Mature Aggressive B-cell Lymphomas Research Articles

MicroRNA Expression in High-Grade B-Cell Lymphoma With 11q Aberration.

Mature aggressive B-cell lymphomas, such as Burkitt lymphoma (BL) and Diffuse large B-cell lymphoma (DLBCL), show variations in microRNA (miRNA) expression. The entity of High-grade B-cell lymphoma with 11q aberration (HGBCL-11q) shares several biological features with both BL and DLBCL but data on its miRNA expression profile are yet scarce. Hence, this study aims to analyze the potential differences in miRNA expression of HGBCL-11q compared to BL and DLBCL. We evaluated the expression profiles of 2083 miRNAs in 25 HGCBL-11q, 7 BL, 131 DLBCL, and tonsils using the HTG EdgeSeq miRNA whole transcriptome assay. Uniform manifold approximation and projection (UMAP) and differential gene expression analyses based on DESeq2 were carried out. UMAP analysis of miRNA expression did not reveal distinct groups among the studied lymphomas. However, differential gene expression investigations detected sets of overexpressed miRNAs in HGBCL-11q when compared to BL (miR-9-3p, miR-9-5p, miR-3919, miR-129-1-3p, miR-129-2-3p, miR-331-3p, miR-196b-5p, and miR-28-5p) and DLBCL (miR-3919, miR-1290, miR-4538, and miR-4791), respectively. Notably, miR-3919 showed heterogeneous but significantly higher expression (p-value < 0.001) in HGBCL-11q than in both, BL and DLBCL. We identified a group of differentially expressed miRNAs between HGBCL-11q vs. BL and DLBCL, with miR-3919 as the most commonly and recurrently overexpressed miRNA in HGBCL-11q.

Beklenmedik bir lokalizasyonda ortaya çıkan primer mediastinal büyük B hücreli lenfoma

Primary mediastinal large B-cell lymphoma (PMLBCL) is a mature aggressive large B-cell lymphoma of putative thymic B-cell origin arising in the mediastinum, with distinctive clinical, immunophenotypic, genotypic, and molecular features. Cases that arise outside the mediastinum are very uncommon. A 27-year-old woman presented with mass which had an extramedullary, extradural component at the right T5-6 foramina indenting to the spinal canal, extending craniocaudally from the middle mediastinum to the level of the aortic hiatus. Pathological examination of the mass revealed atypical lymphoid cells with medium-large size, eosinophilic and clear cytoplasm In our case CD23 and MAL expression with morphological findings supported PMLBCL. PMLBCL may be seen with abnormal localization and clinical presentation. Immunohistochemical profile including MAL is helpful to detect these cases.

Patient parameters and response after administration of rituximab in pediatric mature B-cell non-Hodgkin lymphoma.

Mature aggressive B-cell lymphomas are heterogenous malignancies that make up more than half of all diagnosed non-Hodgkin lymphoma in children and adolescents. The overall survival rate increased over the last decades to 80%-90% due to fine tuning of polychemotherapy. However, new therapeutic implications are needed to further increase the overall survival. Current clinical trials analyze the therapeutic effect of rituximab in pediatric patients, while the mechanism of action in vivo is still not fully understood. Effector molecules important for tumor defense were analyzed before and at day 5 after rituximab treatment via flow cytometry. Serum rituximab levels were measured with an ELISA. We evaluated patient parameters that may affect treatment response in relation to rituximab administration and serum rituximab levels. We indeed found a reduction of Fcγ receptor (FcγR) II levels after rituximab treatment in monocyte subtypes, whereas FcγRI expression was significantly increased. Serum levels of proinflammatory marker proteins S100A8/A9 and S100A12 significantly decreased after treatment to normal levels from an overall proinflammatory state before treatment. CD57, perforin, and granzyme B expression decreased after treatment, comprising a less cytolytic natural killer (NK) cell population. The highlighted effects of rituximab treatment on patient's immune response help in understanding the biology behind tumor defense mechanisms and effector function. After subsequent studies, these novel insights might be translated into patient care and could contribute to improve treatment of pediatric patients with mature aggressive B-cell lymphoma.

Evidence for IL-35 Expression in Diffuse Large B-Cell Lymphoma and Impact on the Patient's Prognosis.

