中耳胆脂瘤上皮过度增殖与MDM2的相关性

目的探讨MDM2（murine double minute）在中耳胆脂瘤上皮增殖机制中的作用，了解胆脂瘤的过度增殖性和生长方式。方法应用免疫组织化学技术检测32例中耳胆脂瘤组和10例正常对照组中MDM2的表达。结果MDM2分布于胆脂瘤上皮全层，但在基底层细胞表达最弱，棘细胞层、颗粒层和角质层依次递增，染色最强的部位是颗粒层和角质层，而正常对照组未见MDM2分布。结论p53／MDM2反馈环异常可能是胆脂瘤上皮异常增殖和凋亡的原因之一。在胆脂瘤基底层细胞表达少量的MDM2可能是维持胆脂瘤不同于恶性肿瘤组织的无限增殖和浸润的基础。

Association between the hyperproliferation of middle ear cholesteatoma and MDM2

OBJECTIVE To study the role of MDM2(murine double minute) in proliferation mechanism ofmiddle ear cholesteatoma and to elucidate the role ofMDM2 in the growth ways and biological behavior ofcholesteatoma. METHODS Expression of MDM2 wasexamined in 32 specimens of middle ear cholesteatomaand 10 specimens of normal ear canal skin. RESULTSThe expression of MDM2 in all epithelial layers of cho-lesteatoma was abundantly stained,especially in thegranular layer and stratum corneum and the lowerexpression was seen in the basal layer,Never detectedMDM2 in the normal ear canal skin. CONCLUSIONThe p53/MDM2 feedback loop were interrupted whichresulted in abnormal proliferation and apoptosis of cho-lesteatoma epidermis. The lower expression of MDM2in the basal layer of cholesteatoma might suggest thatthere was a different mechanism of hyperproliferationand aggression between cholesteatoma and malignanttumor.