The combined presence ofH pyloriinfection and gastro-oesophageal reflux disease leads to an up-regulation ofCDX2gene expression in antrum and cardia
Bornschein J., Wex T., Peitz U., Kuester D., Roessner A., Malfertheiner P.
Background:CDX2 is an epithelial transcription factor that regulates intestinal differentiation and is involved in the development of intestinal metaplasia (IM).Aim:To analyse the expression ofCDX2in the gastric mucosa in various locations and its relationship toHelicobacter pyloriinfection and gastro-oesophageal reflux disease (GORD).Methods:69 patients with upper gastrointestinal symptoms were stratified into four groups according to theirH pyloriand GORD status. Patients without infection and without GORD were the reference group (H pylori(−)/GORD(−)). Biopsies from the antrum, corpus and cardia were assessed by histopathology according to the updated Sydney System.CDX2transcription levels were determined by quantitative RT-PCR and immunohistochemistry.Results:CDX2gene expression was significantly up-regulated in antral and cardia mucosa of patients with bothH pyloriinfection and GORD (26- and 100-fold, respectively; p<0.05), but remained unchanged in corpus mucosa. If onlyH pyloriinfection or GORD was present,CDX2expression levels were 6- to 11-fold increased in the antrum, but without reaching statistical significance.CDX2expression correlated positively with the degree of IM (p<0.01) and the degree ofH pyloriinduced inflammation (p<0.05). Gene expression data were confirmed immunohistochemically by the detection of CDX2 in areas of IM and in focally distributed CDX2-expressing cells in non-metaplastic gastric mucosa.Conclusions:The combined presence ofH pyloriinfection and GORD leads to an up-regulation ofCDX2gene expression in cardia and antral mucosa, but not in the corpus.