Objective: Proteomic analysis with 2D electrophoresis and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) may be a powerful tool for identifying and characterizing the specific proteins relating to the pathogenesis of some diseases, including cholesteatoma. The purpose of this study was to identify upregulated proteins in human cholesteatoma in comparison with canal skin using proteomic analysis.
Material and methods: Three cholesteatoma matrices and three samples of normal retroauricular skin were obtained intraoperatively from cholesteatoma patients. We performed 2D electrophoresis in order to separate the proteins by molecular weight and approximately detected 600 protein spots. We then analyzed the 17 upregulated spots from the cholesteatoma matrices using MALDI-TOF MS. Upregulation of proliferating cell nuclear antigen (PCNA) and osteoclast stimulating factor-1 (OSF-1), two candidate proteins in the pathogenesis of cholesteatoma, was confirmed by means of immunohistochemistry and reverse transcriptase polymerase chain reaction.
Results: Interestingly, two candidate proteins, PCNA and OSF-1, relating to cellular proliferation and bone destruction were identified in the cholesteatoma matrices and we also detected nine proteins relating to the mechanism of signal transduction in the pathogenesis of cholesteatoma, including P-13-kinase P55 gamma subunit, RET proto-oncogene tyrosine kinase receptor and adenosine kinase.
Conclusion: Proteomic analysis may be a powerful tool for the identification and characterization of many promising candidate proteins relating to cholesteatoma.