Differences in lectin binding patterns of normal endometrium and endometrial adenocarcinoma, with special reference to staining with Ulex europeus agglutinin 1 and peanut agglutinin

Abstract

Differences in glycoconjugate composition between proliferative endometrium and endometrial adenocarcinoma were investigated by histochemical techniques using seven different lectins as probes. For light microscopy, the avidin-biotin-peroxidase complex (ABC) method was used. Concanavalin A (Con A), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA) stained almost all glandular cells in both proliferative (normal) and malignant endometria. Ulex europeus agglutinin 1 (UEA-1) strongly stained cancer cells, especially well-differentiated adenocarcinoma, but it scarcely stained normal endometrium. Peanut agglutinin (PNA) binding sites were observed only along the apical surface of normal endometrial glands, while the cytoplasm of endometrial adenocarcinoma cells was often positive for PNA. Soybean agglutinin (SBA) faintly reacted with proliferative endometrium and occasionally with malignant cells. Dolichos biflorus agglutinin (DBA) slightly stained proliferative and malignant endometria. By electron microscopic examinations using horseradish peroxidase (HRP)-labeled lectins, we observed that UEA-1, PNA, and Con A stained the Golgi membranes and plasma membrane of carcinoma cells. In addition, the Con A reaction was positive in the endoplasmic reticulum and nuclear envelope. These results revealed the differences in oligosaccharide chains between normal and malignant endometria, suggesting that UEA-1 and PNA, in particular, may be useful indicators of malignancy of the endometrium.