目的 观察在宫颈癌中过度表达的p16是否仍然具有正常结合Cdk4的功能,进一步阐明过表达的p16不能抑制宫颈癌发生发展的原因.方法 对142例宫颈标本,包括慢性宫颈炎19例,CIN Ⅰ级(LCIN)15例,CIN Ⅱ/Ⅲ级(HCIN)42例,宫颈鳞状细胞癌(SCC)66例进行p16和Cdk4免疫组化染色分析.选取1例p16高表达SCC(22C)和1例p16低表达SCC(43C)的新鲜标本进行免疫沉淀和Western blot分析.结果 按照慢性宫颈炎、LCIN、HCIN和SCC的顺序,p16阳性率分别是0、60.0%、78.6%和92.4%;Cdk4 阳性率分别是21.1%、46.7%、73.2%和92.4%,表明p16和CDK4的表达随宫颈肿瘤的进展而协调性升高.在同一例标本中,83.9%的p16高表达SCC的Cdk4同时呈高表达;86.7%的p16低表达SCC的Cdk4呈高表达或平行低表达,表明大多数SCC含有足够的与p16结合的Cdk4.结合Cdk4的p16与总p16的比例在p16高表达SCC(22C)中是66.9%,在p16低表达SCC(43C)中是42.2%,表明在SCC中过表达p16的近半左右与Cdk4结合,且p16表达越高,其与Cdk4结合的总量也越多.结论 在宫颈癌中过度表达的p16 仍然具有结合Cdk4 的能力.本研究首次从宫颈癌组织水平证实过表达的p16可以结合Cdk4,为研究p16对宫颈癌的作用向前推进了一步.%Objective To observe the hinding capacity of over - expressed p16 with Cdk4 in cervical carcinoma.Methods Immunohistochemiscal staining of p16 and Cdk4 was performed on 142 samples of cervical tissues, including 19, 15 , 42 and 66 cases of cervicitis, low cervical intraepithelial neoplasm ( LCIN ) , high CIN ( HCIN ) and invasive cervical squamous cell carcinoma ( SCC ), respectively. Co - immunoprecipitation ( Co - IP ) and Western blot were used to test the activity of p16 binding Cdk4 in high p16 expression and low p16 expression SCC. Results In the lesions of cervicitis, LCIN, HCIN and SCC, the p16 positive rates were 0, 60. 0％ , 78. 6％ and 92. 4％ , respectively, with Cdk4 positive rates of 21. 1％ , 46. 7％ , 73. 2％ and 92. 4％ , respectively. The expression of p16 and Cdk4 was increasingly high with the progression of cervical tumors. In individual SCC, 83. 9％ of high p16 expression SCC had high Cdk4 expression,and 86. 7％ of low p16 expression SCC had high or parallel low Cdk4 expression, indicating that Cdk4 was adequate in most SCC. The proportion of the p16 binding with Cdk4 to the total p16 was 66. 9％ in the high p16 expression SCC while 42. 2％ for the low p16 expression SCC, indicating that half or so of the over - expressed p16 was bound with Cdk4 , and the higher p16 expressed, the more p16 was bound with Cdk4. Conclusion The over - expressed p16 in cervical carcinoma maintains the normal activity to bind Cdk4. The finding in the tissue level advances a step to further study the role of the over - expressed p16 in the carcinogenesis of cervical carcinoma.
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