| 1. |
- Bartuma, Hammurabi, et al.
(författare)
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Assessment of the clinical and molecular impact of different cytogenetic subgroups in a series of 272 lipomas with abnormal karyotype
- 2007
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 46:6, s. 594-606
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Dahlén, Anna, et al.
(författare)
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Clustering of deletions on chromosome 13 in benign and low-malignant lipomatous tumors
- 2003
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136. ; 103:5, s. 616-623
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Tidskriftsartikel (refereegranskat)abstract
- Deletions and structural rearrangements of the long arm of chromosome 13 are frequently observed in benign and low-malignant lipomatous tumors, but nothing is known about their molecular genetic consequences. We assessed the karyotypes of 40 new and 22 previously published cases (35 ordinary lipomas, 15 spindle cell/pleomorphic lipomas, 2 myxolipomas, 1 angiomyxolipoma and 9 atypical lipomatous tumors) with chromosome 13-abnormalities, and found bands 13q12-22 to be frequently affected. Twenty-seven cases with structural abnormalities within this region were selected for breakpoint and deletion mapping by metaphase fluorescence in situ hybridization (FISH), using a set of 20 probes. Deletions were found in 23 of 27 cases. The remaining 4 cases had seemingly balanced rearrangements. The breakpoints were scattered but clustered to band 13q14, and in all cases with unbalanced abnormalities, a limited region within band 13q14 was partially or completely deleted. A deletion within band 13q14 was found together with a breakpoint on the other homologue in 5 cases, 4 of which could be tested further with regard to the status of the retinoblastoma (RB1)-gene. In all 4 cases, only 1 copy of the gene was deleted. In addition to the breaks and deletions in the vicinity of the RB1-locus, several other regions of 13q were recurrently affected, e.g., in the vicinity of the hereditary breast cancer (BRCA2; 13q12)- and lipoma HMGIC fusion partner (LHFP; 13q13)- genes. Our findings strongly indicate that deletion of a limited region (approximately 2.5 Mbp) within 13q14, distal to the RB1-locus, is of importance in the development of a subset of lipomatous tumors.
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| 3. |
- Hallor, Karolin H, et al.
(författare)
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Genomic profiling of chondrosarcoma: chromosomal patterns in central and peripheral tumors.
- 2009
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 15:8, s. 2685-2694
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Histologic grade is currently the best predictor of clinical course in chondrosarcoma patients. Grading suffers, however, from extensive interobserver variability and new objective markers are needed. Hence, we have investigated DNA copy numbers in chondrosarcomas with the purpose of identifying markers useful for prognosis and subclassification. EXPERIMENTAL DESIGN: The overall pattern of genomic imbalances was assessed in a series of 67 chondrosarcomas using array comparative genomic hybridization. Statistical analyses were applied to evaluate the significance of alterations detected in subgroups based on clinical data, morphology, grade, tumor size, and karyotypic features. Also, the global gene expression profiles were obtained in a subset of the tumors. RESULTS: Genomic imbalances, in most tumors affecting large regions of the genome, were found in 90% of the cases. Several apparently distinctive aberrations affecting conventional central and peripheral tumors, respectively, were identified. Although rare, recurrent amplifications were found at 8q24.21-q24.22 and 11q22.1-q22.3, and homozygous deletions of loci previously implicated in chondrosarcoma development affected the CDKN2A, EXT1, and EXT2 genes. The chromosomal imbalances in two distinct groups of predominantly near-haploid and near-triploid tumors, respectively, support the notion that polyploidization of an initially hyperhaploid/hypodiploid cell population is a common mechanism of chondrosarcoma progression. Increasing patient age as well as tumor grade were associated with adverse outcome, but no copy number imbalance affected metastasis development or tumor-associated death. CONCLUSION: Despite similarities in the overall genomic patterns, the present findings suggest that some regions are specifically altered in conventional central and peripheral tumors, respectively.
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| 4. |
- Mandahl, Nils, et al.
