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Characterization of centromere alterations in liposarcomas
Author(s) -
Sirvent Nicolas,
Forus Anne,
Lescaut Willy,
Burel Fanny,
Benzaken Sylvia,
Chazal Maurice,
Bourgeon André,
Vermeesch Joris R.,
Myklebost Ola,
TurcCarel Claude,
Ayraud Noël,
Coindre JeanMichel,
Pedeutour Florence
Publication year - 2000
Publication title -
genes, chromosomes and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.754
H-Index - 119
eISSN - 1098-2264
pISSN - 1045-2257
DOI - 10.1002/1098-2264(2000)9999:9999<::aid-gcc1014>3.0.co;2-q
Subject(s) - centromere , biology , marker chromosome , small supernumerary marker chromosome , chromosome , karyotype , b chromosome , genetics , cytogenetics , supernumerary , microbiology and biotechnology , gene , anatomy
Supernumerary ring and large marker chromosomes are a characteristic of atypical lipomas and well‐differentiated liposarcomas (ALP‐WDLPS) and are composed of amplified 12q14–15 sequences in association with variable segments from other chromosomes. Although stably transmitted, these chromosomes contain centromeric alterations, showing no detectable alpha‐satellite sequences. We performed C‐banding, fluorescence in situ hybridization, and immunostaining with anti‐centromere antibodies in 8 cases of liposarcomas with supernumerary rings and large markers, including 5 ALP‐WDLPS and 3 dedifferentiated‐LPS and high‐grade LPS. Our results with alpha‐satellite probes and anti‐CENPB antibodies confirm the lack of detectable alpha‐satellite sequences in the five ALP‐WDLPS supernumerary chromosomes, whereas centromeric activity was proved by the detection of kinetochores by using anti‐CENPC antibodies. In contrast, the high grade and dedifferentiated liposarcomas showed a different pattern. In 2 cases, amplified chromosome 12 sequences, including amplification of alpha‐satellite 12 sequences in 1 case, were present on chromosomes with typical centromeres. In another case, the rings were similar to WDLPS‐ALP rings, but a large marker contained a chromosome 5 centromere and amplified alpha‐satellite sequences from chromosome 8. ALP‐WDLPS is the first example of a tumor class for which the presence of stable analphoid chromosomes is a constant and specific abnormality. Formation of newly derived centromeres, so‐called neocentromeres, could be an original and effective way to maintain a selective advantage in neoplastic cells by conferring stability to the supernumerary chromosomes of ALP‐WDLPS. The activation of normally non‐centromeric sequences might be obtained by an epigenetic mechanism due to the peculiar chromatin conformation of these highly complex chromosomes. © 2000 Wiley‐Liss, Inc.