IL-35 is an immunosuppressive cytokine of the IL-12 family consisting of two subunits, EBV-induced gene 3 (EBI3) and p35. It has been shown to play a pro-tumor role in murine tumor models, and in various types of human cancer such as colorectal, pancreatic, or liver carcinoma, its expression has been associated with a worse clinical outcome. Here, we show by analyzing gene expression data from public databases and by immunohistochemical studies that IL-35 is overexpressed by tumor cells in diffuse-large B-cell lymphoma (DLBCL) compared to another type of mature aggressive B-cell lymphoma, Burkitt lymphoma. However, while high IL-35 expression was significantly associated with a worse overall survival in DLBCL patients treated with chemotherapy only (cyclophosphamide, doxorubicin, vincristine, prednisone, CHOP), no significant correlation between IL-35 expression levels and the patient outcome was observed in DLBCL patients treated with CHOP combined to rituximab (R-CHOP), the current conventional treatment. In addition, we found that an anti-IL-35 antibody, clone 15k8D10, used to assess IL-35 expression by immunohistochemistry in various human tissues including tumors does not recognize IL-35 heterodimer, nor its individual subunits EBI3 and p35, but cross-reacts with human IgG1, indicating that IL-35 expression in human cancers needs to be re-evaluated.

Genomics of aggressive B-cell lymphoma.

The growing body of genomic information collected and applied to mature aggressive B-cell lymphoma diagnosis and management has exploded over the last few years due to improved technologies with high-throughput capacity, suitable for use on routine formalin-fixed, paraffin-embedded tissue biopsies, and decreasing costs. These techniques have made evaluation of complete DNA sequences, RNA-expression patterns, translocations, copy-number alterations, loss of heterozygosity, and DNA-methylation patterns possible on a genome-wide level. This chapter will present a case of aggressive B-cell lymphoma and discuss the most important genomic abnormalities that characterize this group of entities in the recent update to the fourth edition of the World Health Organization (WHO) lymphoma classification system. Genomic abnormalities discussed will include those necessary for certain diagnoses such as translocations of MYC, BCL2, or BCL6; gene-expression-profiling categorization; the newly defined Burkitt-like lymphoma with 11q abnormalities; prognostic and predictive mutations, as well as tumor heterogeneity. Finally, our current practices for clinical triage of specimens with a potential diagnosis of aggressive B-cell lymphomas are also described. Options for treatment at relapse, in light of these genomic features, will be discussed in the third presentation from this session.

Portraying the Expression Landscapes of B-CellLymphoma-Intuitive Detection of Outlier Samples and of Molecular Subtypes.

We present an analytic framework based on Self-Organizing Map (SOM) machine learning to study large scale patient data sets. The potency of the approach is demonstrated in a case study using gene expression data of more than 200 mature aggressive B-cell lymphoma patients. The method portrays each sample with individual resolution, characterizes the subtypes, disentangles the expression patterns into distinct modules, extracts their functional context using enrichment techniques and enables investigation of the similarity relations between the samples. The method also allows to detect and to correct outliers caused by contaminations. Based on our analysis, we propose a refined classification of B-cell Lymphoma into four molecular subtypes which are characterized by differential functional and clinical characteristics.

Massive Transcriptional Perturbation in Subgroups of Diffuse Large B-Cell Lymphomas

Based on the assumption that molecular mechanisms involved in cancerogenesis are characterized by groups of coordinately expressed genes, we developed and validated a novel method for analyzing transcriptional data called Correlated Gene Set Analysis (CGSA). Using 50 extracted gene sets we identified three different profiles of tumors in a cohort of 364 Diffuse large B-cell (DLBCL) and related mature aggressive B-cell lymphomas other than Burkitt lymphoma. The first profile had high level of expression of genes related to proliferation whereas the second profile exhibited a stromal and immune response phenotype. These two profiles were characterized by a large scale gene activation affecting genes which were recently shown to be epigenetically regulated, and which were enriched in oxidative phosphorylation, energy metabolism and nucleoside biosynthesis. The third and novel profile showed only low global gene activation similar to that found in normal B cells but not cell lines. Our study indicates novel levels of complexity of DLBCL with low or high large scale gene activation related to metabolism and biosynthesis and, within the group of highly activated DLBCLs, differential behavior leading to either a proliferative or a stromal and immune response phenotype.

