title: Monoclonal antibodies reactive with components in serum-free conditioned medium from a human breast cancer cell line (MCF-7).
abstract: Approximately 10,000 primary hybridomas were generated after immunization with either serum-free conditioned medium (SFCM) or extracts from the human breast cancer cell line MCF-7. A total of 11 different monoclonal antibodies (MAbs; 8 generated against SFCM and 3 generated against cell extracts) were selected on the basis of high specificity in cell-binding ELISA for human breast cancer cell lines. The 8 different MAbs obtained by immunization with SFCM all reacted with secreted components in SFCM from MCF-7 cells and 4 of these MAbs reacted with glycolipids extracted from MCF-7 cells. 1 of these MAbs (S2) also recognized a secreted glycoprotein of approximately 77 kilodaltons (kDa). The remaining 4 MAbs did not show specificity solely for carbohydrate determinants. 1 of these MAbs (S7) recognized a secreted protein of approximately 41 kDa. The 3 MAbs raised against cell extracts from breast cancer cells reacted with cytoplasmic antigens in immunofluorescence but also reacted with a secreted component in SFCM from MCF-7 cells. Immunoblotting experiments with proteins from cell extracts and with proteins in SFCM showed that these antibodies all reacted with a protein of a molecular weight of approximately 40 kDa. Our results suggest that this component is cytokeratin 19 or proteolytically processed cytokeratin 19.
authors.affiliation: Novo Research Institute, Bagsvaerd.
authors.forename: T B
authors.initials: TB
authors.lastname: Kjeldsen
authors.forename: I
authors.initials: I
authors.lastname: Laursen
authors.forename: A
authors.initials: A
authors.lastname: Lykkesfeldt
authors.forename: P
authors.initials: P
authors.lastname: Briand
authors.forename: J
authors.initials: J
authors.lastname: Zeuthen
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000276:immunology*; D003470:Culture Media; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006017:Glycolipids / Q000276:immunology; D006801:Humans; D008970:Molecular Weight; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D003470:Culture Media; D006017:Glycolipids