Identification of Tumor Antigens by Using Proteomics

The recent progress of proteomics has opened new avenues for tumor-associated antigen discovery. Here, I describe a two-dimensional (2D), gel-based Western blot approach for screening and identification of proteins eliciting a humoral response in cancer. Sera from patients are used in 2D Western blot experiments for screening of autoantibodies, and the immunoreactive target proteins are subsequently identified by mass spectrometry. Applied to several types of cancer, this proteomic-based approach has revealed a high frequency of autoantibodies in sera from cancer patients and has led to the identification of novel tumor antigens. Relevant examples are described.