Telomerase activity and cell proliferation index in cholesteatoma

Conclusions. Telomerase activity was expressed in cholesteatomas, and cellular proliferation was significantly higher in cases where the telomerase activity was positive. Telomerase activity was also closely related with cellular proliferation in chronic hyperproliferating tissues such as cholesteatomas. Objective. Telomerase activity is detected in most malignant tumors and is also known to have a close relationship with cell proliferation. Cholesteatoma shows cellular hyperproliferation. We studied telomerase activity in cholesteatoma and its relationship with cellular proliferation and clinical findings. Material and methods. Cholesteatoma tissue was obtained from 40 patients during middle ear surgery. Telomerase activity was measured using a telomeric repeat amplification protocol method. As a cellular proliferation index, expression of Ki-67 was measured by means of immunohistochemical staining. Posterior auricular skin was used as a control. Telomerase activity was compared with Ki-67 expression. Clinical features such as hearing loss, the extension of cholesteatoma, the degree of bone destruction and the cause of cholesteatomas were compared with telomerase activity and the cellular proliferation index. Results. Telomerase activity was positive in 21/40 cholesteatomas (52.5%), but absent in the control group. The average Ki-67 labeling index in the cholesteatoma group was 32.84±10.13, higher than that in the control group (21.83±7.76) (p<0.05). The average Ki-67 labeling indices of the 21 telomerase activity-positive and 19 telomerase activity-negative cholesteatomas were 37.76±8.53 and 27.39±9.06, respectively. The Ki-67 labeling index was significantly higher in telomerase-positive cholesteatomas (p<0.05). The clinical features did not show a relationship with either telomerase activity or the cellular proliferation index.     

上皮细胞增殖和凋亡在中耳胆脂瘤发病学的意义(附33例报告)

目的 :通过探讨胆脂瘤上皮 (CE)、胆脂瘤患者外耳道上皮 (CAMS)和正常健康者外耳道上皮(NAMS)的增殖和凋亡及 p5 3基因与上皮细胞增生和凋亡的关系 ,阐明增殖和凋亡异常在胆脂瘤发病中的作用。方法 :采用免疫组织化学和原位末端标记技术检测细胞增殖标记物 PCNA、Ki- 6 7和 p5 3蛋白在 33例 CE、2 5例CAMS和 10例 NAMS细胞的表达及细胞凋亡。结果 :在上述标本中均有 PCNA表达及凋亡细胞存在 ,但不同类型上皮阳性细胞数量、染色强度及分布不同。 CE存在过度增殖和凋亡 ,CAMS亦存在过度增殖。 p5 3表达与PCNA呈正相关 ,与细胞凋亡呈负相关。结论 :CE具有过度增殖和凋亡的特性 ,增殖与凋亡的紊乱与胆脂瘤形成密切相关。     

Collagenase activity in cholesteatoma

Collagenase activity of cholesteatoma epithelium, temporal bone and ear canal skin was investigated. The enzyme extracted from these tissues was proved to be collagenase by disc electrophoresis. Collagenase activity was measured directly in homogenates of tissues. Activity was greatest in the skin. The activity in cholesteatomas was either higher than that of the bone, or the activity was higher in bone than in the cholesteatoma. These findings suggest that some variation of collagenase activity may be due to the stage of cholesteatoma, active or inactive in collagen metabolism of bone destruction, and that the ear canal skin plays a great role in bone destruction, this supporting the immigration theory.     

Cathepsin activity in cholesteatoma

Collagenolytic cathepsin, presumed to play an important role in bone destruction of cholesteatoma, was investigated in cholesteatoma epithelium, subepithelial granulation tissue, skin from the bony external auditory meatus and, temporal bone. The enzyme extracted from tissues was proven to be lysosomal cathepsin B by SDS gel electrophoresis in the use of human type I and type III collagen. alpha-N-benzoyl-DL-arginine-2-naphthylamide HCl (BANA) was supposed to be specific for cathepsin B, and so BANA-hydrolase activity was measured as collagen-degrading cathepsin. The results showed that tissues had cathepsin B with its optimal pH 6.0, and that cathepsin B activity revealed a significant increase in the subepithelial granulation tissue. A strong activity of acid phosphatase found in the subepithelial granulation tissue seems to reflect the existence of an active metabolism of substances in the granulation tissue. These findings suggest that collagen is resorbed in the subepithelial granulation tissue in the presence of cholesteatoma.     

