| 1. |
- Hallor, Karolin Hansén, et al.
(författare)
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Fusion of the EWSR1 and ATF1 genes without expression of the MITF-M transcript in angiomatoid fibrous histiocytoma
- 2005
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 44:1, s. 97-102
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Tidskriftsartikel (refereegranskat)abstract
- Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that usually occurs in children and young adults. Only two cases of AFH with genetic rearrangements have been reported previously; both of these had a FUS-ATF1 fusion gene. We have studied an AFH from a 9-year-old boy whose tumor displayed a t(12;22)(q13;q12) as the sole cytogenetic aberration. FISH,RT-PCR, and sequence analyses revealed an EWSR1-ATF1 fusion gene that has previously been reported in clear cell sarcoma (CCS), a soft tissue sarcoma that is morphologically and clinically distinct from AFH. This study thus has demonstrated that the EWSR1-ATF1 chimera represents a fusion gene that can be associated with different tumor types. Simultaneous expression of the EWSR1-ATF1 and MITF-M transcripts in CCS has led to the proposal that the MITF-M promoter is transactivated by EWSR1-ATF1. The AFH, however, did not express the MITF-M transcript, supporting the theory that MITF-M expression in CCS is a reflection of its cellular origin, rather than a consequence of the presence of an EWSR1-ATF1 fusion protein. Activation of the EWSR1-ATF1 oncogene is probably an early step in the transformation process, but the overall gene expression patterns are likely to vary considerably between AFH and CCS, in keeping with their clinicopathologic differences.
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| 2. |
- Impera, L., et al.
(författare)
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A novel fusion 5 ' AFF3/3 ' BCL2 originated from a t(2;18)(q11.2;q21.33) translocation in follicular lymphoma
- 2008
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 93, s. 27-27
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Tidskriftsartikel (refereegranskat)abstract
- Follicular lymphoma is the second most frequent type of non-Hodgkin's lymphoma in adults. The basic molecular defect consists of the t(14;18)(q32;q21) translocation, juxtaposing the B-cell lymphoma protein 2 gene BCL2 to the immunoglobulin heavy chain locus IGH@, and leading to the antiapoptotic BCL2 protein overproduction. Variations in the t(14;18) are rare and can be classified into two categories: (i) simple variants, involving chromosomes 18 and 2, or 22, in which the fusion partner of BCL2 is the light-chain IGK@ or IGL@; (ii) complex variant translocations occurring among chromosomes 14, 18 and other chromosomes. We report a follicular lymphoma case showing BCL2 overexpression, detected by immunohistochemistry and real-time quantitative PCR, consequently to the formation of a novel fusion gene between the 5' of the lymphoid nuclear transcriptional activator gene AFF3 at 2q11.2, and the 3' of BCL2. This case shows evidence, for the first time, of BCL2 overexpression consequently to the fusion of BCL2 to a non-IG partner locus.
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| 3. |
- 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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| 4. |
- Hansén Nord, Karolin, et al.
(författare)
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Fusion genes in angiomatoid fibrous histiocytoma
- 2007
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Ingår i: Cancer Letters. - : Elsevier BV. - 1872-7980 .- 0304-3835. ; 251:1, s. 158-163
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Tidskriftsartikel (refereegranskat)abstract
- Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of low malignant potential and uncertain differentiation. Only three genetically investigated cases of AFH have been reported. Two of them displayed a FUS-ATF1 fusion gene and one showed an EWSR1-ATF1 chimera. Using RT-PCR analysis, we have identified the EWSR1-ATF1 fusion transcript, and delineated the genomic breakpoints, in two new cases of AFH. Previously, the EWSR1-ATF1 fusion protein has been suggested to activate expression of the MITF-M transcript, and therefore the expression pattern of the MITF gene was studied. The MITF-M transcript was not detected in either AFH, in line with the finding that the co-activator SOX10 was not expressed. Thus, of the five AFH that have been molecularly analyzed to date, two have displayed a FUS-ATF1 fusion gene and three have shown an EWSR1-ATF1 chimera. There is no apparent correlation between the type of fusion gene and clinicopathologic features. Nonetheless, RT-PCR for these fusion transcripts remains a valuable diagnostic adjunct in the distinction between AFH and other soft tissue tumors or metastases that may simulate it.
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| 5. |
- 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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| 6. |
- Möller, Emely, et al.
(författare)
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Bidirectionality and transcriptional activity of the EWSR1 promoter region
- 2009
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1791-2431 .- 1021-335X. ; 21:3, s. 641-648
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Tidskriftsartikel (refereegranskat)abstract
- EWSR1 is involved in chimeric proteins which play crucial roles in the development of a variety of bone and soft tissue tumors. Many of the chimeric genes involving EWSR1 have been extensively studied, whereas less is known about the wild-type (wt) gene and its regulation. As the expression of the chimeric gene is driven by the EWSR1 promoter, it is of importance to study the mechanisms regulating wt EWSR1 expression. We estimated the transcriptional activity of the EWSR1 promoter through deletion fragments driving reporter gene expression. This assay identified the 100-bp region immediately downstream of the EWSR1 transcriptional start site (+1) and the downstream region from +100 to +300 as important regions for transcriptional regulation. We also found that EWSR1 and RHBDD3, a gene located directly upstream of EWSR1 that is likely to share regulatory elements with EWSR1, were co-expressed in the tissue panels, Ewing tumor biopsies and cell lines. Thus, our results show that the EWSR1 promoter functions in a bidirectional manner, thereby regulating also RHBDD3, and identifies specific regions that strongly influence promoter activity.
