: In this pilot study, rats that underwent esophagoduodenal anastomosis (EDA) surgery to induce reflux were exposed to whole-body cigarette smoke 3 weeks after surgery. Smoke exposure (135 mg/m3/day) was done for 4 h/day for 5 consecutive days and animals were euthanized after a 48-h recovery period.Results: Exposure to EDA-smoke accelerated the development of BE when compared to EDA-air. The presence of reflux caused a significant 3.5-fold increase in nuclear factor-κB-inducing kinase (NIK) staining (1.47 ± 0.6; p = 0.01). Animals with both reflux and smoking had the highest (10-fo...