Comparison of Endoplasmic Reticulum Stress Messenger Ribonucleic Acid Expression Between Chronic Otitis Media With and Without Cholesteatoma.

BACKGROUND: We evaluated and compared the role of endoplasmic reticulum stress in chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma. METHODS: The messenger ribonucleic acid expression of endoplasmic reticulum stress was measured and compared between chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma according to the presence or absence of bacteria, type of hearing loss, ossicle destruction, and facial canal dehiscence. RESULTS: The expression of immunoglobulin heavy chain-binding protein messenger ribonucleic acid was higher in the chronic otitis media without cholesteatoma group than in the chronic otitis media with cholesteatoma group, and Protein kinase RNA (PKR)-like endoplasmic reticulum kinase and activating transcription factor 6 messenger ribonucleic acid expression were higher in the chronic otitis media with cholesteatoma group than in the chronic otitis media without cholesteatoma group. CONCLUSION: Endoplasmic reticulum stress messenger ribonucleic acids were expressed in both chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma. The levels of expression of endoplasmic reticulum stress messenger ribonucleic acids differed according to clinical features, suggesting that different endoplasmic reticulum stress pathways are involved in the pathophysiology of different types of chronic otitis media.

Expression and Correlation Research of MicroRNA10a-5p and PIK3CA in Middle Ear Cholesteatoma.

BACKGROUND: This study aimed to examine the roles of miR-10a-5p and phosphatidylinositol-4,5-bisphosphonate 3-kinase catalytic subunit α in the pathogenesis of middle ear cholesteatoma. METHODS: We enrolled 27 patients with middle ear cholesteatoma and collected samples of intraoperative cholesteatoma and normal posterior ear skin tissues. The mRNA expression levels of miR-10a-5p and PIK3CA were detected using real-time quantitative polymerase chain reaction. PIK3CA protein expression was measured by immunohistochemistry and western blotting. RESULTS: Middle ear cholesteatoma tissues showed significantly lower miR-10a-5p expression levels and significantly higher PIK3CA expression levels than normal posterior ear skin tissues (both P < .05). Furthermore, the miR-10a-5p and PIK3CA expression levels were significantly negatively correlated in middle ear cholesteatoma tissues (r = -0.926, P < .001). CONCLUSION: Low miR-10a-5p expression levels in middle ear cholesteatoma tissues may inhibit the growth and proliferation of cholesteatoma, whereas high PIK3CA expression level may promote its growth and proliferation. In addition, miR-10a-5p may affect the proliferation and differentiation of cholesteatoma by negatively regulating its target gene, PIK3CA.

Bacterial diversity of middle ear cholesteatoma by 16S rRNA gene sequencing in China.

In this study, the bacterial diversity of acquired middle ear cholesteatoma (MEC) was evaluated to reveal its pathogenesis and provides a guide for the use of antibiotics. Twenty-nine cases of acquired MEC and eight cases of healthy middle ears undergoing cochlear implantation (CI) were evaluated. Full-length 16S rRNA gene sequencing was performed to profile the bacterial communities in lesions and healthy tissues of the middle ear. ACE (P = 0.043) and Chao1 (P = 0.039) indices showed significant differences in alpha diversity (P < 0.05). Analysis of PERMANOVA/Anosim using the Bray-Curtis distance matrix results suggested that the between-group differences were greater than the within-group differences (R = 0.238, P < 0.05, R2 = 0.066, P < 0.05). Bacterial community analysis revealed that Alphaproteobacteria at the class level and Caulobacterales and Sphingomonadales at the order level were significantly different (P < 0.05). In the LefSe (Linear discriminant analysis effect size) analysis, Porphyromonas bennonis was elevated, and Bryum argenteum and unclassified Cyanobacteriales were reduced at the species level in MEC (P < 0.05). Fifteen metabolic pathways were found to be significantly different between the two groups by analysing the abundance of metabolic pathways in level 2 of the Kyoto Encyclopaedia of Genes and Genomes (KEGG). Seven and eight metabolic pathways were significantly elevated in the MEC and control groups, respectively (P < 0.05). The role of bacteria in the pathogenesis of acquired MEC was further refined through analysis of metabolic pathways. These findings indicate that the acquired MEC and healthy middle ear contain more diverse microbial communities than previously thought.

The Risk of Cholesteatoma in Individuals With First-degree Relatives Surgically Treated for the Disease.

