Abstract
To identify cancer-associated antigens and their corresponding autoantibodies, we applied the novel approach, autoantibodiomics, established by Brichory et al., who reported annexins I and II as specific antigens in sera from adenocarcinoma patients. Solubilized proteins from cancer cell lines were separated using one or two dimensional polyacrylamide gel electrophoresis, followed by Western-blotting analysis, in which sera from individual patients were tested for primary antibodies. In cases of adenocarcinoma, we found several positive spots on PVDF membrane using a WB/enhanced chemiluminescence (ECLplus) detection kit, and identified 8 proteins, including α-enolase and peroxiredoxin IV in an adenocarcinoma A549 cell using matrix laser desorption time-of-flight mass spectrometry (MALDI-TOF MS). In cases of esophageal cancer, we also detected some positive spots on PVDF membrane and 2 proteins, peroxiredoxin-VI and heat shock 70 isoform in soluble proteins of a TE-2 cell by MALDI-TOF MS. Moreover, we detected non-Hodgkin’s lymphoma associated autoantibody in patients’ sera and identified L-plastin in the corresponding specific antigen derived from a Raji cell (one of B lymphoma cell lines). This technique, autoantibodiomics, was a powerful tool for the identification of candidate cancer-associated antigens and could be applied for the detection of these antigens and autoantibodies regardless of the selected cancer cell lines.
