Immunohistochemical characterization of the expression of cell adhesion molecules E-cadherin and β-catenin in the invasive endometrioid endometrial carcinoma

Abstract

Aim. In order to determine E-cadherin and β-catenin expression levels in the invasive endometrioid endometrial carcinoma (EEC) cells and areas of the immunopositive cells in the center of the tumor and in the area of tumor invasion into the myometrium a pathohistological and immunohistochemical study of histological specimens of operative material of 20 patients with pT1-3 stage of tumor was performed. In the comparison group the proliferative-phase endometrium of 20 women was studied. E-cadherin expression by tumor cells was determined using monoclonal antibodies E-Cadherin, Clone NCH-38 and expression of β-catenin – in the use of monoclonal antibodies Beta-Catenin, Clone E247 s-Catenin-1.Methods and results. The expression levels of immunohistochemical markers in tumor cells and tumor cells immunopositive areas were determined by photo digital morphometry in digital image processing program Image J. It was found that E-cadherin expression occurs in 95% of invasive endometrioid endometrial carcinomas and β-catenin expression takes place in 100% of EEC. Membrane-cytoplasmic expression of E-cadherin was observed in 40% of tumors, and 10% of endometrioid adenocarcinomas of the uterus with squamous differentiation showed nuclear β-catenin expression. There was a moderate expression level of E-cadherin (52,23 ± 8,59 CUOD) and high expression level of β-catenin (107,72 ± 9,73 CUOD) in the cells of invasive EEC. These levels are 2 and 5 times lower than in normal proliferative endometrium: the expression level of E-cadherin is 116,51±8,5 CUOD and β-catenin expression level is 159,7815±3,57 CUOD. E-cadherin immunopositive cells make up 20,58% ± 3,3% of area of invasive EEC tissue section and β-catenin-immunopositive cells make up 42,61 ± 4,14% of area of tumor tissue section. That is statistically significantly less than in normal proliferative endometrium, which has 100% β-catenin and E-Cadherin immunopositive cells of endometrial glands. The differences between low E-cadherin expression level in the center of EEC and moderate expression level of this marker in the region of tumor myometrial invasion, as well as differences between high expression levels of β-catenin in these areas of the tumor were not statistically significant. There is a direct strong correlation between the E-cadherin and β-catenin expression levels in the cells of EEC (Pearson correlation coefficient r = +0,73). The inverse moderate correlation is revealed between the expression level of E-cadherin in tumor cells and the degree of tumor differentiation (Pearson correlation coefficient r = –0,67).