Localization of matrix metalloproteinase 1 in cholesteatoma and deep meatal skin

Elevated level of tenascin and matrix metalloproteinase 9 correlates with the bone destruction capacity of cholesteatomas

OBJECTIVES

Bone destruction is a key step in the progression of cholesteatomas. Some of the lesions can grow without affecting the surrounding anatomic structures, whereas others can cause severe bone destruction despite their limited size. This study aims to identify factors that could play important role during the invasion of the disease.

METHODS

Cholesteatoma tissue samples were examined immunohistochemically. Tissue samples were arranged on the basis of bone destruction (destructive cholesteatomas [DC] and nondestructive cholesteatomas [NDC]). Double-immunofluorescent labeling was performed to detect simultaneously 1) tenascin (TN) and cytokeratin; 2) matrix metalloproteinase 9 (MMP-9) and TN; 3) TN and Ki-67. An in situ apoptosis detection kit was used to detect apoptotic cells. External auditory canal skin samples were used as control.

RESULTS

1) In DCs, more widespread stromal TN labeling was seen compared with NDCs or external auditory canal skin samples. 2) More enhanced MMP-9 staining was detected in DCs compared with NDCs. 3) The proportion of Ki-67-positive cells in DC samples was significantly higher than in NDCs. 4) The percentage of apoptotic cells was higher in NDC than in DC samples.

CONCLUSION

Our present study demonstrates that levels of TN, MMP-9, and proliferative activity are increased in cholesteatomas. It has also been shown that increased levels of TN, MMP-9-positive cells, and proliferative activity of the lesions, as well as decreased levels of apoptosis, can be linked to more aggressive clinical behavior of cholesteatomas. Our findings also indicate that TN and MMP-9 can be key molecules of bone destruction during cholesteatoma progression.

Cholesteatoma triggering squamous cell carcinoma: case report and literature review of a rare tumor

BACKGROUND

The aim of this study was to report a case of squamous cell carcinoma of the petrous part of the temporal bone associated with a long history of secondary acquired cholesteatoma in a 71-year-old man.

PATIENTS AND METHODS

We present the case of a 71-year-old man diagnosed with secondary acquired cholesteatoma in 1950. Treatments consisted of repetitive surgery owing to several relapses. In 2004, he presented with progressive fetid otorrhea. Clinical and computed tomography findings were indicative for relapsing cholesteatoma and a subtotal petrosectomy was performed.

RESULTS

Histologic work-up demonstrated a moderately differentiated squamous cell carcinoma. The staging revealed stadium pT3 cN0 cM0. Postoperative treatment consisted of local radiation therapy with intensity-modulated beam geometry with a total of 64.2 Gy in 30 fractions using a simultaneous integrated boost.

CONCLUSION

Middle ear carcinoma can arise from acquired cholesteatoma. The pathogenesis of squamous cell carcinoma associated with cholesteatoma has not been elucidated satisfactorily. Due to the complex anatomic features, intensity-modulated radiation therapy is the technique of choice for postoperative radiotherapy.

Comparative analysis of the epithelium stroma interaction of acquired middle ear cholesteatoma in children and adults

In the clinical setting, pediatric cholesteatomas frequently behave more aggressively than similar lesions in adults. The reason for the difference in behavior is still unclear. The purpose of the present study was to investigate the cell to cell and epithelial-stroma interaction of acquired cholesteatoma in adults and children and search for differences on the cellular level, which might explain the different behavior of these lesions. Operative specimens of 54 patients [40 adults (average age of 39.7 years), 14 children (average age of 8.3 years)] who underwent primary surgery for an acquired cholesteatoma of the middle ear were examined by histopathology and DNA-image cytometry (DNA-ICM). Immunohistochemical investigations included expression of proliferation markers (proliferation cell nuclear antigen and MIB-1) along with cell surface markers reflecting the cell-to-cell interaction (i.e. alpha1beta6-integrin, E-cadherin, I-CAM = CD54), and the epithelial to stroma interaction (i.e. alphav and beta3 intergin chains, V-CAM = CD106, CD44v6 and fibronectin). Pediatric cholesteatomas demonstrated higher incidence of acute inflammation and more extensive disease relative to those from the adults. Indices of DNA-ICM, however, revealed normal diploid DNA content in both groups. Higher proliferation scores occurred in the pediatric group compared to adult cholesteatoma. Cell surface markers and cell adhesion molecules were equally expressed in both groups except alpha1beta6-integrin and fibronectin, which were over expressed in pediatric cholesteatomas. Statistically, however, these differences showed only a trend towards significance. According to the results of the present study, pediatric and adult cholesteatomas do not show any marked differences on the cellular level. Thus the observed clinical more aggressive behavior of pediatric cholesteatoma is likely due to other secondary factors such as more intense inflammation, disturbed middle ear ventilation or the diminished calcium salt content of pediatric bone.

