Expression Of Correlative Factors And Genes In Otitis Media Cholesteatomatica And Its Relationship With HRCT Manifestation

Otitis media cholesteatomatica which is also call middle ear cholesteatoma is a common disease in otolaryngology. As one type of chronic purulent tympanitis and the most harmful disease of otitis media, it is progressively damaging middle ear and its surrounding structures. Its main features are invasive, aggressive, migratory, and recidivistic. Although middle ear cholesteatoma is not a true tumor, it does own some features of tumor such as proliferation and invasion. Osseous destruction is the typical manifestation and the severe syndrome of choleseatoma. Due to HRCT's precise space and density resolving power, clear pictures, accurate anatomic orientation, it is able to vividly demonstrate the delicate structures of ears, and make precise judgment for the invaded ranges and degrees of pathological changes.TNF-αwas discovered in 1975. In addition to its anti-tumor function, it also boasts the important functions like regulating and guiding immune response, mechanism metabolism, and inflammation reaction. Recent studies have shown that TNF-αmay function in the following ways to dissolve osseous destruction: as an autocrine growth factor, TNF-αcan stimulate osteoblasts to produce a bone destruction stimulating factor, and increase the bone absorption of osteoclasts through activation. As a cytokine, TNF-αcauses bone absorption of osseous destruction indirectly, whose functioning mechanism needs further exploration.Matrix Metalloproteinases (MMPs) are a recently discovered proteolytic enzyme, and play an important role in the stability of extracellular matrix and bones, as well as in the inflammatory and soluble diseases. Recent years has witnessed significant breakthroughs in the research in regard to MMPs'role in the mechanism of bone absorption. Osseous collagen fibers mainly refer to type I collagen and type III collagen, which are the most suitable substrates for MMP-I, and MMP-1 can equally degrade type II collagen. Recent study has also shown that MMP-1 can directly degrade ossein and BM, to create conditions for other dissolving bone factors.Survivin genes are the new members of recently discovered Inhibitor of Apoptosis Protein (IAP), and also the smallest IAP cloned so far. Survivin possesses the biological traits including inhibiting the apoptosis , and accelerating the cell proliferation . They can inhibit the apoptosis of cells through direct or indirect intervention of the functions of caspase. Cholesteatoma tissues are equipped with strong multiplication capacity. Till now there has not been any report concerning the relations between this strong multiplication capacity with the functions of survivin.As a type of anti-oncogene, PTEN can guide cell cycle halt and initiate procedural cell death. Its abnormality and the lack of its expressions can result in the canceration of many cells, the abnormal multiplication of cells. In particular, recent discoveries have unveiled the lack or the mutation of PTEN in many kinds of tumors. However, reports about the expression of PTEN in middle ear cholesteatoma are rather rare. The present experimentation included the following researches:1. Through study of the consistency in HRCT scanning and operation assessment in cholesteatoma osseous destruction, for evaluating the value of HRCT in the diagnosis of cholesteatoma osseous destruction.2.To study the correlation between HRCT scanning's degree in cholesteatoma osseous destruction and duration of illness.3.Immunohistochemical technique and reverse transcription - polymerase chain reaction (RT-PCR) were used to examine expression of TNF-α, MMP-1, survivin, PTEN proteins and mRNA in middle ear cholesteatoma tissues.4. Through the correlation study between the expression of TNF-α, MMP-1 in cholesteatoma tissues and HRCT scanning's degree in osseous destruction, for further exploring the relation between TNF-α, MMP-1 and middle ear cholesteatoma osseous destruction.The significant results of the present study:1.Temporal bones of 43 cholesteatoma patients were scanned before surgery, and osseous destruction was graded in terms of Saleh's and Jiang Chaowu's suggestions on cholesteatoma invasive power and osseous destruction. Statistical analysis demonstrates that there does exist evident consistency between HRCT scanning's degree of osseous destruction and surgeries'degree.2.43 cholesteatoma patients based on 5-year duration of illness as a unit were grouped, and the relation between HRCT scanning's degree in osseous destruction and the duration of illness was analyzed. Statistical analysis demonstrates that there is a strong correlation between HRCT scanning's degree in osseous destruction and duration of illness.3.The expression of TNF-α,MMP-1 proteins and mRNA on the epidermis of cholesteatoma is significantly higher than that of normal external auditory canal, and the difference between each other is notable (P<0.05).4.There is a close relation between the expression level of TNF-α, MMP-1 and HRCT scanning's degree osseous destruction. With the increase of the expression of TNF-α,MMP-1, osseous destruction is increased accordingly, and a significantly difference exists between the groups (P<0.05).5.69.8 % positive expression of survivin protein and mRNA exists in the middle ear cholesteatoma tissues, whereas there is no expression in the normal external auditory canal derma.6.The expression of PTEN protein and PTENmRNA in middle ear cholosteatoma tissues share the similar expression in normal external auditory canal derma, and no statistical significance can be found through the difference (P>0.05).The main conclusions of the present study:1. There is a close consistency between HRCT scanning's degree and surgeries'degree in middle ear cholesteatoma invasive power and osseous destruction, and HRCT scanning has the guiding significance to frame surgery plans and estimate the hearing recovery.2. TNF-α,MMP-1 in middle ear cholesteatoma are significantly highly than those in normal tissue, and have a notable correlation with HRCT scanning's degree in the osseous destruction, for futher confirm that TNF-α,MMP-1 are key factor of osseous destruction caused by cholesteatoma.3. To explore mechanism of excessive proliferation of cholesteatoma epidermis from different apoptosis pathway. The result indicates that surviving might participate in the excessive proliferation of middle ear cholesteatoma cells, to provide theoretical foundation for future gene therapy. PTEN has not participated in the abnormal multiplication of cholesteatoma epidermis, and PTEN may play an important role in maintaining a normal biological status of epithelial cells.Innovation:1. To study the consistency of HRCT scanning's degree and surgeries findings in cholesteatoma invasive power and osseous destruction.2. To study the correlation between expression of TNF-α,MMP-1 and osseous destructive degree in middle ear cholesteatoma.3. Molecular biology technique and HRCT scanning were combined to detect the mechanism of middle ear cholesteatoma osseous destruction.