(författare)
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Cytogenetic aberrations and their prognostic impact in chondrosarcoma
- 2002
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257. ; 33:2, s. 188-200
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Tidskriftsartikel (refereegranskat)abstract
- Chondrosarcoma is the second most common primary malignancy of bone. Cytogenetic data are available from close to 100 cases, including all subtypes of chondrosarcoma. Specific chromosomal rearrangements have been identified only in extraskeletal myxoid chondrosarcoma (EMC). Strong prognostic factors are largely missing, although size and, in particular, histologic tumor grade have been implicated. In the present study, we investigated the genomic aberrations in 59 chondrosarcomas (six grade 1, 24 grade 2, and 29 grade 3, including dedifferentiated tumors), excluding EMC, by chromosome banding analysis and DNA flow cytometry and correlated the findings with clinical outcome. Hyperhaploid to near-diploid karyotypes were found in half of the cases, and there was a good correlation between cytogenetics and flow cytometry data; discrepancies were seen primarily in cases with normal karyotypes and in those with -Y as the sole anomaly. Abnormal karyotypes, excluding those with -Y as the only change, were found in 36 cases. No recurrent structural aberration was found, but a nonrandom pattern of aberrations was seen. Total or partial gains and losses were the dominant karyotypic features. Genomic imbalances found in at least 10 cases included -1p36, -1p13-p22, -4, -5q13-q31, -6q22-qter, +7p13-pter, -9p22-pter, -10p, -10q24-qter, -11p13-pter, -11q25, +12q15-qter, -13q21-qter, -14q24-qter, -18p, -18q22-qter, +19, +20pter-q11, +21q, and -22q13. At the latest follow-up, 19 patients had experienced distant metastases, and the 5-year metastasis-free survival rate was 0.69. By univariate analysis, malignancy grade and loss of material from 6q, 10p, 11p or 11q, 13q, and 22q were associated with impaired metastasis-free survival. Only -13q was an independent prognostic factor for metastasis, regardless of tumor grade or size.
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| 5. |
- Mertens, Fredrik, et al.
(författare)
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Prognostic significance of chromosome aberrations in high-grade soft tissue sarcomas
- 2006
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Ingår i: Journal of Clinical Oncology. - 1527-7755. ; 24:2, s. 315-320
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To investigate whether previously observed correlations between tumor karyotype and risk of metastases could be reproduced in an independent set of high-grade soft tissue sarcomas (STSs). Patients and Methods In a previous study on high-grade STSs with clonal chromosome aberrations, we identified a number of cytogenetic variables, besides tumor grade and size, that were associated with significantly increased risk of metastases. In the present study, we have tested the predictive value of these cytogenetic variables in a new set of 156 high-grade STSs, all located in the extremities or trunk wall. Results Of the 10 cytogenetic variables that turned out to provide prognostic information in the previous series, encompassing 122 trunk wall or extremity STSs, three were significantly associated with metastases also in the new series. In a final Cox regression analysis including these three cytogenetic variables, as well as tumor grade and size, on the combined series of 278 high-grade STSs, four parameters were found to be significantly associated with metastasis risk: tumor grade 3, tumor size >= 5 cm, breakpoint in region 1p1, and gain of region 6p1. Conclusion Our findings suggest that independent prognostic information may be gained from cytogenetic analysis of high-grade STS.
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| 6. |
- Walther, Charles, et al.
(författare)
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Cytogenetic and single nucleotide polymorphism array findings in soft tissue tumors in infants
- 2013
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Ingår i: Cancer Genetics. - : Elsevier BV. - 2210-7762. ; 206:7-8, s. 299-303
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Tidskriftsartikel (refereegranskat)abstract
- Soft tissue tumors in children under one year of age (infants) are rare. The etiology is usually unknown, with external factors or congenital birth defects and hereditary syndromes being recognized in only a small proportion of the cases. We ascertained the cytogenetic findings in 16 infants from whom tumor tissue had been obtained during a 25-year period. In eight of them, single nucleotide polymorphism (SNP) array analyses could also be performed. No constitutional chromosome aberrations were detected, and assessment of clinical files did not reveal any congenital or later anatomical defects. Three tumors--one infantile fibrosarcoma, one embryonal rhabdomyosarcoma, and one angiomatoid fibrous histiocytoma (AFH)--had abnormal karyotypes. As the AFH had an exchange between chromosome arms 12p and 15q, additional fluorescence in situ hybridization and reverse transcription-polymerase chain reaction analyses were performed, unexpectedly revealing an ETV6/NTRK3 fusion. Three of the eight tumors, including the AFH with an abnormal karyotype, analyzed by SNP array showed aberrations (loss of heterozygosity or imbalances). The present series suggests that the addition of array-based technologies is valuable for detecting underlying pathogenetic mechanisms.
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