New Pathogenetic Insights Into Classical Hodgkin Lymphoma Revealed by Gene Expression Profiling of Microdissected Hodgkin/Reed-Sternberg Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 266-266 ◽  
Author(s):  
Enrico Tiacci ◽  
Verena Brune ◽  
Susan Eckerle ◽  
Wolfram Klapper ◽  
Ines Pfeil ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Hodgkin Lymphoma ◽  
Cell Lines ◽  
Expression Profiling ◽  
Expression Profiles ◽  
B Cell Lymphoma ◽  
Cell Phenotype

Abstract Abstract 266 Background. Previous gene expression profiling studies on cHL have been performed on whole tissue sections (mainly reflecting the prominent reactive background in which the few HRS cells are embedded), or on cHL cell lines. However, cultured HRS cells do not likely reflect primary HRS cells in all aspects, being derived from end-stage patients and from sites (e.g. pleural effusions or bone marrow) which are not typically involved by cHL and where HRS cells lost their dependence on the inflammatory microenvironment of the lymph node. Methods. ∼1000–2000 neoplastic cells were laser-microdissected from hematoxylin/eosin-stained frozen sections of lymph nodes taken at disease onset from patients with cHL (n=16) or with various B-cell lymphomas (n=35), including primary mediastinal B-cell lymphoma (PMBL) and nodular lymphocyte-predominant Hodgkin lymphoma (nLPHL). After two rounds of in vitro linear amplification, mRNA was hybridized to Affymetrix HG-U133 Plus 2.0 chips. Expression profiles were likewise generated from sorted cHL cell lines and several normal mature B-cell populations. Results. Primary and cultured HRS cells, although sharing hallmark cHL signatures such as high NF-kB transcriptional activity and lost B-cell identity, showed considerable transcriptional divergence in chemokine/chemokine receptor activity, extracellular matrix remodeling and cell adhesion (all enriched in primary HRS cells), as well as in proliferation (enriched in cultured HRS cells). Unsupervised and supervised analyses indicated that microdissected HRS cells of cHL represent a transcriptionally unique lymphoma entity, overall closer to nLPHL than to PMBL but with differential behavior of the cHL histological subtypes, being HRS cells of the lymphocyte-rich and mixed-cellularity subtypes close to nLPHL cells while HRS cells of NS and LD exhibited greater similarity to PMBL cells. HRS cells downregulated a large number of genes involved in cell cycle checkpoints and in the maintenance of genomic integrity and chromosomal stability, while upregulating gene and gene signatures involved in various oncogenic signaling pathways and in cell phenotype reprogramming. Comparisons with normal B cells highlighted the lack of consistent transcriptional similarity of HRS cells to bulk germinal center (GC) B cells or plasma cells and, interestingly, a more pronounced resemblance to CD30+ GC B cells and CD30+ extrafollicular B cells, two previously uncharacterized subsets that are transcriptionally distinct from the other mature B-cell types. Conclusions. Gene expression profiling of primary HRS cells provided several new insights into the biology and pathogenesis of cHL, its relatedness to other lymphomas and normal B cells, and its enigmatic phenotype. Disclosures: No relevant conflicts of interest to declare.

Specific Micro-RNA Expression Profile in Hodgkin Lymphoma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 381-381
Author(s):  
Lu Ping Tan ◽  
Geert Harms ◽  
Tjasso Blokzijl ◽  
Rikst Nynke Schakel ◽  
Johan Gibcus ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Hodgkin Lymphoma ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Differentially Expressed ◽  
Cell Phenotype ◽  
Qrt Pcr

