CDK4、P16在中耳胆脂瘤中的表达及意义

目的:观察细胞周期蛋白依赖性激酶CDK4、细胞周期蛋白依赖性激酶抑制因子P16在中耳胆脂瘤上皮的表达情况,探讨它们在胆脂瘤发病机制中的作用。方法:采用免疫组织化学技术SABC法检测CDK4、P16在中耳胆脂瘤35例、正常外耳道皮肤20例中的表达,并结合胆脂瘤对听小骨骨质破坏程度,采用SPSS11.5软件进行统计学分析。结果:CDK4、P16均表达于胆脂瘤上皮的棘细胞层、颗粒层和角质层,阳性率分别为68.6%、88.6%,高于对照组(前者P=0.011,后者P=0.02)。二者在胆脂瘤上皮的表达有一定的相关性,P<0.05;与中耳胆脂瘤听小骨骨质破坏程度之间无明显相关性,P>0.05。结论:CDK4与P16在中耳胆脂瘤发生中是共同而非单独起作用的,从细胞周期的角度可反映胆脂瘤上皮细胞过度增殖的同时也增强负调控因子来抑制增殖,使凋亡同时加快而达到新的平衡。但与骨质破坏程度可能无直接关系。

Expression of CDK4 and P16 in human middle ear cholesteatoma

Objective: To observe the expression of cyclin-dependent kinase-4(CDK4) and cyclin-dependent kinase inhibitor P16 in human middle ear cholesteatoma and to explore their roles in the development of cholesteatoma.Methods: Thirty-five cholesteatomas tissues and twenty normal human external ear canal skin were used in this study.All specimens were stained by an immunohistochemical SABC method to detect the expression of CDK4 and P16.Correlations between the above indexes and between the above indexes and the degree of ossicular destruction were investigated.Result: CDK4 and P16 were expressed in parabasal layers and the upper layer,mainly in the prickle and granular layers of cholesteatoma epithelium.Their positive rates were 68.6% and 88.6%,respectively.Statistical analysis showed that there was a significant difference in positive rates between the normal external ear canal epithelium and the cholesteatoma epithelium(P=0.011,P=0.02),and a positive correlation between CDK4 and P16 in the cholesteatoma group(P<0.05).The statistical results indicated that the expression of CDK4 and P16 did not related to the extent of ossicular damage in cholesteatoma(P>0.05).Conclusion: CDK4 and P16 are over-expressed in human middle ear cholesteatoma epithelium and positively correlate with each other,suggesting that they play a cooperative role in the development of cholesteatoma.The cholesteatoma epithelium has a hyper-proliferation ability and a mechanism of inhibiting the proliferation.The result of immunohistochemical examination is not related to the degree of ossicular destruction.