Expression of a carbohydrate signal, sialyl dimeric Le(x) antigen, is associated with metastatic potential of transitional cell carcinoma of the human urinary bladder.

Sialyl dimeric Le(x) antigen was expressed in significant portion of transitional cell carcinoma of the human urinary bladder, but not in the normal uroepithelial tissue. Primary tumors with weak or no expression of the antigen scarcely metastasized to lymph nodes, whereas tumors with high levels of antigen expression metastasized frequently. Metastatic lymph nodes expressed the antigen in most cases. Sialyl dimeric Le(x) antigen was mainly located on 60 and 42 KDa glycoproteins. Since a group of cell adhesion molecules, called LECCAMs, recognize a portion of the antigen, the above results strongly suggest that a LECCAM on the surface of host cells recognizes the carbohydrate structure on the glycoprotein, leading to promotion of metastasis.