Chaperonin containing TCP1 subunit 5 is a tumor associated antigen of non-small cell lung cancer

• Published in: Oncotarget Vol. 8; no. 38; pp. 64170 - 64179
• Main Authors: Gao, Hongjun, Zheng, Min, Sun, Sijin, Wang, Hongwu, Yue, Zhigang, Zhu, Yun, Han, Xiaochen, Yang, Junquan, Zhou, Yanqiu, Cai, Yiran, Hu, Wanning
• Format: Journal Article
• Language: English
• Published: United States Impact Journals LLC 08.09.2017
• Subjects: Research Paper; non-small cell lung cancer; CYFRA 21-1; CCT5; CEA
• ISSN: 1949-2553; 1949-2553
• DOI: 10.18632/oncotarget.19369

Novel tumor antigens and their related autoantibodies have tremendous potential for early diagnosis of non-small cell lung cancer (NSCLC). In this study, we identify antigens from NSCLC tissue and autoantibodies in sera of patients with NSCLC using a modified proteomics-based approach. We seperated and identified four NSCLC-associated proteins extracted from the cytosol in tumor tissues by mini-two-dimensional gel electrophoresis, followed by Western blot and hybridization with individual sera for confirmation of antibody binding. Of the proteins we identified, we selected 58 kDa chaperonin containing TCP1(T-Complex Protein 1) subunit 5 (CCT5) for validation. Serum levels of carcinoembryonic antigen (CEA) and cytokeratin 19 fragments (CYFRA 21-1) were measured in all serum samples with an immunoluminometric assay and a receiver operating characteristic (ROC) curve was analyzed for autoantibodies against CCT5, CEA and CYFRA 21-1. The results show that CCT5 can induce an autoantibody response in NSCLC sera and show higher expression in NSCLC tissues by immunohistochemistry and Western blot. Anti-CCT5 autoantibody was found in 51% (23/45) of patients with NSCLC, but only 2.5% (1/40) in non-tumor individual controls. A receiver operating characteristic curve constructed with a panel of autoantibodies against CCT5 (AUC=0.749), CEA (AUC=0.6758), and CYFRA 21-1(AUC=0.760) show a sensitivity of 51.1% and 97.5% specificity in discriminating NSCLC from matched controls. These results indicate the potential utility of screening autoantibodies in sera, show that CCT5 could be used as a biomarker in cancer diagnosis.