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Identification of putative serum glycoprotein biomarkers for human lung adenocarcinoma by multilectin affinity chromatography and LC‐MS/MS
Author(s) -
Heo SunHee,
Lee SeungJin,
Ryoo HyunMo,
Park JaeYong,
Cho JeYoel
Publication year - 2007
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200700433
Subject(s) - pngase f , glycoprotein , haptoglobin , lung cancer , adenocarcinoma , microbiology and biotechnology , trypsin , glycosylation , blood proteins , biology , biomarker , chemistry , cancer , biochemistry , glycan , immunology , medicine , enzyme , genetics
Glycoproteins in human serum play fundamental roles in many biological processes, and also have clinical value as biomarkers for disease progression and treatment. In this study, we isolated glycoproteins from the sera of three healthy individuals and three lung adenocarcinoma patients using multilectin affinity chromatography. The recovered glycoproteins were subjected to treatment with peptide‐ N ‐glycosidase F (PNGase F) and in‐gel digestion by trypsin. Tryptic peptides were analyzed by nano‐LC coupled to ESI‐MS/MS and the MS/MS spectra were processed by Bioworks 3.2 and an in‐house bioinformatics tool, ProtAn. Approximately 90% of the proteins identified contained more than one potential glycosylation site. Comparison of the serum glycoproteome of healthy and adenocarcinoma individuals revealed 38 cancer‐selective proteins. Among them, 60% have previously been reported as low abundance proteins in human sera. We identified several cancer‐selective proteins that have been previously characterized as potential indicators of lung cancer in serum or plasma, including haptoglobin (HP), inter‐α‐trypsin inhibitor heavy chain 4 (ITI‐H4), complement C3 precursor, and leucine‐rich α‐2‐glycoprotein. In addition, plasma kallikrein (KLKB1) and inter‐α‐trypsin inhibitor heavy chain 3 (ITI‐H3) were identified as being potentially elevated in the lung cancer group, and were validated by Western blot analysis. Furthermore, ∼18 kDa plasma kallirein protein fragment was detected at high levels in 25 out of 28 adenocarcinoma patients, while one of the eight normal individuals showed moderate positive. The results suggest that KLKB1 represents a potential candidate serum biomarker of lung cancer.