DELETION AND TRANSLOCATION INVOLVING CHROMOSOME 3(P14) IN 2 TUMORIGENIC KAPOSIS-SARCOMA CELL-LINES

Background: Two neoplastic Kaposi's sarcoma (KS) cell lines, KS Y-1 (d erived from a patient with KS associated with acquired immunodeficienc y syndrome) and KS SLK (derived from an immunosuppressed patient with a renal transplant and KS or iatrogenic KS), have been shown to have a bnormal chromosome constitution and to require no exogenous growth fac tors. They produce malignant tumors in immunodeficient mice. In contra st, all other cell cultures prepared in the past from KS specimens hav e been shown to have normal diploid characteristics, are hyperplastic, and depend on cytokines for growth, but they do not produce malignant tumors in immunodeficient mice. Purpose: We investigated whether the chromosomal changes that occurred in these KS cell lines were random o r nonrandom and if such changes contribute to the pathogenesis of KS. Methods: We used the conventional G-banding technique and fluorescence in situ hybridization to identify structural and numerical chromosoma l changes in the KS cell lines. Results: We demonstrated that both cel l lines are aneuploid and have some additional features in common, i.e ., loss of copies of chromosomes 14 and 21 and nonrandom translocation s and deletions in the short arm of chromosome 3 at region 3p14. These KS cell lines also exhibit loss of heterozygosity of loci at region 3 p14-ter. Conclusion: This is the first time nonrandom chromosomal alte rations have been described in KS neoplastic cells. On the basis of in formation available on other cancers, the chromosome 3 alterations obs erved here can be expected to contribute to the neoplastic process in KS. Implications: Future research should focus on the identification o f cytogenetic markers, thus facilitating generation of specific molecu lar probes for detecting neoplastic cells early in the disease process .