Targeting CUB domain-containing protein 1 with a monoclonal antibody inhibits metastasis in a prostate cancer model.

Through a whole-cell panning approach, we previously identified a panel of antibodies that bound to prostate cancer cell surface antigens. One such antigen, CUB domain-containing protein 1 (CDCP1), was recognized by monoclonal antibody 25A11 and is a single transmembrane molecule highly expressed in several metastatic cancers as well as on CD34(+)CD133(+) myeloid leukemic blast cells. We show CDCP1 expression on prostate cancer cell lines by real-time quantitative PCR (RT-qPCR), flow cytometry, and immunohistochemistry and on prostate cancer patient samples by RT-qPCR and immunohistochemical staining.

Selection of anti-cancer antibodies from combinatorial libraries by whole-cell panning and stringent subtraction with human blood cells.

Traditional strategies for the identification of cell-surface cancer targets often fall short of their objective. For example, whole-cell panning of antibody libraries to isolate a diverse panel of antibodies directed against targets on cancer cells often identifies all immunogenic and/or abundant cell-surface antigens, not simply tumor-specific or tumor-associated antigens. Here we describe the use of stringent negative selection in combination with positive panning to increase tumor specificity and clinical relevance of selected antibodies.