Redox- and expression-proteomic analysis of plasma biomarkers in bladder transitional cell carcinoma.

Recent progress in quantitative proteomics has offered opportunities in discovering plasma proteins as biomarkers to track the progression and understand the molecular mechanisms of bladder transitional cell carcinoma (TCC). In this study, differential plasma protein levels and redox regulation were analyzed by lysine- and cysteine-labeling two-dimensional differential gel electrophoresis (2D-DIGE), and combined with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS/MS). This study shows 50 and 34 plasma protein features that were significantly changed in protein expression and thiol reactivity, respectively, and shows that plasma proteins involved in inflammatory responses are up-regulated in bladder TCC. In contrast, plasma proteins responsible for cytoskeleton and cytoskeleton regulation are down-regulated. In addition, plasma proteins involving cell adhesion, inflammatory responses, protease inhibitors, and plasma protein transport are shown to be altered in their thiol reactivity. In summary, we perform a comprehensive patient-based plasma proteomic approach for the identification of potential plasma biomarkers in bladder TCC screening and detection.