Importance: Cholesteatoma in the middle ear is not regarded as a hereditary disease, but case reports of familial clustering exist in the literature, as well as observed familial cases in the clinical work. However, the knowledge regarding cholesteatoma as a hereditary disease is lacking in the literature. Objective: To assess the risk of cholesteatoma in individuals with a first-degree relative surgically treated for the same disease. Design, Setting, and Participants: In this nested case-control study in the Swedish population between 1987 and 2018 of first-time cholesteatoma surgery identified from the Swedish National Patient Register, 2 controls per case were randomly selected from the population register through incidence density sampling, and all first-degree relatives for cases and controls were identified. Data were received in April 2022, and analyses were conducted between April and September 2022. Exposure: Cholesteatoma surgery in a first-degree relative. Main Outcomes and Measures: The main outcome was first-time cholesteatoma surgery. The association between having a first-degree relative with cholesteatoma and the risk of cholesteatoma surgery in the index persons was estimated by odds ratios (ORs) and 95% CIs through conditional logistic regression analysis. Results: Between 1987 and 2018, 10 618 individuals with a first-time cholesteatoma surgery (mean [SD] age at surgery, 35.6 [21.5] years; 6302 [59.4%] men) were identified in the Swedish National Patient Register. The risk of having a cholesteatoma surgery was almost 4 times higher in individuals having a first-degree relative surgically treated for the disease (OR, 3.9; 95% CI, 3.1-4.8), but few cases were exposed overall. Among the 10 105 cases with at least 1 control included in the main analysis, 227 (2.2%) had at least 1 first-degree relative treated for cholesteatoma, while the corresponding numbers for controls were 118 of 19 553 control patients (0.6%). The association was stronger for individuals under the age of 20 years at first surgery (OR, 5.2; 95% CI, 3.6-7.6) and for a surgery involving the atticus and/or mastoid region (OR, 4.8; 95% CI, 3.4-6.2). There was no difference in the prevalence of having a partner with cholesteatoma between cases and controls (10 cases [0.3%] and 16 controls [0.3%]; OR, 0.92; 95% CI, 0.41-2.05), which implies that increased awareness does not explain the association. Conclusions and Relevance: In this Swedish case-control study using nationwide register data with high coverage and completeness, the findings suggest that the risk of cholesteatoma in the middle ear is strongly associated with a family history of the condition. Family history was nevertheless quite rare and can therefore only explain a limited number of all cases; these families could be an important source for information regarding the genetic background for cholesteatoma disease.

Congenital cholesteatoma in identical twins.

Congenital cholesteatoma in identical twins has only been described once in Otolaryngology literature thus far. This report describes a case of monozygotic twins with a history of recurrent acute otitis media and bilateral middle ear effusions without tympanic membrane perforation. Upon myringotomy with pressure equalization tube insertion, both were found to have right-sided cholesteatoma with nearly identical location and pattern of progression. In the context of previous case series demonstrating familial clustering and reports of possible genetic associations of this condition, the authors present an important addition to the current understanding of congenital cholesteatoma disorder.

Association Between Earwax-Determinant Genotypes and Acquired Middle Ear Cholesteatoma in a Japanese Population.

OBJECTIVE: A single-nucleotide polymorphism 538G>A in the human ABCC11 gene is a determinant of the earwax morphotype. ABCC11 538GG and GA correspond to wet earwax and 538AA to dry earwax. Despite a putative positive correlation between the frequency of the 538G allele and the prevalence of cholesteatoma, minimal clinical information is currently available. We aimed to evaluate this association between the ABCC11 genotypes and acquired middle ear cholesteatoma. STUDY DESIGN: Case-control study. SETTING: Single-center academic hospital. METHODS: We recruited 67 Japanese patients with acquired middle ear cholesteatoma (cholesteatoma group) and 100 Japanese controls with no history of middle ear cholesteatoma. We assessed the ABCC11 genotypes for all participants. Clinical information was collected from the cholesteatoma group. The genotype data of 104 Japanese people from the 1000 Genomes Project who represent the general population were used. RESULTS: The proportion of participants with ABCC11 538GG or GA was significantly higher in the cholesteatoma group than in the control group or general Japanese population (P < .001). The ABCC11 538G allele frequency was also significantly higher in the cholesteatoma group than in the control group or general Japanese population (P < .001). Multivariate logistic regression analyses revealed a significant association between the ABCC11 genotype and acquired middle ear cholesteatoma (odds ratio, 5.49; 95% CI, 2.61-11.5; P < .001). CONCLUSION: Our results suggest that the ABCC11 genotypes could be associated with the development of acquired middle ear cholesteatoma among Japanese people.

