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ABSTRACT: The chromosomal translocation t(8;14)(q24;q32) with juxtaposition of MYC to enhancer elements in the immunoglobulin heavy chain (IGH) gene locus is the genetic hallmark of the majority of Burkitt lymphoma and a subset of Diffuse large B-cell lymphoma patients. Around 3% of adult B-lineage acute lymphoblastic leukemia (ALL) patients show this aberration. Flow cytometry mostly reveals a "mature B-ALL" or "Burkitt-type" ALL immunophenotype. Using long-distance PCR for t(8;14)/MYC-IGH fusion, we investigated bone marrow, peripheral blood and a few other samples with suspected Burkitt-ALL or mature B-ALL and identified 133 MYC-IGH-positive cases. The location of the chromosomal breaks in the IGH joining and the 8 different switch regions was determined using a set of long-distance PCRs. The chromosomal breakpoints with the adjacent MYC regions on 8q24 were characterized by direct sequencing in 49 cases. The distribution of chromosomal breaks among the IGH joining and switch regions was the following: JH 23.3%, M 21.8%, G1 15.0%, G2 7.5%, G3 3.8%, G4 4.5%, A1 12.8%, A2 3.8%, E 7.5%. Two breakpoint clusters near MYC were delineated. There was no clear correlation between the degree of somatic hypermutation and the chromosomal break locations. Epstein Barr virus was detected in 5 cases (4%). This detailed and extensive molecular analysis illustrates the molecular complexity of the MYC-IGH translocations and the detected distribution of breakpoints provides additional evidence that this translocation results from failed switch and VDJ recombinations. This study may serve as a model for the analysis of other IGH translocations in B-cell lymphoma.
Molecular oncology 04/2013; · 4.10 Impact Factor
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ABSTRACT: Burkitt lymphoma and a subset of diffuse large B-cell lymphomas are characterized by chromosomal alterations affecting the MYC oncogene on 8q24. In most cases MYC is found juxtaposed to the immunoglobulin heavy chain (IGH) gene locus. Translocations to the immunoglobulin kappa (IGK) gene locus on 2p11 are observed in around 5-10% of cases. Little data exist on the molecular mechanisms leading to this aberration. The chromosomal breakpoints on chromosome 8 have been found dispersed over a large area 3' of MYC. In order to obtain a better understanding of this chromosomal translocation we developed a long-distance inverse (LDI) PCR method for the identification of chromosomal translocations affecting the IGK locus. We investigated a number of cytogenetically mostly uncharacterized high-grade lymphoma samples and identified a MYC-IGK juxtaposition in seven patients and three t(2;8)-positive cell lines. The chromosomal breakpoints were molecularly characterized and analyzed. The linear distance of the breakpoints on chromosome 8 to MYC ranged from some 100 bp to more than 0.5 MB. The reciprocal translocated allele could be characterized in the majority of cases. This study represents the largest series of t(2;8)-positive cases analyzed so far. The LDI PCR method developed here should also be useful for the analysis of chromosomal translocations affecting the IGK locus in general.
Genes Chromosomes and Cancer 11/2011; 51(3):290-9. · 3.31 Impact Factor
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ABSTRACT: The chromosomal translocation t(9;22)(q34;q22), with expression of the BCR-ABL1 fusion gene is the cytogenetic and molecular hallmark of chronic myeloid leukemia (CML) and a subset of acute lymphoblastic leukemia (ALL). Basically two types of BCR-ABL1 chimeric mRNA transcripts have been observed: (1) e13a2/e14a2 transcripts in CML and ALL, resulting from chromosomal breaks in the major breakpoint cluster region (M-bcr) of the BCR gene and (2) e1a2 transcripts in ALL resulting from breaks in the minor breakpoint cluster region (m-bcr) of the BCR gene. To gain a better understanding of this molecular alteration, we developed a long-distance inverse PCR (LDI PCR) method for M-bcr breakpoint identification in BCR-ABL1-positive cases and were thus able to identify the chromosomal breakpoints within the M-bcr in 62 BCR-ABL1-positive samples. The corresponding reciprocal breakpoints were identified and molecularly characterized in 45 of these cases. In 2 samples, the breaks were located 5' to the ABL1 locus and in one case, the der(9) break was identified on 9q34.13 several hundred kB 3' telomeric to ABL1. The analysis of breaks revealed no significant clustering and no association with repetitive elements (Alu, L1, L2) or recombination signal sequence sites. The established LDI PCR permits fast, relatively easy and unbiased identification of breakpoints in the M-bcr region of BCR and also enables the molecular analysis of more complex translocations with breakpoints outside the ABL1 gene locus or other BCR fusion genes.