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| 7. |
- Möller, Emely, et al.
(författare)
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Comparison of the proximal promoter regions of the PAX3 and PAX7 genes
- 2007
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Ingår i: Cancer Genetics and Cytogenetics. - : Elsevier BV. - 0165-4608. ; 178:2, s. 114-119
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Tidskriftsartikel (refereegranskat)abstract
- Translocations t(2;13)(q35;q14) and t(1;13)(p36;q14), which fuse PAX3 and PAX7, respectively, to FOXO1A, characterize alveolar rhabdomyosarcoma. Previous studies have suggested that the expression of PAX7-FOXO1A is copy-number dependent, but that of PAX3-FOXO1A is not, which may be due to a weaker PAX7 than PAX3 promoter. The aim of the present study was to compare the transcriptional activities of the PAX3 and PAX7 proximal promoter regions, using the dual-luciferase reporter assay with three vector systems in eight cell lines. The PAX3 promoter was found to have higher transcriptional activity than that of PAX7 irrespective of the vector system or cell line used. These findings are consistent with the idea that an amplification event is required for the PAX7-FOXO1A chimeric transcript to reach a critical expression level.
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| 8. |
- Panagopoulos, Ioannis, et al.
(författare)
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Absence of mutations of the BRAF gene in malignant melanoma of soft parts (clear cell sarcoma of tendons and aponeuroses)
- 2005
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Ingår i: Cancer Genetics and Cytogenetics. - : Elsevier BV. - 0165-4608. ; 156:1, s. 74-76
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Tidskriftsartikel (refereegranskat)abstract
- Malignant melanoma of soft parts (MMSP), also called clear cell sarcoma of tendons and aponeuroses, is cytogenetically characterized by the t(12;22)(q13;q12) resulting in the chimeric EWSR1/ATF1 gene. MMSP shares a number of morphologic, histologic, and immunohistochemical features with malignant melanoma of the skin, causing diagnostic difficulties in the distinction between MMSP and metastatic malignant melanoma with an unknown primary site. Recently, a high incidence of activating mutations in the kinase domain of the BRAF gene has been reported in malignant melanoma of the skin. The most common mutation (V599E) is the T1796A substitution in exon 15, leading to an exchange of valine for glutamic acid at position 599. Because of the extensive clinical, histologic, and immunohistochemic similarities with melanoma, we decided to analyze whether MMSP also has mutations in the BRAF gene. Eight MMSP with an EWSR1/ATF1 chimeric transcript, one soft tissue metastasis of a malignant melanoma of the skin, and one malignant melanoma cell line were examined. Both conventional melanomas had the exon 15 T1796A (V599E) mutation, but none of the MMSP was found to harbor any mutation in exon 11 or 15 of the BRAF gene. Our data further emphasize that MMSP and conventional malignant melanoma develop through different genetic pathways.
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| 9. |
- Panagopoulos, Ioannis, et al.
(författare)
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An endometrial stromal sarcoma cell line with the JAZF1/PHF1 chimera
- 2008
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Ingår i: Cancer Genetics and Cytogenetics. - : Elsevier BV. - 0165-4608. ; 185:2, s. 74-77
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Tidskriftsartikel (refereegranskat)abstract
- Endometrial stromal sarcomas (ESS) are rare malignancies, accounting for less than 10% of uterine sarcomas. Apart from the chromosomal rearrangement t(7;17)(p15;q21), which leads to the JAZF1/SUZ12 chimera, cytogenetic studies have shown that the chromosome band 6p21 is often rearranged in ESS. The translocation partners involved in the 6p21 rearrangements differ among the tumors, but chromosome 7 is involved in most aberrations. A JAZF1/PHF1 fusion gene was recently found in two tumors showing an exchange between 6p and 7p rearrangement. In the present study, we show that a low-grade ESS cell line carrying a der(7)t(6;7)(p21;p22) also harbors the a JAZF1/PHF1 fusion. In the fusion transcript, exon 3 of JAZF1 was fused with exon 2 of PHF1. At the junction, there was an insertion of 26 nucleotides, originating from intron 3 of JAZF1, thus maintaining an open reading frame of the chimeric transcript. The predicted 684-amino acid JAZF1/PHF1 chimeric protein retained one zinc finger domain from JAZF1 and the two zinc finger domains from PHF1, and its oncogenic mechanism should be similar to that of the JAZF1/SUZ12 protein. The present cell line constitutes an excellent model for further studies on the impact of the JAZF1/PHF1 fusion.
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| 10. |
- Panagopoulos, Ioannis, et al.
(författare)
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Characterization of the human CREB3L2 gene promoter
- 2009
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1791-2431 .- 1021-335X. ; 21:3, s. 615-624
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Tidskriftsartikel (refereegranskat)abstract
- CREB3L2 encodes a member of the CREB3 family of transcription factors. We characterized its promoter region, showing that it is asymmetrically bidirectional, also driving the expression of a variant of AKR1D1. It has a CRE binding site which is conserved among mammalians; removal or alteration of it resulted in reduced promoter activity. When transiently transfecting the HEK293 cell line with constructs with partially deleted promoter regions, 5' deletions beyond 1058-bp upstream of the transcription starting site resulted in successive reduction of the activity. The inclusion of the untranslated part of CREB3L2 exon 1 strongly inhibited the promoter activity. Forskolin resulted in a decreased reporter activity, whereas phorbol 12-myristate 13-acetate increased the promoter activity irrespective of the status of the CRE binding site. The presence of the CRE site indicates autoregulation of CREB3L2 and/or regulation via other members of the CREB3 family or a variety of bZIP transcription factors.
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