MiR-142-5p directly targets cyclin-dependent kinase 5-mediated upregulation of the inflammatory process in acquired middle ear cholesteatoma.

MicroRNAs (miRNAs) play important roles in the regulation of cell proliferation, differentiation, apoptosis, and inflammatory responses. MiR-142-5p is an important inflammation-associated miRNA, whose abnormal expression has been associated with a variety of inflammation-related diseases. However, the role and signaling pathways targeted by miR-142-5p in acquired middle ear cholesteatoma (AMEC) have not been fully elucidated. Cyclin-dependent kinase 5 (CDK5), a special member of the CDK family compared with classic cyclins that plays a critical role in the inflammatory response. In this study, we investigated the roles of miR-142-5p and CDK5 in inflammatory responses in AMEC. Our results revealed that the expression of miR-142-5p was significantly reduced in AMEC, and was negatively correlated with the expression of CDK5 (r=-0.5451). We also found that miR-142-5p can inhibit CDK5 expression by directly target 3' untranslated region (UTR) of CDK5. Additionally, our findings indicated that the increased expression of CDK5 induces the secretion of inflammatory cytokines. In order to further confirm the involvement of miR-142-5p in the regulation of the inflammatory response in AMEC through its inhibitory effect on CDK5 expression, we studied the inflammatory response in HaCaT cells transfected with small interfering RNA against CDK5 (si-CDK5) and a miR-142-5p inhibitor. The results confirmed that miR-142-5p regulates the inflammatory response in AMEC by downregulating CDK5. In summary, miR-142-5p directly inhibits the CDK5-mediated upregulation of inflammatory cytokines in AMEC, which makes it a potential therapeutic target in this disease.

Microarray analysis and functional prediction of differentially expressed circular RNAs in acquired middle ear cholesteatoma.

BACKGROUND: Middle ear cholesteatoma is characterized by hyper-proliferation of keratinocytes. Circular RNA (circRNA) plays an essential role in the pathogenesis of many proliferative diseases. However, the role of circRNA in the etiopathogenesis of middle ear cholesteatoma is rarely investigated so far. We aimed to investigate the differential expression profiling of circRNAs between acquired middle ear cholesteatoma and normal skin, and to identify potential circRNAs contributing to the etiopathogenesis of middle ear cholesteatoma. Microarray analysis and functional prediction were performed to investigate the circRNA expression profiling between middle ear cholesteatoma and normal skin. Validation of differentially expressed circRNAs was conducted by qRT-PCR. Prediction of m6A modification was also carried out. RESULTS: Microarray analysis displayed that totally 93 up-regulated and 85 down-regulated circRNAs were identified in middle ear cholesteatoma. Through validation, expressions of hsa_circRNA_104327 and hsa_circRNA_404655 were significantly higher, while hsa_circRNA_000319 was significantly down-regulated in cholesteatoma. GO classification, KEGG pathway, and ceRNA network analyses suggested that these differentially expressed circRNAs might play important roles in the etiopathogenesis of middle ear cholesteatoma. Prediction of m6A modification exhibited that hsa_circRNA_000319 possessed 4 m6A sites with very high confidence, and hsa_circRNA_404655 had 3 m6A sites with high confidence. CONCLUSIONS: Our study revealed that these differentially expressed circRNAs might contribute to the etiopathogenesis of middle ear cholesteatoma. Further researches should be conducted to investigate the exact mechanism of these differentially expressed circRNAs in the etiopathogenesis of middle ear cholesteatoma. Targeting on these circRNAs may provide a new strategy for middle ear cholesteatoma therapy in the future.

miR-199a Targeting PNRC1 to Promote Keratinocyte Proliferation and Invasion in Cholesteatoma.

