The investigation of protein biomarkers of tissue from non-small cell lung cancer patients by comparative proteomics and bioinformatics analysis

Lung cancer is one of the most common causes of cancer-related mortality, and its incidence is steadily increasing in worldwide. NSCLC represents approximately 83% of lung cancer cases, and includes a range of different clinical histological lung cancer subtypes. Aim of this study was to identify proteome level differences between NSCLC tumor and tumor-adjacent non-tumor tissue samples using gel-based comparative proteomics. Additionally, proteins were classified using PANTHER, protein-protein interactions were mapped by STRING, and the top canonical pathway was identified using an IPA network system. Western blot analysis was used for the validation of the proteomics findings. A total of 40 protein spots were successfully identified by MALDI-TOF/TOF, where 33 proteins were found differentially expressed. Of these, 27 proteins were up-regulated and 6 proteins were down-regulated in NSCLC tumor tissues. Differential expression of GDIR1, GDIR2, PARK7, CAPG, and PRDX was found to be distinctive for NSCLC. These findings showed that proteome level differences between NSCLC tumor and non-tumor tissue samples. Results of this study indicated that the expression levels of some proteins may be linked to disease-associated changes in NSCLC through combination with different bioinformatics tools. Key Words: Bioinformatics, comparative proteomics, mass spectrometry, non-small cell lung cancer (NSCLC), 2DE.