Association of Matrix Metalloproteinase-2 mRNA Expression with Subtypes of Pediatric Cholesteatoma

Objective. Cholesteatoma is a clinically heterogeneous disease, with some patients showing spontaneous regression, while others experiencing an aggressive, lethal disease. Cholesteatoma in children can be divided into two types: congenital and acquired. Identifying good prognostic markers is needed to help select patients who will require immediate surgical intervention. Matrix metalloproteinase-2 (MMP2) was previously reported to play an important role in cholesteatoma progression, by promoting bone destruction and keratinocyte infiltration. Herein, we analyzed MMP2 mRNA expression level in cholesteatoma using RNA-in situ hybridization in formalin-fixed, paraffin-embedded (FFPE) tissue samples. Methods. Sixty patients with cholesteatoma under 15 years old, who underwent their primary surgery at Aichi Medical University’s Otolaryngology Department, were analyzed for MMP2 expression level, using RNA-in situ hybridization. Results. There were no significant differences in MMP2 mRNA expression level between congenital cholesteatoma and acquired cholesteatomas. In congenital cholesteatoma, higher MMP2 signals were observed in the open type than in the closed type (p<0.001). In acquired cholesteatoma, higher MMP2 signals were observed in the pars tensa than in the pars flaccida (p