Comparative proteome analysis of human adenocarcinoma

This study was designed to use comparative proteomics technology to find the differentially expressed proteins between human lung adenocarcinoma and paired normal tumor-adjacent lung tissues. The total proteins of 20 human lung adenocarcinoma tissues and paired normal tumor-adjacent lung tissues were separated by means of immobilized pH gradient-based two-dimensional gel electrophoresis (2-DE) and Coomassie Blue staining. The differentially expressed proteins were analyzed with image analysis software and then identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and quadrupole time of flight mass spectrometry (Q-TOF-MS/MS). (1) Well-resolved, highly reproducible 2-DE patterns of human lung adenocarcinoma and paired normal tumor adjacent lung tissues were obtained. (2) PDQUEST 2D image analysis software was used to analysis 20 cases of lung adenocarcinoma and paired normal lung tissues, 1006 +/- 54 spots were matched among tumor tissues and normal lung tissues. Twenty-eight differentially expressed spots were screened. (3) Twenty non-redundant differentially expressed proteins were identified by mass spectrometry, thirteen proteins were up-regulated, and seven proteins were down-regulated, some proteins were involved in the regulation of cell signal transduction or metabolized enzyme of cell. (4) To validate the results screened by proteome research, immunohistochemistry was used to validate several lung adenocarcinoma differentially expressed proteins including 14-3-3 sigma, annexin 1, and manganese superoxide dismutase. The results showed that these three proteins were really differentially expressed between lung adenocarcinoma and paired normal lung tissues. These results will provide scientific foundation and new clue for the research of human lung adenocarcinoma.