Distinct Chemokine Receptor Profile In Chronic Lymphocytic Leukaemia and Richter Transformed Diffuse Large B Cell Lymphomas Compared To Germinal Center B Cells and De Novo Diffuse Large B Cell Lymphomas

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4852-4852
Author(s):  
Kerstin Wenzl ◽  
Katharina Troppan ◽  
Alexander JA Deutsch ◽  
Werner Linkesch ◽  
Peter Neumeister ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Chemokine Receptor ◽  
Germinal Center ◽  
Chemokine Receptors ◽  
Lymphocytic Leukaemia ◽  
De Novo ◽  
Richter Syndrome ◽  
Large B Cell ◽  
Germinal Center B Cells

Abstract Chemokine receptors are G-protein-coupled cell surface receptors, which dissociate upon activation by their ligands and cause downstream signaling. Recently, several studies have revealed the crucial contribution of chemokine receptors and their ligands in normal B-cell differentiation and development of hematopoietic malignancies. The Richter syndrome (RS) represents the clinico-pathologic transformation of chronic lymphocytic leukaemia (CLL) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). Due to the lack of knowledge on the chemokine receptors in RS, we aimed to investigate their expression profile in Richter syndrome patients. Therefore, we investigated the mRNA expression levels of 18 known chemokine receptors (CCR1-CCR9, CXCR1-CXCR7, XCR1, CX3CR1) by using semi-quantitative real time PCR on seven samples of paired (CLL and transformed DLBCL) RS samples, and six samples of de novo DLBCL, additionally four CLL samples –all of them transformed into DLBCL-, and eight transformed DLBCL samples –all of them originated from CLL- were included. Four samples of peripheral B cells and four samples of germinal center B cells (GCB) served as non-neoplastic controls. 11 out of 18 chemokine receptors were differentially expressed in CLL (RL) and transformed DLBCL originated from CLL (RH) compared to GCBs. RL exhibited an at least 15-fold higher expression of CCR2, CCR4, CCR7, CXCR3, and XCR1, as well as a de novo expression of CCR3, CCR8, CXCR1, CXCR2, and CX3CR1 compared to GCB. Additionally to these chemokine receptors, CCR1 also showed significant higher expression levels comparing GCB and RH samples. Only one chemokine receptor was found to be differentially expressed in our seven paired RS samples: CCR6 showed a trend of up-regulation in CLL components. Interestingly, the transformed DLBCL originated from CLL were characterized by a significant up-regulation of six chemokine receptors (CCR3, CCR7, CXCR1, CXCR3, CXCR4, and CX3CR1) and a down-regulation of CCR5 compared to DLBCL. Our data indicate that the chemokine receptor expression profile of CLL and transformed DLBCL, originated from CLL samples, differs substantially from those of non neoplastic germinal center B cells and de novo DLBCL, suggesting other cellular origin and an impact on more aggressive clinical course of Richter syndrome patients. Hence, these multiple deregulated CC and CXC receptor might serve as useful prognostic tool to separate high malignant Richter syndrome from de novo DLBCL. Disclosures: No relevant conflicts of interest to declare.

The Chemokine Receptor Profile As Distinctive Criterion Between Normal B-Cell Subsets and As Potential Discriminative Marker to Identify the Cell of Origin in Patients with Chronic Lymphocytic Leukemia and Richter Syndrome

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3890-3890
Author(s):  
Katharina Troppan ◽  
Kerstin Wenzl ◽  
Peter Neumeister ◽  
Christine Beham-Schmid ◽  
Martina Przekopowitz ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
De Novo ◽  
Memory B Cells ◽  
Cell Of Origin ◽  
Richter Syndrome ◽  
Receptor Profile ◽  
B Cell Subsets

