Mutation analysis of PIK3CA and PIK3CB in esophageal cancer and Barrett's esophagus

Abstract

Mutation of PIK3CA, the gene coding for the p110alpha catalytic subunit of phosphoinositide 3-kinase (PI3K), has been reported in a limited range of human tumors. We now report that PIK3CA is also mutated in esophageal tumors. Single-strand conformational polymorphism (SSCP) and denaturing high-performance liquid chromatography (DHPLC) were used to screen all 20 exons of PIK3CA in 101 samples from 95 individuals with esophageal cancer and/or Barrett's esophagus. Somatic mutation of PIK3CA was detected in 4 of 35 (11.8%) of esophageal squamous cell carcinomas (SCC) and 3 of 50 (6%) adenocarcinomas. No mutations were detected in any of 17 samples of Barrett's esophagus. For PIK3CB, we screened..