原发性肝癌拓扑异构酶Ⅱα的表达及其与P53基因突变之间的关系

STUDY ON EXPRESSION OF TOPOISOMERASE Ⅱα IN PRIMARY HEPATOCARCINOMA TISSUES AND ITS RELATIONSHIP WITH p53 GENE MUTATION

目的研究原发性肝癌拓扑异构酶Ⅱα(Topoisom eraseⅡ,αToPoⅡα)的表达及临床意义,并探讨其与p53基因突变之间的关系。方法免疫组织化学法和W estern B lotting方法检测57例未经化疗过的原发性肝癌肿瘤组织和32例肝硬化组织ToPoⅡα蛋白的表达,并用聚合酶链反应-单链构象多态性(PCR-SSCP)分析p53基因7、8外显子的突变。结果To-PoⅡα蛋白在肝癌组织中阳性率为87.7%(50/57),在肝硬化组织中阳性率为50%(16/32),两者有显著差异(P<0.05)。蛋白印迹结果显示肝癌组织中ToPoⅡα蛋白表达显著高于肝硬化组织(P<0.05),高分化肿瘤与中、低分化的肿瘤组织之间有显著差异(P<0.05),有转移的病人高于无转移者(P<0.05).等级相关分析显示ToPoⅡα蛋白的表达与p53基因突变呈正相关(r=0.914,P=0.001)。p53基因突变组ToPoⅡ蛋白的表达显著高于野生型组(P<0.01)。结论ToPoⅡα的检测可作为肝癌分化程度的特异指标,同时p53基因突变可能诱导ToPoⅡα蛋白的表达。

Objective To investigate the expression and clinical significance of Topoisomerase Ⅱα protein in hepatocellular carcinoma （HCC） tissues and its relationship with p53 gene mutation. Methods Immunohistochemistry （IHC） and Western blotting technique were used to detect the expression of the Topeisomerase Ⅱαprotein in HCC tissues,cirrhosis of liver tissues which were not treated with preoperative chemotherapy from 57 and 32 patients respectively. Their relations with clinical pathology characters were analysed and polymerase chain reaction single strand conformation polymorphism （PCR-SSCP）was performed to investigate mutations of p53 Gene. Results The positive rate of Topoisomerase Ⅱαexpression in HCC tissues was 87.7% ,which was significantly higher than that in liver cirrhosis tissues of 50% （P 〈 0. 001 ） . The results from Western blotting was in accordance to that by IHC. In addition, Topoisomerase Ⅱα overexpression in HCC tissues was significantly different between well differentiated tumors and moderately differentiated tumors,poorly differentiated tumors（P 〈 0. 05 ） . With respect to the clinical character , Topoisomerase Ⅱα overexpression in HCC tissues with metastasis was higher than that in HCC tissues with nonmetastasis and postive correlation was found between ToPo Ⅱαoverexpression and p53 gene mutation （ Spearman＇s r = 0. 914 , P = 0. 001 ） . Furthermore, the expression of ToPo Ⅱαin HCC tissues with mutant p53 gene was higher than that in wild-type p53 gene （ P 〈 0. 05 ） . Conclusion The detection of Topoisomerase Ⅱα expression can be used an indicator for predicting proliferative behavior of HCC, and the overexpression of ToPo Ⅱαmay be induceded by mutant p53.