Study for pathogenesis of congenital cholesteatoma with comparison of proteins expressed in congenital cholesteatoma, acquired cholesteatoma and skin of the external auditory canal through proteomics

Abstract

Congenital cholesteatomas are epithelial lesions which represent invasive growth and osteolysis. The incidence consists of 1-5 % in middle ear cholesteatoma, but the detection rate is increasing. Especially congenital cholesteatoma can make hearing function worse, when it is not properly managed. While the biochemical study of acquired cholesteatomas is progressed some degree, the pathogenesis of congenital cholesteatomas is nearly unknown. Therefore the biochemical study regarding it is necessary now. Considering limitations of genetic study, crossover analysis of proteins expressed in congenital cholesteatomas via proteomics and ELISA can give us some clue for the understanding of its pathogenesis and make progress in treatment for it.Four congenital cholesteatoma matrices, and four samples of normal external auditory canal skin and two acquired cholesteatoma were obtained intraoperatively. We performed 2D electrophoresis in order to separate the proteins by molecular weight and detected. We then analyzed the upregulated spots from the congenital cholesteatoma matrices comparing the acquired cholesteatoma specimens through MALDI-TOF MS and immunohistochemical staining.In the 2D electrophoresis, four samples of congenital cholesteatoma showed very similar pattern of proteins expression. Comparing protein expression of acquired cholesteatoma and congenital cholesteatoma, some proteins were simultaneously expressed and the others not. Similar and different components of protein expression between the skin and congenital cholesteatoma sample were identified. The total number of spots in the 2-DE image from congenital cholesteatoma, acquired cholesteatoma and the skin was 556, 460 and 624. In the congenital and acquired cholesteatoma 326 proteins were simultaneously expressed. Of them, 56 proteins were not expressed in the skin. In the skin and congenital cholesteatoma 373 proteins were simultaneously expressed. Therefore 127 proteins were expressed only on congenital cholesteatoma. Major spots expressed in congenital cholesteatoma gels more than in acquired cholesteatoma gels were selected and analyzed, which included titin, PRO2619, forkhead transcription activator homolog, ryanodine receptor 2, plectin 1, keratin 10 and leucine zipper protein 5. Spots which were densitometrically expressed in congenital cholesteatoma gels more than spots of acquired cholesteatoma and were not expressed in the skin gels, were analyzed. They were nine spots, which were Ig heavy chain variable region (gi

951281), chain A structure of human muscle pyruvate kinase (Pkm2, gi

223462173). In immunostaining assay, forkhead transcription activator homolog (FKH 5-3), keratin-10 and titin in congenital cholesteatoma specimen was identified in contrast to the negative control.In this study, we found the proteins expressed in congenital cholesteatoma more than in acquired cholesteatoma. Among them, proteins which were not expressed in the skin were found. Some of them maybe play an important role in the pathogenesis of congenital cholesteatoma. But the function study for them should be continued.

34810359) and cyclic nucleotide gated channel beta 3 (gi

81170715), chain B crystal structure of human caspase-2 in complex with Acetyl-Leu-Asp-Glu-Ser-Asp-Cho (gi

115298657), caspase-5/f (gi

327532753), protein S100-A7 (gi

119612656), DNA repair and recombination protein RAD54B isoform 3 (gi

67464392), ribosomal protein L35a isoform CRA_c (gi