iTRAQ-based quantitative proteomic analysis of esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers. In this study, our objective was to identify differentially regulated proteins in ESCC using isobaric tag for relative and absolute quantification (iTRAQ) technique and liquid chromatography-tandem mass spectrometry (LC-MS/MS). We compared the protein expression profiles of ESCC tumor tissues with the corresponding adjacent normal tissue from three patients. It was determined that 72 and 57 unique proteins were significantly up-regulated and down-regulated in all three samples. In addition, there were 431 significantly differentially regulated proteins having at least two biological samples. This subject found some of the differential proteins, such as prolyl 4-hydroxylase subunit alpha-1, prolyl 4-hydroxylase subunit alpha-2, and calponin-2, immunoglobulin superfamily containing leucine-rich repeat protein, and prolyl 3-hydroxylase1, which were few studies about them in ESCC. In order to determine the results, we performed another independent experiment. Our results indicated quantitative proteomics, as a robust discovery tool for the identification, differentially regulated proteins in cancers.