title: The role of p21 and p53 proteins in congenital cholesteatoma.
abstract: OBJECTIVE
  Immunoexpression analysis of p53 and p21 in congenital cholesteatoma with assessing their exact localization in cholesteatoma layers and the level of expression. P53 and p21 are apoptosis-related molecules that regulate cell cycle. These markers have been not completely evaluated in congenital cholesteatoma, and the role of apoptosis in congenital cholesteatoma is also not completely understood.
  
  
  METHODS
  Congenital cholesteatoma samples, a study group (n = 13) and normal auditory meatal skin, a control group (n = 12) from patients who underwent surgery for cholesteatoma were included in the study. Acquired cholesteatoma samples were used as a comparable group (n = 12). Tissue sections were investigated with the immunohistochemistry technique based on binding of biotinylated secondary antibody with the enzyme-labeled streptavidin with using appropriate primary antibodies. Cells with immunoexpression of analyzed antigens: p53 and p21 were defined as antigen positive. In each section, cells were counted, and the percentage of positive cells was determined. The level of significance was set at p < 0.05.
  
  
  RESULTS
  The mean percentage of p21-positive was statistically significant higher in congenital cholesteatoma than in the control group (p < 0.05). There was no meaningful difference between congenital and acquired cholesteatoma with respect to p21 expression. There was significant difference between congenital and acquired cholesteatoma regarding p53.
  
  
  CONCLUSIONS
  Up-regulation of p21 protein is expected to play a significant role in CC development. Apoptosis is an important process in the pathogenesis of congenital cholesteatoma. It seems reasonable to perform studies on apoptosis in congenital cholesteatoma in the prospective way taking into consideration more specimens.
authors: Department of Otolaryngology, Medical University of Białystok, ul. M. Skaodowskiej-Curie 24 A, Białystok, Poland. ewa.olszewska@umwb.edu.pl
authors: Ewa
authors: E
authors: Olszewska
authors: Justyna
authors: J
authors: Rutkowska
authors: Amir
authors: A
authors: Minovi
authors: Andrzej
authors: A
authors: Sieskiewicz
authors: Marek
authors: M
authors: Rogowski
authors: Stefan
authors: S
authors: Dazert
mesh_terms: D018424:Cholesteatoma, Middle Ear / Q000151:congenital / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics* / Q000502:physiology; D004424:Ear Canal / Q000473:pathology; D015870:Gene Expression / Q000235:genetics / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D016707:Tissue Fixation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000502:physiology
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53