P27^(kip1)在肾癌中的表达及临床意义

Expression of P27^(kip1) in renal cell carcinoma and its clinical significance

目的检测细胞周期素依赖性蛋白激酶抑制蛋白p27kip1在肾癌中的表达及临床意义。方法采用基于组织芯片的免疫组化方法、Westernblotting及RT-PCR检测80例肾癌组织、40例配对的癌旁肾组织及786-0细胞系中p27kip1蛋白及mRNA的表达情况,观察其表达与肿瘤临床参数之间的关系,并对3种检测方式(免疫组织化学、Westernblotting及RT-PCR)在p27kip1基因及蛋白水平上的检测结果进行分析和评价。结果免疫组化及Westernblotting检测显示,p27kip1蛋白主要在细胞核中表达,肾癌组表达率明显低于正常组(P<0.05),且在肿瘤不同的临床分期及病理分级间的表达有显著差异(P<0.05);p27kip1mRNA的表达在正常组织和肾癌组织中无明显差异。Westernblotting与免疫组化法检测蛋白表达有较一致的效果。结论正常肾组织与肾癌组织之间p27kip1的基因水平并无差异,而肾癌中p27kip1蛋白阳性表达率低于正常肾组织,其表达的调控可能是基于翻译阶段的蛋白降解。p27kip1低表达可能促进肿瘤的演进与发展。检测p27kip1蛋白可能成为评价肾癌预后的参考指标,为肾癌诊治的研究提供了新的思路。

Objective To investigate the expression of cyclin-dependent kinase inhibitor p27kip1 in renal cell carcinoma and its clinical significance. Methods The expressions of p27kip1 mRNA and protein were evaluated using reverse transcription polymerase chain reaction （RT-PCR）, Western blotting and immunohistochemistry with tissue chip technique in renal cell carcinoma （RCC） tissues, adjacent tissues and 786-0 cell line. The relationship between the expression of p27kip1 and the tumor size, the clinical stage, pathological type and stage were evaluated, and the results by the 3 methods were analyzed to evaluate the relationship between the mRNA and protein of p27kip1. Results The expression of p27kip1 protein （detected by immunohistochemistary and Western blotting） in RCC tissue was significantly lower than that in the adjacent normal tissues （P〈0.05）. The expression of p27kip1 mRNA （by RT-PCR） showed no significant difference between the two groups. p27kip1 protein expression was found to be inversely correlated to the tumor grade and clinical stage （P〈0.05）. Western blotting and immunohistochemistary showed a high coincidence rate in the detection of P27kip1 protein expression in RCC samples （P〈0.001, K=0.828）. Conclusion p27kip1 mRNA expression shows no difference between RCC and normal tissues, while the protein expression is significantly lower in the cancer tissues, suggesting a regulatory mechanism of p27kip1 expression at the transcriptional level. Low expression of p27kip1 protein may promote the development and progression of RCC. p27kip1 protein may serve as a diagnostic and prognostic marker of RCC.