Argyrophilic nucleolar organizer regions in auditory meatal skin and middle ear cholesteatoma

Down-regulation of exosomal miR-106b-5p derived from cholesteatoma perimatrix fibroblasts promotes angiogenesis in endothelial cells by overexpression of Angiopoietin 2

Human cholesteatoma perimatrix fibroblasts (hCPFs) can stimulate the endothelial cells of nearby microvessels to proliferate and migrate in a paracrine manner. Exosomes, secreted from various cell types, are one of the most important paracrine factors and play critical roles in intercellular communication. However, whether exosomes derived from human cholesteatoma perimatrix fibroblasts (hCPFs-Exo) can promote angiogenesis has not been reported. In this study, we isolated exosomes secreted by hCPFs and observed that hCPFs-Exo was able to promote migration and tube formation in human umbilical vein endothelial cells (HUVECs). Advanced studies revealed hCPFs-Exo with low expression of miR-106b-5p was transferred into HUVECs, and decreased expression of miR-106b-5p could promote angiogenesis by targeting Angiopoietin 2 (Angpt2) via binding to its 3'-UTR. Furthermore, low levels of miR-106b-5p triggered overexpression of Angpt2, and significantly increased HUVEC migration and tube formation. Taken together, our results suggest that hCPFs-Exo transports low expressed exosomal miR-106b-5p to endothelial cells and promotes angiogenesis by overexpression of Angpt2.

Etiopathogenesis of cholesteatoma

Cholesteatoma is a destructive lesion of the temporal bone that gradually expands and causes complications by erosion of the adjacent bony structures. Bone resorption can result in destruction of the ossicular chain and otic capsule with consecutive hearing loss, vestibular dysfunction, facial paralysis and intracranial complications. Surgery is the only treatment of choice. The etiopathogenesis of cholesteatoma, however, is still controversial. This review was designed to understand the reasons for these disparities and to reduce or eliminate them. Future studies focused on developmental, epidemiological, hormonal and genetic factors as well as on treatment are likely to contribute to further understanding of cholesteatoma pathogenesis.

p53 Expression and keratinocyte hyperproliferation in middle ear cholesteatoma

Keratinocytes in middle ear cholesteatoma have hyperproliferative properties. There is controversy regarding the role of p53 and its effect on cellular proliferation in cholesteatoma. This study was instituted to examine this. Cholesteatoma and deep meatal skin control specimens were analysed for MIB-1 (n = 7, controls = 7), a marker of cellular proliferation, and p53 (n = 17, controls = 17) expression by immunocytochemistry. Expression of p53 was minimal or absent in both cholesteatoma and controls (P = 0.2). MIB-1 expression was higher, but not significantly so, in cholesteatoma than in controls (P = 0.09). Our study has shown no significant p53 expression in cholesteatoma epithelium. This suggests that there is no dysfunction in the p53-mediated cell cycle control mechanisms in cholesteatoma.

Cholesteatoma in children

Cholesteatoma in children is generally considered to be more aggressive and destructive than in adults. Each otologic surgeon has experienced widely extended cholesteatomas in children with large pneumatized mastoid processes. In this paper, we want to present clinical and experimental observations which imply that the destructive potential in children is similar to that in adults. Factors and observations that have led to the assumption that cholesteatoma in children is more aggressive will be discussed. Based on our experience and the literature, we tried to distill the current and leading thoughts concerning this intriguing entity.

Congenital cholesteatoma and malformations of the facial nerve: rare manifestations of the BOR syndrome

We describe a 14-month-old girl with unilateral congenital cholesteatoma and anomalies of the facial nerve in addition to the more common branchial arch, otic, and renal malformations comprising the branchio-oto-renal (BOR) syndrome. Her mother also has the BOR syndrome and unilateral duplication of the facial nerve. This is the first study of a BOR patient with congenital cholesteatoma and the second family in which cholesteatoma and anomalies of the facial nerve are described in patients with the BO/BOR syndrome. We review the congenital cholesteatoma literature and discuss hypotheses for the pathogenesis of this entity in light of this new report.