Sialyl-Lewis(x/a)-decorated selectin ligands in head and neck tumours

Purpose: E- and P-selectins, expressed on vascular endothelium, and their s ialyl-Lewis(x) (sLe(x))- and/or sialyl-Lewis(a) (sLe(a))-containing ligands have a crucial role in extravasation and metastasis of circulating cells. We wanted to analyse the role of selectins and their ligands in head and ne ck tumours. Methods: A total of 40 consecutive biopsy specimens were collec ted from surgery performed at the Helsinki University Central Hospital betw een September 1995 and November 1996. The series of specimens contained bot h benign and malignant head and neck tumours of epithelial, lymphoid or mes enchymal origin. All these were analysed with immunohistochemistry for epit helial and endothelial expression of sLe(x) and sLe(a) glycans and E- and P -selectins. Results: Epithelial expression of sLe(x) and sLe(a) glycans was higher in benign than in malignant lesions in both epithelial and lymphoid tumours. On the other hand, endothelial expression of sLe(x), sLe(a), E- a nd P-selectin was lower in benign than in malignant :lesions in both epithe lial and lymphoid tumours. Conclusions: These data suggest that altered epi thelial and endothelial expression of sLe(x) and sLe(a) glycans acting on s electin ligands is linked to the development of head and neck tumours.