食管上皮癌前期病变细胞p53基因的突变

目的 比较p53基因的突变在食管癌前期病变和正常食管上皮中的差异，了解癌前期病变细胞中p53基因的突变与癌变的关系。方法 应用PCR－SSCP方法和PCR－RFLP方法对四川盐亭县1982年施行食管癌普查的食管拉网脱落细胞，进行p53基因第5外显子及第7外显子的突变检测。结果 48例标本p53基因检测均得成功；食管上皮重度不典型增生细胞中发现有5例突变发生均为p53基因第7外显子，而第5外显子未发现突变。检测到的5例突变中，有3例分别在为查后10年，12年和14年后转变为食管癌。正常食管上皮拉网脱落细胞中均未发现突变。结论 p53基因保持正常状态是食管上皮维持正常的前提条件；p53基因的突变歙良管上皮癌前期病变细胞具有了癌变趋势。

Mutation of p53 Gene in Esophageal Precancerous Cells

Objective To make a comparison of gene mutation between precancerous lesions and normal esophageal epicytes and investigate the correlation between p53 gene mutation of precancerous lesions and esophagus carcinogenesis. Methods We made use of forty eight samples (24 normal squamous epithelia and 24 squamous severe dysplasia) obtained by balloon cytologic evidence in 1982 from a high incidence area, Yanting County of Sichuan Province, China. The 5th and 7th exons of p53 gene mutation were analyzed by single strand conformation polymorphism method and restriction fragment length polymorphism method. Results p53 gene was successfully checked and measured in all samples. Mutation was noted in exon 7 of p53 gene in 5 cases, but it was not found in exon 5. No mutation was detected in normal exfoliative epicytes. In 3 out of the 5 mutation cases, there were evidences for carcinogenesis in 1992, 1994 and 1996 respectively. Conclusion The normal state of p53 gene is a prerequisite condition to the maintaining of normal squamous epithelia. Carcinogenesis dominates over the precancerous lesions due to p53 gene mutation.