The invention is composed of
monoclonal human MN antibodies or MN
antibody fragments that target the GEEDLP (SEQ ID NO: 118) repeat within the
proteoglycan domain. The
proteoglycan domain of the MN
cell surface protein contains four of these identical GEEDLP (SEQ ID NO: 118) repeats. Binding to the desired
epitope is verified by competition ELISA, where ELISA
signal can be attenuated by co-incubation with
a peptide containing this repeat (PGEEDLPGEEDLP (SEQ ID NO: 119)). This inhibition of binding can also be verified using Biacore assays, where binding of desired antibodies to immobilized MN or
proteoglycan peptides can be inhibited by the
peptide repeat. In addition to binding to the
peptide repeat, human anti-MN antibodies can inhibit the
cell adhesion of CGL-1 cells to MN coated plastic plates. Human anti-MN antibodies have been used to diagnose and quantify MN expression in
cancer cells and tumors using FACS and immunohistochemical methods. An example is also provided where a human anti-MN IgG1 mediates tumor
cell lysis though
antibody-dependent cell-mediated
cytotoxicity. Therefore, these antibodies will be useful for the treatment of cancers in which MN is upregulated or can be useful for the diagnosis of cancers in which MN is upregulated.