Publications

76 Publications visible to you, out of a total of 76

Abstract (Expand)

We investigated 41 diffuse large B-cell lymphomas (DLBCL) diagnosed at one center harboring >/=50% of latently Epstein-Barr virus (EBV)-infected neoplastic cells occurring in 34 patients aged >/=50 years and in 7 patients younger than 50 years in the absence of any known immunodeficiency for the expression patterns of EBV latent and immediate-early proteins, for the differentiation stage of the neoplastic cells, the presence of cytogenetic alterations and a possible co-infection with the human herpes virus (HHV)-8. Here, we show that EBV-positive DLBCLs rarely arise from naive and more frequently from post-germinal center B-cells that often contain crippling immunoglobulin gene mutations. Most of the lymphomas did not exhibit breaks in the BCL2, BCL6, and MYC genes and none of the cases investigated contained HHV-8 sequences. Patients aged <50 years performed better than older ones while in patients aged >/=50 years only the cellular composition had an impact on overall survival.

Authors: K. Johrens, R. U. Trappe, D. Lenze, M. Pfreundschuh, M. Ziepert, M. Hummel, I. Anagnostopoulos

Date Published: 29th Apr 2016

Publication Type: Not specified

Human Diseases: diffuse large B-cell lymphoma

Abstract (Expand)

BACKGROUND: Histologically, follicular lymphoma (FL) grades 1, 2 and 3A are composed of two distinct cell types, centroblasts and centrocytes. FL grade 3B is composed only of centroblasts and has been shown to differ in immunophenotype and genetics from FL that contain centrocytes. We aimed to understand the pathogenetic and clinical relation between FL grade 3A to FL grade 1/2 on the one hand and FL grade 3B on the other hand. PATIENTS AND METHODS: Trial patients with long-term follow-up and diagnosis of FL grade 3 were selected and samples underwent a second central pathological review using a multiple-observer approach to assess grading. RESULTS: Interobserver variability for diagnosing FL grade 3 was high. FL grade 3A frequently harbored areas of FL grade 1/2 within the same tissue specimen. FL grade 3B rarely coexisted with grade 1/2 or 3A, suggesting divergent pathogenesis. There was no statistically significant difference in outcome between 47 cases of FL grade 3A and 14 cases of grade 3B. Compared with grade 1/2 FL, both groups showed longer progression-free survival without late events, especially after immunochemotherapy; this outcome difference was retained after adjustment for clinical prognostic factors. The subgroup of FL grade 3A with an additional FL grade 1/2 component or a translocation t(14;18) showed a poorer outcome. In contrast, the FL grade 3A lacking t(14;18) and of localized stage resembled the pediatric type of FL and showed a very good outcome. FL3 with MYC breaks showed a poor outcome. CONCLUSIONS: The results suggest that first-line immunochemotherapy might allow long-lasting remissions in a subgroup of FL grade 3A similar to diffuse large B-cell lymphoma. Within FL3A, prognostic subgroups can be identified by analyzing for coexisting FL1/2 and MYC breaks.

Authors: K. Koch, E. Hoster, M. Ziepert, M. Unterhalt, G. Ott, A. Rosenwald, M. L. Hansmann, W. Bernd, H. Stein, V. Poschel, M. Dreyling, L. Trumper, M. Loffler, N. Schmitz, W. Hiddemann, M. Pfreundschuh, W. Klapper

Date Published: 28th Apr 2016

Publication Type: Not specified

Human Diseases: follicular lymphoma

Abstract (Expand)

We systematically studied the expression of more than fifty histone and DNA (de)methylating enzymes in lymphoma and healthy controls. As a main result, we found that the expression levels of nearly all enzymes become markedly disturbed in lymphoma, suggesting deregulation of large parts of the epigenetic machinery. We discuss the effect of DNA promoter methylation and of transcriptional activity in the context of mutated epigenetic modifiers such as EZH2 and MLL2. As another mechanism, we studied the coupling between the energy metabolism and epigenetics via metabolites that act as cofactors of JmjC-type demethylases. Our study results suggest that Burkitt's lymphoma and diffuse large B-cell Lymphoma differ by an imbalance of repressive and poised promoters, which is governed predominantly by the activity of methyltransferases and the underrepresentation of demethylases in this regulation. The data further suggest that coupling of epigenetics with the energy metabolism can also be an important factor in lymphomagenesis in the absence of direct mutations of genes in metabolic pathways. Understanding of epigenetic deregulation in lymphoma and possibly in cancers in general must go beyond simple schemes using only a few modes of regulation.