Abstract Chemokine receptors are G-protein-coupled cell surface receptors, which dissociate upon activation by their ligands and cause downstream signaling. Several studies have revealed the crucial contribution of chemokine receptors and their ligands in normal B-cell differentiation and development of hematopoietic malignancies. The Richter syndrome (RS) represents the clinico-pathologic transformation of chronic lymphocytic leukaemia (CLL) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). Due to the lack of knowledge on the chemokine receptor, we aimed to investigate their expression profile in patients with CLL and Richter syndrome. Therefore, we investigated the mRNA expression levels of 18 known chemokine receptors (CCR1-CCR9, CXCR1-CXCR7, XCR1, CX3CR1) by using semi-quantitative real-time PCR on seven samples of paired (CLL and transformed DLBCL) RS samples, additionally four CLL samples -all of them subsequently transformed into DLBCL-, and eight transformed DLBCL samples originating from CLL. Additionally, 30 samples of de-novo DLBCL, including 10 germinal center B-cell (GCB) lymphomas, 12 non-germinal center B-cell lymphomas (non-GCB), and 8 unclassified DLBCL were included. Four samples of naïve B-cells (CD5 neg), CD5+ naïve B-cells and CD27+ memory B-cells (n=12) served as non-neoplastic controls. No differences in the chemokine receptor profile were detected between CD5+ and negative naïve B-cells. When comparing CD27+ memory B-cells to naïve B-cells a significant lower expression level was found for CCR7 (7-fold), CXCR4 (4-fold), and CXCR5 (1.5 fold). CCR7 (5-fold) and CXCR4 (5-fold) were also lower expressed in CD27+ memory B-cells compared to CD5+ naïve B-cells. Five out of 18 chemokine receptors were differentially expressed comparing the distinct normal B-cell subsets with RS samples. Comparing CLL samples and RS samples to CD5+ naïve B-cells, CXCR4 (12-fold for CLLs and 10-fold for RS samples) and CXCR5 (2-fold for CLLs and 2.4-fold for RS samples) were lower expressed, whereas CXCR3 (10-fold for CLLs and 8.5-fold for the transformed samples) was higher expressed and CCR5 de-novo expressed. Compared to naïve B-cells, the same chemokine receptors were deregulated: CXCR4 (10-fold for CLLs and 8.5-fold for the RS samples) and CXCR5 (2-fold for CLLs and 2.4-fold for the transformed samples) were lower expressed, CXCR3 (45-fold for CLLs and 30-fold for the transformed samples) was higher expressed and CCR5 was de-novo expressed. Comparing CLL samples and transformed RS samples to CD27+ memory B-cells, CCR5 (5.1-fold for CLLs and 4.3-fold for the RS samples) and CCR7 (8.7-fold for CLLs and 10-fold for the transformed samples) were higher expressed in both malignancies. Only one chemokine receptor was found to be differentially expressed in our seven paired RS samples: CCR6 showed a trend of a higher expression (1.4-fold) in CLL components. Considering RS and GCB DLBCL, CCR1, CCR5, and CXCR6 were found to be significantly down-regulated in RS (at least 4-fold), in contrast to CCR7 and CXCR4, which showed higher expression levels in RS (6-fold). CCR1 and CCR5 were lower expressed comparing RS and non-GCB DLBCL (25-fold and 8-fold), whereas CCR7 again, together with CXCR7, was higher expressed (3- fold and 6-fold respectively). Our data indicate a difference in the chemokine receptor profile within normal B-cell subsets. These differences are also reflected in the different expression profile of low and high aggressive component of CLL/RS compared to the distinct B cell subtypes. Hence, in future these multiple deregulated CC and CXC receptors might serve as a further hint in identifying the cell of origin of different B-cell malignancies. Disclosures No relevant conflicts of interest to declare.

