Expression of E-Cadherin and alpha-Catenin in Patients with Colorectal Cancer

ABSTRACT

PURPOSE: E-cadherin plays a crucial role in cell-cell adhesion in epithelial tissues. The function of E-cadherin is thought to be regulated by its associated cytoplasmic proteins including alpha-catenin. Recent studies have shown a correlation between decreased E-cadherin and alpha-catenin expression and tumor invasion and metastasis. METHODS: We conducted an immunohistochemical staining of epithelial (E)-cadherin and alpha-catenin expression in 129 tissue samples taken from colorectal cancer patients undergoing surgical treatment by the avidin-biotin-peroxidase complex method. We classified tumors into three types according to the expression modality. Cancer cells with strong expression at the cell-cell boundaries were defined as two positive (++);, when the expression was positive, but not concentrated at the cell-cell boundaries and weak, they were defined as one positive (+);, and when the tumor showed no staining, they were defined as negative (-). The relationships between these three expression types and the clinicopathological features of colorectal cancer were investigated. RESULTS: The expression type of E-cadherin and alpha-catenin was two positive (++) in 5 and 20 of the cancer tissue specimens, one positive (+) in 66 and 56, and negative (-) in 58 (45%) and 53 (41.1%). Negative expression of E-cadherin and alpha-catenin were significantly correlated with tumor differentiation, Dukes'stage, and lymph node metastasis of the colorectal cancer patients (P<0.05). CONCLUSION: The expression type of E-cadherin is signifi-cantly corretated to that of alpha-catenin, and the loss of their expression indicates the invasion and metastasis of colorectal cancer. To predict tumor invasion and metastasis in colorectal carcinoma, it is useful to investigate both the expression of E-cadherin and of alpha-catenin.