INTRODUCTION: miR-199a has been reported as an oncogene of various cancers. However, the biological function and regulatory mechanism of miR-199a in keratinocytes of cholesteatoma are still unclear. METHODS: Detection by qRT-PCR was conducted on miR-199a's expression in both thirty pairs of cholesteatoma tissues and normal skins. For characterizing the function of miR-199a, this research adopted transwell assay, wound healing assay, and CCK8 assays. Under the support of qRT-PCR, efforts were made to investigate the relative expression of candidate target genes. Moreover, the evaluation of the targeting relationship between miR-199a and the candidate target gene was conducted with the dual-luciferase reporter assay. RESULTS: The upregulation of miR-199a was found in cholesteatoma tissues, which facilitated the proliferation, migration, and invasion of HaCaT cells, while its downregulation caused opposite results. CONCLUSIONS: The findings of the present research offer more insights into the molecular mechanism of cholesteatoma progression.

The Effect of Zbxz23ir-21 NANO(nanomaterials) Delivery Vector on Apoptosis and PTEN(phosphatase and tensin homolog deleted on chromosome ten)/PI3K(Intracellular phosphatidylinositol kinase)/AKT(related to the A and C kinase) in Children with CHOLESTEATOMA in Middle Ear.

Cholesteatoma of the middle ear is a kind of cystic disease with clear boundary formed by the abnormal growth of keratosquamous epithelium in temporal bone. Cholesteatoma otitis caused by it is a common disease in otorhinolaryngology. The EPR effect promotes the selective distribution of macromolecular substances in tumor tissues, which can increase drug efficacy. The purpose of this paper is to prepare and deliver the mir34a small molecule regulator, rubine, by nanotechnology, and to deliver it to the cells successfully. It can passively target tumor tissue through EPR effect, and play its regulatory role on miR-34a, thus inhibiting the growth of cholesteatoma cells. The effects of nano delivery on apoptosis and PIEN/P13K/AKt of children with middle ear choledochoma were tested in this paper. The experimental results were conducted on cholesteatoma cells as cell lines and balb/c nude mice as experimental objects. The expression of PTEN/PI3K/AKT in experimental group and control group was detected by immunohistochemistry. Apoptosis was discussed by cell activity detection. The physical and chemical properties, encapsulation efficiency, drug release ability in vitro and antitumor activity of nanoparticles in vitro and in vivo were studied. The results of cell level experiments in vitro showed that free RUBINE caused about 15% apoptosis, which was not different from RC NPs. The results showed that the nanoparticles could improve the expression of miR-34 in the cells, and then regulate the expression of Bcl-2, Cdk6 and CyclinD1, and play the inhibitory effect of miR-34a on the proliferation and migration of tumor cells.

MiR-508-3p promotes proliferation and inhibits apoptosis of middle ear cholesteatoma cells by targeting PTEN/PI3K/AKT pathway.

Cholesteatoma of the middle ear is a common disease in otolaryngology, which can lead to serious intracranial and extracranial complications. Recent studies showed that the dysregulation of microRNA may be involved in the formation of middle ear cholesteatoma. This study aimed to explore the regulatory effect of micro ribonucleic acid 508-3p (miR-508-3p) on proliferation and apoptosis of middle ear cholesteatoma cells and excavate its underlying regulatory mechanism. We found miR-508-3p expression was upregulated in tissues and cells of cholesteatoma which was inversely related to the expression of hsa_circ_0000007. Overexpression of miR-508-3p could notably facilitate cholesteatoma cell proliferation. Luciferase reporter assay showed that miR-508-3p bound the 3'-untranslated region of its downstream mRNA PTEN. Gain and loss of functions of miR-508-3p were performed to identify their roles in the biological behaviors of cholesteatoma cells, including proliferation and apoptosis. Rescue assays confirmed that PTEN could reverse the effect of miR-508-3p overexpression on cell proliferation. In a word, this study validated that the development of cholesteatoma may regulated by hsa_circ_0000007/miR-508-3p/ PTEN/ PI3K/Akt axis.

Notch Signaling in Acquired Middle Ear Cholesteatoma.

