Analysis of Loss of Heterozygosity (LOH) in Thorotrast-induced liver angiosarcoma

Abstract

Thorotrast is colloidal solution of natural alpha-emitter, thorium dioxide, which was used as a radiological contrast medium during World War II. Decades after injection, it caused hepatic tumors by local exposure to alpha-particles. Histological examination revealed that about 1/3 cases of Thorotrast-induced cancers consist of angiosarcoma (AS). In order to elucidate carcinogenic mechanisms of radiation-induced cancers, we performed genome wide scan of loss of heterozygosity (LOH) in Thorotrast-induced AS. As well as ICC, Thorotrast-induced AS showed more LOH frequency compared with non-Thorotrast cases. LOH frequency at loci common to liver cancer was low in AS. We found a Thorotrast-induced cancer specific locus on chromosome 8q. These indicate that LOH loci specific to the origin of cancer cells and Thorotrast-induced cancers exist, respectively. [J Radiat Res 44:397 (2003)]