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HMGA2 and MDM2 expression in lipomatous tumors with partial, low-level amplification of sequences from the long arm of chromosome 12.

Mandahl, Nils LU ; Bartuma, Hammurabi LU ; Magnusson, Linda LU ; Isaksson, Margareth LU ; Macchia, Gemma and Mertens, Fredrik LU (2011) In Cancer genetics 204(10). p.550-556
Abstract
Ordinary lipomas are cytogenetically characterized primarily by simple balanced chromosome aberrations with stable morphologies, most of which affect chromosome segment, 12q13-15, where the HMGA2 gene plays a key pathogenetic role. Atypical lipomatous tumors (ALTs) display supernumerary ring or giant marker chromosomes with amplification of several genes including HMGA2 and MDM2. A study of HMGA2 expression in a variety of adipocytic tumors showed aberrant expression in lipomas with 12q13-15 aberrations and ring chromosomes as well as in ALTs and well-differentiated liposarcomas (WDLSs), and frequent differential expression of HMGA2 exons 1-2 versus that of exons 4-5. A minor subset of adipocytic tumors harbors unbalanced karyotypes with... (More)
Ordinary lipomas are cytogenetically characterized primarily by simple balanced chromosome aberrations with stable morphologies, most of which affect chromosome segment, 12q13-15, where the HMGA2 gene plays a key pathogenetic role. Atypical lipomatous tumors (ALTs) display supernumerary ring or giant marker chromosomes with amplification of several genes including HMGA2 and MDM2. A study of HMGA2 expression in a variety of adipocytic tumors showed aberrant expression in lipomas with 12q13-15 aberrations and ring chromosomes as well as in ALTs and well-differentiated liposarcomas (WDLSs), and frequent differential expression of HMGA2 exons 1-2 versus that of exons 4-5. A minor subset of adipocytic tumors harbors unbalanced karyotypes with extra copies of 12q sequences in structures that are not giant marker or ring chromosomes. Out of a series of ten such tumors, three lipomas and four ALTs with more than two copies of 12q13-15 and breakpoints in 12q13-15 could be analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) to find out whether HMGA2 and MDM2 expression was more similar to the levels seen in lipomas with cytogenetically balanced aberrations of 12q13-15, or to ALTs with giant ring or marker chromosomes. One of two ALTs with more complex, hyperdiploid karyotypes had expression levels closer to those seen in ALT, whereas the remaining six cases were similar to lipomas with 12q13-15 changes and ring chromosomes. Differential expression was seen in two ALTs and all three lipomas. Two cases showed MDM2 expression levels similar to those found among WDLSs, two cases showed levels similar to those found among lipomas, whereas the remaining three cases displayed intermediate expression levels. The studied cases represent intermediates between lipoma and ALT, insofar as they shared 12q13-15 rearrangements and karyotypic stability with lipomas and gain of 12q sequences with ALTs. Neither of these characteristics can be used to discriminate between lipoma and ALT. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Cancer genetics
volume
204
issue
10
pages
550 - 556
publisher
Elsevier
external identifiers
  • wos:000298068600004
  • pmid:22137485
  • scopus:84859230232
ISSN
2210-7762
DOI
10.1016/j.cancergen.2011.09.005
language
English
LU publication?
yes
id
61646f3e-44d6-4d7c-afa6-967956bfc659 (old id 2274611)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/22137485?dopt=Abstract
date added to LUP
2012-01-02 13:20:07
date last changed
2017-04-02 04:14:19
@article{61646f3e-44d6-4d7c-afa6-967956bfc659,
  abstract     = {Ordinary lipomas are cytogenetically characterized primarily by simple balanced chromosome aberrations with stable morphologies, most of which affect chromosome segment, 12q13-15, where the HMGA2 gene plays a key pathogenetic role. Atypical lipomatous tumors (ALTs) display supernumerary ring or giant marker chromosomes with amplification of several genes including HMGA2 and MDM2. A study of HMGA2 expression in a variety of adipocytic tumors showed aberrant expression in lipomas with 12q13-15 aberrations and ring chromosomes as well as in ALTs and well-differentiated liposarcomas (WDLSs), and frequent differential expression of HMGA2 exons 1-2 versus that of exons 4-5. A minor subset of adipocytic tumors harbors unbalanced karyotypes with extra copies of 12q sequences in structures that are not giant marker or ring chromosomes. Out of a series of ten such tumors, three lipomas and four ALTs with more than two copies of 12q13-15 and breakpoints in 12q13-15 could be analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) to find out whether HMGA2 and MDM2 expression was more similar to the levels seen in lipomas with cytogenetically balanced aberrations of 12q13-15, or to ALTs with giant ring or marker chromosomes. One of two ALTs with more complex, hyperdiploid karyotypes had expression levels closer to those seen in ALT, whereas the remaining six cases were similar to lipomas with 12q13-15 changes and ring chromosomes. Differential expression was seen in two ALTs and all three lipomas. Two cases showed MDM2 expression levels similar to those found among WDLSs, two cases showed levels similar to those found among lipomas, whereas the remaining three cases displayed intermediate expression levels. The studied cases represent intermediates between lipoma and ALT, insofar as they shared 12q13-15 rearrangements and karyotypic stability with lipomas and gain of 12q sequences with ALTs. Neither of these characteristics can be used to discriminate between lipoma and ALT.},
  author       = {Mandahl, Nils and Bartuma, Hammurabi and Magnusson, Linda and Isaksson, Margareth and Macchia, Gemma and Mertens, Fredrik},
  issn         = {2210-7762},
  language     = {eng},
  number       = {10},
  pages        = {550--556},
  publisher    = {Elsevier},
  series       = {Cancer genetics},
  title        = {HMGA2 and MDM2 expression in lipomatous tumors with partial, low-level amplification of sequences from the long arm of chromosome 12.},
  url          = {http://dx.doi.org/10.1016/j.cancergen.2011.09.005},
  volume       = {204},
  year         = {2011},
}