Authors: L. Hopp, L. Nersisyan, H. Loffler-Wirth, A. Arakelyan, H. Binder

Date Published: 21st Oct 2015

Publication Type: Not specified

Human Diseases: non-Hodgkin lymphoma

Abstract (Expand)

Mature B-cell lymphoma is a clinically and biologically highly diverse disease. Its diagnosis and prognosis is a challenge due to its molecular heterogeneity and diverse regimes of biological dysfunctions, which are partly driven by epigenetic mechanisms. We here present an integrative analysis of DNA methylation and gene expression data of several lymphoma subtypes. Our study confirms previous results about the role of stemness genes during development and maturation of B-cells and their dysfunction in lymphoma locking in more proliferative or immune-reactive states referring to B-cell functionalities in the dark and light zone of the germinal center and also in plasma cells. These dysfunctions are governed by widespread epigenetic effects altering the promoter methylation of the involved genes, their activity status as moderated by histone modifications and also by chromatin remodeling. We identified four groups of genes showing characteristic expression and methylation signatures among Burkitt's lymphoma, diffuse large B cell lymphoma, follicular lymphoma and multiple myeloma. These signatures are associated with epigenetic effects such as remodeling from transcriptionally inactive into active chromatin states, differential promoter methylation and the enrichment of targets of transcription factors such as EZH2 and SUZ12.

Authors: L. Hopp, H. Loffler-Wirth, H. Binder

Date Published: 7th Sep 2015

Publication Type: Not specified

Human Diseases: non-Hodgkin lymphoma, B-cell lymphoma

Abstract (Expand)

BACKGROUND: Chemotherapy-associated ovarian damage comprises not only infertility, but also premature menopause. The latter has been reported as a consequence of alkylating chemotherapy for breast cancer or Hodgkin's lymphoma. In this study, we assessed the long-term impact of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like regimens on ovarian function in patients with aggressive non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS: Long-term survivors after CHOP or CHOP plus etoposide (CHOEP) treatment within the Mabthera International Trial or the NHL-B1 trial of the German NHL Study Group were requested to respond to a questionnaire and to consent to blood sampling for hormone assessment. RESULTS: A total of 46 of 81 contacted patients with a median age of 32.5 years at the time of enrolment into the aforementioned clinical trials responded to the questionnaire. The median follow-up after completion of treatment was 14 years. Last menstrual bleeding occurred significantly earlier in patients compared with the general population (47 versus 51 years, P < 0.0001). In comparison to the distribution of menopausal symptoms in the general population, the percentage of women with moderate or severe menopausal symptoms was increased. In 23 patients who agreed to participate in laboratory analyses, anti-Muller hormone as a marker of ovarian reserve was decreased when compared with correspondent age groups of the general population. CONCLUSION: Although most female patients regain fertility after CHOP-like chemotherapy, late ovarian impairment occurs frequently. Therefore, awareness of such delayed side-effects at the time of counselling is of importance.

Authors: J. Meissner, D. Tichy, V. Katzke, T. Kuhn, S. Dietrich, T. Schmitt, M. Ziepert, E. Kuhnt, T. Rixecker, M. Zorn, M. Witzens-Harig, M. Pfreundschuh, A. D. Ho

Date Published: 13th May 2015

Publication Type: Not specified

Human Diseases: lymphoma

Abstract (Expand)

AIM: To identify gene variants responsible for anthracycline-induced cardiotoxicity. PATIENTS & METHODS: Polymorphisms of the NADPH oxidase subunits and of the anthracycline transporters ABCC1, ABCC2 and SLC28A3 were genotyped in elderly patients (61-80 years) treated for aggressive CD20(+) B-cell lymphomas with CHOP-14 with or without rituximab and followed up for 3 years. RESULTS: The accumulation of RAC2 subunit genotypes TA/AA among cases was statistically significant upon adjustment for gender, age and doxorubicin dose in a multivariate logistic regression analysis (OR: 2.3, p = 0.028; univariate: OR: 1.8, p = 0.077). RAC2 and CYBA genotypes were significantly associated with anthracycline-induced cardiotoxicity in a meta-analysis of this and a similar previous study. CONCLUSION: Our results support the theory that NADPH oxidase is involved in anthracycline-induced cardiotoxicity. Original submitted 9 July 2014; Revision submitted 19 December 2014.

Authors: A. Reichwagen, M. Ziepert, M. Kreuz, U. Godtel-Armbrust, T. Rixecker, V. Poeschel, M. Reza Toliat, P. Nurnberg, M. Tzvetkov, S. Deng, L. Trumper, G. Hasenfuss, M. Pfreundschuh, L. Wojnowski

Date Published: 1st Apr 2015

Publication Type: Not specified

Human Diseases: B-cell lymphoma

Abstract (Expand)

The pathogenesis of diffuse large B-cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by single nucleotide polymorphism (SNP)-chips to characterize genomic imbalances. Seventy-nine cases were of the germinal center B-cell like (GCB) type of DLBCL, 49 of the activated B-cell like (ABC) subtype and 20 were unclassified DLBCL. Twenty-four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC-DLBCL and 19 per case for GCB-DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB- and ABC-DLBCL subgroups, including gains of HDAC7A predominantly in GCB-DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC-DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in ten and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. Our study thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.

Authors: R. Scholtysik, M. Kreuz, M. Hummel, M. Rosolowski, M. Szczepanowski, W. Klapper, M. Loeffler, L. Trumper, R. Siebert, R. Kuppers

Date Published: 1st Mar 2015

Publication Type: Not specified

Human Diseases: diffuse large B-cell lymphoma

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