HYPOTHESIS: We hypothesized that an anomalous change of Notch signaling might be involved in the pathophysiology of cholesteatoma. BACKGROUND: The Notch signaling pathway regulates integrated growth and differentiation control of keratinocytes. Its involvement in cholesteatoma proliferation has not been elucidated. METHODS: We obtained cholesteatoma and external auditory canal (EAC) skin samples from patients with middle ear cholesteatoma who underwent tympanomastoid surgery. We performed polymerase chain reaction using the RT2 Profiler™ PCR Array Human Notch Signaling Pathway (Qiagen) in the cholesteatoma and EAC skin samples (n = 6 each). This was followed by immunohistochemical staining of Notch1, enhancer of split-1 (HES1), and p53 in 41 and 8 cholesteatoma and EAC skin samples, respectively. RESULTS: The fold change of Notch1 gene expression was lowest in cholesteatoma, with a statistically significant difference (p = 0.0424). Moreover, the fold change of HES1 expression decreased (p = 0.272). The positive rates of Notch1 and HES1 protein expressions in the cholesteatoma (48.5 ±â€Š32.4% and 44.9 ±â€Š17.8%, respectively) were significantly lower than in the EAC skin (83.4 ±â€Š17.5% and 55.7 ±â€Š7.1%, respectively) (p < 0.001 and p < 0.01). In contrast, the positive rate of p53 expression in the cholesteatoma (8.5 ±â€Š11.4%) was significantly higher than in the EAC skin (0.5 ±â€Š0.7%) (p < 0.001). CONCLUSION: The decreases in Notch1 and HES1 protein expression might play an important role in the hyperproliferative character of the keratinizing squamous epithelium in cholesteatoma. An increase in p53 might reflect the reaction to cellular hyperproliferation.

Chronic inflammation of middle ear cholesteatoma promotes its recurrence via a paracrine mechanism.

BACKGROUND: Cholesteatoma disease is an expanding lesion in the middle ear. Hearing loss and facial paralysis alongside with other intracranial complications are found. No pharmaceutical treatment is available today and recurrence after surgical extraction occurs. We investigated possible TLR4-based mechanisms promoting recurrence and explore possible treatments strategies. METHODS: We isolated fibroblasts and epidermal stem cells from cholesteatoma tissue and healthy auditory canal skin. Subsequently, their expression under standard culture conditions and after stimulation with LPS was investigated by RT-qPCR. Cell metabolism and proliferation were analysed upon LPS treatment, with and without TLR4 antagonist. An indirect co-culture of fibroblasts and epidermal stem cells isolated from cholesteatoma tissue was utilized to monitor epidermal differentiation upon LPS treatment by RT-qPCR and immunocytochemistry. RESULTS: Under standard culture conditions, we detected a tissue-independent higher expression of IL-1ß and IL-8 in stem cells, an upregulation of KGF and IGF-2 in both cell types derived from cholesteatoma and higher expression of TLR4 in stem cells derived from cholesteatoma tissue. Upon LPS challenge, we could detect a significantly higher expression of IL-1α, IL-1ß, IL-6 and IL-8 in stem cells and of TNF-a, GM-CSF and CXCL-5 in stem cells and fibroblasts derived from cholesteatoma. The expression of the growth factors KGF, EGF, EREG, IGF-2 and HGF was significantly higher in fibroblasts, particularly when derived from cholesteatoma. Upon treatment with LPS the metabolism was elevated in stem cells and fibroblasts, proliferation was only enhanced in fibroblasts derived from cholesteatoma. This could be reversed by the treatment with a TLR4 antagonist. The cholesteatoma fibroblasts could be triggered by LPS to promote the epidermal differentiation of the stem cells, while no LPS treatment or LPS treatment without the presence of fibroblasts did not result in such a differentiation. CONCLUSION: We propose that cholesteatoma recurrence is based on TLR4 signalling imprinted in the cholesteatoma cells. It induces excessive inflammation of stem cells and fibroblasts, proliferation of perimatrix fibroblasts and the generation of epidermal cells from stem cells thru paracrine signalling by fibroblasts. Treatment of the operation site with a TLR4 antagonist might reduce the chance of cholesteatoma recurrence. Video Abstract.

Association of CARD8 Activating Polymorphism With Bone Erosion in Cholesteatoma Patients.

