title: MUC1 in human and murine mammary carcinoma cells decreases the expression of core 2 β1,6-N-acetylglucosaminyltransferase and β-galactoside α2,3-sialyltransferase.
abstract: A good correlation between the expression of mucin1 (MUC1) and T antigen was found in breast cancer tumors and breast cancer cell lines, especially after treatment with neuraminidase. The association between the appearance of T antigen and the overexpression of MUC1 was further confirmed by transfecting MDA-MB-231 cells and murine 4T1 mammary carcinoma cells with cDNA for MUC1 and using an RNAi approach to inhibit the expression of MUC1 gene in T47D cells. Furthermore, we discovered that in 4T1 cells which express the sialyl Le(X) antigen, overexpression of MUC1 caused not only appearance of T antigen, but also loss of the sialyl Le(X) structure. As the observed changes in O-glycan synthesis can be associated with changes in the expression of specific glycosyltransferases, core 1 β1,3-galactosyltransferase, core 2 β1,6-N-acetylglucosaminyltransferase (C2GnT1) and β-galactoside α2,3-sialyltransferase (ST3Gal I), we studied their expression in parental, vector-transfected and MUC1-transfected MDA-MB-231 and 4T1 cells as well as T47D cells transduced with small hairpin RNA targeted MUC1 mRNA. It was found that the expression of C2GnT1 and ST3Gal I is highly decreased in MUC1-expressing MDA-MB-231 and 4T1 cells and increased in T47D cells with suppressed expression of MUC1. Therefore, we found that changes in the structure of O-linked oligosaccharides, resulting in the occurrence of T antigen, are at least partially associated with MUC1 overexpression which down-regulates the expression of C2GnT1 and ST3Gal I. We showed also that the overexpression of MUC1 in 4T1 cells changes their adhesive properties, as MUC1-expressing cells do not adhere to E-selectin, but bind galectin-3.
authors.affiliation: Laboratory of Glycobiology and Cell Interactions,  Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, 53-114 Wroclaw,  Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Solatycka
authors.forename: Tomasz
authors.initials: T
authors.lastname: Owczarek
authors.forename: Friedrich
authors.initials: F
authors.lastname: Piller
authors.forename: Véronique
authors.initials: V
authors.lastname: Piller
authors.forename: Bartosz
authors.initials: B
authors.lastname: Pula
authors.forename: Lukasz
authors.initials: L
authors.lastname: Wojciech
authors.forename: Marzena
authors.initials: M
authors.lastname: Podhorska-Okolow
authors.forename: Piotr
authors.initials: P
authors.lastname: Dziegiel
authors.forename: Maciej
authors.initials: M
authors.lastname: Ugorski
mesh_terms: D000818:Animals; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism*; D002448:Cell Adhesion; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D005700:Galactosyltransferases / Q000378:metabolism*; D037502:Galectin 3 / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D018396:Mucin-1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012799:Sialyltransferases / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D019040:E-Selectin; D037502:Galectin 3; D018396:Mucin-1; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C016467:Thomsen-Friedenreich antigen; C505293:C1GALT1 protein, human; D005700:Galactosyltransferases; D017351:N-Acetylglucosaminyltransferases; C053024:beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-acetylglucosaminyl transferase; D012799:Sialyltransferases; D019158:N-Acetylneuraminic Acid; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase