Publications by authors named "Monika Szczepanowski"

55 Publications

Molecular characterization of Burkitt lymphoma in the breast or ovary.

Leuk Lymphoma 2021 Jun 24:1-10. Epub 2021 Jun 24.

Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany.

Breast and ovary have been described as rare but typical sites of presentation of Burkitt lymphoma (BL) in females, particularly after puberty. We revised a historic series of 44 lymphomas of the breast or the ovary in women diagnosed between 1973 and 2014 as BL. Fluorescence hybridization (FISH) was applied to all, and array-based copy number analysis as well as expression profiling to a subset of those cases. Of the 42 cases evaluable for FISH, 19 cases showed an IG- translocation but only 9 of those fulfilled the criteria of the current WHO classification for the diagnosis of BL. Those nine cases resembled BL of other sites with regard to molecular features. Our findings along with literature data suggest that breast and ovarian BL (1) seem to be rarer than hitherto assumed, (2) share typical molecular features with other BL, and (3) predominantly affect women in the fertile age.
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http://dx.doi.org/10.1080/10428194.2021.1907374DOI Listing
June 2021

Mutational mechanisms shaping the coding and noncoding genome of germinal center derived B-cell lymphomas.

Leukemia 2021 07 5;35(7):2002-2016. Epub 2021 May 5.

University of Duesseldorf, Medical Faculty, Department of Pediatric Oncology, Hematology and Clinical Immunology, Center for Child and Adolescent Health, Düsseldorf, Germany.

B cells have the unique property to somatically alter their immunoglobulin (IG) genes by V(D)J recombination, somatic hypermutation (SHM) and class-switch recombination (CSR). Aberrant targeting of these mechanisms is implicated in lymphomagenesis, but the mutational processes are poorly understood. By performing whole genome and transcriptome sequencing of 181 germinal center derived B-cell lymphomas (gcBCL) we identified distinct mutational signatures linked to SHM and CSR. We show that not only SHM, but presumably also CSR causes off-target mutations in non-IG genes. Kataegis clusters with high mutational density mainly affected early replicating regions and were enriched for SHM- and CSR-mediated off-target mutations. Moreover, they often co-occurred in loci physically interacting in the nucleus, suggesting that mutation hotspots promote increased mutation targeting of spatially co-localized loci (termed hypermutation by proxy). Only around 1% of somatic small variants were in protein coding sequences, but in about half of the driver genes, a contribution of B-cell specific mutational processes to their mutations was found. The B-cell-specific mutational processes contribute to both lymphoma initiation and intratumoral heterogeneity. Overall, we demonstrate that mutational processes involved in the development of gcBCL are more complex than previously appreciated, and that B cell-specific mutational processes contribute via diverse mechanisms to lymphomagenesis.
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http://dx.doi.org/10.1038/s41375-021-01251-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8257491PMC
July 2021

Double-hit lymphoma of the male breast: a case report.

J Med Case Rep 2020 Dec 18;14(1):245. Epub 2020 Dec 18.

Institute of Human Genetics, Ulm University and Ulm University Medical Center, D-89081, Ulm, Germany.

Background: Whereas lymphoma of the female breast is already rare, lymphoma of the male breast has only anecdotally been reported. Within a study of 32 lymphoma of the breast reported between 1973 and 2014 as Burkitt lymphoma, we observed a single male case, which we report here.

Case Presentation: A 72-years-old Caucasian man presented with a mass in his left breast. Clinical history included prior basal cell carcinoma, leiomyosarcoma, and administration of spironolactone. The reference pathology diagnosis at presentation was Burkitt lymphoma according to the Kiel Classification. The present re-investigation using fluorescence in situ hybridization revealed an IGH-MYC translocation and a break in the BCL2 locus in the tumor cells. Thus, in light of the current WHO classification, the diagnosis was revised to high-grade B-cell lymphoma with MYC and BCL2 rearrangement, Burkitt morphology (so-called "double-hit" lymphoma). Genome-wide chromosomal imbalance mapping revealed a complex pattern of aberrations in line with this diagnosis. The aberrations, including copy-number gains in chromosomes 3q and 18 and focal homozygous loss in 9p21.3, resembled typical changes of lymphomas affecting "immune-privileged" sites.

Conclusion: The present case adds to the understanding of the pathogenesis of male breast lymphomas, about which hardly any molecular characterization has been published yet.
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http://dx.doi.org/10.1186/s13256-020-02526-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7747391PMC
December 2020

Platform independent protein-based cell-of-origin subtyping of diffuse large B-cell lymphoma in formalin-fixed paraffin-embedded tissue.

Sci Rep 2020 05 12;10(1):7876. Epub 2020 May 12.

Chair and Institute of Functional Genomics, University of Regensburg, 93053, Regensburg, Germany.

Diffuse large B-cell lymphoma (DLBCL) is commonly classified by gene expression profiling according to its cell of origin (COO) into activated B-cell (ABC)-like and germinal center B-cell (GCB)-like subgroups. Here we report the application of label-free nano-liquid chromatography - Sequential Window Acquisition of all THeoretical fragment-ion spectra - mass spectrometry (nanoLC-SWATH-MS) to the COO classification of DLBCL in formalin-fixed paraffin-embedded (FFPE) tissue. To generate a protein signature capable of predicting Affymetrix-based GCB scores, the summed log-transformed fragment ion intensities of 780 proteins quantified in a training set of 42 DLBCL cases were used as independent variables in a penalized zero-sum elastic net regression model with variable selection. The eight-protein signature obtained showed an excellent correlation (r = 0.873) between predicted and true GCB scores and yielded only 9 (21.4%) minor discrepancies between the three classifications: ABC, GCB, and unclassified. The robustness of the model was validated successfully in two independent cohorts of 42 and 31 DLBCL cases, the latter cohort comprising only patients aged >75 years, with Pearson correlation coefficients of 0.846 and 0.815, respectively, between predicted and NanoString nCounter based GCB scores. We further show that the 8-protein signature is directly transferable to both a triple quadrupole and a Q Exactive quadrupole-Orbitrap mass spectrometer, thus obviating the need for proprietary instrumentation and reagents. This method may therefore be used for robust and competitive classification of DLBCLs on the protein level.
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http://dx.doi.org/10.1038/s41598-020-64212-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7217957PMC
May 2020

Cathepsin S Alterations Induce a Tumor-Promoting Immune Microenvironment in Follicular Lymphoma.

Cell Rep 2020 05 23;31(5):107522. Epub 2020 Apr 23.

Blood Cancer Research Group, Mater Research, University of Queensland, Translational Research Institute, Brisbane, QLD 4101, Australia.

Tumor cells orchestrate their microenvironment. Here, we provide biochemical, structural, functional, and clinical evidence that Cathepsin S (CTSS) alterations induce a tumor-promoting immune microenvironment in follicular lymphoma (FL). We found CTSS mutations at Y132 in 6% of FL (19/305). Another 13% (37/286) had CTSS amplification, which was associated with higher CTSS expression. CTSS Y132 mutations lead to accelerated autocatalytic conversion from an enzymatically inactive profrom to active CTSS and increased substrate cleavage, including CD74, which regulates major histocompatibility complex class II (MHC class II)-restricted antigen presentation. Lymphoma cells with hyperactive CTSS more efficiently activated antigen-specific CD4 T cells in vitro. Tumors with hyperactive CTSS showed increased CD4 T cell infiltration and proinflammatory cytokine perturbation in a mouse model and in human FLs. In mice, this CTSS-induced immune microenvironment promoted tumor growth. Clinically, patients with CTSS-hyperactive FL had better treatment outcomes with standard immunochemotherapies, indicating that these immunosuppressive regimens target both the lymphoma cells and the tumor-promoting immune microenvironment.
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http://dx.doi.org/10.1016/j.celrep.2020.107522DOI Listing
May 2020

The A818-6 system as an in-vitro model for studying the role of the transportome in pancreatic cancer.

BMC Cancer 2020 Mar 30;20(1):264. Epub 2020 Mar 30.

Institute for Experimental Cancer Research, Christian-Albrechts-University of Kiel, Arnold-Heller Str. 3, 24105, Kiel, Germany.

Background: The human pancreatic cancer cell line A818-6 can be grown in vitro either as a highly malignant, undifferentiated monolayer (ML) or as three-dimensional (3D) single layer hollow spheres (HS) simulating a benign, highly differentiated, duct-like pancreatic epithelial structure. This characteristic allowing A818-6 cells to switch from one phenotype to another makes these cells a unique system to characterize the cellular and molecular modifications during differentiation on one hand and malignant transformation on the other hand. Ion channels and transport proteins (transportome) have been implicated in malignant transformation. Therefore, the current study aimed to analyse the transportome gene expression profile in the A818-6 cells growing as a monolayer or as hollow spheres.

Methods & Results: The study identified the differentially expressed transportome genes in both cellular states of A818-6 using Agilent and Nanostring arrays and some targets were validated via immunoblotting. Additionally, these results were compared to a tissue Affymetrix microarray analysis of pancreatic adenocarcinoma patients' tissues. The overall transcriptional profile of the ML and HS cells confirmed the formerly described mesenchymal features of ML and epithelial nature of HS which was further verified via high expression of E-cadherin and low expression of vimentin found in HS in comparison to ML. Among the predicted features between HS and ML was the involvement of miRNA-9 in this switch. Importantly, the bioinformatics analysis also revealed substantial number (n = 126) of altered transportome genes. Interestingly, three genes upregulated in PDAC tissue samples (GJB2, GJB5 and SLC38A6) were found to be also upregulated in ML and 3 down-regulated transportome genes (KCNQ1, TRPV6 and SLC4A) were also reduced in ML.

Conclusion: This reversible HS/ML in vitro system might help in understanding the pathophysiological impact of the transportome in the dedifferentiation process in pancreatic carcinogenesis. Furthermore, the HS/ML model represents a novel system for studying the role of the transportome during the switch from a more benign, differentiated (HS) to a highly malignant, undifferentiated (ML) phenotype.
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http://dx.doi.org/10.1186/s12885-020-06773-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7106758PMC
March 2020

A novel lymphoma-associated macrophage interaction signature (LAMIS) provides robust risk prognostication in diffuse large B-cell lymphoma clinical trial cohorts of the DSHNHL.

Leukemia 2020 02 17;34(2):543-552. Epub 2019 Sep 17.

Statistical Bioinformatics, Institute of Functional Genomics, University of Regensburg, Regensburg, Germany.

Diffuse large B-cell lymphoma (DLBCL) is a disease with heterogeneous outcome. Stromal signatures have been correlated to survival in DLBCL. Their use, however, is hampered by the lack of assays for formalin-fixed paraffin-embedded material (FFPE). We constructed a lymphoma-associated macrophage interaction signature (LAMIS) interrogating features of the microenvironment using a NanoString assay applicable to FFPE. The clinical impact of the signature could be validated in a cohort of 466 patients enrolled in prospective clinical trials of the German High-Grade Non-Hodgkin Lymphoma Study Group (DSHNHL). Patients with high expression of the signature (LAMIS) had shorter EFS, PFS, and OS. Multivariate analyses revealed independence from IPI factors in EFS (HR 1.7, 95% CI 1.2-2.4, p-value = 0.001), PFS (HR 1.8, 95% CI 1.2-2.5, p-value = 0.001) and OS (HR 1.8, 95% CI 1.3-2.7, p-value = 0.001). Multivariate analyses adjusted for the IPI factors showed the signature to be independent from COO, MYC rearrangements and double expresser status (DE). LAMIS and simultaneous DE status characterized a patient subgroup with dismal prognosis and early relapse. Our data underline the importance of the microenvironment in prognosis. Combined analysis of stromal features, the IPI and DE may provide a new rationale for targeted therapy.
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http://dx.doi.org/10.1038/s41375-019-0573-yDOI Listing
February 2020

A modular transcriptome map of mature B cell lymphomas.

Genome Med 2019 04 30;11(1):27. Epub 2019 Apr 30.

Interdisciplinary Centre for Bioinformatics, Universität Leipzig, Härtelstr. 16-18, 04107, Leipzig, Germany.

Background: Germinal center-derived B cell lymphomas are tumors of the lymphoid tissues representing one of the most heterogeneous malignancies. Here we characterize the variety of transcriptomic phenotypes of this disease based on 873 biopsy specimens collected in the German Cancer Aid MMML (Molecular Mechanisms in Malignant Lymphoma) consortium. They include diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), Burkitt's lymphoma, mixed FL/DLBCL lymphomas, primary mediastinal large B cell lymphoma, multiple myeloma, IRF4-rearranged large cell lymphoma, MYC-negative Burkitt-like lymphoma with chr. 11q aberration and mantle cell lymphoma.

Methods: We apply self-organizing map (SOM) machine learning to microarray-derived expression data to generate a holistic view on the transcriptome landscape of lymphomas, to describe the multidimensional nature of gene regulation and to pursue a modular view on co-expression. Expression data were complemented by pathological, genetic and clinical characteristics.

Results: We present a transcriptome map of B cell lymphomas that allows visual comparison between the SOM portraits of different lymphoma strata and individual cases. It decomposes into one dozen modules of co-expressed genes related to different functional categories, to genetic defects and to the pathogenesis of lymphomas. On a molecular level, this disease rather forms a continuum of expression states than clearly separated phenotypes. We introduced the concept of combinatorial pattern types (PATs) that stratifies the lymphomas into nine PAT groups and, on a coarser level, into five prominent cancer hallmark types with proliferation, inflammation and stroma signatures. Inflammation signatures in combination with healthy B cell and tonsil characteristics associate with better overall survival rates, while proliferation in combination with inflammation and plasma cell characteristics worsens it. A phenotypic similarity tree is presented that reveals possible progression paths along the transcriptional dimensions. Our analysis provided a novel look on the transition range between FL and DLBCL, on DLBCL with poor prognosis showing expression patterns resembling that of Burkitt's lymphoma and particularly on 'double-hit' MYC and BCL2 transformed lymphomas.

Conclusions: The transcriptome map provides a tool that aggregates, refines and visualizes the data collected in the MMML study and interprets them in the light of previous knowledge to provide orientation and support in current and future studies on lymphomas and on other cancer entities.
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http://dx.doi.org/10.1186/s13073-019-0637-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6492344PMC
April 2019

Genomic and transcriptomic changes complement each other in the pathogenesis of sporadic Burkitt lymphoma.

Nat Commun 2019 03 29;10(1):1459. Epub 2019 Mar 29.

Medical Faculty, Department of Pediatric Oncology, Hematology and Clinical Immunology, Heinrich-Heine-University, 40225, Düsseldorf, Germany.

Burkitt lymphoma (BL) is the most common B-cell lymphoma in children. Within the International Cancer Genome Consortium (ICGC), we performed whole genome and transcriptome sequencing of 39 sporadic BL. Here, we unravel interaction of structural, mutational, and transcriptional changes, which contribute to MYC oncogene dysregulation together with the pathognomonic IG-MYC translocation. Moreover, by mapping IGH translocation breakpoints, we provide evidence that the precursor of at least a subset of BL is a B-cell poised to express IGHA. We describe the landscape of mutations, structural variants, and mutational processes, and identified a series of driver genes in the pathogenesis of BL, which can be targeted by various mechanisms, including IG-non MYC translocations, germline and somatic mutations, fusion transcripts, and alternative splicing.
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http://dx.doi.org/10.1038/s41467-019-08578-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440956PMC
March 2019

Non-leukemic pediatric mixed phenotype acute leukemia/lymphoma: Genomic characterization and clinical outcome in a prospective trial for pediatric lymphoblastic lymphoma.

Genes Chromosomes Cancer 2019 06 21;58(6):365-372. Epub 2019 Jan 21.

Department of Pathology, Hematopathology Section and Lymph Node Registry, University Hospital Schleswig-Holstein, Campus Kiel/Christian-Albrechts University, Kiel, Germany.

Rare cases of hematological precursor neoplasms fulfill the diagnostic criteria of mixed phenotype acute leukemia (MPAL), characterized by expression patterns of at least two hematopoietic lineages, for which a highly aggressive behavior was reported. We present a series of 11 pediatric non-leukemic MPAL identified among 146 precursor lymphoblastic lymphomas included in the prospective trial Euro-LBL 02. Paraffin-embedded biopsies of 10 cases were suitable for molecular analyses using OncoScan assay (n = 7), fluorescence in situ hybridization (FISH; n = 7) or both (n = 5). Except for one case with biallelic KMT2A (MLL) breaks, all cases analyzed by FISH lacked the most common translocations defining molecular subsets of lymphoblastic leukemia/lymphomas. Two non-leukemic B-myeloid MPALs showed the typical genomic profile of hyperdiploid precursor B-cell lymphoblastic leukemia with gains of chromosomes 4, 6, 10, 14, 18, and 21. One B-T MPAL showed typical aberrations of T-cell lymphoblastic lymphoma, such as copy number neutral loss of heterozygosity (CNN-LOH) at 9p targeting a 9p21.3 deletion of CDKN2A and 11q12.2-qter affecting the ATM gene. ATM was also mutated in a T-myeloid MPAL case with additional loss at 7q21.2-q36.3 and mutation of NRAS, two alterations common in myeloid disorders. No recurrent regions of CNN-LOH were observed. The outcome under treatment was good with all patients being alive in first complete remission after treatment according to a protocol for precursor lymphoblastic lymphoma (follow-up 3-10 years, median: 4.9 years). In summary, the present series of non-leukemic MPALs widely lacked recurrently reported translocations in lymphoid/myeloid neoplasias and showed heterogeneous spectrum of chromosomal imbalances.
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http://dx.doi.org/10.1002/gcc.22726DOI Listing
June 2019

Hyper--glycosylated SAMD14 and neurabin-I as driver autoantigens of primary central nervous system lymphoma.

Blood 2018 12 24;132(26):2744-2753. Epub 2018 Sep 24.

José Carreras Center for Immuno- and Gene Therapy and Internal Medicine I, Saarland University Medical School, Homburg/Saar, Germany.

To address the role of chronic antigenic stimulation in primary central nervous system lymphoma (PCNSL), we searched for autoantigens and identified sterile α-motif domain containing protein 14 (SAMD14) and neural tissue-specific F-actin binding protein I (neurabin-I) as autoantigenic targets of the B-cell receptors (BCRs) from 8/12 PCNSLs. In the respective cases, SAMD14 and neurabin-I were atypically hyper--glycosylated (SAMD14 at ASN339 and neurabin-I at ASN1277), explaining their autoimmunogenicity. SAMD14 and neurabin-I induced BCR pathway activation and proliferation of aggressive lymphoma cell lines transfected with SAMD14- and neurabin-I-reactive BCRs. Moreover, the BCR binding epitope of neurabin-I conjugated to truncated exotoxin-killed lymphoma cells expressing the respective BCRs. These results support the role of chronic antigenic stimulation by posttranslationally modified central nervous system (CNS) driver autoantigens in the pathogenesis of PCNSL, serve as an explanation for their CNS tropism, and provide the basis for a novel specific treatment approach.
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http://dx.doi.org/10.1182/blood-2018-03-836932DOI Listing
December 2018

Duodenal-type and nodal follicular lymphomas differ by their immune microenvironment rather than their mutation profiles.

Blood 2018 10 20;132(16):1695-1702. Epub 2018 Aug 20.

Department of Medicine III, University Hospital, Ludwig-Maximilians-University, Munich, Germany.

Duodenal-type follicular lymphoma (DTFL) is a rare and highly indolent follicular lymphoma (FL) variant. It is morphologically and immunophenotypically indistinguishable from typical FL, characterized by restricted involvement of intestinal mucosa, and lacks extraintestinal manifestations. The molecular determinants of this distinct clinical behavior are largely unknown. Thirty-eight diagnostic biopsies from patients with DTFL were evaluated. The 10-year overall survival rate was 100% in clinically evaluable patients (n = 19). We compared the targeted mutation profile of DTFL (n = 31), limited-stage typical FL (LSTFL; n = 17), and advanced-stage typical FL (ASTFL; n = 241). The mutation frequencies of recurrently mutated genes, including , /, and were not significantly different. However, was less commonly mutated in DTFL (52%) and LSTFL (24%) as compared with ASTFL (79%). In ASTFL, 41% of mutated cases harbored multiple mutations in , as compared with only 12% in LSTFL ( = .019) and 0% in DTFL ( < .0001). Whole exome and targeted sequencing of DTFL revealed high mutation frequencies of (35%) and (22%). We compared the immune microenvironment gene expression signatures of DTFL (n = 8) and LSTFL (n = 7). DTFL clearly separated from LSTFL by unsupervised, hierarchical clustering of 147 chemokines and cytokines and was enriched for a chronic inflammation signature. In conclusion, the mutational landscape of DTFL is highly related to typical FL. The lower frequency of multiple mutations in in DTFL and LSTFL indicates an increasing selection pressure for complete KMT2D loss in ASTFL pathogenesis. The highly dissimilar immune microenvironment of DTFL suggests a central role in the biology of this disease.
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http://dx.doi.org/10.1182/blood-2018-03-837252DOI Listing
October 2018

Advanced patient age at diagnosis of diffuse large B-cell lymphoma is associated with molecular characteristics including ABC-subtype and high expression of MYC.

Leuk Lymphoma 2018 05 25;59(5):1213-1221. Epub 2017 Aug 25.

b Hematopathology Section , Christian-Albrecht University , Kiel , Germany.

The incidence of diffuse large B-cell lymphoma (DLBCL) increases with age being patient age at diagnosis an adverse prognostic factor. However, elderly patients are often underrepresented in common studies. To investigate the effect between age and biological characteristics in DLBCL, we analyzed data of 1534 patients encompassing all adult age groups, enriched for the age ≥75 years. Follicular lymphoma (FL) grade 3B with histopathological characteristics of DLBCLs were included. Gender, centroblastic cytology, FL grade 3B morphology, CD10 expression, and ABC/non-GCB-subtype were significantly associated with age after correction for multiple testing and after adjusting for cohorts. Analysis of a subgroup points towards an association of MYC expression with age. Our data indicate that biological features of DLBCL and FL grade 3B are associated with increasing age among adult patients. The prevalence of the ABC/non-GCB-subtype in elderly patients suggests that therapies targeting this molecular subtype should be specifically explored in this subgroup.
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http://dx.doi.org/10.1080/10428194.2017.1365851DOI Listing
May 2018

Spindle-Cell Variants of Primary Cutaneous Follicle Center B-Cell Lymphomas Are Germinal Center B-Cell Lymphomas by Gene Expression Profiling Using a Formalin-Fixed Paraffin-Embedded Specimen.

J Invest Dermatol 2017 11 3;137(11):2450-2453. Epub 2017 Jul 3.

Department of Pathology, Hematopathology Section and Lymph Node Registry, Christian-Albrechts-University of Kiel, University-Hospital Schleswig-Holstein (UKSH), Campus Kiel, Kiel, Germany.

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http://dx.doi.org/10.1016/j.jid.2017.06.016DOI Listing
November 2017

Cell-of-origin classification by gene expression and MYC-rearrangements in diffuse large B-cell lymphoma of children and adolescents.

Br J Haematol 2017 10 23;179(1):116-119. Epub 2017 Jun 23.

Department of Pathology, Haematopathology Section and Lymph Node Registry, University Hospital Schleswig-Holstein, Campus Kiel/Christian-Albrecht University, Kiel, Germany.

We present the largest series of diffuse large B-cell lymphoma (DLBCL) in patients younger than 18 years analysed to date by gene expression profiling using Nanostring technology to identify molecular subtypes and fluorescent in situ hybridization for translocations of MYC. We show that the activated B cell-like subtype of DLBCL is exceedingly rare in children and - in contrast to adults- not associated with outcome. Furthermore, we review the current literature and demonstrate that MYC translocations are not more frequent in paediatric compared to adult DLBCL. A prognostic role of MYC in the paediatric age groups seems unlikely.
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http://dx.doi.org/10.1111/bjh.14812DOI Listing
October 2017

Clinical Impact of the Cell-of-Origin Classification and the MYC/ BCL2 Dual Expresser Status in Diffuse Large B-Cell Lymphoma Treated Within Prospective Clinical Trials of the German High-Grade Non-Hodgkin's Lymphoma Study Group.

J Clin Oncol 2017 Aug 19;35(22):2515-2526. Epub 2017 May 19.

Annette M. Staiger, Heike Horn, and German Ott, Institute of Clinical Pathology, Robert-Bosch-Krankenhaus, Stuttgart; Annette M. Staiger and Heike Horn, Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart; Annette M. Staiger and Heike Horn, University of Tuebingen, Tuebingen; Marita Ziepert and Markus Löffler, Institute for Medical Informatics, Statistics and Epidemiology, Universität Leipzig, Leipzig; Thomas F.E. Barth and Peter Möller, Institute of Pathology, Universitätsklinikum Ulm, Ulm; Heinz-Wolfram Bernd and Alfred C. Feller, Haematopathologie Luebeck, Luebeck; Wolfram Klapper and Monika Szczepanowski, Institute of Pathology, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel; Monika Szczepanowski, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel; Michael Hummel and Dido Lenze, Institute of Pathology, Campus Benjamin Franklin, Charité Universitätsmedizin; Harald Stein, Pathodiagnostik Berlin, Berlin; Martin-Leo Hansmann and Sylvia Hartmann, Dr. Senckenberg Institute of Pathology, Goethe University Hospital, Frankfurt; Georg Lenz, Translational Oncology, Albert-Schweitzer-Campus 1, University Hospital Münster, and Cluster of Excellence EXC 1003, Cells in Motion, Münster; Lorenz Trümper, Georg-August Universität, Göttingen; Norbert Schmitz, Asklepios Klinik St Georg, Hamburg; Michael Pfreundschuh, Saarland University Medical School, Homburg/Saar; Andreas Rosenwald, Institute of Pathology, Universität Würzburg and Comprehensive Cancer Center Mainfranken, Würzburg, Germany; David W. Scott, Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada; and Sergio Cogliatti, Institute of Pathology, Kantonal Hospital St Gallen, St Gallen, Switzerland.

