Analysis of a heterogeneous group of human breast carcinoma associated glycoproteins bearing the Tn determinant
| Autor: | Nicole Porchet, Jean-Pierre Aubert, D. Mistro, Fabien Calvo, E. Osinaga, N. Berois, Alberto Roseto, P. De Cremoux, G. Pancino |
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| Rok vydání: | 1994 |
| Předmět: |
Cancer Research
Glycosylation medicine.drug_class Tn antigen Molecular Sequence Data Neuraminidase Breast Neoplasms Biology Adenocarcinoma Monoclonal antibody Epitope Epitopes Mice Antigen Antigens Neoplasm Lectins medicine Tumor Cells Cultured Animals Humans Antigens Tumor-Associated Carbohydrate Threonine Amino Acids Polyacrylamide gel electrophoresis Glycoproteins chemistry.chemical_classification Membrane Glycoproteins Milk Human Mucin Mucin-1 Mucins Antibodies Monoclonal Neoplasm Proteins Molecular Weight Oncology chemistry Biochemistry Carbohydrate Sequence Female Glycoprotein Protein Processing Post-Translational Protein Binding Subcellular Fractions |
| Zdroj: | Breast cancer research and treatment. 32(2) |
| ISSN: | 0167-6806 |
| Popis: | The Tn determinant (GalNAc alpha-O-Ser/Thr) is expressed by about 90% of human carcinomas, but is cryptic in most normal human tissues. A murine monoclonal antibody (MAb) 83D4, developed following immunization with human breast carcinoma cells, reacts with a Tn-related epitope. In the present study we characterized the glycoprotein antigen identified by 83D4 in the human breast carcinoma cell line MCF-7. We further showed that the 83D4 antigenic determinant is masked in human milk fat globule membranes (HMFGM), and can be exposed upon mild m-periodate treatment after desialylation. Western-blot analysis resolved the 83D4 antigen from MCF-7 into two main components of 120-190 kD and500 kD respectively. Non equilibrium pH gradient electrophoresis/SDS PAGE revealed the acidic nature of the reactive glycoproteins (pI 4.43-4.70). 83D4 antigenic activity resolved by CsCl gradient ultracentrifugation layered on a wide range of densities (1.30-1.46 g/ml) including typical densities of mucin-like glycoproteins but also lower densities. The amino acid composition of the antigen, relatively rich in serine but poor in threonine and proline, confirmed the divergence from other mucin-like carcinoma-associated glycoproteins. Dicarboxylic amino acids were abundant, accounting in part for the acidic nature of the molecules. ELISA and Western-blot analysis of the subcellular fractions from MCF-7 cells revealed that the 83D4 antigen is mainly contained in plasma membranes (85%) from which it may be resolved into two broad bands (slow and fast migrating components). These results provide information on a group of breast carcinoma associated glycoproteins related to but different from typical mucins, and provide data on alteration of O-glycosylation in tumor cells. |
| Databáze: | OpenAIRE |
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