Mapping of a new target region of allelic loss at 21q22 in primary gastriccancers

To determine the minimal region of deletion on 21q22 in gastric cancer, we performed a high-density loss of heterozygosity (LOH) study with eight poly morphic microsatellite markers. Among the 43 tumors examined, 20 (50%) of 4 0 informative carcinomas showed LOH at one or more loci. The peak LOH frequ ency was identified at D21S1820 (34.2%) in 21q22.3. This data suggests that this locus might harbor a new tumor suppressor gene in an area <0.332 Mb i n physical map distance defined by D21S1820 and D21S49. Thus, we speculate that trefoil factor family 1 (TFF1), located in this narrow region, might b e the most probable candidate gene involved in gastric cancer carcinogenesi s. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.