Purpose To explore the prognostic impact and interdependence of the cell-of-origin (COO) classification, dual expression (DE) of MYC and BCL2 proteins, and MYC, BCL2, and BCL6 translocations in two prospectively randomized clinical trials of patients with diffuse large B-cell lymphoma (DLBCL). Patients and Methods Overall, 452 formalin-fixed paraffin-embedded samples from two prospective, randomized DLBCL trials (RICOVER-60, prospective, randomized study for patients > 60 years, all IPI groups; and R-MegaCHOEP, prospective, randomized study for patients ≤ 60 years with age-adjusted IPI 2,3) of the German High-Grade Non-Hodgkin Lymphoma Study Group were analyzed with the Lymph2Cx assay for COO classification, with immunohistochemistry for MYC and BCL2, and with fluorescent in situ hybridization for MYC, BCL2, and BCL6 rearrangements. Results COO classification was successful in 414 of 452 samples. No significant differences with respect to COO (activated B-cell [ABC]-like DLBCL v germinal center B-cell [GCB]-like DLBCL) were observed in event-free survival, progression-free survival, and overall survival in patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in the RICOVER-60 trial. Also, no differences with respect to COO were observed in multivariable analyses adjusted for International Prognostic Index factors in event-free survival (hazard ratio [HR] of ABC-like disease v GCB-like disease, 1.0; 95% CI, 0.6 to 1.6; P = .93), progression-free survival (HR, 1.1; 95% CI, 0.6 to 1.8; P = .82), and overall survival (HR, 1.0; 95% CI, 0.6 to 1.8; P = .96). Similar results were observed in the R-MegaCHOEP trial. In patients treated with R-CHOP, DE status was associated with significantly inferior survival compared with nonDE within the GCB, but not within the ABC subgroup. DE status was associated with significantly inferior outcome compared with patients with ABC-like DLBCL without DE (5-year PFS rate, 39% [95% CI,19% to 59%] v 68% [95% CI, 52% to 85%]; P = .03) and compared with patients with GCB-like DLBCL without DE. When data from patients with nonDE were analyzed separately, the outcome of patients in the ABC subgroup was inferior to that of patients in the GCB subgroup (5-year PFS rate, 68% [95% CI, 52% to 85%] v 85% [95% CI, 74% to 96%]; P = .04). Conclusion COO profiling in two prospective randomized DLBCL trials failed to identify prognostic subgroups, whereas dual expression of MYC and BCL2 was predictive of poor survival. Evaluation of prognostic or predictive biomarkers in the management of DLBCL, such as the COO, within prospective clinical trials will be important in the future.
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http://dx.doi.org/10.1200/JCO.2016.70.3660DOI Listing
August 2017

Relevance of ID3-TCF3-CCND3 pathway mutations in pediatric aggressive B-cell lymphoma treated according to the non-Hodgkin Lymphoma Berlin-Frankfurt-Münster protocols.

Haematologica 2017 06 16;102(6):1091-1098. Epub 2017 Feb 16.

Pediatric Hematology and Oncology, University Hospital Münster, Germany

Mature B-cell non-Hodgkin lymphoma is the most common subtype of non-Hodgkin lymphoma in childhood and adolescence. B-cell non-Hodgkin lymphomas are further classified into histological subtypes, with Burkitt lymphoma and Diffuse large B-cell lymphoma being the most common subgroups in pediatric patients. Translocations involving the oncogene are known as relevant but not sufficient for Burkitt lymphoma pathogenesis. Recently published large-scale next-generation sequencing studies unveiled sets of additional recurrently mutated genes in samples of pediatric and adult B-cell non-Hodgkin lymphoma patients. and are potential drivers of Burkitt lymphomagenesis. In the study herein, frequency and clinical relevance of mutations in and were analyzed within a well-defined cohort of 84 uniformly diagnosed and treated pediatric B-cell non-Hodgkin lymphoma patients of the Berlin-Frankfurt-Münster group. Mutation frequency was 78% (), 13% () and 36% () in Burkitt lymphoma (including Burkitt leukemia). and mutations were associated with more advanced stages of the disease in rearrangement positive Burkitt lymphoma. In conclusion, pathway genes are mutated in more than 88% of -rearranged pediatric B-cell non-Hodgkin lymphoma and the pathway may represent a highly relevant second hit of Burkitt lymphoma pathogenesis, especially in children and adolescents.
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http://dx.doi.org/10.3324/haematol.2016.156885DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451341PMC
June 2017

Comprehensive Metaboproteomics of Burkitt's and Diffuse Large B-Cell Lymphoma Cell Lines and Primary Tumor Tissues Reveals Distinct Differences in Pyruvate Content and Metabolism.

J Proteome Res 2017 03 16;16(3):1105-1120. Epub 2017 Feb 16.

Institute of Hematopathology, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel , 24118 Kiel, Germany.

Burkitt's lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) are pathologically and clinically distinct subtypes of aggressive non-Hodgkin B-cell lymphoma. To learn more about their biology, we employed metabolomic and proteomic methods to study both established cell lines as well as cryopreserved and formalin-fixed paraffin-embedded (FFPE) tissue sections of BL and DLBCL. Strikingly, NMR analyses revealed DLBCL cell lines to produce and secrete significantly (p = 1.72 × 10) more pyruvic acid than BL cell lines. This finding could be reproduced by targeted GC/MS analyses of cryopreserved tissue sections of BL and DLBCL cases. Enrichment analysis of an overlapping set of N = 2315 proteins, that had been quantified by nanoLC-SWATH-MS in BL and DLBCL cultured cells and cryosections, supported the observed difference in pyruvic acid content, as glycolysis and pyruvate metabolism were downregulated, while one-carbon metabolism was upregulated in BL compared to DLBCL. Furthermore, 92.1% of the overlapping significant proteins showed the same direction of regulation in cryopreserved and FFPE material. Proteome data are available via ProteomeXchange with identifier PXD004936.
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http://dx.doi.org/10.1021/acs.jproteome.6b00164DOI Listing
March 2017

Alterations of microRNA and microRNA-regulated messenger RNA expression in germinal center B-cell lymphomas determined by integrative sequencing analysis.

Haematologica 2016 11 6;101(11):1380-1389. Epub 2016 Jul 6.

Department of Pediatric Hematology and Oncology University Hospital Giessen, Germany.

