ALLELOTYPE ANALYSIS OF ESOPHAGEAL ADENOCARCINOMAS - EVIDENCE FOR THE INVOLVEMENT OF SEQUENCES ON THE LONG ARM OF CHROMOSOME-4

The incidence of esophageal adenocarcinoma has increased dramatically over the past 20 years. The causes for this change in incidence and th e genetic defects that underlie tumorigenesis are unknown. We performe d loss of heterozygosity (LOH) studies in esophageal adenocarcinomas i n an effort to map the location of tumor suppressor genes involved in the initiation or progression of this cancer. A genome-wide search for LOH was undertaken using microsatellite repeat polymorphisms and a pa nel of 27 tumor and matched normal DNAs. This is the first report of a n allelotype analysis of esophageal adenocarcinomas. We observed frequ ent loss of sequences on the short arm of chromosome 17 in the region of the TP53 gene. We also identified a region on 4q lost in more than half of the tumors investigated. The high rate of LOH for 4q sequences speaks to the involvement of an as yet unidentified tumor suppressor gene in esophageal adenocarcinoma tumorigenesis.