| 1. |
- Gebre-Medhin, Samuel, et al.
(författare)
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Telomeric associations correlate with telomere length reduction and clonal chromosome aberrations in giant cell tumor of bone.
- 2009
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Ingår i: Cytogenetic and Genome Research. - : S. Karger AG. - 1424-859X .- 1424-8581. ; 124:2, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- Giant cell tumor of bone (GCTB) is characterized cytogenetically by frequent telomeric associations (tas). To explore the mechanisms behind the formation of tas in GCTB and to investigate their karyotypic consequences, the frequencies of tas and clonal aberrations other than tas in 20 GCTBs were compared to telomere length and status, as assessed by quantitative PCR, fluorescence in situ hybridization (FISH), and expression levels of four genes involved in telomere maintenance. Based on the G-banding results, the tumors were divided into two groups, one with a high frequency of tas and one with a low frequency. Clonal aberrations were found to be restricted to the group with a high level of tas, and the same group showed a significantly larger reduction in telomere length in tumor cells compared to peripheral blood cells. Furthermore, 65 out of 66 tas analyzed by FISH were negative for telomeric sequences. The expression levels of TERT, TERF1, TERF2, and POT1 did not correlate with telomere length or the frequency of tas. Thus, the present findings provide strong support for the notion that decreased telomere length is a prerequisite for tas in GCTBs and that the clonal changes occurring in GCTBs are derived from tas.
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| 2. |
- Gorunova, Ludmila, et al.
(författare)
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Cytogenetic Analysis of 101 Giant Cell Tumors of Bone: Nonrandom Patterns of Telomeric Associations and Other Structural Aberrations
- 2009
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 48:7, s. 583-602
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Tidskriftsartikel (refereegranskat)abstract
- Giant cell tumor of bone (GCTB) is a benign but locally aggressive tumor with metastatic potential. We performed cytogenetic analysis on 10 1 GCTB from 92 patients. Karyotypes were obtained from 95 tumors, 47 of which had clonal aberrations. The majority of the cytogenetically abnormal GCTB had multiple, up to 28 per tumor, clones. Clonal telomeric associations (tas) and other structural and numerical changes were found in about 70, 60, and 30%, respectively, of clonally abnormal tumors. Forty-seven aberrations were recurrent, of which 35 are novel. The vast majority of the recurrent aberrations were tas, confirming the important role of telomeric fusions in the development of GCTB. The frequency of tas in GCTB cultures increased with passaging, suggesting a selective advantage of tas-positive cells in vitro. The termini most frequently involved in tas were 22p, 13p, 15p, 21p, 14p, 19q, 1q, 12p, 11p, and 20q. The frequency of tas (irrespective of their clonality) was significantly higher in tumors carrying clonal changes, indicating that tas are precursors of other types of aberrations. In line with this assumption, the chromosomes preferentially involved in tas in a given tumor were also the ones most often affected by other rearrangements. We did not find the previously reported amplicon in 20q11.1, assessed by fluorescence in situ hybridization in 10 tumors. Nor did we find any association between cytogenetic features and adverse clinical outcome. Thus, local recurrences probably depend more on the adequacy of surgical treatment than on the intrinsic biology of the tumors. (C) 2009 Wiley-Liss, Inc.
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