The combined expression of VPREB3 and ID3 represents a new helpful tool for the routine diagnosis of mature aggressive B‐cell lymphomas

Genomic studies, such as gene expression profiling and next-generation sequencing studies, have provided new insights into the phenotypic characteristics and pathogenesis of mature aggressive B-cell lymphomas. In particular, mutations in the transcription factors ID3 and TCF3, leading to overexpression of B-cell receptor components such as VPREB3, have been shown to be specific for Burkitt lymphoma (BL) and play an important tumourigenic role by mediating the activation of the pro-survival phosphatidylinositol-3-OH kinase pathway. We performed immunohistochemical analysis by applying commercially available anti-VPREB3 antibody to a large cohort of 185 genetically and immunophenotypically characterized mature aggressive B-cell lymphomas and analyzed these results together with recent data on ID3 expression. The combined expression of both VPREB3 and ID3 was associated with a diagnosis of BL with high sensitivity (0.77), high specificity (0.75) and high negative predictive values (0.96), however, with lower positive predictive value (0.30). Double negative cases were absent in the group of BLs but could be found in approximately one third of the remaining cases of mature aggressive B-cell lymphomas. Further, we could not identify a correlation with MYC, BCL2 or BCL6 aberrations with neither VPREB3 nor ID3 expression in each of the diagnostic groups analyzed. Our results, which are in line with recently discovered mutations in next-generation sequencing studies, suggest that the combined immunohistochemical detection of VPREB3 and ID3 is applicable to the routine diagnostic in case of mature aggressive B-cell lymphomas. In particular, it represents a useful and routinely applicable diagnostic tool to exclude BL diagnosis in case of single positive or double negative cases.

Genetic sequencing studies in Burkitt’s lymphoma: what can we learn about tumorigenesis?

Burkitt’s lymphoma (BL) is a mature aggressive B-cell lymphoma with an extremely short doubling time that often presents in extranodal sites or less frequently as an acute leukemia. The morphologic...

Recurrent mutation of the ID3 gene in Burkitt lymphoma identified by integrated genome, exome and transcriptome sequencing

Burkitt lymphoma is a mature aggressive B-cell lymphoma derived from germinal center B cells. Its cytogenetic hallmark is the Burkitt translocation t(8;14)(q24;q32) and its variants, which juxtapose the MYC oncogene with one of the three immunoglobulin loci. Consequently, MYC is deregulated, resulting in massive perturbation of gene expression. Nevertheless, MYC deregulation alone seems not to be sufficient to drive Burkitt lymphomagenesis. By whole-genome, whole-exome and transcriptome sequencing of four prototypical Burkitt lymphomas with immunoglobulin gene (IG)-MYC translocation, we identified seven recurrently mutated genes. One of these genes, ID3, mapped to a region of focal homozygous loss in Burkitt lymphoma. In an extended cohort, 36 of 53 molecularly defined Burkitt lymphomas (68%) carried potentially damaging mutations of ID3. These were strongly enriched at somatic hypermutation motifs. Only 6 of 47 other B-cell lymphomas with the IG-MYC translocation (13%) carried ID3 mutations. These findings suggest that cooperation between ID3 inactivation and IG-MYC translocation is a hallmark of Burkitt lymphomagenesis.

Patient age at diagnosis is associated with the molecular characteristics of diffuse large B-cell lymphoma

AbstractDiffuse large B-cell lymphoma is the most frequent type of B-cell lymphoma in adult patients but also occurs in children. Patients are currently assigned to therapy regimens based on arbitrarily chosen age limits only (eg, 18 or 60 years) and not biologically justified limits. A total of 364 diffuse large B-cell lymphomas and related mature aggressive B-cell lymphomas other than Burkitt lymphoma from all age groups were analyzed by comprehensive molecular profiling. The probability of several biologic features previously reported to be associated with poor prognosis in diffuse large B-cell lymphoma, such as ABC subtype, BCL2 expression, or cytogenetic complexity, increases with age at diagnosis. Similarly, various genetic features, such as IRF4 translocations, gains in 1q21, 18q21, 7p22, and 7q21, as well as changes in 3q27, including gains and translocations affecting the BCL6 locus, are significantly associated with patient age, but no cut-offs between age groups could be defined. If age was incorporated in multivariate analyses, genetic complexity lost its prognostic significance, whereas the prognostic impact of ABC subtype and age were additive. Our data indicate that aging is a major determinant of lymphoma biology. They challenge current concepts regarding both prognostic biomarkers and treatment stratification based on strict age cut-offs.

