Deletion and translocation involving chromosome 3(p14) in two tumorigenic Kaposi's sarcoma cell lines

Abstract

Background: Two neoplastic Kaposi's sarcoma (KS) cell lines, KS Y-1 (derived from a patient with KS associated with acquired immunodeficiency syndrome) and KS SLK (derived from an immunosuppressed patient with a renal transplant and KS or iatrogenic KS), have been shown to have abnormal chromosome constitution and to require no exogenous growth factors. They produce malignant tumors in immunodeficient mice. In contrast, all other cell cultures prepared in the past from KS specimens have 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 or 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 chromosomal changes in the KS cell lines. Results: We demonstrated that both cell lines are aneuploid and have some additional features in common, i.e., loss of copies of chromosomes 14 and 21 and nonrandom translocations 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 3p14-ter. Conclusion: This is the first time nonrandom chromosomal alterations have been described in KS neoplastic cells. On the basis of information available on other cancers, the chromosome 3 alterations observed here can be expected to contribute to the neoplastic process in KS. Implications: Future research should focus on the identification of cytogenetic markers, thus facilitating generation of specific molecular probes for detecting neoplastic cells early in the disease process.