Human blood plasma proteome mapping for search of potential markers of the lung squamous cell carcinoma.

Blood plasma proteomes obtained from 77 lung squamous cell carcinoma (LSCC) patients (Stages I–III) and 67 healthy controls (all males) were analyzed by using the label-free liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the search of potential cancer biomarkers. All plasma samples were depleted of 14 highly-abundant plasma proteins by immune-affinity column chromatography before LC-MS/MS. We identified and quantified 809 differential proteins with molecular weights from 6.4 kDa to 3900 kDa using a label-free method. Three hundred and sixty four proteins were identified in all three groups. Changes in levels of an expression of blood plasma proteins associated with LSCC were discovered. Among them, 43 proteins were overexpressed and 39 proteins were down-regulated by more than two-fold between the plasmas of lung cancer patients and healthy men. We focused our attention on proteins whose expression levels increased from control to early stage and then to advanced stage tumor. Each of...