Characterization of panel antibodies for classification of cancer type using novel antibody-based phosphoproteomics

Abstract

Cancer types can be classified according to novel antibody-based proteomics using anti-phosphoprotein monoclonal antibodies (PPmAbs) and multiple discriminant analysis. The antibody-based phosphoproteomics using an antibody panel from over 150 uncharacterized PPmAbs combined with multiple discriminant analysis makes it possible to classify cancer cells. To improve the system, new antibody panels need to be developed using characterized PPmAbs for clinical diagnosis. The uncharacterized 154 PPmAbs were tested for reactivity based on immunohistostaining of several cancer tissues. We focused on AKPS288 PPmAb, and the PPmAb-related antigen was localized in the cytoplasm of tumor cells of the colon and stomach but did not react with non-tumor cells in both tissues. Moreover, the AKPS288 PPmAb showed positive staining in the cytoplasm of normal prostate tissue but not cancer tissue. Based on the mass spectrometry (MS), the PPmAb-related antigen was identified as TATA-element modulatory factor 1 (TMF/ARA160), a tumor-associated antigen (TAA). These results indicate that the use of a novel antibody panel consisting of anti-TAA mAbs could have considerably greater utility for cancer classification than the PPmAb panel with unknown specificity identified in our previous study.