Altered glycosylation of the MUC-1 protein core contributes to the colon carcinoma-associated increase of mucin-bound sialyl-Lewis(x) expression.
The mucin carbohydrate epitope sialyl-Le(x), detected with the monoclonal antibody AM-3, is strongly overexpressed in > 90% of human colon carcinomas. We show here that in colon carcinoma one of the mucin cores bearing the sialyl-Le(x) group is MUC-1, whereas sialyl-Le(x) present in normal colon is not detectable on MUC-1. The amounts of MUC-1 core detectable with the monoclonal antibody BC3 in extracts of tumor tissue are 60-180% of those in normal tissue. Two other carbohydrate epitopes located on MUC-1 in mucins from normal and tumor tissue have also been characterized. In contrast to sialyl-Le(x), their expression on MUC-1 is variable and does not correlate with the malignant transformation of colonic mucosa. The transfer of the sialyl-Le(x) group onto the MUC-1 core contributes to the colon carcinoma-associated overexpression of the sialyl-Le(x) epitope.
Hanski
C
C
Klinikum Steglitz, Freien Universität Berlin, Germany.
Drechsler
K
K
Hanisch
F G
FG
Sheehan
J
J
Manske
M
M
Ogorek
D
D
Klussmann
E
E
Hanski
M L
ML
Blank
M
M
Xing
P X
PX
D000941:Antigens / Q000032:analysis*; D002277:Carcinoma / Q000276:immunology*; D003106:Colon / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000939:Epitopes / Q000032:analysis*; D006031:Glycosylation; D006801:Humans; D009077:Mucins / Q000737:chemistry*
D000941:Antigens; D000939:Epitopes; D009077:Mucins