Discovery of Key Candidate Protein Biomarkers in Early-Stage Nonsmall Cell Lung Carcinoma through Quantitative Proteomics.

Difficulties in early-stage diagnosis are among the factors contributing to the high mortality of nonsmall cell lung carcinoma (NSCLC) patients. Unfortunately, diagnostic biomarkers are currently lacking, limiting options in the clinic. To discover proteins that have potential for biomarker applications, we performed an in-depth quantitative proteomic analysis on a cohort of Filipino early-stage NSCLC lung adenocarcinoma (LUAD) patients. Differentially expressed proteins (DEPs) were obtained by using tandem mass tag (TMT) labeling and mass spectrometry (MS)-based quantitative proteomics. A total of 6240 quantified proteins were identified with 3155 significantly upregulated and 1248 significantly downregulated. Integration of the proteomic result with curated transcriptome data allowed the identification of 33 proteins with biomarker potential. This study also provided insights into relevant pathways in NSCLC LUAD, such as protein translation and metabolic pathways. Interestingly, all of the enzymes in the hexosamine biosynthetic pathway (HBP) are found to be upregulated, suggesting its important role in NSCLC LUAD. It is worthwhile to look at the potential of targeting the metabolic vulnerability of NSCLC LUAD as a new strategy in drug development. All MS data were deposited into ProteomeXchange with the identifier PXD050598.