Breakpoints and Recipient Chromosomes in Pleomorphic Adenomas, Lipomas, and Uterine Leiomyomas — What Do They Tell Us?

Abstract

It has now been well documented that several tumors of epithelial and mesenchymal origin have typical or even specific chromosomal alterations involving 12q13–15. The currently best investigated examples are pleomorphic adenomas (Mark et al. 1980, 1988; Bullerdiek et al. 1987a,b), lipomas (Heim et al. 1986; Turc-Carel et al. 1986a; Mandahl et al. 1988), myxoid liposarcomas (Turc-Carel et al. 1986b), and uterine leiomyomas (Heim et al. 1988; Turc-Carel et al. 1988; Vanni and Lecca 1988). Similar results have recently been obtained from other benign tumors, e.g., cervical polyps (Vanni et al. 1993) or epithelial hyperplasia of the breast (Rohen et al. 1993). For the group of pleomorphic adenomas, lipomas, myxoid liposarcomas, and uterine leiomyomas, Schoenmakers et al. (1993) were able to show that the specific breakpoints in all tumors mentioned above fell within the 7cM region between loci D12S19 and D12S8. Other chapters of this book have dealt with details of the cytogenetic findings in these tumors. Usually, the aberrations of chromosomal region 12q13–15 are the only karyotypic abnormality, thus indicating that a causal relationship between the cytogenetic changes and tumorigenesis exists. However, up to now the molecular analysis of the mechanisms underlying the chromosomal alterations has remained open and can be expected to fully elucidate as to how these changes contribute to tumorigenesis.