KCS

Human lung cancer is a major cause of cancer mortality worldwide. Understanding the pathophysiological features and the development of novel biomarkers for diagnosis as well as treatment are major tasks. In this presentation, I will show some of our recent lung cancer proteome biomarker development by glycoproteomic approaches and their validation processes. Sera from the patients of lung adenocarcinoma, squamous cell lung cancer, and small cell lung cancers were depleted of the abundant proteins such as albumin and immunoglobulin via an immunoaffinity method. Then the sera were further subjected to total glycoprotein enrichment by multilectin column or fucosylated protein enrichment by Aleuria aurantia lectin (ALL) column. Enriched total glycoproteins or fucosylated glycoproteins were resolved by SDS-PAGE and digested with trypsin and subsequently analyzed by LC-ESI-MS/MS. From comparative proteomic analysis, we identified Plasma Kallikrein, Haptoglobin beta chain, Complement component 9, Serum Paraoxygenase, etc as a potential lung cancer biomarkers. These biomarkers were validated by Western blot, tissue microarray, lectin-hybrid ELISA, protein chips, etc. Then, we pursued to develop a pair of target specific monoclonal antibodies which can be used for the pair-test assay development. After optimization of the test kits, we finally used them for the test of the sera from lung cancer patients, healthy controls and other samples in several hundred cases. Our results showed that the glycoproteomics approaches are useful for the discovery of lung cancer biomarkers and diagnostic assay development using the biomarkers.