中耳胆脂瘤上皮细胞增生与凋亡状态的研究

目的 :研究中耳胆脂瘤上皮细胞增生和凋亡的状态。方法 :应用免疫组化染色 SABC技术及原位凋亡细胞标记技术 (TU NEL 法 ) ,对 2 0例中耳胆脂瘤上皮组织和 10例外耳道正常上皮组织样本进行研究。结果 :在中耳胆脂瘤上皮中 ,增殖细胞核抗原 (PCNA )阳性细胞大量存在于基底细胞层、棘细胞层及颗粒细胞层 ,而在正常外耳道上皮中 PCNA阳性细胞仅存在于基底层 ;在胆脂瘤上皮中 PCNA阳性细胞率和平均光密度分别为(36 .91± 2 2 .77) %和 0 .2 4 2 7± 0 .0 5 86 ,明显高于正常外耳道上皮中的 PCNA阳性细胞率 (10 .2 5± 2 .6 5 ) %及平均光密度 (0 .1340± 0 .0 36 3) ,其差异有显著性意义 (P<0 .0 5 )。同时 ,在胆脂瘤上皮中 ,凋亡细胞存在于棘细胞层及颗粒细胞层 ,而外耳道正常上皮与之相似 ,但两者的凋亡率分别为 (2 7.5 0± 12 .5 0 ) %和 (9.96± 3.86 ) % ,其差异有显著性意义 (P <0 .0 5 )。结论 :中耳胆脂瘤上皮具有高度增生和凋亡的能力 ,并因上皮细胞的增生、分化、凋亡导致角化碎片累积而形成胆脂瘤     

头颈部鳞癌及癌旁组织端粒酶活性检测

目的：研究原发头颈部鳞癌及相关癌旁组织中端粒酶活性表达,探讨春作为头颈部鳞癌分子生物学标志物的可能性。方法：采用ＴＲＡＰ－ＰＣＲ－ＥＬＩＳＡ,对３２例原发头颈部鳞癌及１５例癌旁组织进行端粒酶活性检测。结果：３２例原发头颈部鳞癌中,２７例端粒酶活化,阳性率为８４．４％;１５例癌旁组织中５例端粒酶活化,阳性率为３３．３％。有淋巴结累及者端粒酶阳性率（８６．７％）高于无淋巴结累及者（８２．４％）,低分化     

Markers of epidermal proliferation in middle ear cholesteatoma

Middle ear cholesteatoma is characterized by the presence in the middle ear cavity of a stratified squamous epithelium with keratin deposits which by constant proliferation leads to extensive bone destruction. The goal of this study was to evaluate, by immunohistochemical study, the expression of epithelial markers of proliferation--Ki-67 and PCNA in the matrix of cholesteatoma. The materials used in this study were 16 acquired cholesteatoma tissues collected from patients in the age 6-17 years during surgery. The specimens from the skin of the external ear canal were employed as the control. In the immunohistochemical specimens staining intensity and distribution of Ki67 and PCNA positive cells in various layers of the epithelium were assessed in three stages scale. The results were compared to the clinical parameters such as--type of cholesteatoma (pars flaccida or tensa), presence of ear discharge, degree of ossicular destruction and involvement of attic and mastoid. In the cholesteatoma matrix Ki-67 and PCNA positive cells were present in basal and suprabasal cell layers and also more superior layers, unlike the control skin were only basal cells show positive staining. The number of positive cells and intensity of staining was also greater in the cholesteatoma matrix than in skin of external auditory meatus. No correlation was found between results of immunohistochemical examination and clinical parameters.     

Evaluation of epithelial proliferation and apoptosis in cholesteatoma of adults

The aim of the study was to determine the correlation between proliferation and apoptosis in cholesteatoma epithelium with that in normal skin. Cholesteatomas were collected from 20 patients during surgical procedures. 13 normal skin preparations collected from outside of the external ear were used as controls. Dako detective kit with Ki-67 antigen and PCNA was used to assess cell proliferation. Immunohistochemical reaction intensities in the cells were determined. Mebstain Apoptosis kit Direct with antigen APO 2.7 were used to estimate apoptosis. Positive PCNA cells in the suprabasal layer were observed in 9 preparations, 9--in parabasal layer, and in 2--in both basal and stromal layers. Skin preparations showed decreased proliferative ability in comparison to cholesteatoma epithelium. The presence of Ki-67 antigen was presented in cell nuclei of parabasal and stromal layers mainly. Apoptotic cells were detected in suprabasal, prickle and granular cell layers of cholesteatoma epithelium. CONCLUSIONS: 1. Proliferation and apoptosis are significantly higher in cholesteatoma epithelium as compared with the epidermis of the skin. 2. Proliferative activity and apoptosis were observed mainly in the suprabasal layers in the cholesteatoma epithelium. 3. Hyperproliferation and apoptosis in cholesteatoma do not depend on the thickness of the epithelium.     

