Murine embryonal carcinoma cell-surface sialyl LeX is present on a novel glycoprotein and on high-molecular-weight lactosaminoglycan.
Carbohydrate-specific monoclonal antibodies were used to demonstrate the expression of a new membrane glycoprotein on F9 murine embryonal carcinoma cells. Sialyl LeX was detected using monoclonal antibody FH6 in a sensitive, cell monolayer radioimmunoassay. The antigen codistributed in gel filtration of a crude homogenate and in a membrane-enriched fraction with two known lactosaminoglycan markers, i and SSEA-1 (LeX or X hapten). Sialyl LeX was further shown to be carried by a novel glycoprotein, termed small lactosaminoglycan-like glycoprotein (sLAG) which could be purified by immunoaffinity chromatography. In two-dimensional polyacrylamide gel electrophoresis this glycoprotein had an apparent molecular weight of 45 kDa and a pI of about 6.5. The more differentiated cell line PYS-2 also expressed sialyl LeX and i antigens but not LeX, and FH6-reactive sLAG could be extracted from PYS-2 membranes. Sialylation of fucosylated type 2 carbohydrate chains (X haptens) thus may be an early modification of embryonic carbohydrate antigens.
Rosenman
S J
SJ
Program in Biochemical Oncology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Fenderson
B A
BA
Hakomori
S I
SI
D000606:Amino Sugars / Q000032:analysis* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D014408:Biomarkers, Tumor; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D002846:Chromatography, Affinity; D054278:Embryonal Carcinoma Stem Cells; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D006017:Glycolipids / Q000032:analysis* / Q000276:immunology; D016256:Lewis X Antigen; D051379:Mice; D008970:Molecular Weight; D014411:Neoplastic Stem Cells / Q000032:analysis* / Q000473:pathology; D011134:Polysaccharides / Q000032:analysis* / Q000276:immunology; D011863:Radioimmunoassay
D000606:Amino Sugars; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D000939:Epitopes; D006017:Glycolipids; D016256:Lewis X Antigen; D011134:Polysaccharides; C039448:lactosaminoglycan