INHIBITION OF SELECTIN-DEPENDENT TUMOR-CELL ADHESION TO ENDOTHELIAL-CELLS AND PLATELETS BY BLOCKING O-GLYCOSYLATION OF THESE CELLS

Expression of sialosyl-Lex (SLex) and sialosyl-Lea (SLea) on tumor cell lines HL60, Colo205, and U937 was greatly suppressed by application of benzyl-α-GalNAc for inhibition of O-linked carbohydrate chain extension, which resulted in reduced adhesion of tumor cells to activated endothelial cells or platelets mediated by ELAM-1 (E-selectin) or GMP-140 (P-selectin). Inhibitors or modifiers of N-glycosylation had no effect on expression of SLex or SLea in these tumor cells. These findings suggest the possibility that targeting of O-glycosylation inhibitors or modifiers to tumor cells may effectively suppress metastatic potential. © 1992.