ABSTRACT
BACKGROUND@#Non-small cell lung cancer (NSCLC) have the highest incidence of lung cancer which treatment principles are diagnosis and treatment as early as possible. Because of its insidious onset and lack of specific markers for early screening, most patients are at an advanced stage when diagnosed which results in a low 5-year survival rate and poor prognosis. Therefore Exploring a sensitive biomarker is the focus of current diagnosis and treatment of lung cancer. The aim of this study is to investigate the biological markers in serum of patients with I-IIb stage NSCLC by differential peptidomics analysis.@*METHODS@#The serum peptidome was compared and analyzed among the groups of normal health controls, benign lung diseases and early stage NSCLC patients using a nano ultra-performance liquid chromatography combined with a quadrupole-orbitrap mass spectrometer. The differentially expressed polypeptides were identified and analyzed quantitatively to screen the tumor biomarkers for the early diagnosis of NSCLC patients.@*RESULTS@#According to the Swiss-Prot database, a total of 545 polypeptides originated from 118 proteins were identified. The spectral numbers of serum polypeptides in each group were compared and a total of 201 polypeptides differentially expressed were found. Following a quantitative analysis of the above peptides, we found that there were 7 peptides with the coefficient of variation (CV) less than 30% and among them the peptide of QGAKIPKPEASFSPR from ITIH4 was down-regulated and the peptide of CDDYRLC from MGP was up-regulated in NSCLC group.@*CONCLUSIONS@#The tumor biomarkers obtained by serum peptidome technology can provide a new clue for early diagnosis of NSCLC and the specific peptides hydrolyzed from ITIH4 and MGP may be the serum biological markers for early NSCLC patients.