ABSTRACT
<p><b>OBJECTIVE</b>To investigate the differentially expressed proteins among chronic sinusitis, nasal polyps and normal nasal mucosa by means of proteomic technology, and select the candidate biomarkers of chronic sinusitis and nasal polyps.</p><p><b>METHODS</b>Proteins extracted from chronic sinusitis, nasal polyps and normal nasal mucosa were separated and the differentially expressed proteins were identified by series of proteomic tools, including immobilized pH4-7 gradient two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, modified coomassie brilliant blue staining, images scanning by the Image Scanner apparatus, PDQuest analysis software, peptide mass fingerprinting based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) by in-gel digestion extract, and Mascot searching in NCBInr and SWISS-PROT databases.</p><p><b>RESULTS</b>The 2-DE patterns with high resolution and reproducibility were obtained. The protein spots separated and visualized in chronic sinusitis, nasal polyps and normal nasal mucosa gel were 1020 +/- 40, 1112 +/- 10 and 1008 +/- 25, respectively. And the match rates were (93 +/- 2)%, (95 +/- 1)% [see text] (90 +/- 3)% respectively. Thirteen differentially expressed spots were found from chronic sinusitis, nasal polyps and normal nasal mucosa gel. We selected and recommend Keratin 8 and APOA1 proteins as candidate biomarkers of nasal polyps, and PLUNC protein, PACAP protein, NKEF-B and SOD as candidate biomarkers of chronic sinusitis.</p><p><b>CONCLUSIONS</b>The differentially expressed proteins among chronic sinusitis, nasal polyps and normal nasal mucosa can be efficiently and relatively reliably identified via the techniques of proteomics. These techniques will play a very important role in the researches for new objective indicators possibly employed in the future classifying, staging and prognosis.</p>