| 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. |
- Mertens, Fredrik, et al.
(författare)
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Clinicopathologic and molecular genetic characterization of low-grade fibromyxoid sarcoma, and cloning of a novel FUS/CREB3L1 fusion gene
- 2005
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Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 85:3, s. 408-415
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Tidskriftsartikel (refereegranskat)abstract
- Low-grade fibromyxoid sarcoma (LGFMS) is an indolent, late-metastasizing malignant soft-tissue tumor that is often mistaken for either more benign or more malignant tumor types. Cytogenetic analyses have identified a recurrent balanced translocation t(7;16) (q32-34;p11), later shown by molecular genetic approaches to result in a FUS/CREB3L2 fusion gene. Whereas preliminary studies suggest that this gene rearrangement is specific for LGFMS, its incidence in this tumor type and the possible existence of variant fusion genes have not yet been addressed. For this purpose, a series of potential LGFMS were obtained from nine different soft-tissue tumor centres and subjected to molecular analysis as well as careful histopathologic review. Reverse transcriptase-polymerase chain reaction analysis disclosed a FUS/CREB3L2 fusion transcript in 22 of the 23 (96%) cases that remained classified as LGFMS after the histologic re-evaluation and from which RNA of sufficient quality could be extracted, whereas none of the cases that were classified as other tumor types was fusion-positive. In one of the tumors with typical LGFMS appearance, we found that FUS was fused to the CREB3L1 gene instead of CREB3L2. The proteins encoded by these genes both belong to the same basic leucine-zipper family of transcription factors, and display extensive sequence homology in their DNA-binding domains. Thus, it is expected that the novel FUS/CREB3L1 chimera will have a similar impact at the cellular level as the much more common FUS/CREB3L2 fusion protein. Taken together, the results indicate that virtually all LGFMS are characterized by a chimeric FUS/CREB3L2 gene, and that rare cases may display a variant FUS/CREB3L1 fusion.
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| 4. |
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| 5. |
- Storlazzi, Tiziana, et al.
(författare)
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A novel fusion gene, SS18L1/SSX1, in synovial sarcoma
- 2003
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 37:2, s. 195-200
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Tidskriftsartikel (refereegranskat)abstract
- Synovial sarcoma is an aggressive soft tissue tumor that is characterized cytogenetically by the t(X;18)(p11;q11) translocation, resulting in fusion between the SS18 gene on chromosome 18 and one of the SSX genes on the X chromosome. The three fusion genes that have been detected thus far, SS18/SSX1, SS18/SSX2, and SS18/SSX4, account for more than 95% of the synovial sarcomas. Because SS18/SSX fusions do not seem to occur in other tumor types, and because synovial sarcomas may sometimes be difficult to distinguish from other spindle cell tumors, molecular genetic analysis has become established as an important diagnostic tool. Upon cytogenetic analysis of a soft-tissue tumor that showed classic synovial sarcoma morphology, we detected two supernumerary marker chromosomes but no rearrangement of chromosomes X or 18. By fluorescence in situ hybridization, the marker chromosomes were shown to contain material from chromosomes X and 20, including the SSX gene cluster on the X chromosome and the SS18L1 gene, which shows strong homology with the SS18 gene, on chromosome 20. Further RT-PCR analysis and sequencing of the amplified products revealed a novel SS18L1/SSX1 fusion transcript in which nucleotide 1216 (exon 10) of SS18L1 was fused in-frame with nucleotide 422 (exon 6) of SSX1. Thus, the existence of genetic heterogeneity has to be taken into account when RT-PCR is used for the diagnosis of synovial sarcoma.
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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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