Expression of hypoxia inducible factor 1 alpha and Von Hippel Lindau protein in human middle ear cholesteatoma

OBJECTIVE

To evaluate the role of hypoxia in cholesteatoma progression.

STUDY DESIGN

Immunohistochemical analysis of paraffin-embedded human specimens.

METHODS

Thirteen middle ear cholesteatomas and 10 samples of normal human external ear canal skin were stained immunohistochemically for the presence of hypoxia inducible factor 1 alpha (HIF 1 alpha) and Von Hippel Lindau protein. Specimens were then analyzed semiquantitatively.

RESULTS

Staining for both antibodies could be detected in all cholesteatomas (perimatrix and matrix), as well as in the samples of normal human ear canal skin. Cholesteatoma specimens showed statistically significant increased staining when compared with normal human skin and mucosa. The age of patients and relapse surgery affected immunohistochemical staining of HIF 1 alpha and Von Hippel Lindau protein.

CONCLUSIONS

Elevated staining intensities for HIF 1 alpha and Von Hippel Lindau protein in cholesteatoma tissue indicated that cholesteatoma may be hypoxic. In addition, our data indicated that relapse cholesteatomas yield a higher degree of hypoxia than ears without surgery.

Telomerase activity, telomere length, and apoptosis: a comparison between acquired cholesteatoma and squamous cell carcinoma

BACKGROUND

Cholesteatoma disease is characterized by accumulation of keratinizing epithelium. Several molecular markers of tumor formation have been found in cholesteatoma (e.g. upregulation of matrix metalloproteinases, c and activation of angiogenesis). Other molecular findings clearly distinguish between cholesteatoma and malignant tumors (e.g., lack of chromosomal instability, intact checkpoint responses). To further distinguish the molecular mechanisms in cholesteatoma from malignant tumors, the authors determined telomerase activity and telomere length in both tissue types.

METHODS

To evaluate the role of telomerase activation and telomere length in cholesteatoma, 29 cholesteatoma samples and 9 squamous cell carcinomas were analyzed for telomerase activity and telomere length. In addition, the rate of apoptosis was determined in both groups, using the TdT-mediated dUTP nick end labeling technique.

RESULTS

As previously described, a high proportion of squamous cell carcinoma exhibited telomerase activity (6/9, 66%). By contrast, a significantly lower rate of telomerase activity was found in cholesteatoma samples (1/29, 3.4%, p = 0.0002). Despite the differences in telomerase activity, the telomere length was similar in cholesteatoma (mean length 7.43 kb) and in squamous cell carcinoma (mean length 7.99 kb; difference not significant, p = 0.1364). The low rate of telomerase activity in cholesteatoma was accompanied by significantly higher rates of apoptosis in cholesteatoma (mean 30%) compared with squamous cell carcinoma tissue (mean 3%, p = 0.0031).

CONCLUSIONS

Taken together, these data show that telomerase activation is a rare event in cholesteatoma and that the absence of telomerase activity is accompanied by high rates of apoptosis in cholesteatoma. It is proposed that the absence of telomerase limits the proliferative capacity of cholesteatoma by induction of apoptosis, whereas the presence of telomerase allows immortal growth of squamous cell carcinoma.