MicroRNA are well-established players in post-transcriptional gene regulation. However, information on the effects of microRNA deregulation mainly relies on bioinformatic prediction of potential targets, whereas proof of the direct physical microRNA/target messenger RNA interaction is mostly lacking. Within the International Cancer Genome Consortium Project "Determining Molecular Mechanisms in Malignant Lymphoma by Sequencing", we performed miRnome sequencing from 16 Burkitt lymphomas, 19 diffuse large B-cell lymphomas, and 21 follicular lymphomas. Twenty-two miRNA separated Burkitt lymphomas from diffuse large B-cell lymphomas/follicular lymphomas, of which 13 have shown regulation by MYC. Moreover, we found expression of three hitherto unreported microRNA. Additionally, we detected recurrent mutations of hsa-miR-142 in diffuse large B-cell lymphomas and follicular lymphomas, and editing of the hsa-miR-376 cluster, providing evidence for microRNA editing in lymphomagenesis. To interrogate the direct physical interactions of microRNA with messenger RNA, we performed Argonaute-2 photoactivatable ribonucleoside-enhanced cross-linking and immunoprecipitation experiments. MicroRNA directly targeted 208 messsenger RNA in the Burkitt lymphomas and 328 messenger RNA in the non-Burkitt lymphoma models. This integrative analysis discovered several regulatory pathways of relevance in lymphomagenesis including Ras, PI3K-Akt and MAPK signaling pathways, also recurrently deregulated in lymphomas by mutations. Our dataset reveals that messenger RNA deregulation through microRNA is a highly relevant mechanism in lymphomagenesis.
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http://dx.doi.org/10.3324/haematol.2016.143891DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394868PMC
November 2016

Clinicogenetic risk models predict early progression of follicular lymphoma after first-line immunochemotherapy.

Blood 2016 08 14;128(8):1112-20. Epub 2016 Jul 14.

Medical Department III, University Hospital of the Ludwig Maximilians University Munich, Munich, Germany; German Cancer Consortium and German Cancer Research Center, Heidelberg, Germany; and.

Follicular lymphoma (FL) is a clinically and molecularly heterogeneous disease. Posttreatment surrogate end points, such as progression of disease within 24 months (POD24) are promising predictors for overall survival (OS) but are of limited clinical value, primarily because they cannot guide up-front treatment decisions. We used the clinical and molecular data from 2 independent cohorts of symptomatic patients in need of first-line immunochemotherapy (151 patients from a German Low-Grade Lymphoma Study Group [GLSG] trial and 107 patients from a population-based registry of the British Columbia Cancer Agency [BCCA]) to validate the predictive utility of POD24, and to evaluate the ability of pretreatment risk models to predict early treatment failure. POD24 occurred in 17% and 23% of evaluable GLSG and BCCA patients, with 5-year OS rates of 41% (vs 91% for those without POD24, P < .0001) and 26% (vs 86%, P < .0001), respectively. The m7-FL International Prognostic Index (m7-FLIPI), a prospective clinicogenetic risk model for failure-free survival, had the highest accuracy to predict POD24 (76% and 77%, respectively) with an odds ratio of 5.82 in GLSG (P = .00031) and 4.76 in BCCA patients (P = .0052). A clinicogenetic risk model specifically designed to predict POD24, the POD24-PI, had the highest sensitivity to predict POD24, but at the expense of a lower specificity. In conclusion, the m7-FLIPI prospectively identifies the smallest subgroup of patients (28% and 22%, respectively) at highest risk of early failure of first-line immunochemotherapy and death, including patients not fulfilling the POD24 criteria, and should be evaluated in prospective trials of precision medicine approaches in FL.
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http://dx.doi.org/10.1182/blood-2016-05-717355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457130PMC
August 2016

Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data.

Oncotarget 2016 Jul;7(30):47061-47081

Department of Haematology and Medical Oncology, University Medical Centre of the Georg-August University Göttingen, Göttingen, Germany.

To discover new regulatory pathways in B lymphoma cells, we performed a combined analysis of experimental, clinical and global gene expression data. We identified a specific cluster of genes that was coherently expressed in primary lymphoma samples and suppressed by activation of the B cell receptor (BCR) through αIgM treatment of lymphoma cells in vitro. This gene cluster, which we called BCR.1, includes numerous cell cycle regulators. A reduced expression of BCR.1 genes after BCR activation was observed in different cell lines and also in CD10+ germinal center B cells. We found that BCR activation led to a delayed entry to and progression of mitosis and defects in metaphase. Cytogenetic changes were detected upon long-term αIgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc co-regulated genes in distinct groups of lymphoma patients was observed. Finally, we showed that the BCR.1 index discriminates activated B cell-like and germinal centre B cell-like diffuse large B cell lymphoma supporting the functional relevance of this new regulatory circuit and the power of guided clustering for biomarker discovery.
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http://dx.doi.org/10.18632/oncotarget.9219DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5216924PMC
July 2016

Immunohistochemical detection of inhibitor of DNA binding 3 mutational variants in mature aggressive B-cell lymphoma.

Haematologica 2016 06 18;101(6):e259-61. Epub 2016 Mar 18.

Institute of Pathology, Hematopathology Section and Lymph Node Registry, University Hospital Schleswig-Holstein Campus Kiel, Christian-Albrechts University Kiel, Germany

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http://dx.doi.org/10.3324/haematol.2015.138701DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013970PMC
June 2016

DNA methylome analysis in Burkitt and follicular lymphomas identifies differentially methylated regions linked to somatic mutation and transcriptional control.

Nat Genet 2015 Nov 5;47(11):1316-1325. Epub 2015 Oct 5.

BLUEPRINT project.

Although Burkitt lymphomas and follicular lymphomas both have features of germinal center B cells, they are biologically and clinically quite distinct. Here we performed whole-genome bisulfite, genome and transcriptome sequencing in 13 IG-MYC translocation-positive Burkitt lymphoma, nine BCL2 translocation-positive follicular lymphoma and four normal germinal center B cell samples. Comparison of Burkitt and follicular lymphoma samples showed differential methylation of intragenic regions that strongly correlated with expression of associated genes, for example, genes active in germinal center dark-zone and light-zone B cells. Integrative pathway analyses of regions differentially methylated in Burkitt and follicular lymphomas implicated DNA methylation as cooperating with somatic mutation of sphingosine phosphate signaling, as well as the TCF3-ID3 and SWI/SNF complexes, in a large fraction of Burkitt lymphomas. Taken together, our results demonstrate a tight connection between somatic mutation, DNA methylation and transcriptional control in key B cell pathways deregulated differentially in Burkitt lymphoma and other germinal center B cell lymphomas.
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http://dx.doi.org/10.1038/ng.3413DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5444523PMC
November 2015

MINCR is a MYC-induced lncRNA able to modulate MYC's transcriptional network in Burkitt lymphoma cells.