DNA repair 09/2011; 10(11):1131-7. · 4.20 Impact Factor
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ABSTRACT: Abnormalities of the long arm of chromosome 6 are a common feature in various B-cell malignancies. In most cases, the genes involved have not yet been clearly identified. We have molecularly characterized the recently established Burkitt lymphoma cell line BLUE-1 that carries a t(6;20)(q15;q11.2) rearrangement in addition to the typical t(8;14) with MYC-IGH fusion. To identify the gene loci involved on both chromosomes we applied a sequential BAC clone mapping strategy. By using RT-PCR we were finally able to detect a chimeric mRNA transcript showing a fusion of the first (non-coding) exon of BACH2 (BTB and CNC homology 1, basic leucine zipper transcription factor 2) on 6q15 to the second exon of BCL2L1 (BCL-X) on 20q11. Various fusion transcripts were detected for different BCL2L1 (BCL-XL) isoforms. The fusion ultimately results in strong expression of the BCL2L1 (BCL-XL) anti-apoptosis protein, as demonstrated by immunoblotting. This is the first report that shows the involvement of both BCL2L1 and the transcription factor BACH2 in a chromosomal rearrangement. It points to BACH2 as a possibly important target in lymphomas with 6q aberrations, although other genes on 6q are probably also involved in these cases. Moreover, it suggests that members of the BCL2 anti-apoptosis gene family other than BCL2 itself might also be involved in lymphoma.
Genes Chromosomes and Cancer 03/2011; 50(6):389-96. · 3.31 Impact Factor
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Thomas Burmeister,
Claus Meyer,
Stefan Schwartz,
Julia Hofmann,
Mara Molkentin,
Eric Kowarz,
Björn Schneider,
Thorsten Raff, Richard Reinhardt,
Nicola Gökbuget,
Dieter Hoelzer,
Eckhard Thiel,
Rolf Marschalek
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ABSTRACT: MLL translocations in adult B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) are largely restricted to the immature CD10– immunophenotypes. MLL-AF4 is known to be the most frequent fusion transcript, but the exact frequencies of MLL aberrations in CD10– adult BCP-ALL are unknown. We present a genetic characterization of 184 BCR-ABL– CD10– adult ALL cases (156 cyIg–, 28 cyIg+) diagnosed between 2001 and 2007 at the central diagnostic laboratory of the GMALL study group. Patient samples were investigated by RT-PCR for MLL-AF4, MLL-ENL, and MLL-AF9 and by long-distance inverse polymerase chain reaction, thus also allowing the identification of unknown MLL fusion partners at the genomic level. MLL-AF4 was detected in 101 (54.9%) and MLL-ENL in 11 (6.0%) cases. In addition, rare MLL fusion genes were found: 2 MLL-TET1 cases, not previously reported in ALL, 1 MLL-AF9, 1 MLL-PTD, a novel MLL-ACTN4, and an MLL-11q23 fusion. Chromosomal breakpoints were determined in all 118 positive cases, revealing 2 major breakpoint cluster regions in the MLL gene. Characteristic features of MLL+ patients were significantly lower CD10 expression, expression of the NG2 antigen, a higher white blood count at diagnosis, and female sex. Proposals are made for diagnostic assessment. The clinical studies are registered at http://www.clinicaltrials.gov as NCT00199056 [ClinicalTrials.gov] and NCT00198991 [ClinicalTrials.gov] .
