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

Purpose: E- and P-selectins, expressed on vascular endothelium, and their sialyl-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 neck tumours.
Methods: A total of 40 consecutive biopsy specimens were collected from surgery performed at the Helsinki University Central Hospital between September 1995 and November 1996. The series of specimens contained both benign and malignant head and neck tumours of epithelial, lymphoid or mesenchymal origin. All these were analysed with immunohistochemistry for epithelial 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- and P-selectin was lower in benign than in malignant lesions in both epithelial and lymphoid tumours.
Conclusions: These data suggest that altered epithelial and endothelial expression of sLe(x) and sLe(a )glycans acting on selectin ligands is linked to the development of head and neck tumours.