Proc Natl Acad Sci U S A 2015 Sep 8;112(38):E5261-70. Epub 2015 Sep 8.

Institute of Pathology, University of Würzburg and Comprehensive Cancer Center Mainfranken, D-97080 Würzburg, Germany;

Despite the established role of the transcription factor MYC in cancer, little is known about the impact of a new class of transcriptional regulators, the long noncoding RNAs (lncRNAs), on MYC ability to influence the cellular transcriptome. Here, we have intersected RNA-sequencing data from two MYC-inducible cell lines and a cohort of 91 B-cell lymphomas with or without genetic variants resulting in MYC overexpression. We identified 13 lncRNAs differentially expressed in IG-MYC-positive Burkitt lymphoma and regulated in the same direction by MYC in the model cell lines. Among them, we focused on a lncRNA that we named MYC-induced long noncoding RNA (MINCR), showing a strong correlation with MYC expression in MYC-positive lymphomas. To understand its cellular role, we performed RNAi and found that MINCR knockdown is associated with an impairment in cell cycle progression. Differential gene expression analysis after RNAi showed a significant enrichment of cell cycle genes among the genes down-regulated after MINCR knockdown. Interestingly, these genes are enriched in MYC binding sites in their promoters, suggesting that MINCR acts as a modulator of the MYC transcriptional program. Accordingly, MINCR knockdown was associated with a reduction in MYC binding to the promoters of selected cell cycle genes. Finally, we show that down-regulation of Aurora kinases A and B and chromatin licensing and DNA replication factor 1 may explain the reduction in cellular proliferation observed on MINCR knockdown. We, therefore, suggest that MINCR is a newly identified player in the MYC transcriptional network able to control the expression of cell cycle genes.
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http://dx.doi.org/10.1073/pnas.1505753112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586867PMC
September 2015

Integration of gene mutations in risk prognostication for patients receiving first-line immunochemotherapy for follicular lymphoma: a retrospective analysis of a prospective clinical trial and validation in a population-based registry.

Lancet Oncol 2015 Sep 6;16(9):1111-1122. Epub 2015 Aug 6.

Haematopathology Section, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.

Background: Follicular lymphoma is a clinically and genetically heterogeneous disease, but the prognostic value of somatic mutations has not been systematically assessed. We aimed to improve risk stratification of patients receiving first-line immunochemotherapy by integrating gene mutations into a prognostic model.

Methods: We did DNA deep sequencing to retrospectively analyse the mutation status of 74 genes in 151 follicular lymphoma biopsy specimens that were obtained from patients within 1 year before beginning immunochemotherapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). These patients were recruited between May 4, 2000, and Oct 20, 2010, as part of a phase 3 trial (GLSG2000). Eligible patients had symptomatic, advanced stage follicular lymphoma and were previously untreated. The primary endpoints were failure-free survival (defined as less than a partial remission at the end of induction, relapse, progression, or death) and overall survival calculated from date of treatment initiation. Median follow-up was 7·7 years (IQR 5·5-9·3). Mutations and clinical factors were incorporated into a risk model for failure-free survival using multivariable L1-penalised Cox regression. We validated the risk model in an independent population-based cohort of 107 patients with symptomatic follicular lymphoma considered ineligible for curative irradiation. Pretreatment biopsies were taken between Feb 24, 2004, and Nov 24, 2009, within 1 year before beginning first-line immunochemotherapy consisting of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP). Median follow-up was 6·7 years (IQR 5·7-7·6).

Findings: We established a clinicogenetic risk model (termed m7-FLIPI) that included the mutation status of seven genes (EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP, and CARD11), the Follicular Lymphoma International Prognostic Index (FLIPI), and Eastern Cooperative Oncology Group (ECOG) performance status. In the training cohort, m7-FLIPI defined a high-risk group (28%, 43/151) with 5-year failure-free survival of 38·29% (95% CI 25·31-57·95) versus 77·21% (95% CI 69·21-86·14) for the low-risk group (hazard ratio [HR] 4·14, 95% CI 2·47-6·93; p<0·0001; bootstrap-corrected HR 2·02), and outperformed a prognostic model of only gene mutations (HR 3·76, 95% CI 2·10-6·74; p<0·0001; bootstrap-corrected HR 1·57). The positive predictive value and negative predictive value for 5-year failure-free survival were 64% and 78%, respectively, with a C-index of 0·80 (95% CI 0·71-0·89). In the validation cohort, m7-FLIPI again defined a high-risk group (22%, 24/107) with 5-year failure-free survival of 25·00% (95% CI 12·50-49·99) versus 68·24% (58·84-79·15) in the low-risk group (HR 3·58, 95% CI 2·00-6·42; p<0.0001). The positive predictive value for 5-year failure-free survival was 72% and 68% for negative predictive value, with a C-index of 0·79 (95% CI 0·69-0·89). In the validation cohort, risk stratification by m7-FLIPI outperformed FLIPI alone (HR 2·18, 95% CI 1·21-3·92), and FLIPI combined with ECOG performance status (HR 2·03, 95% CI 1·12-3·67).

Interpretation: Integration of the mutational status of seven genes with clinical risk factors improves prognostication for patients with follicular lymphoma receiving first-line immunochemotherapy and is a promising approach to identify the subset at highest risk of treatment failure.

Funding: Deutsche Krebshilfe, Terry Fox Research Institute.
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http://dx.doi.org/10.1016/S1470-2045(15)00169-2DOI Listing
September 2015

Clinical and pathological features of Burkitt lymphoma showing expression of BCL2--an analysis including gene expression in formalin-fixed paraffin-embedded tissue.

Br J Haematol 2015 Nov 27;171(4):501-8. Epub 2015 Jul 27.

Department of Pathology, Haematopathology Section and Lymph Node Registry, University Hospital Schleswig-Holstein, Campus Kiel/Christian-Albrecht University, Kiel, Germany.

