[Mutation of p53 gene in esophageal precancerous cells]

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.

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.

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.

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.