High polymorphism in the trisomic portion of a gastric cancer cell line

BackgroundGenetic instability is a hallmark of malignancy, and microsatellite instability is a widely appreciated mechanism of generating genetic changes. We have recently observed four markers clustered on chromosome 20 that showed the effects of microsatellite instability in the gastric adenocarcinoma cell line SNU-1. Each affected marker had alleles of three different sizes. The aim of this study was to investigate the origin for this high-density polymorphism on a single chromosome.