Tyrosine 641 of the EZH2 Oncogene Is Frequently Mutated in Follicular and Diffuse Large B-Cell Lymphomas of Germinal Center Origin.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 139-139 ◽  
Author(s):  
Ryan Morin ◽  
Nathalie Johnson ◽  
Tesa Severson ◽  
Andrew J. Mungall ◽  
Jianghong An ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Sanger Sequencing ◽  
De Novo ◽  
B Cell Lymphoma ◽  
Epigenetic Mark ◽  
Tyrosine Residue ◽  
Enhancer Of Zeste ◽  
Large B Cell

Abstract Abstract 139 Background: Diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) constitute 70% of all non-Hodgkin lymphomas (NHL). Both malignancies derive from germinal center (GC) B-cells and are characterized by clinical and genomic heterogeneity. Chromosomal alterations that deregulate oncogenes as well as mutations in genes involved in cell proliferation and apoptosis have been described in DLBCL. This disease can also be divided into distinct molecular subtypes by gene expression profiling. Differences observed between the activated B-cell (ABC) and germinal center B cell (GCB) subtypes result in part from distinct genomic alterations (Lenz, PNAS 2008) . For example, recent targeted re-sequencing efforts have revealed mutations in various genes in the NFkB signaling pathway, which likely contribute mainly to the ABC subtype (Compagno, Nature 2009). Thus far, few GCB-specific mutations other than t(14;18) have been identified. Methods: Targeted re-sequencing studies are only able to reveal mutations in pre-selected candidate genes and so much of the genome has not yet been investigated in lymphomas. To obtain a more global view of the mutational landscape of NHL, we applied Illumina massively parallel second-generation sequencing to sequence the genomic DNA of a FL tumor sample. In parallel, we sequenced the transcriptomes (i.e. mRNA) of 31 DLBCL tumor samples using the same technology. Results: Genomic sequencing revealed a mutation altering tyrosine 641 (Y641) in the polycomb group oncogene Enhancer of Zeste Homolog 2 (EZH2), a gene responsible for trimethylating lysine 27 on histone H3 (H3K27). Mutations affecting the same codon were also observed in 4 DLBCL samples. These mutations were confirmed to be somatic in nature by Sanger sequencing exon 15 in tumor DNA and germline DNA derived from peripheral blood in these 5 patients. Sanger sequencing all coding exons in EZH2 from an additional 25 FL samples revealed that mutations were restricted to codon 641. These mutations could change the tyrosine residue to Asparagine, Serine, Phenylalanine or Histidine. The frequency of EZH2 Y641 mutations in GCB-derived lymphomas was determined by Sanger sequencing exon 15 in a total of 479 lymphoma samples. EZH2 (Y641) mutations occurred predominantly in lymphomas of the GCB type: 18/80 (22%) GCB-type de novo DLBCL, 6/52 (11.5)% of “transformed” DLBCL derived from FL and 16/225 (7.1%) of pre-treatment FL samples. No EZH2 mutations were found in 42 DLBCL of the ABC subype, 25 mantle cell lymphomas, 30 small lymphocytic lymphomas or 25 T cell lymphomas or 23 reactive tonsils. Introducing each of the four Y641 mutations into wild-type EZH2 resulted in 15-fold reduction in the ability to trimethylate lysine 27 on H3 peptides in-vitro. Discussion: Over-expression of EZH2 is thought to drive malignancy in a variety of solid tumors but mutations in this gene have never been described. The trimethylated H3K27 epigenetic mark is used to silence the transcription of genes involved in differentiation and hematopoiesis. In Drosophila, the phenotypic consequence of mutating the orthologous tyrosine residue in the E(z)(“Enhancer of Zeste”) gene indicates an apparent gain-of-function (Jones, Genetics 1990). Taken together, our mutation frequency and biochemical data are compatible with the notion that alteration of the ability of germinal center B-cells to trimethylate H3K27 may promote the development of FL and the GCB subtype of DLBCL. Disclosures: Zhu: BPS Biosciences: Employment. Kimbara:BPS Biosciences: Employment. Shashkin:BPS Biosciences: Employment. Charlot:BPS Biosciences: Employment. Tcherpakov:BPS Biosciences: Employment.

