A nude mouse Wilms' tumor line (KCMC-WT-1) derived from an aniridia patient with monoalleleic partial deletion of chromosome 11p

Abstract

BACKGROUND. A candidate tumor suppressor gene, WT-1, is believed to have an important role in the pathogenesis of Wilm's tumor, especially that occurring in patients with congenital aniridia. METHODS. To obtain a stable tumor line to work with, Wilms' tumor tissue was serially transplanted in athymic nude mice. Biopsied Wilm's tumor tissue, derived from an aniridia patient, was transplanted subcutaneously to an athymic nude mouse, and then transplanted serially. Histopathologic and molecular biologic studies were performed on the xenotransplants. RESULTS. The aniridia patients showed partial deletion in one short arm of chromosome 11, which bears the WT-1 gene. The tumor was successfully transplanted in the nude mouse. Although the tumor contained blastemic, organoid, and stromal histologic elements, the organoid element began to decrease after more than 20 passages. Cytogenetic analysis revealed an additional abbreviations of one long arm of chromosome 6. Dot blot analysis showed that the copy number of WT-1 gene was decreased to half the amount in the tumor, in spite of the WT-1 transcript with normal size detected by Northern blotting. CONCLUSIONS. The tumor is expected to bear one WT-1 gene with minute abnormalities as well as one congenitally deleted gene. This tumor line is useful when examining the effect caused by introduction of WT-1 gene to Wilm's tumor in vivo.