Blood 02/2009; · 9.90 Impact Factor
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ABSTRACT: RT-PCR is the method of choice for detecting BCR-ABL in CML and ALL. The three predominant mRNA transcripts found are e1a2 (in ALL), e13a2, and e14a2 (in CML and ALL). However, a number of "atypical"BCR-ABL transcripts (e1a3, e13a3, e14a3, e19a2, e6a2, e8a2, etc.) resulting from chromosomal breakpoints outside ABL intron 1 or BCR intron 1, 13 or 14, respectively, have been reported. These atypical transcripts may escape detection when using methods that are optimized to detect just the typical ones. We present here a novel, fast, and reliable multiplex PCR for improved detection of typical and atypical BCR-ABL transcripts.
Leukemia Research 05/2008; 32(4):579-85. · 2.92 Impact Factor
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ABSTRACT: The NUP214-ABL1 fusion gene in T-cell acute lymphoblastic leukemia (T-ALL) has recently been identified as a possible target for imatinib and related tyrosine kinase inhibitors, but exact data regarding the prognostic impact and frequency of the several putative NUP214-ABL1 mRNA transcripts are still missing. We investigated 279 adult patients with T-ALL treated within the framework of the GMALL 5/93 and 6/99 therapy trials for NUP214-ABL1 by using a novel multiplex real-time, quantitative polymerase chain reaction (PCR). Eleven (3.9%) patients were NUP214-ABL1 positive, and 5 different transcripts were observed; 8 patients had a thymic immunophenotype, 1 had an early T-cell immunophenotype, and 2 had a mature T-cell immunophenotype. NUP214-ABL1-positive and -negative patients did not differ significantly in their major clinical features. In contrast to previous reports suggesting an adverse clinical course for NUP214-ABL1-positive patients, no significant difference in overall survival was observed. Based on the results, we have established and tested a novel PCR method for simplified detection of the NUP214-ABL1 fusion gene.
Blood 12/2006; 108(10):3556-9. · 9.90 Impact Factor
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ABSTRACT: We report the establishment and characterization, including HLA-typing, immunophenotypic and molecular cytogenetic analysis, of a novel EBV-negative cell line (BLUE-1) derived from adult relapsed sporadic Burkitt lymphoma. BLUE-1 carries the pathognomonic t(8;14)(q24;q32) effecting MYC/IgHJ fusion and a novel t(6;20)(q15;q11.2) originally present in the patient, analysis of which may facilitate identification of gene target(s) of recurrent 6q rearrangements in B-cell neoplasia. Our findings are discussed in light of the current understanding of endemic and sporadic Burkitt lymphoma. BLUE-1 grows well in culture and should be a useful lymphoma research tool.
Leukemia Research 12/2006; 30(11):1417-23. · 2.92 Impact Factor
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ABSTRACT: MLL aberrations are found in approximately 10% of acute leukemias. More than 80 different MLL fusion genes have been cytogenetically described but a significant number of MLL fusion partners remain unidentified on the molecular level. We describe here the case of a patient who developed secondary acute myeloid leukemia five years after the patient had received adjuvant radiochemotherapy because of breast cancer. This therapy comprised 4 cycles epirubicin/cyclophosphamide, a mitoxantrone-based high-dose chemotherapy with autologous stem cell transplantation and a subsequent radiation. Cytogenetic bone marrow analysis revealed a translocation t(11;14)(q23;q32), with a MLL split signal in FISH analysis. By applying a long-distance inverse PCR method the KIAA0284 gene was identified as translocation partner. Both breakpoints, on chromosomes 11 and 14, were characterized. The breakpoint in the KIAA0284 gene was located 5' of the putative start codon and an in-frame MLL-KIAA0284 transcript was detectable by RT-PCR. The KIAA0284 gene has hitherto not been implicated in hematologic diseases and has never been reported as a translocation partner. Its physiological function is unknown. The expression of KIAA0284 in various tissues and hematologic diseases was investigated by real time quantitative PCR and turned out to be very low in all lymphatic and myeloid diseases investigated.
Blood Cells Molecules and Diseases 41(2):210-4. · 2.35 Impact Factor
