p53基因突变与食管贲门多源癌的相关性

Relationship between p53 gene mutation and the concurrent cancers of the esophagus and gastric cardia

目的 探讨食管贲门双源癌组织 p5 3基因突变的特征及其与 p5 3蛋白表达的关系。 方法 采用显微切割、PCR、DNA测序和免疫组化ABC法 ,分析 4例食管贲门多源癌p5 3基因突变和蛋白表达状况。结果 4例食管贲门双源癌中 ,1例食管鳞癌和贲门腺癌同时发生 p5 3基因突变 ,并均发生第 7外显子 2 31、2 32密码子的点突变和 2 2 5、2 32～ 2 33、2 34密码子的缺失 /插入改变。食管鳞癌p5 3基因突变率为 5 0 %(2 /4 ) ,贲门腺癌为 75 %(3/4 )。所有检测到的突变均发生在第 7和 8外显子。食管癌和贲门癌分别有 1例 p5 3蛋白阴性表达的患者检测到p5 3基因突变 ,食管癌中 1例 p5 3蛋白阳性表达患者未检测到基因突变。结论 同一个体食管鳞癌和贲门腺癌组织同时发生相似位点的 p5 3基因突变 ,提示二者具有相似的发病因素和分子机制 ,为进一步揭示林州地区相似的食管 /贲门癌区域分布特征提供了重要的理论依据和线索。

Purpose To investigate the characteristic of p53 gene mutation and protein expression in the concurrent cancers of the esophagus and gastric cardia in the same patients (CC). Methods Microdissection?PCR and DNA sequencing were applied to analyze p53 gene mutation in exon 5～8 of 4 CC patients. Immunohistochemistry (ABC) method was undertaken to determine the expression of p53 proteins. Results Of the 4 CC patients analyzed, there were one which showed consistent p53 gene mutation both in SCC and GCA, and all the mutations occurred in codons 231,232 and deletion/ insertion in codons 225,232～233,234. In SCC and GCA, the frequency of p53 gene mutation were 50%(2/4)and 75%(3/4), respectively, and mutation clustered in exon 7 and exon 8 only. Conclusions The similar p53 gene mutation patterns in SCC and GCA from the same patient provide important molecular basis and etiological clue for similar geographic distribution and risk factors of SCC and GCA.