Expression of claudin-2 in the multistage process of gastric carcinogenesis.

OBJECTIVE: Claudin-2 is an important component of the tight junction (TJ) of epithelial cells, and its protein expression between many tumours is significantly different. It is unclear if Claudin-2 overexpression is a trigger or a consequence during carcinogenesis. The multistage tissues of gastric carcinogenesis provides us a valuable model for determining tumourigenicity. METHODS: This paper investigated, for the first time, claudin-2 expression in the pathological paraffin tissues of sinus ventriculi from gastroscopic biopsy. To determine claudin-2 expression in gastric carcinogenesis by immunochemical ABC technique. RESULTS: Altogether, 108 chronic superficial gastritis, 55 chronic atrophic gastritis, 109 intestinal-type metaplasia, 93 dysplasia and 52 gastric intestinal-type adenocarcinoma samples were analyzed. Results indicated that the percentage of claudin-2-positive cases was 0% for chronic superficial gastritis (0/108), 0% for chronic atrophic gastritis (0/55), 0% for intestinal-type metaplasia (0/109), 35.87% for dysplasia (33/92), and 73.47% for gastric intestinal-type adenocarcinoma (36/49) respectively, primarily in the cell membrane, and gradually increased in the multistage process of gastric carcinogenesis (P