The differential diagnosis between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) can be challenging. BL has been reported to express less BCL2 than DLBCL, but this issue has not been analysed systematically. BL expressing BCL2 can be considered to be MYC/BCL2 co-expressors, a feature that is associated with poorer outcome in DLBCL but that has not been correlated with outcome in BL so far. We analysed the expression of BCL2 in 150 cases of conventionally diagnosed BL using two different BCL2 antibodies. BCL2 expression was detected in 23% of the cases, though the expression varied in intensity and number of positive cells. We did not detect any relevant differences in clinical presentation and outcome between BCL2-positive and BCL2-negative BL in a subgroup of 43 cases for which detailed clinical data were available. An independent cohort of 17 BL with expression of BCL2 were analysed molecularly, with 13 of 17 cases classified as molecularly defined BL (Burkitt Lymphoma) using gene expression profiling on formalin-fixed paraffin-embedded tissues. The four lymphomas diagnosed molecularly as intermediates did not differ in clinical presentation and outcome from molecularly defined BL.
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http://dx.doi.org/10.1111/bjh.13624DOI Listing
November 2015

The PCBP1 gene encoding poly(rC) binding protein I is recurrently mutated in Burkitt lymphoma.

Genes Chromosomes Cancer 2015 Sep 14;54(9):555-64. Epub 2015 Jul 14.

Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.

The genetic hallmark of Burkitt lymphoma is the translocation t(8;14)(q24;q32), or one of its light chain variants, resulting in IG-MYC juxtaposition. However, these translocations alone are insufficient to drive lymphomagenesis, which requires additional genetic changes for malignant transformation. Recent studies of Burkitt lymphoma using next generation sequencing approaches have identified various recurrently mutated genes including ID3, TCF3, CCND3, and TP53. Here, by using similar approaches, we show that PCBP1 is a recurrently mutated gene in Burkitt lymphoma. By whole-genome sequencing, we identified somatic mutations in PCBP1 in 3/17 (18%) Burkitt lymphomas. We confirmed the recurrence of PCBP1 mutations by Sanger sequencing in an independent validation cohort, finding mutations in 3/28 (11%) Burkitt lymphomas and in 6/16 (38%) Burkitt lymphoma cell lines. PCBP1 is an intron-less gene encoding the 356 amino acid poly(rC) binding protein 1, which contains three K-Homology (KH) domains and two nuclear localization signals. The mutations predominantly (10/12, 83%) affect the KH III domain, either by complete domain loss or amino acid changes. Thus, these changes are predicted to alter the various functions of PCBP1, including nuclear trafficking and pre-mRNA splicing. Remarkably, all six primary Burkitt lymphomas with a PCBP1 mutation expressed MUM1/IRF4, which is otherwise detected in around 20-40% of Burkitt lymphomas. We conclude that PCBP1 mutations are recurrent in Burkitt lymphomas and might contribute, in cooperation with other mutations, to its pathogenesis.
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http://dx.doi.org/10.1002/gcc.22268DOI Listing
September 2015

Sequential karyotyping in Burkitt lymphoma reveals a linear clonal evolution with increase in karyotype complexity and a high frequency of recurrent secondary aberrations.

Br J Haematol 2015 Sep 24;170(6):814-25. Epub 2015 Jun 24.

Institute of Human Genetics, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel, Kiel, Germany.

Typical Burkitt lymphoma is characterized by an IG-MYC translocation and overall low genomic complexity. Clinically, Burkitt lymphoma has a favourable prognosis with very few relapses. However, the few patients experiencing disease progression and/or relapse have a dismal outcome. Here we report cytogenetic findings of seven cases of Burkitt lymphoma in which sequential karyotyping was performed at time of diagnosis and/or disease progression/relapse(s). After case selection, karyotype re-review and additional molecular analyses were performed in six paediatric cases, treated in Berlin-Frankfurt-Münster-Non-Hodgkin lymphoma study group trials, and one additional adult patient. Moreover, we analysed 18 cases of Burkitt lymphoma from the Mitelman database in which sequential karyotyping was performed. Our findings show secondary karyotypes to have a significant increase in load of cytogenetic aberrations with a mean number of 2, 5 and 8 aberrations for primary, secondary and third investigations. Importantly, this increase in karyotype complexity seemed to result from recurrent secondary chromosomal changes involving mainly trisomy 21, gains of 1q and 7q, losses of 6q, 11q, 13q, and 17p. In addition, our findings indicate a linear clonal evolution to be the predominant manner of cytogenetic evolution. Our data may provide a biological framework for the dismal outcome of progressive and relapsing Burkitt lymphoma.
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http://dx.doi.org/10.1111/bjh.13501DOI Listing
September 2015

Epstein-Barr virus-negative diffuse large B-cell lymphoma hosts intra- and peritumoral B-cells with activated Epstein-Barr virus.

Virchows Arch 2015 Jan 23;466(1):85-92. Epub 2014 Oct 23.

Department of Pathology, Hematopathology Section and Lymph Node Registry, Christian-Albrecht University, Kiel, Germany,

Although the vast majority of diffuse large B-cell lymphomas (DLBCL) are negative for the Epstein-Barr virus (EBV), a subset of DLBCL in immunocompetent patients carries EBV in the lymphoma cells and expresses EBV-encoded RNA and/or proteins. EBV-positive DLBCL are rare and represent either pyothorax associated DLBCL or EBV-positive DLBCL of the elderly. In all cases of EBV-positive DLBCL, EBV is detectable in virtually all lymphoma cells, indicating that EBV was present at an initial phase of lymphomagenesis. We identified four lymphomas with an unusual EBV expression pattern. The majority of B-cell blasts were EBV-negative, but accompanied by a small number (less than 10 % of all B-cells) of EBV-positive B-cells with blastic morphology. The median age of the patients was 56.5 years, and no clinically evident immunosuppression was reported. In one patient EBV-positive blasts occurred in the gastric mucosa which resembled an EBV-positive mucocutaneous ulcer. In all cases EBV-positive B-cells occurred in small loose clusters within or adjacent to an EBV-negative DLBCL. In one case we were able to study immunoglobulin gene rearrangement in microdissected EBV-positive B-cells and the EBV-negative lymphoma compartment. This revealed different rearrangement patterns in EBV-negative DLBCL than in EBV-positive peritumoral B-cells, without clonal relationship between these B-cell populations. Despite the molecular data being limited to one patient, we suggest that in close proximity to EBV-negative DLBCL intra- and peritumoral EBV-positive B-cells may occur, possibly due to local immune escape mechanisms. This represents a diagnostic pitfall.
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http://dx.doi.org/10.1007/s00428-014-1661-zDOI Listing
January 2015

Multiplex ligation-dependent probe amplification validates LOH6q analyses and enhances insight into chromosome 6q aberrations in pediatric T-cell lymphoblastic leukemia and lymphoma.

Leuk Lymphoma 2015 Jun 19;56(6):1884-7. Epub 2014 Nov 19.

NHL-BFM Study Center and Department of Pediatric Hematology and Oncology, Justus Liebig University Giessen , Giessen , Germany.

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http://dx.doi.org/10.3109/10428194.2014.976820DOI Listing
June 2015
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