The distinct expression patterns of claudin-2, -6, and –11 between human gastric neoplasms and adjacent non-neoplastic tissues.

Background: Cancers have a multifactorial etiology a part of which is genetic. Recent data indicate that expression of the tight junction claudin proteins is involved in the etiology and progression of cancer. Methods: To explore the correlations of the tight junction proteins claudin-2,-6, and −11 in the pathogenesis and clinical behavior of gastric cancer, 40 gastric cancer tissues and 28 samples of non-neoplastic tissues adjacent to the tumors were examined for expression of claudin-2,-6, and −11 by streptavidin-perosidase immunohistochemical staining method. Results: The positive expression rates of claudin-2 in gastric cancer tissues and adjacent tissues were 25% and 68% respectively (P < 0.001). The positive expression rates of claudin-6 in gastric cancer tissues and adjacent tissues were 55% and 79% respectively (P = 0.045 < 0.05). In contrast, the positive expression rates of claudin-11 in gastric cancer tissues and gastric cancer adjacent tissues were 80% and 46% (P = 0.004 < 0.01). Thus in our study, the expression of claudin-2, and claudin-6 was down regulated in gastric cancer tissue while the expression of claudin-11 was up regulated. Correlations between claudin expression and clinical behavior were not observed. Conclusion: Our study provides the first evidence that claudin-2,-6, and −11 protein expression varies between human gastric cancers and adjacent non-neoplastic tissues. [ABSTRACT FROM AUTHOR]