Methylation of DAPK and THBS1 genes in esophageal gastric-type columnar metaplasia

Figure 1 Islets of non-keratinized squamous epithelium can be observed intermingling with cardiac-type gastric mucosa. Superficial and glandular gastric epithelial linings demonstrate infiltration by polymorphonuclear leukocytes (Hematoxylin-eosin staining; original magnification × 10).

Figure 2 Histological section of gastric-type columnar mucosa of the esophagus. Moderate mononuclear infiltrate in the lamina propria and polymorphonuclear leukocytes infiltrating the mucosa layer can be observed (Hematoxylin-eosin staining stain; original magnification × 40).

Figure 3 Numerous rod-shape bacilli can be seen attached to the gastric-type metaplastic columnar epithelium (Giemsa staining; original magnification × 100).

Figure 4 cagA detection and DNA promoter methylation status of DAPK, THBS1, CDH1 and p14 genes in esophageal and gastric mucosa tissue samples. A: Helicobacter pylori cagA⁺ detection by polymerase chain reaction (PCR) amplification in tissue samples, (+) positive and (-) negative; B: Analysis of methylation status of DAPK, THBS1, CDH1, and p14 genes promoters in esophageal mucosa and gastric biopsies tissue samples detected by methyl-sensitive PCR. Blood cells were used as control of unmethylated promoter regions. M represents methylated and U represent unmethylated; the status of Helicobacter pylori cagA is indicated as (+) positive and (-) negative.