p53基因在大肠癌发生转移及预后过程中的动态变化(英文)

Dynamic changes in p53 gene during metastasis and prognosis of colorectal carcimona

背景:肿瘤相关基因在癌瘤发生、发展、转移及预后过程中的作用如何一直是医学界研究的难点。目的:了解变性梯度凝胶电泳(DGGE)和自动DNA序列分析方法检测肿瘤基因变异及p53基因、p53蛋白在大肠癌发生、转移过程中的动态变化,为大肠癌预后评估提供依据。设计:以组织标本为研究对象的单一样本研究。单位:一所军医大学医院肿瘤科。对象:收集1994-01/2000-12解放军第一军医大学南方医院住院治疗的41例因大肠癌接受大肠根治性切除并于手术后5个月至5年内因肝转移接受肝切除术患者的大肠癌原发灶及肝转移灶标本。方法:以DGGE及自动DNA序列分析法检测41例大肠癌原发病灶和肝转移灶p53外显子5～11的基因突变。以免疫组织化学方法检测p53蛋白表达。主要观察指标:①p53基因突变在DGGE中的检出情况及突变。②p53基因的序列分析。③p53免疫组织化学染色结果。结果:41例中24例有p53基因突变(62%),其中6例仅在肝转移灶发现p53基因突变,其余均为原发灶、转移灶有一致性的突变。另有3例原发灶即有p53基因突变的患者,在转移灶除保留原有突变外,还出现新增加的突变。在原发、转移灶同时有突变的16例中,14例呈现突变的p53碱基峰和正常峰之比在肝转移灶明显高于大肠癌原发灶(P<0.001)。p53免疫组织化学染色结果和DGGE,DNA序?

BACKGROUND:What role tumor related genes play in the process of tumor generation,development,metastasis and prognosis has always been a thorny issue in medical field? OBJECTIVE:To study the detection of gene mutation in tumor by denaturing gradient gel electrophoresis(DGGE) and automated DNA sequence analysis and the change of p53 gene and p53 protein during the development and metastasis of colorectal carcinoma so as to provide basis for evaluating the prognosis of colorectal carcinoma. DESIGN:Single sample study using the tissue specimen as subject. SETTING:Department of oncology in an affiliated hospital of a military medical university. PARTICIPANTS:We collected the primary focus and liver metastasis focus specimens from 41 patients with colon cancer who had hepatectomy because of liver metastasis 5 months to 5 years after radical operation for colon cancer.They were inpatients in Nanfang Hospital,First Military Medical University of Chinese PLA,from January 1994 to December 2000. METHODS:p53 gene(exons 5- 11) mutation of primary focus and liver metastasis focus specimens from 41 cases of colon cancer was examined by DGGE and automated DNA sequencing.Expression of p53 protein was detected by immunohistochemistry. MAIN OUTCOME MEASURES:① Detection of the mutation of p53 gene by DGGE;② Analysis of p53 gene sequence;③ Results of p53 immunohistochemical staining. RESULTS:p53 gene mutation was detected in exons 5- 9 in 24 out of 41 patients(62% ).Among them,6 patients had p53 mutation in liver metastasis.The others had consistent mutations in both primary colorectal and hepatic metastatic lesions.In addition,p53 mutation was also found in the metastatic lesion in three patients.Among the 16 cases of mutation in primary colorectal and hepatic metastatic lesions,14 cases showed that the ratio of p53 base peak to normal peak was significantly higher in hepatic metastatic lesions than in primary colorectal lesions(P< 0.001).Results of p53 immunohistochemical staining were highly consistent with those of DGGE and DNA sequence analysis.However,gene analysis detected focus with nonsense mutation while immunohistochemistry detected overexpression of p53 protein. CONCLUSION:p53 mutation,in patients with colorectal carcinoma followed by hepatic metastases,mostly originates from primary colorectal lesion and then is kept and metastasizes into hepatic cells. The amount of mutated p53 gene and the number of tumor cells containing p53 mutation are increased in hepatic metastatic lesion. P53 mutation is positively correlated with overexpression of p53 protein.