OBJECTIVES: We compared the incidence of polymorphisms activating the NLRP3 inflammasome between controls and patients with cholesteatoma and its potential association with bone erosion in patients with cholesteatoma. METHODS: This is a case-control study assessing the mutation rates in genes of interest in patients with and without cholesteatoma. A total of 133 saliva samples from control (n = 65) and cholesteatoma (n = 68) patients were collected for DNA extraction. Caspase recruitment domain family member 8 (CARD8) (AA: homozygous wild type, AT: heterozygous, TT: homozygous mutant polymorphism) and NLRP3 (CC: homozygous wild type, CA: heterozygous, AA: homozygous mutant) polymorphisms were analyzed with TaqMan single-nucleotide polymorphism (SNP) quantitative polymerase chain reaction (ThermoFisher Scientific, Waltham, MA). Mutation status was correlated with a novel bone erosion scoring model developed as a part of this study. Summary statistics, including frequencies (%) and median (Q1, Q3) were used to describe the sample. RESULTS: The presence of CARD8 and NLRP3 homozygous wild-type polymorphisms were generally similar for the control and cholesteatoma patient groups. CARD8 homozygous TT polymorphisms were an exception, occurring more frequently in patients who developed a cholesteatoma compared to the control group (29% vs. 10%, P = .009). Those patients with CARD8 homozygous TT polymorphism had higher median scores of bone erosion as compared to subjects with nonhomozygous mutant genotypes (median [interquartile range]: 4.0 [3.0, 5.5] vs. 2.5 [1.0, 3.5], P = .0142). CONCLUSION: Cholesteatoma patients have a significant, twofold higher incidence of CARD8 homozygous TT polymorphism. Furthermore, cholesteatoma patients with this homozygous polymorphism had greater bone erosion rates than controls. These findings suggest that genetic mutations may increase host susceptibility to cholesteatomas. Specifically, the CARD8 TT polymorphism may influence the severity of cholesteatoma-induced bone erosion. LEVEL OF EVIDENCE: 3B.

Analysis of Inflammatory and Homeostatic Roles of Tissue-resident Macrophages in the Progression of Cholesteatoma by RNA-Seq.

BACKGROUND: Tissue-resident macrophages (TRMØs) can act as innate-immune sentinels to protect body against microbe invaders and stimulating materials such as cholesterol crystals in cholesteatoma, as well as to preserve tissue integrity by cleaning unwanted cellular debris. METHODS: TRMØs in the incised middle ear tissues were obtained from the patients with cholesteatoma as an experimental group and the patients without cholesteatoma as a control group. Differential gene expression profiling of TRMØs was conducted between two groups by analyzing GO processes, KEGG and GSEA pathways of inflammation, tissue repair and homeostasis. RESULTS: The current study showed that 145 of 7060 genes were significantly up-regulated (logFC>2 and FDR <0.05) when compared with the patients without cholesteatoma. GO process, GSEA and Cytoscape analysis of the over-expressed genes illustrated the boosted inflammatory and anti-infection functions of TRMØs existed neutrophil function, leukocyte migration, and adaptive immune response involved receptors and signaling pathways. Whereas the homeostasis and repair functions of TRMØs were affected from up-regulated genes, such as over-expressed keratin-13 that helped form the outer keratinising squamous epithelial layer, and over-expressed MMPs that activated the extracellular matrix molecules to promote inflammation and disturb tissue remodeling. Additionally, 74 down-regulated genes (logFC<-2 and FDR <0.05) also affected the homeostasis and repair functions by affecting extracelluar matrix structure and contractile fibres in TRMØs. CONCLUSIONS: The cellular and molecular levels in cholesteatoma is attributable to chronic infection and several disturbed cellular biological processes involving cell integrity and tissue remodeling.

Extensive qPCR analysis reveals altered gene expression in middle ear mucosa from cholesteatoma patients.

The middle ear is a small and hard to reach compartment, limiting the amount of tissue that can be extracted and the possibilities for studying the molecular mechanisms behind diseases like cholesteatoma. In this paper 14 reference gene candidates were evaluated in the middle ear mucosa of cholesteatoma patients and two different control tissues. ACTB and GAPDH were shown to be the optimal genes for the normalisation of target gene expression when investigating middle ear mucosa in multiplex qPCR analysis. Validation of reference genes using c-MYC expression confirmed the suitability of ACTB and GAPDH as reference genes and showed an upregulation of c-MYC in middle ear mucosa during cholesteatoma. The occurrence of participants of the innate immunity, TLR2 and TLR4, were analysed in order to compare healthy middle ear mucosa to cholesteatoma. Analysis of TLR2 and TLR4 showed variable results depending on control tissue used, highlighting the importance of selecting relevant control tissue when investigating causes for disease. It is our belief that a consensus regarding reference genes and control tissue will contribute to the comparability and reproducibility of studies within the field.

Cholesteatoma and family history: An international survey.

