[Contribution of carbohydrate antigens to endothelial E-selectin binding in cancer cells]

We first investigated the difference in carbohydrate antigens' expression between primary tumors and matched metastatic liver lesions of colorectal carcinomas, using immunohistochemical methods. Regarding the degree of expression, SLA, SLX and SPan-1 antigens were found to be expressed on a larger proportion of tumor cells in liver metastases than in primary tumors. Second, comparing the expression of carbohydrate antigens on highly metastatic colon cancer cell line to the parental line, the expression of SLA on the surface of highly metastatic variant was increased more intensively than the parental line. Finally, we investigated the contribution of carbohydrate antigens to endothelial E-selectin binding in colon and pancreatic cancer cells, and the results indicated that SLA might play a significant role in this binding. These findings suggest that the expression of carbohydrate antigens on the surface of cancer cells obviously contributed to E-selectin binding and also to metastatic potential.