Different Subtypes of Difffuse Large B-Cell Lymphomas Identified Using Microarrays and Phenotyping.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4293-4293
Author(s):  
Christian Bjorn Poulsen ◽  
Rehannah Borup ◽  
Finn Cilius Nielsen ◽  
Niels Borregaard ◽  
Mads Hansen ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Expression Profile ◽  
Germinal Center ◽  
Gene Profiling ◽  
B Cell Lymphomas ◽  
Affymetrix Genechips ◽  
Type 3 ◽  
Large B Cell ◽  
Germinal Center B Cells

Abstract The mRNA expression profile in diagnostic, pretreatment samples from 52 primary nodal diffuse large B-cell lymphomas (DLBCL) were investigated using a commercially available oligonucleotide array (the Affymetrix Genechip HU133A) that contains >22.000 probe sets representing 18.400 transcripts. Hierarchical clustering indicated that 3 subtypes could be distinguishes. These included a GCB type (n=20) that showed an expression profile as similar to germinal center B-cells, an ABC type (n=25) that showed a profile as in vitro activated B-lymphocytes, and an intermediate group, type-3 (n=5) that did not fit into either of these categories. Two samples could not be classified due to inconsistency in clustering. Correlation with the genotype and phenotype showed that markers of germinal center B-cells (CD10, Bcl-6, t(14;18)) were prevalent but not exclusive to the GCB type. By contrast, MUM1 (a marker of terminal B-cell differentiation) was only expressed in the ABC type and in type-3. These results are similar to results obtained using a custom-made, spotted array - the Lymphochip (Alizadeh et al. Nature 2000; Wright et al, PNAS 2003). Comparison with the clinical features indicated that patients with GCB types of lesions showed a better initial response to CHOP or CHOP-like regimens than the remaining patients. However there was no significant difference in over-all survival. It is concluded that gene profiling with Affymetrix Genechips can be used to distinguish between GCB and ABC types of DLBCL and that these subtypes are likely to represent different, biological entities. Affymetrix Genechips should constitute a useful platform for prospective investigations, which are needed to elucidate whether gene profiling in DLBCL can be of use in choosing which treatment should be offered to patients.

UCH-L1 Cooperates with BCL6 and Identifies Patients with Aggressive Germinal Center Diffuse Large B-Cell Lymphoma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2673-2673
Author(s):  
Tibor Bedekovics ◽  
Sajjad Hussain ◽  
Andrew L Feldman ◽  
Paul J. Galardy
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Substantial Impact ◽  
Large B Cell Lymphoma ◽  
Large B Cell ◽  
Germinal Center B Cells

Abstract Gene expression profiling has identified two major subclasses of diffuse large B-cell lymphoma. Cases resembling germinal center B-cells (GCB-DLBCL) generally occur in younger patients, have a distinct molecular pathophysiology, and have improved outcomes compared with those similar to activated post-germinal center cells (ABC-DLBCL). We previously found that the ubiquitin hydrolase UCH-L1 is frequently overexpressed in mature B-cell malignancies and is a potent oncogene in mice. The cause for its overexpression in lymphoma, and whether it impacts the outcome of patients with DLBCL is unknown. Here we show that UCH-L1 reflects germinal center lineage in lymphoma and is an oncogenic biomarker of aggressive GCB-DLBCL. We find that UCH-L1 is specifically induced in germinal center B-cells in mice and humans, and that its expression correlates highly with the GCB subtype in DLBCL. Despite the typically good outcomes of GCB-DLBCL, increased UCHL1 identifies a subgroup with early relapses independent of MYC expression, suggesting biologic diversity in this subset of disease. We also find that UCH-L1 synergizes with BCL6 in a mouse model of germinal center B-cell lymphoma, but not with the development of multiple myeloma derived from post-germinal center cells. Consistent with this, forced Uchl1 overexpression had a substantial impact on gene expression in germinal center B-cells including pathways of cell cycle progression, cell death and proliferation, and DNA replication. These data demonstrate a novel role for UCH-L1 outside of the nervous system and suggest its potential use as a biomarker and therapeutic target in DLBCL. Disclosures Galardy: Mission Therapeutics: Research Funding.

