The expression of E-cadherin-catenin complex in patients with advanced gastric cancer: role in formation of metastasis

The E-cadherin-catenin complex plays an important role in the process of cell adhesion. Its dysfunction is associated with a decrease in cell differentiation and with increased invasiveness and metastasis. Our aim was to evaluate the expression of E-cadherin and B-catenin in advanced gastric cancer in relation to selected clinico-pathomorphological parameters. Formalin-fixed, paraffin-embedded tissue specimens were immunohistochemically stained with monoclonal antibodies E-cadherin (NCL-E-Cad, Novocastra Laboratiries Ltd; dilution 1:50), beta-catenin (NCL-B-CAT, Novocastra Laboratories Ltd; dilution 1:100), alpha-catenin (alpha-E-caten, Santa Cruz Biotechnology; dilution 1:300) and gamma-catenin (gamma-catenin, Santa Cruz Biotechnology; dilution 1:100). The expressions of E-cadherin and alpha-, beta-, gamma-catenins in the main mass of tumor and lymph node metastasis were investigated in 91 patients with gastric cancer. No statistically significant correlation was observed between the expressions of E-cadherin, alpha-, beta-catenins and histological differentiation and between the expressions of E-cadherin, alpha-, gamma-catenins and location or depth of invasion. Moreover, the expression of alpha-, gamma-catenins in the main mass of tumor was not associated with lymph node metastasis. However, we found a relationship between the expression of beta-catenin in the main mass of tumor and lymph node metastasis and tumor location. The depth of invasion was correlated with positive expression of beta-catenin in the main mass of gastric cancer. A statistically significant association was observed between the expressions of E-cadherin and beta-catenin in the main mass of tumor and lymph node involvement. The expression of alpha-catenin in the main mass of tumor was also associated with histological differentiation and Lauren's classification. Statistical analysis showed an association between the expression of E-cadherin and postoperative survival time. No significant correlation was found between the expression of alpha-, beta-, gamma-catenins and survival time. Our results may suggest that the E-cadherin-catenin complex is the factor indicative of metastasis and disease progression in gastric cancer. Also the expression of E-cadherin may play a role as a prognostic factor.

β-Catenin expression in benign and malignant salivary gland tumors

OBJECTIVE

To assess the expression of β-catenin in benign and malignant salivary gland tumors and to investigate the possible role of β-catenin in the behavior of salivary gland tumors.

STUDY DESIGN

Paraffin embedded tissues from 45 salivary gland tumors were studied immunohistochemically for expression of β-catenin.

RESULT

Reduced/aberrant β-catenin expression was seen in benign and malignant salivary gland tumors. Cytoplasmic localization and reduced membranous expression were comparatively observed more in malignant salivary gland tumors. Additionally, in pleomorphic adenomas (PAs), β-catenin exhibited intense staining in cells arranged in the form of ducts/tubules, whereas cells in clusters and sheets showed weaker immunoreactivity.

CONCLUSION

Reduced and cytoplasmic localization of β-catenin could indicate lack of differentiation, invasive potential, and aggressive behavior in malignant salivary gland tumors. Furthermore, change in expression based on the arrangement of tumor cells may suggest that β-catenin may have a role in morphological variations seen in PAs.