p53通路相关基因和EZH2在鼻咽癌中的表达关系及意义

Expressions of p53 pathway genes and EZH2 in undifferentiated nasopharyngeal carcinoma

目的探讨p53通路相关基因p53、mdm2、p63蛋白和EZH2在鼻咽癌中的表达关系和意义。方法用免疫组化法检测47例鼻咽未分化癌及12例慢性鼻咽炎中p53、mdm2、p63和EZH2蛋白的表达状况并分析其与临床参数、预后,以及相互关系。结果 p53、mdm2、p63及EZH2蛋白在鼻咽癌的阳性表达率分别为31.9%,85.1%,95.7%;mdm2、EZH2与p53蛋白的表达无关,EZH2与p63蛋白的表达呈正相关,p53与p63蛋白的表达呈正相关;EZH2和p63蛋白的高表达与T分期和临床分期的升高有关(P<0.05);EZH2蛋白的高表达组的五年无疾病生存率明显低于低表达组(P<0.05)。结论在鼻咽癌中mdm2的表达可能与p53蛋白失活的关系不大,p63蛋白的过表达可能与p53蛋白的失活有关,EZH2的过表达与鼻咽癌的进展及不良预后有关。

Objective To investigate the relationship between the expressions of p53 pathway genes and EZH2 in nasopharyngeal carcinoma （NPC）. Methods The expression levels of p53, mdm2, p63 and EZH2 proteins were detected by immunohistochemistry in 47 cases of undifferentiated NPC and 12 cases of chronic nasopharyngitis, and their correlation to the clinical parameters and prognosis were analyzed. Results The protein expressions of p53, mdm2, p63 and EZH2 in NPC were 31.9%, 85.1%, and 95.7%, respectively. mdm2 and EZH2 was not correlated to p53 protein expression （P〉0.05）; positive correlations was found between EZH2 and p63 expressions and between p53 and p63. The high expression of EZH2 and p63 proteins was correlated to advanced T stage and clinical stage of NPC （P〈0.05）. The five-year disease-free survival rate in patients with high EZH2 protein expression was significantly lower than that in patients with low EZH2 expression. Conclusions mdm2 does not show an obvious correlation to p53 protein inactivation in NPC. p63 protein overexpression may be associated with p53 protein inactivation. The overexpression of EZH2 is correlated to NPC progression and poor prognosis