Lectin-Binding Patterns in Normal Endometrium and Endometrial Adenocarcinoma

Phenotypic aspects of glycoconjugates in human endometrium were examined in association with the menstrual cycle and malignant transformation by horseradish peroxidase (HRP)-labeling method using seven different lectins as a probe. At the light microscopic level, Concanavalin A (ConA), Ricinus communis agglutinin (RCA), and wheat germ agglutinin (WGA) stained almost all glandular cells in both normal endometrium and endometrial adenocarcinoma. Dolichos biflorus agglutinin (DBA) and soybean agglutinin (SBA) demonstrated markedly enhanced binding in secretory endometrium compared with endometrium in the proliferative phase. Ulex europeus agglutinin 1 (UEA-1) strongly stained endometrial adenocarcinoma, especially the well differentiated type, but scarcely stained normal endometrium. The reaction with peanut agglutinin (PNA) was characterized by cytoplasmic staining in the carcinoma cells, whereas its binding was restricted to the apical surface in the normal cells. At the electron microscopic level, the reaction products representing UEA-1 and PNA binding sites were observed in the plasma and Golgi membranes of malignant cells. DBA stained the same membranes in the normal endometrium, with the number of positive cells being markedly increased in the secretory phase. Whereas ConA binding was proved to be positive in the plasma membrane, endoplasmic reticulum, Golgi apparatus and nuclear envelope of normal and malignant cells. These results indicate that sugar components of endometrial glycoconjugates change during the menstrual cycle and differ between normal endometrium and endometrial adenocarcinoma.