earticle

영어

Autoantibodies, which are generated by immune system recognizing the presence of the abnormal tumor-associated antigens, are promising biomarkers for the early detection of tumors. Recently, we established a B cell hybridoma pool derived from HBx transgenic mouse, as a source of tumor-associated autoantibodies without using any extracellular antigens, and have characterized the specific target antigens against them. XC154 autoantibody, one of them, has been investigated in this study and its target antigen was identified by mass spectrometric analysis as aminoimidazole carboxamide ribonucleotide transformylase / inosine monophosphate cyclohydrolase (ATIC) that catalyzes the last two steps of de novo purine biosynthesis. A specific mimotope against XC154 autoantibody was screened from the cyclic random hepta-peptide phage library and, using mimotope display M13 phage as a coating antigen for ELISA, we could distinguish patients with hepatocellular carcinoma (HCC) vs. normal subjects with 86.96% sensitivity and 88.24% specificity. These results imply that anti-ATIC autoantibody is induced in patients with HCC and detection of anti-ATIC autoantibody can be used for the diagnosis of HCC. Now, several attempts have been performed to establish a more reliable and convenient assay to detect tumor-assocoated autoantibodies using recombinant proteins displaying cycling peptide instead of mimotope display M13 phage and the usefulness of improved assay will be discussed.