Proteomics-based analysis of differentially expressed proteins in the sera of stage I non-small cell lung cancer patients compared with those of benign pulmonary disease and healthy subjects

Abstract

Objective To identify differentially expressed proteins related to stage I non-small cell lung cancer. Methods Sera were selected from 6 patients with stage I non-small cell lung cancer, 7 pa- tients with benign lung disease confirmed surgically and pathologically, and 15 healthy volunteers. Two-di- mensional gel electrophoresis （2-DE） and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） were employed to screen and identify differentially expressed serum pro- teins between lung cancer group and the other two groups. Results The average protein spots were （323 _＋ 11 ）. Ninety differentially expressed protein spots between lung cancer group and the other two groups were screened with PDQuest software, including 67 overexpressed protein spots and 25 underexpressed protein spots. Fifty significantly differentially expressed protein spots were excavated and 5 proteins were success- fully identified via peptide mass fingerprinting using MALDI-TOF-MS, and all of them were overexpressed in the sera of lung cancer group, including Alpha-l-acid glycoprotein, C1 inhibitor, angiotensinogen, transferrin chain A and transthyrctin. Conclusion Five overexpressed proteins can be identified in the sera of stage I non-small cell lung cancer using 2-DE and MALDI-TOF-MS, which may serve as important can- didate biomarkers for early detection of non-small cell lung cancer. Key words: Lung neoplasms ; Proteomics ; Serum