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Cycline-dependent kinase inhibitor, p27 (KIP1), is associated with cholesteatoma
Y A Bayazít1, M Karakök, R Uçak
1Department of Otolaryngology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey. bayazity@yahoo.com
Objective:
Cyclin-dependent kinases (CDKis) can arrest the cell cycle, which in turn inhibits the cell proliferation. P27 (KIP1) is a CDKi and acts as a tumor suppressor gene. In this study, we aimed to investigate the role of p27 CDKi in cholesteatoma, a disease characterized by the presence of hyperproliferative squamous epithelium.
Study Design:
Immunohistochemical staining of 15 cholesteatoma and 18 control ear canal skin samples, which were taken intraoperatively, was performed for p27 positivity.
Methods:
The monoclonal antibodies to p27 were used for immunohistochemical staining of the sections. The streptavidin-biotin horseradish method was used. The number of cells staining positive for p27 was calculated, and the intensity of p27 positivity was graded.
Results:
P27 positivity was obtained in 9 (50%) of 18 skin tissues. In the cholesteatoma tissues, p27 positivity was found only in 2 (13.3%) tissue samples. The difference between the groups were statistically significant (P =.03). The mean numbers of p27 positivity were 11.8 +/- 15.5 and 1.4 +/- 3.8 (mean +/- standard deviation) in the skin and cholesteatoma samples, respectively. This difference was also statistically significant (P =.02). The p27 results of primary and secondary cholesteatoma samples were not significantly different (P =.3). The results of p27 were not related to the gender of the patients (P =.8).
Conclusion:
P27 is involved directly or indirectly in the occurrence of cholesteatoma. Alterations of p27 levels in keratinocytes can influence the proliferative state of the keratinocytes. Altered p27 levels in cholesteatoma may suggest a molecular pathology in cholesteatoma. The search for significance of CDKis seems promising to better understand the pathogenesis of cholesteatoma.
Insights
Cyclin-dependent kinase inhibitor p27 (KIP1) is significantly reduced in cholesteatoma tissues compared to normal skin. This suggests altered p27 levels contribute to the hyperproliferation seen in cholesteatoma, indicating a potential molecular pathology.
Area of Science:
- Cell biology
- Oncology
- Otolaryngology
Background:
- Cholesteatoma is characterized by hyperproliferative squamous epithelium.
- Cyclin-dependent kinase inhibitors (CDKis) regulate the cell cycle and inhibit proliferation.
- P27 (KIP1) is a known CDKi and tumor suppressor gene.
Purpose of the Study:
- To investigate the role of p27 CDKi in cholesteatoma.
- To determine if p27 expression differs between cholesteatoma and normal ear canal skin.
Main Methods:
- Immunohistochemical staining for p27 positivity in 15 cholesteatoma and 18 control ear canal skin samples.
- Quantification of p27-positive cells and grading of staining intensity.
- Statistical analysis to compare p27 levels between groups.
Main Results:
- P27 positivity was significantly lower in cholesteatoma (13.3%) compared to normal skin (50%) (P = .03).
- Mean p27 positivity was significantly reduced in cholesteatoma samples (1.4) versus skin samples (11.8) (P = .02).
- P27 levels did not differ significantly between primary and secondary cholesteatoma or by patient gender.
Conclusions:
- P27 is implicated in the pathogenesis of cholesteatoma, likely through its influence on keratinocyte proliferation.
- Altered p27 levels in cholesteatoma suggest a molecular basis for the disease.
- Further research into CDKis may elucidate cholesteatoma pathogenesis.