Anti-CDH3 monoclonal antibody, clone 67D2

P-cadherin is a member of the cadherin family and is expressed in several solid tumors. This molecule was recently highlighted with the development of a new targeted compound being studied in a clinical trial on solid tumors. In the present study, we examined the protein and messenger RNA (mRNA) expression status of P-cadherin and its promoter methylation in gastric carcinoma cell lines and tissues. Of the 10 cell lines, 4 were found to express P-cadherin protein and mRNA, and the P-cadherin gene was found to be hypomethylated in its promoter region in these cell lines. Nonneoplastic gastric mucosal tissues from gastric carcinoma patients were negative for P-cadherin protein evaluated by immunohistochemistry and Western blotting and had a methylated P-cadherin promoter region. In carcinoma tissues, 70.8% (749/1058) of cases showed P-cadherin protein expression, and P-cadherin positive cases had a well or moderately differentiated histology according to the World Health Organization classification, intestinal-type histology by Lauren classification, and an earlier pT class. Furthermore, patients with P-cadherin expressing tumors had a favorable prognosis by univariate and multivariate survival analyses. In addition, P-cadherin protein expression was found to be significantly correlated with promoter hypomethylation. In summary, P-cadherin is silenced in nonneoplastic gastric mucosa, and P-cadherin expressing tumors constitute a subset of gastric carcinoma with intestinal-type histology and a favorable prognosis. In addition, our findings suggest that P-eadherin promoter methylation underlies the regulation of its expression. These findings may aid patient selection and the interpretation of P-cadherin targeted therapy and clinical trial results. (C) 2010 Elsevier Inc. All rights reserved.

Background: Recently, it has been proven that the CDH3 promoter was hypomethylated in colonic aberrant foci and colorectal cancer. The hypomethylation was also associated with induction of CDH3 expression in colorectal cancer. These results indicated that epigenetic demethylation of the CDH3 promoter in the human intestine permits its ectopic expression in colorectal cancer. Materials and Methods: The demethylation status of the CDH3 gene was examined in primary carcinomas and the corresponding normal tissues derived from 53 patients with colorectal cancer using quantitative methylation-specific PCR (qMSP) and the correlation between the demethylation status and the clinicopathological findings was evaluated. Results. Aberrant demethylation of the CDH3 gene was detected in 41 out of the 53 (77%) primary colon carcinomas. The clinicopathological data were correlated with the demethylation results. A significant difference was observed in the tumor site and Dukes' stage (p=0.0187 and p=0.0192, respectively). Moreover, a trend was shown toward preferentially developing tumor size (p=0.140). Conclusion: These results indicated that CDH3 was more frequently demethylated in advanced colorectal carcinomas.