Study for Reversibility of Experimental Cholesteatoma Using Mongolian Gerbil

Abstract

BACKGROUND AND OBJECTIVES: Epidermal characteristics of cholesteatoma such as invasion, migration, uncoordinated proliferation, and altered differentiation may arise as a result of defectiVe wound healing process, induction of preneoplastic transformation or genetic alteration. To date, a number of genes haVe been shown to be differentially regulated in cholesteatoma, which might be responsible for these clinical characteristics. HoweVer, it is still unclear whether these phenomena is only oVert when cholesteatoma is under specific conditions such as inflammation or infection. If these genetic alterations in the deVelopment of cholesteatoma are transient, the pathology of cholesteatoma may be reVersible. We hypothesized that once cholesteatoma is in the normal environment, the cellular or molecular pathology of cholesteatoma can return to normal epidermal characteristics. The aim of this study was to determine whether common molecular characteristics are reVersible or not after removal of inductive factors in aural cholesteatoma induced gerbils. MATERIALS AND METHODS: We induced canal ligation cholesteatoma using Mongolian gerbils. The treated group was untied and managed for 2 weeks. We examined differences between treated cholesteatoma and untreated cholesteatoma by using a TUNEL staining and immunohistochemical technique with proliferation markers (PCNA, cytokeratin 13/16). RESULTS: With PCNA and CK 13/16, untreated group showed positive staining in the suprabasal cells as well as in the basal cells, but the treated group showed weakly positive staining only in the basal cell layer. With TUNEL staining, positive cells increased more in the untreated group than in the treated group. CONCLUSION: These results encourage our belief that some cholesteatomas, especially cholesteatoma in early stages, might be managed with only minimal treatments such as control of inflammation and maintenance of adequate Ventilation.