中国南北方食管癌患者中 p53基因外显子突变谱的差异研究

摘要

目的：探讨南北方食管癌患者中抑癌基因p53全部编码外显子基因突变谱的差异。方法各选取揭阳居民食管癌患者42例，佛山患者52例，常规提取DNA， PCR扩增p53第2-11外显子全部编码区和附近的一部分非编码区，扩增产物用DHPLC进行突变的筛查。筛查出的突变样本进行DNA纯化测序分析，测序结果在NCBI网站进行p53突变位点的比对和定位。结果高、低发区组中p53至少有1个外显子基因突变的突变率分别为63．8％（28／42）和61．5％（32／52），两者比较差异无统计学意义（P＝0．607＞0．05）； p53有2个外显子基因突变的突变率分别为14．3％（6／42）和15．4％（8／52），两者比较差异也无统计学意义（P＝0．881＞0．05）。结论高低发区间可能具有相似的环境致癌物质，通过相同的p53基因突变机制导致了两地食管癌的发生。%Objective To compare the mutation spectrum of p53 coding exons in esophageal carcinomas in southern and northern China by denaturing high performance liquid chromatography( DHPLC) .Methods 42 and 52 cases of esophageal carci-nomas were respectively collected from the high and low risk areas in southern China.The 2-11 coding exons of p53 ( including all coding area and part of non-coding area) were amplifyied by PCR after DNA routine extraction.DHPLC was processesd for mutation screening of the products after PCR.Then those with mutations were purified and sequenced of their DNAs.The results were compared with the sequence of wild p53 on NCBI website.The locations of the mutations were confirmed.Information was ob-tained of the p53 mutations spectrum in the patients from the high and low risk areas.Results In the high risk area group,28 specimens were found with at least 1 coding exon mutations,the p53 mutation rate was 63.8%(28/42);In the low risk area group,32 pecimens were found with at least 1 coding exon mutations,the p53 mutation rate was 61.5%(32/52),the difference had no statistic significance between the 2 groups(P=0.881>0.05).Conclusion Low and high risk areas may have a similar range of environmental carcinogens,through the same mechanism of p53 gene mutation leads to the occurrence of esophageal canc-er.