OBJECTIVE: To explore the relative frequency of a family history of cholesteatoma in patients with known cholesteatoma, and whether bilateral disease or earlier diagnosis is more likely in those with a family history. Associations between cleft lip or palate and bilateral disease and age of diagnosis were also explored. DESIGN: An online survey of patients with diagnosed cholesteatoma was conducted between October 2017 and April 2019. PARTICIPANTS: The sample consisted of patients recruited from two UK clinics and self-selected respondents recruited internationally via social media. MAIN OUTCOME MEASURES: Side of cholesteatoma, whether respondents had any family history of cholesteatoma, age of diagnosis and personal or family history of cleft lip or palate were recorded. RESULTS: Of 857 respondents, 89 (10.4%) reported a positive family history of cholesteatoma. Respondents with a family history of cholesteatoma were more likely to have bilateral cholesteatoma (P = .001, odds ratio (OR) 2.15, 95% confidence interval (CI) 1.35-3.43), but there was no difference in the age of diagnosis (P = .23). Those with a history of cleft lip or palate were not more likely to have bilateral disease (P = .051, OR 2.71, CI 1.00-7.38), and there was no difference in age of diagnosis (P = .11). CONCLUSION: The relatively high proportion of respondents that reported a family history of cholesteatoma offers supporting evidence of heritability in cholesteatoma. The use of social media to recruit respondents to this survey means that the results cannot be generalised to other populations with cholesteatoma. Further population-based research is suggested to determine the heritability of cholesteatoma.

Comprehensive circular RNA expression profiling with associated ceRNA network reveals their therapeutic potential in cholesteatoma.

Cholesteatoma is a chronic disease that pathologically displays a benign tumor with excessive squamous epithelial cell proliferation in the middle ear. Clinically, however, it can manifest malignant behavior by destroying adjacent tissues and organs. Although previous studies have demonstrated that the pathogenesis of cholesteatoma is correlated with epigenetic dysregulation, the exact mechanism remains unclear. Circular RNAs (circRNAs) have been revealed as being abundantly expressed in various organisms and have been found to contribute to the regulation of many diseases. To date, no reports have elucidated their expression profiles and functions in cholesteatoma. In the present study, the circRNA expression profile in cholesteatoma was explored for the first time by using microarray analysis. We obtained a total of 355 significantly differentially expressed circRNAs in cholesteatoma, among which 101 were identified to be upregulated and 254 downregulated. By constructing circRNA­lncRNA­miRNA­mRNA competing endogenous RNA (ceRNA) network, it was discovered that circRNAs may function as ceRNAs and contribute to the formation of cholesteatoma. These results provide novel insight into the pathogenesis of cholesteatoma and suggest circRNAs as potential promising therapeutic targets for cholesteatoma.

Perimatrix of middle ear cholesteatoma: A granulation tissue with a specific transcriptomic signature.

OBJECTIVES/HYPOTHESIS: To establish comprehensive transcriptomic profiles of cholesteatoma perimatrix tissue and granulation tissue from chronic otitis media (COM) that did not develop cholesteatoma, which can indicate molecular pathways involved in the cholesteatoma perimatrix pathology and invasiveness. STUDY DESIGN: Retrospective Case Series. METHODS: Transcriptome data were obtained from cholesteatoma perimatrix tissue and COM granulation tissue by an Illumina iScan microarray. Differentially expressed genes (DEGs) were subsequently analyzed using both bioinformatical functional annotation and network analysis. Expression of candidate genes (MMP9 and LCN2) was validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on a larger group of samples. RESULTS: Analysis of the transcriptome led to the identification of 169 differentially expressed genes between investigated tissues. Bioinformatic analysis suggested that most significant biological processes involving DEGs were previously described in cholesteatoma pathology. Network analysis identified ERBB2, TFAP2A, and TP63 as major hubs of the DEGs molecular network. Furthermore, it was observed that the cellular component most significantly enriched in DEGs was extracellular space containing 47 DEGs. Using qRT-PCR, it was confirmed that mRNA levels of the major extracellular hub (MMP9) are increased, whereas its interacting molecule (LCN2) mRNA levels were decreased in cholesteatoma perimatrix tissue compared to COM granulation tissue. CONCLUSIONS: The current study approach offers an overall look at molecular mechanisms that describe the cholesteatoma entity by focusing exclusively on the perimatrix processes in comparison to COM granulation tissue. The observed differences in gene expression between cholesteatoma perimatrix and COM granulation tissue could suggest novel markers potentially influenced by the perimatrix-matrix molecular interplay, which is not present in COM without cholesteatoma. LEVEL OF EVIDENCE: NA Laryngoscope, 130:E220-E227, 2020.