Epstein-Barr Virus-Induced Gene 3 (EBI3): A Novel Diagnosis Marker in Burkitt Lymphoma and Diffuse Large B-Cell Lymphoma

The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), two types of mature aggressive B-cell lymphomas that require distinct treatments, can be difficult because of forms showing features intermediate between DLBCL and BL (here called BL/DLBCL). They can be discriminated by the presence of c-myc translocations characteristic of BL. However, these are not exclusive of BL and when present in DLBCL are associated with lower survival. In this study, we show that Epstein-Barr virus-induced gene 3 (EBI3) is differentially expressed among BL and DLBCL. Analysis of gene expression data from 502 cases of aggressive mature B-cell lymphomas available on Gene Expression Omnibus and immunohistochemical analysis of 184 cases of BL, BL/DLBCL or DLBCL, showed that EBI3 was not expressed in EBV-positive or -negative BL cases, whereas it was expressed by over 30% of tumoral cells in nearly 80% of DLBCL cases, independently of their subtypes. In addition, we show that c-myc overexpression represses EBI3 expression, and that DLBCL or BL/DLBCL cases with c-myc translocations have lower expression of EBI3. Thus, EBI3 immunohistochemistry could be useful to discriminate BL from DLBCL, and to identify cases of BL/DLBCL or DLBCL with potential c-myc translocations.

Morphological, immunophenotypic and molecular characterization of mature aggressive B-cell lymphomas in Chinese pediatric patients

Differential diagnosis of Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) and B cell lymphoma, unclassifiable, with features intermediate between BL and DLBCL (intermediate BL/DLBCL) can be difficult. We studied 97 Chinese pediatric mature aggressive B-cell lymphomas including 81 BL cases, eight DLBCL cases and eight intermediate BL/DLBCL cases using immunohistochemistry, interphase fluorescence in situ hybridization (FISH) and Epstein–Barr virus (EBV) in situ hybridization. Our results showed that there were no significant differences in the expression of CD10 and BCL6 among cases of BL (91% and 86%, respectively), DLBCL (75% and 63%, respectively) and intermediate BL/DLBCL (75% and 63%, respectively) (p > 0.05). The expression of BCL2 (3% in BL, 50% in DLBCL, 50% in intermediate BL/DLBCL), expression of MUM1 (17% in BL, 63% in DLBCL, 63% in intermediate BL/DLBCL) and mean Ki-67 proliferation index (PI) (93% in BL, 83% in DLBCL, 80% in intermediate BL/DLBCL) were significantly different between BL and DLBCL and between BL and intermediate BL/DLBCL. The frequency of an extra copy of BCL6 (0% in BL, 37.5% in DLBCL, 25% in intermediate BL/DLBCL) and EBV-encoded RNA (EBER) positivity (48% in BL, 0% in DLBCL and intermediate BL/DLBCL) were also significantly different between BL and DLBCL and between BL and intermediate BL/DLBCL. The frequency of C-MYC rearrangement in BL (98%) was much higher than in DLBCL (37.5%) and intermediate BL/DLBCL (50%). Our findings suggest that diagnosis of the mature aggressive B-cell lymphomas in pediatrics should be based on the comprehensive review and integration of morphological, immunohistochemical and molecular genetic features. The expression of CD10 and BCL6 but not BCL2, a high Ki-67 PI (>90%) and a C-MYC rearrangement but not BCL2 or BCL6 rearrangement are the features of BL. MUM1 is not an exclusionary diagnostic marker for BL. As the immunophenotype and molecular genetic features of DLBCL and intermediate BL/DLBCL are similar, intermediate BL/DLBCL is more likely a subgroup of DLBCL in the pediatric population. Regardless of the expression of CD10 and BCL6, strong staining for BCL2, Ki-67 PI below 90% and the presence of extra copies of BCL6 favor a diagnosis of DLBCL or intermediate BL/DLBCL.

The Gray Zone Between Burkitt's Lymphoma and Diffuse Large B-Cell Lymphoma From a Genetics Perspective

It has long been recognized that the border between classical Burkitt's lymphoma (BL) and classical diffuse large B-cell lymphoma (DLBCL) is hard to determine. Instead, both classical lymphoma entities seem to be the extreme ends of a spectrum of diseases that contains a group of lymphomas characterized predominately by the fact that they are hard to assign to the one or the other group. This gray zone has been recently termed "lymphoma, unclassifiable, with features intermediate between DLBCL and BL" by the updated WHO classification. The term "intermediate" resembles that from a recent gene-expression study of mature aggressive B-cell lymphomas, although, notably, it is used differently. Intermediate lymphomas according to the WHO classification clearly are a temporary container of different biologic subtypes of aggressive lymphoma, from which several might be associated with an unfavorable clinical outcome. The present review aims at describing the morphologic, clinical, and biologic heterogeneity of the intermediate lymphomas and, moreover, attempts to propose testable subgroups based on age and presence of genetic aberrations.

