P53 MUTATIONS IN ESOPHAGEAL TUMORS FROM HIGH-INCIDENCE AREAS OF CHINA

Carcinomas of the upper digestive tract (squamous-cell carcinoma of th e esophagus, adenocarcinoma of the cardia) from 24 patients residing i n Linxian (China) and near-by high-incidence areas were analyzed for m utations in exons 5-8 of the p53 tumor-suppressor gene. Mutations were identified by polymerase chain reaction amplification and direct sequ encing in 50% of the specimens. Eleven tumors harbored a single base-p air substitution leading to either an amino-acid substitution (8 tumor s) or a chain-termination signal (3 tumors), and one tumor revealed a 15-bp deletion in exon 7 with a silent base substitution adjacent to t he deletion site. Mutations occurred in all 4 exons examined, with a p reponderance in exon 5. Of the 6 mutations identified among the 14 ade nocarcinomas examined, 3 were G to T transversions, a mutation that ha s thus far been absent from reported mutations in Barrett's esophageal adenocarcinomas and dysplasias from patients residing in Europe and N orth America. (C) 1995 Wiley-Liss, Inc.