scholarly journals Distinctive expression pattern of the BCL-6 protein in nodular lymphocyte predominance Hodgkin's disease

Blood ◽  
1996 ◽  
Vol 87 (2) ◽  
pp. 465-471 ◽  
Author(s):  
B Falini ◽  
B Bigerna ◽  
L Pasqualucci ◽  
M Fizzotti ◽  
MF Martelli ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Hodgkin's Disease ◽  
Cd4 T Cells ◽  
Zinc Finger Protein ◽  
Hodgkin’S Disease ◽  
Malignant Cell ◽  
Germinal Center B Cells

The BCL-6 gene encoding a nuclear-located Kruppel-type zinc finger protein is rearranged in about 30% diffuse large B-cell lymphomas and is expressed predominantly in normal germinal center B cells and related lymphomas. These findings suggest that BCL-6 may play a role in regulating differentiation of normal germinal center B cells and that its deregulated expression caused by rearrangements may contribute to lymphomagenesis. This prompted us to investigate the expression of the BCL-6 protein in Hodgkin's disease (HD), focusing on the nodular lymphocyte predominance subtype (NLPHD), which differs from classical HD by virtue of the B-cell nature of the malignant cell population (so- called L&H cells) and its relationship with germinal centers. Forty-one HD samples (19 NLPHD, 12 nodular sclerosis, and 10 mixed cellularity) were immunostained with the monoclonal antibodies PG-B6 and PG-B6p that react with a fixative-sensitive and a formalin-resistant epitope on the aminoterminal region of the BCL-6 gene product, respectively. Strong nuclear positivity for the BCL-6 protein was detected in tumor (L&H) cells in all cases of NLPHD. In contrast, BCL-6 was expressed only in a small percentage of Hodgkin and Reed-Sternberg cells in about 30% of classical HD cases. Notably, the nuclei of reactive CD3+/CD4+ T cells nearby to and rosetting around L&H cells in NLPHD were also strongly BCL-6+, but lacked CD40 ligand (CD40L) expression. This staining pattern clearly differed from that of classical HD, whose cellular background was made up of CD3+/CD4+ T cells showing the BCL-6-/CD40L+ phenotype. These results further support the concept that NLPHD is an histogenetically distinct, B-cell-derived subtype of HD and suggest a role for BCL-6 in its development.

scholarly journals Telomerase activation in normal B lymphocytes and non-Hodgkin's lymphomas

Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 222-229 ◽  
Author(s):  
KF Norrback ◽  
K Dahlenborg ◽  
R Carlsson ◽  
G Roos
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Telomerase Activity ◽  
Lymphoid Tissues ◽  
Low Grade ◽  
Malignant Lymphomas ◽  
Hodgkin's Lymphomas ◽  
Germinal Center B Cells

Abstract Activation of telomerase seems to be a prerequisite for immortalization and is found in permanent cell lines and most malignant tumors. Normal somatic cells are generally telomerase negative, except for bone marrow stem cells. Weak activity is also present in peripheral blood cells. In the present study strong telomerase activity was demonstrated in vivo in normal mature cells of the immune system, as well as in malignant lymphomas. Benign lymph nodes had lower telomerase activity than benign tonsils, which exhibited intermediate to high activity comparable with findings in malignant lymphomas. In benign tonsils the activity seemed to be restricted to germinal center B cells. In benign lymphoid tissues telomerase activity correlated with B-cell numbers and cell proliferation, but this was not observed in the lymphoma group. High- grade lymphomas exhibited higher levels of telomerase compared with low- grade cases. The data showed that in vivo activation of telomerase is a characteristic feature of germinal center B cells. Different signals for activation of telomerase are likely to exist, one of them being immune stimulation. The data suggest that telomerase activity in malignant lymphomas can be explained by an “induction and retention” model, ie, transformation occurs in a normal, mature B cell with reactivated telomerase, which is retained in the neoplastic clone.

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