title: E-selectin-dependent adhesion efficiency of colonic carcinoma cells is increased by genetic manipulation of their cell surface lysosomal membrane glycoprotein-1 expression levels.
abstract: Lysosomal membrane glycoprotein (lamp)-1 and lamp-2 are the most abundant glycoproteins within the lysosomal membrane. A small amount of lamp-1 and lamp-2 molecules, however, can be present on the cell surface. We have shown previously that highly metastatic colonic carcinoma L4 cells express more lamp-1 and lamp-2 on the cell surface than low metastatic SP cells (Saitoh, O., Wang, W.-L., Lotan, R., and Fukuda, M. (1992) J. Biol. Chem. 267, 5700-5711). Since lamp-1 and lamp-2 are the major carriers for poly-N-acetyllactosamines that are able to display sialyl-Le(x) termini, we sought to determine if an increased amount of lamp-1 on the cell surface would lead to increased expression of cell surface sialyl-Le(x) determinants and to the increased adhesion of those cells to E-selectin. Expression of increased amounts of lamp-1 on the cell surface was achieved either by overexpression of lamp-1 or by expressing a mutant lamp-1 molecule preferentially at the plasma membrane, rather than in lysosomes. Cells that express variable amounts of cell surface lamp-1 were tested for their adhesion to activated endothelial cells or E-selectin expressing Chinese hamster ovary cells. The results clearly show that the extent of adhesion to E-selectin and cell surface sialyl-Le(x) determinants is proportional to the amount of cell surface lamp-1. Moreover, it was demonstrated that such adhesion can be inhibited by soluble lamp-1 generated from Chinese hamster ovary cells expressing sialyl-Le(x) structures. These results indicate that lamp-1 can efficiently present ligands for E-selectin and at the same time can be a useful reagent for inhibition of E-selectin (and possibly P-selectin)-mediated interaction.
authors.affiliation: La Jolla Cancer Research Foundation, California 92037.
authors.forename: R
authors.initials: R
authors.lastname: Sawada
authors.forename: J B
authors.initials: JB
authors.lastname: Lowe
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
mesh_terms: D000818:Animals; D015703:Antigens, CD; D001483:Base Sequence; D016466:CHO Cells; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003110:Colonic Neoplasms; D006224:Cricetinae; D004247:DNA; D004252:DNA Mutational Analysis; D019040:E-Selectin; D004730:Endothelium, Vascular / Q000378:metabolism; D005434:Flow Cytometry; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D016256:Lewis X Antigen / Q000096:biosynthesis / Q000378:metabolism*; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D014407:Tumor Cells, Cultured
chemical_list: D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D019040:E-Selectin; D007375:Interleukin-1; D016256:Lewis X Antigen; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; D004247:DNA