Assessment of the clinical and molecular impact of different cytogenetic subgroups in a series of 272 lipomas with abnormal karyotype

• Published in: Genes chromosomes & cancer 2007-06, Vol.46 (6), p.594-606
• Main Authors: Bartuma, Hammurabi, Hallor, Karolin H., Panagopoulos, Ioannis, Collin, Anna, Rydholm, Anders, Gustafson, Pelle, Bauer, Henrik C. F., Brosjö, Otte, Domanski, Henryk A., Mandahl, Nils, Mertens, Fredrik
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Basic Medicine; Cancer and Oncology; Cancer och onkologi; Child; Child, Preschool; Chromosome Aberrations; Chromosomes, Human, Pair 13; Chromosomes, Human, Pair 13 - genetics; Clinical Medicine; Cohort Studies; Female; HMGA2 Protein; HMGA2 Protein - genetics; HMGA2 Protein - metabolism; Humans; In Situ Hybridization, Fluorescence; Infant; Infant, Newborn; Karyotyping; Karyotyping - methods; Klinisk medicin; Lipoma; Lipoma - genetics; Male; Medical and Health Sciences; Medical Genetics; Medicin och hälsovetenskap; Medicinsk genetik; Medicinska och farmaceutiska grundvetenskaper; Middle Aged; Neoplasms; Neoplasms - genetics; Research Support, Non-U.S. Gov't; Reverse Transcriptase Polymerase Chain Reaction; Soft Tissue Neoplasms; Soft Tissue Neoplasms - genetics
• ISSN: 1045-2257; 1098-2264
• DOI: 10.1002/gcc.20445

Conventional lipomas harbor karyotypic changes that could be subdivided into four, usually mutually exclusive, categories: rearrangement, in particular through translocations, of chromosome bands 12q13‐15, resulting in deregulation of the HMGA2 gene, loss of material from or rearrangement of chromosome 13, supernumerary ring or giant marker chromosomes, and aberrations of chromosome band 6p21. In the present study, 272 conventional lipomas, two‐thirds of them deep‐seated, with acquired clonal chromosome changes were assessed with regard to karyotypic and clinical features. A nonrandom distribution of breakpoints and imbalances could be confirmed, with 83% of the cases harboring one or more of the previously known cytogenetic hallmarks. Correlation with clinical features revealed that lipomas with rings/giant markers were larger, occurred in older patients, were more often deep‐seated, and seemed to have an increased tendency to recur locally, compared with tumors with other chromosome aberrations. The possible involvement of the HMGA2 gene in cases that did not show any of the characteristic cytogenetic changes was further evaluated by locus‐specific metaphase fluorescence in situ hybridization (FISH) and RT‐PCR, revealing infrequent cryptic disruption of the gene but abundant expression of full length or truncated transcripts. By FISH, we could also show that breakpoints in bands 10q22‐23 do not affect the MYST4 gene, whereas breakpoints in 6p21 or 8q11‐12 occasionally target the HMGA1 or PLAG1 genes, respectively, also in conventional lipomas. © 2007 Wiley‐Liss, Inc.