Description
The aim of this study is to generate and validate biomarkers to stratify patients with Barretts esophagus in terms of risk for developing cancer. We studied gene expression profiling in 69 frozen specimens, consisting of esophageal squamous epithelium from 19 healthy subjects, 20 specimens from patients with Barretts esophagus and 21 cases of esophageal adenocarcinoma, 9 cased of esophageal squamous cell carcinoma by whole genome microarray analysis. Laser capture microdissection technique was applied to procure cells from defined regions of Barretts esophagus metaplasia and esophageal adenocarcinoma. Microarray results were validated by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent cohort consisting of 42 cases. Furthermore, immunohistochemistry was performed using antibodies to two selected target molecules on a third independent cohort of 36 specimens, consisting of 36 cases. A total of 1176 genes were associated significantly with esophageal adenocarcinoma. The expression pattern of a 4 gene signature with the highest discriminant score based on linear discriminant analysis (GeneSpring GX10.2), was identified and validated by qRT-PCR in independent cohort.