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

Occurrence of mucosa-affecting diseases of the upper airways in middle ear cholesteatoma patients: a nationwide case-control study

PURPOSE

Exploring a possible link between upper airway inflammation and the development of cholesteatoma by studying the association between mucosa-affecting diseases of the upper airways and cholesteatoma surgery.

METHODS

This is a nationwide case-control study of 10,618 patients who underwent surgery for cholesteatoma in Sweden between 1987 and 2018. The cases were identified in the National Patient Register and 21,235 controls matched by age, sex and place of residency were included from national population registers. Odds ratios (OR) and corresponding 95% confidence intervals were used to assess the association between six types of mucosa-affecting diseases of the upper airways and cholesteatoma surgery.

RESULTS

Chronic rhinitis, chronic sinusitis and nasal polyposis were more common in cholesteatoma patients than in controls (OR 1.5 to 2.5) as were both adenoid and tonsil surgery (OR > 4) where the strongest association was seen for adenoid surgery. No association was seen between allergic rhinitis and cholesteatoma.

CONCLUSION

This study supports an association between mucosa-affecting diseases of the upper airways and cholesteatoma. Future studies should aim to investigate the mechanisms connecting mucosa-affecting diseases of the upper airways and cholesteatoma formation regarding genetic, anatomical, inflammatory and mucosa properties.

Proto-oncogene mutations in middle ear cholesteatoma contribute to its pathogenesis

BACKGROUND

Chronic inflammation causes bone destruction in middle ear cholesteatomas (MECs). However, the causes of their neoplastic features remain unknown. The present study demonstrated for the first time that neoplastic features of MEC are based on proto-oncogene mutations.

RESULTS

DNA was extracted from MEC and blood samples of five patients to detect somatic mutations using depth-depth exome sequencing. Exons with somatic variants were analyzed using an additional 17 MEC/blood test pairs. Variants detected in MECs but not in blood were considered pathogenic variant candidates. We analyzed the correlation between proto-oncogene (NOTCH1 and MYC) variants and the presence of bone destruction and granulation tissue formation. MYC and NOTCH1 variants were detected in two and five of the 22 samples, respectively. Two of the NOTCH1 variants were located in its specific functional domain, one was truncating and the other was a splice donor site variant. Mutations of the two genes in attic cholesteatomas (n = 14) were significantly related with bone destruction (p = 0.0148) but not with granulation tissue formation (p = 0.399).

CONCLUSIONS

This is the first study to demonstrate a relationship between neoplastic features of MEC and proto-oncogene mutations.

Nitric Oxide Is Locally Produced in the Human Middle Ear and Is Reduced by Acquired Cholesteatoma

OBJECTIVE

To find out if nitric oxide (NO) can be locally produced in the middle ear and if chronic otitis media (COM) and acquired cholesteatoma affect the production.

DESIGN

Case-control study.

SETTING

Two tertiary-referral hospitals.

PATIENTS

Gaseous NO from 11 patients with unilateral perforations or grommet openings was measured with chemiluminescence. Middle ear mucosa from 48 patients with COM and 26 patients with cholesteatoma was investigated.

MAIN OUTCOME MEASURES

Detection of NO. Expression of nitric oxide synthase (NOS) mRNA, in mucosa from COM, cholesteatoma and healthy controls, quantified using polymerase chain reaction.

RESULTS

The gaseous NO from ears with a unilateral tympanic membrane perforation or a grommet was higher (9 ± 3 ppb, n = 11) than among the controls (4 ± 1 ppb, n = 11, p = 0.04). Lower levels of eNOS (2.64 ± 0.86 mol/100,000 mol ACTB) were detected in the pooled samples from the COM group (n = 48), compared with the control group (140.48 ± 92 mol/100,000 mol ACTB, n = 45, p = 0.010). In the cholesteatoma group (n = 26), a lower expression of nNOS (5.78 × 10-6 ± 1.13 × 10-6 ΔCt) was found in comparison with the controls (1.23 × 10-4 ± 3.18 × 10-5 ΔCt, n = 15, p = 0.011).

CONCLUSIONS

NO is likely a natural and permanent part of the gas mixture in the human middle ear. The presence of NOS enzymes in the middle ear mucosa indicates an ongoing NO production and the reduction of NOS in ears with cholesteatoma, and pooled samples from ears with COM, suggest a role for locally produced NO in middle ear disease.

[Immunomodulation in Cholesteatoma]

INTRODUCTION

The etiopathogenesis of chronic otitis media epitympanalis/cholesteatoma and its proliferative destructive course with possible complications such as destruction of bony structures with hearing loss, vestibular dysfunction, facial nerve paralysis and intracranial complications are still unexplained. Surgery is still the way to go. New studies are increasingly looking at the innate immune system.

METHODS

Our studies were carried out in a mouse model in WT mice and immundeficient KO-mice, as well as in cholestatoma and healthy ear canal skin and middle ear tissue, which was removed during ear surgery. The expression analyses were carried out at the gene and protein level using TNF as the major target for therapy evaluation. By means of TUNEL staining and immunohistochemistry the level of apoptosis was evaluated.

RESULTS

The uncontrolled undirected cholesteatoma growth shows an immunomodulatory profile with up and down-regulation of various gene networks, especially those involved in TNF downstream and upstream signaling pathways. TNF in cholesteatoma is modulated both inflammatorily and apoptotically and therefore is suitable as a possible therapeutic approach in various models.

CONCLUSIONS

Cholestatoma might be immunomodulatory regulated.