The expression of Claudin 1 correlates with ∼- catenin and is a prognostic factor of poor outcome in gastric cancer

Claudin 1 is one of the tight junction proteins, which are critical in the maintenance of epithelial integrity. Aberrant regulation of CLDN1 and its correlation with -catenin have been discovered in malignant tumors. The present study aimed to investigate the expression profile and clinical relevance of CLDN1 and -catenin. The protein levels of CLDN1 and -catenin were examined using immunohistochemical staining. The characteristics of expression profile and prognostic value were analyzed using Pearson's (2) test and Kaplan-Meier analysis, respectively. -catenin overexpression and knockdown were used to investigate its role in regulating CLDN1 expression. We showed that CLDN1 was overexpressed in intestinal-type, presence of lymph node metastasis, higher TNM stage in gastric cancer patients and correlated with decreased overall survival. The characteristics of CLDN1 expression were associated with that of -catenin. CLDN1 and -catenin showed similar prognostic value in intestinal-type gastric cancers. -catenin knockdown and overexpression in cell models revealed a positive relation between CLDN1 and -catenin. Our study demonstrated that CLDN1 is a biomarker for intestinal-type gastric cancer with shorter survival. The expression of CLDN1 was strongly associated with -catenin in gastric cancer patients and a gastric cancer cell model.