Frequent loss of copy number on the long arm of chromosome 21 in human esophageal squamous cell carcinoma

To understand the molecular pathogenesis of human esophageal cancer, we performed a comparative genomic hybridization (CGH) analysis using 10 esophageal squamous cell carcinomas. Frequent gains of Iq, 3q, 7p, 7q, 8q, 11q, and 20q and losses of 3p, 4p, 4q, 5q, 9p, 11p, 11q, 13q, 18q, 21q, and Y were observed. Among these regions, 21q has not yet been investigated in detail. We performed an allelotype study using 55 squamous cell carcinomas of the esophagus and 20 microsatellite markers on 21q and found LOH in 36 cases (65%): 22 (61%) of 36 cases with LOH indicated allelic loss in all informative loci, suggesting loss of the whole chromosome arm 21q, and five smallest regions of overlap were found. Our present results suggest the existence of a tumor suppressor gene(s) that plays a role in the genesis of squamous cell carcinoma of the esophagus.