COMMONLY DELETED REGIONS ON THE LONG ARM OF CHROMOSOME-21 IN DIFFERENTIATED ADENOCARCINOMA OF THE STOMACH

During an allelotype analysis of differentiated adenocarcinoma of the stomach, we observed frequent loss of heterozygosity (LOH) on several chromosomes including the long arm of chromosome 21 (21 q). Therefore, we analyzed DNA isolated from 45 tumors for LOH at 10 loci on 21 q by using polymorphic microsatellite markers. In 20 (44%) of 45 tumors, w e detected LOH at single or multiple loci on 21q. Deletion mapping of these 20 tumors revealed two separate commonly deleted regions. Our fi ndings suggest that 21 q contains at least two potential tumor suppres sor genes which play crucial roles in the development of differentiate d adenocarcinoma of the stomach. (C) 1997 Wiley-Liss, Inc.