The relationship between survival and cell proliferation index in squamous cell carcinoma of larynx

Cell proliferation index is one of the most important factors in assessment of growth and progression of tumours. At present, the most suitable method of determining cell proliferation is by means of immunohistochemical techniques which use the monoclonal anti-body MIB-1 which reacts against Ki-67, a protein released only in the proliferation phases of the cell cycle. In this study, 44 patients diagnosed with squamous cell carcinoma of the larynx were analysed retrospectively and different macroscopic and microscopic parameters were assessed, such as MIB-1 in relation to the current status of the patient. A statistically significant relationship was found between the cell proliferation index, the histological grade of differentiation and the clinical evolution of the illness.     

端粒酶与喉癌相关性研究进展

端粒酶激活与恶性肿瘤发生发展之间存在着密切的关系。本文就端粒酶结构、功能及其与喉癌发生发展关系的最新研究进展作简要综述。     

中耳胆脂瘤上皮增殖能力的研究

目的 :探讨增殖细胞核抗原 (proliferating cell nuclear antigen,PCNA)在中耳胆脂瘤上皮中的表达和定位以及与中耳炎症的关系。方法 :采用 PCNA单克隆抗体对 16例中耳胆脂瘤组织和 6例正常外耳道皮肤 ,面部皮肤以及鼓膜进行免疫定位检测。结果 :PCNA阳性细胞仅见于正常外耳道、面部皮肤和鼓膜的基底细胞层和棘细胞层的开始部位 ,亦可见于胆脂瘤组织上皮全层。上皮下炎性细胞浸润愈重 ,PCNA阳性细胞率愈高。结论 :中耳胆脂瘤上皮组织具有过度增殖能力。上皮下炎症反应可能是角化细胞过度增殖的一个原因     

喉癌和癌旁组织的端粒酶活性检测

目的：探索端粒酶活性与喉癌发生发展的关系。方法：采用重复序列扩增法（TRAP－PCR）检测56例手术切除的喉癌组织和癌旁粘膜组织的端粒酶活性。喉癌组织均经病理证实,喉癌旁粘膜组织中有正常喉粘膜41例,轻度不典型增生15例。结果：喉癌组织端粒酶活性阳性率为91．07％（51／56）,正常喉粘膜和轻度不典型增生喉粘膜的阳性率分别为9．76％（4／41）和33．33％（5／15）,喉癌组织和癌旁粘膜组织中端粒酶活性阳性率有显著差异（P<0．01）。癌旁上皮端粒酶活性阳性的9例患者其喉癌组织端粒酶活性皆为阳性。结论：端粒酶激活与喉癌的发生发展有密切关系,并可作为喉癌分子诊断的肿瘤标记物。     

Expression of telomerase activity in cholesteatoma otitis media.

Telomerase maintains the length of telomeres in immortal cells and is also often associated with cell proliferation. Cholesteatoma epithelium is characterized by a dysregulation with hyperproliferative growth. The study evaluated the telomerase activity in cholesteatoma and normal retro-auricular skin to discover the relationship between telomerase expression and clinical findings. Twenty-two samples of cholesteatoma and 15 samples of retro-auricular skin were obtained from patients undergoing middle-ear surgery. The telomerase activity was detected by the telomerase repeat amplification protocol (TRAP) assay method. Seventeen of the 22 (77.3 per cent) cholesteatoma cases expressed telomerase activity, whereas none of the 15 retro-auricular normal skin (0 per cent) detected telomerase activity. There was no significant difference between telomerase expressions and clinical findings, including hearing level, duration of disease, and the degree of extension (p>0.05). The high expression of telomerase in cholesteatoma suggests that the activation of telomerase may be related to the proliferative nature of cholesteatoma.     

Immunohistochemical study of cell proliferation using BrdU labelling on tympanic membrane, external auditory canal and induced cholesteatoma in Mongolian gerbils

The Mongolian gerbil is a well-known animal model for induction of aural cholesteatomas. This animal model is useful for studying changes in the keratinizing epithelium. It is not known whether keratin accumulation can increase the proliferative activity of the keratinizing epithelium in tympanic membrane and meatal skin. In this study, we investigated the proliferative activity of the epidermis in induced aural cholesteatoma at various stages and in different areas of the tympanic membrane and meatal skin in normal gerbils. Anti-5-bromo-2- deoxyuridine (BrdU) was injected intraperitoneally to detect the proliferative activity of keratinizing epithelium. Immunohistochemistry with monoclonal BrdU antibody in the normal gerbil showed intense immunolabelled keratinocytes at the handle of malleus, and the superior parts of pars tensa and pars flaccida. Also, mitotic activity in the deep meatal skin was more active than in the lateral meatal skin. The induced aural cholesteatoma showed more active proliferation centre of the epithelial cell than eardrum and external ear canal of the normal gerbil. These observations suggest that the accumulation of the keratin debris might induce changes of the cellular proliferation in the external auditory meatus.