New insights into the biology and origin of mature aggressive B-cell lymphomas by combined epigenomic, genomic, and transcriptional profiling

AbstractLymphomas are assumed to originate at different stages of lymphocyte development through chromosomal aberrations. Thus, different lymphomas resemble lymphocytes at distinct differentiation stages and show characteristic morphologic, genetic, and transcriptional features. Here, we have performed a microarray-based DNA methylation profiling of 83 mature aggressive B-cell non-Hodgkin lymphomas (maB-NHLs) characterized for their morphologic, genetic, and transcriptional features, including molecular Burkitt lymphomas and diffuse large B-cell lymphomas. Hierarchic clustering indicated that methylation patterns in maB-NHLs were not strictly associated with morphologic, genetic, or transcriptional features. By supervised analyses, we identified 56 genes de novo methylated in all lymphoma subtypes studied and 22 methylated in a lymphoma subtype–specific manner. Remarkably, the group of genes de novo methylated in all lymphoma subtypes was significantly enriched for polycomb targets in embryonic stem cells. De novo methylated genes in all maB-NHLs studied were expressed at low levels in lymphomas and normal hematopoietic tissues but not in nonhematopoietic tissues. These findings, especially the enrichment for polycomb targets in stem cells, indicate that maB-NHLs with different morphologic, genetic, and transcriptional background share a similar stem cell–like epigenetic pattern. This suggests that maB-NHLs originate from cells with stem cell features or that stemness was acquired during lymphomagenesis by epigenetic remodeling.

Pathway activation patterns in diffuse large B-cell lymphomas

Deregulation of cell signaling pathways controlling cell growth and cell survival is a common feature of all cancers. Although a core repertoire of oncogenic mechanisms is widely conserved between various malignancies, the constellation of pathway activities can vary even in patients with the same malignant disease. Modern molecularly targeted cancer drugs intervene in cell signaling compensating for pathway deregulation. Hence characterizing tumors with respect to pathway activation will become crucial for treatment decisions. Here we have used semi-supervised machine learning methodology to generate signatures of eight oncogene-inducible pathways, which are conserved across epithelial and lymphoid tissues. We combined them to patterns of pathway activity called PAPs for pathway activation patterns and searched for them in 220 morphologically, immunohistochemically and genetically well-characterized mature aggressive B-cell lymphomas including 134 cases with clinical data available. Besides Burkitt lymphoma, which was characterized by a unique pattern, the PAPs identified four distinct groups of mature aggressive B-cell lymphomas across independent gene expression studies with distinct biological characteristics, genetic aberrations and prognosis. We confirmed our findings through cross-platform analysis in an independent data set of 303 mature aggressive B-cell lymphomas.

Gene Expression Studies in Mature Aggressive B-cell Lymphomas: Molecular Insights Into the Differential Diagnosis of Burkitt Lymphoma and Diffuse Large B-cell Lymphoma

Gene Expression Studies in Mature Aggressive B-cell Lymphomas: Molecular Insights Into the Differential Diagnosis of Burkitt Lymphoma and Diffuse Large B-cell Lymphoma

A Biologic Definition of Burkitt's Lymphoma from Transcriptional and Genomic Profiling

The distinction between Burkitt's lymphoma and diffuse large-B-cell lymphoma is unclear. We used transcriptional and genomic profiling to define Burkitt's lymphoma more precisely and to distinguish subgroups in other types of mature aggressive B-cell lymphomas. We performed gene-expression profiling using Affymetrix U133A GeneChips with RNA from 220 mature aggressive B-cell lymphomas, including a core group of 8 Burkitt's lymphomas that met all World Health Organization (WHO) criteria. A molecular signature for Burkitt's lymphoma was generated, and chromosomal abnormalities were detected with interphase fluorescence in situ hybridization and array-based comparative genomic hybridization. We used the molecular signature for Burkitt's lymphoma to identify 44 cases: 11 had the morphologic features of diffuse large-B-cell lymphomas, 4 were unclassifiable mature aggressive B-cell lymphomas, and 29 had a classic or atypical Burkitt's morphologic appearance. Also, five did not have a detectable IG-myc Burkitt's translocation, whereas the others contained an IG-myc fusion, mostly in simple karyotypes. Of the 176 lymphomas without the molecular signature for Burkitt's lymphoma, 155 were diffuse large-B-cell lymphomas. Of these 155 cases, 21 percent had a chromosomal breakpoint at the myc locus associated with complex chromosomal changes and an unfavorable clinical course. Our molecular definition of Burkitt's lymphoma clarifies and extends the spectrum of the WHO criteria for Burkitt's lymphoma. In mature aggressive B-cell lymphomas without a gene signature for Burkitt's lymphoma, chromosomal breakpoints at the myc locus were associated with an adverse clinical outcome.