Abstract Introduction Classical Hodgkin lymphoma (cHL) and nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) differs not only in the form of histology and reactive background but also in the phenotypes of the tumor cells. Although tumor cells from both HL subtypes are originated from the germinal center (GC) B cell, gene expression studies show that lymphocytic and histiocytic (L&H) cells from NLPHL resembles normal B cells while Hodgkin/Reed-Sternberg cells (H/RS) from cHL demonstrate a loss of B cell phenotype and have significant overlap with primary mediastinal B cell lymphoma (PMBL). Recently, a new class of small RNAs, namely the micro-RNAs (miRNAs), has been identified. It is now known that at the post-transcriptional level, miRNAs negatively regulate gene expression in a sequence specific manner. Unique miRNAs expression patterns have been reported in various tissue types and also during a wide range of physiological states, such as cell proliferation, development, differentiation, apoptosis and hypoxia. As miRNAs play important roles in many cellular processes, it is proposed that there is a link between aberrant miRNA expression and loss of B cell phenotype in cHL. Methods In this study, miRNA profiles from cell lines of various B cell lymphoma subtypes were examined by qRT-PCR. Also, several B cell subsets were sorted from tonsil by FACS and the miRNA profiles studied by qRT-PCR. Some of the miRNAs are analyzed by in situ hybridization (ISH) in both HL tissue and tonsil samples. Results The miRNA profiling data indicated that cHL cell lines cluster together with PMBL while DEV, an NLPHL cell line, clusters together with CB. Upon validation of differentially expressed miRNAs on a cell line panel of 33 cell lines by monoplex qRT-PCR, 5/8 miRNAs identified as differentially expressed between cHL and GC B cells, were confirmed. Four out of six miRNAs differentially expressed between cHL and PMBL, were also confirmed as being differentially expressed in a larger cell panel. A high degree of overlap was observed between the most abundantly expressed miRNAs in the four HL cell lines. Expression of these miRNAs in HRS cells was verified by ISH in HL tissue samples. miRNA profiles of naive, GC and memory B cells display unique patterns. The overall miRNA expression levels were much lower than observed in the cell lines. Results of miRNA ISH in tonsil tissue demonstrated a specific staining pattern for each miRNA. These data indicate that miRNAs are particularly important for subsets of lymphocytes. Conclusion Several miRNAs that are expressed specifically in Hodgkin lymphoma have been identified. However, the effect of the aberrant expressions of these miRNAs in HL is yet to be elucidated, as the targets of these miRNAs remain unknown.

Gene Expression Profiling Data in Lymphoma and Leukemia: Review of the Literature and Extrapolation of Pertinent Clinical Applications

2006 ◽  
Vol 130 (4) ◽  
pp. 483-520 ◽  
Author(s):  
Cherie H. Dunphy
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Hodgkin Lymphoma ◽  
Expression Profiling ◽  
Myeloid Leukemia ◽  
Lymphoblastic Leukemia ◽  
B Cell Lymphoma ◽  
Clinical Applications

Abstract Context.—Gene expression (GE) analyses using microarrays have become an important part of biomedical and clinical research in hematolymphoid malignancies. However, the methods are time-consuming and costly for routine clinical practice. Objectives.—To review the literature regarding GE data that may provide important information regarding pathogenesis and that may be extrapolated for use in diagnosing and prognosticating lymphomas and leukemias; to present GE findings in Hodgkin and non-Hodgkin lymphomas, acute leukemias, and chronic myeloid leukemia in detail; and to summarize the practical clinical applications in tables that are referenced throughout the text. Data Source.—PubMed was searched for pertinent literature from 1993 to 2005. Conclusions.—Gene expression profiling of lymphomas and leukemias aids in the diagnosis and prognostication of these diseases. The extrapolation of these findings to more timely, efficient, and cost-effective methods, such as flow cytometry and immunohistochemistry, results in better diagnostic tools to manage the diseases. Flow cytometric and immunohistochemical applications of the information gained from GE profiling assist in the management of chronic lymphocytic leukemia, other low-grade B-cell non-Hodgkin lymphomas and leukemias, diffuse large B-cell lymphoma, nodular lymphocyte–predominant Hodgkin lymphoma, and classic Hodgkin lymphoma. For practical clinical use, GE profiling of precursor B acute lymphoblastic leukemia, precursor T acute lymphoblastic leukemia, and acute myeloid leukemia has supported most of the information that has been obtained by cytogenetic and molecular studies (except for the identification of FLT3 mutations for molecular analysis), but extrapolation of the analyses leaves much to be gained based on the GE profiling data.

scholarly journals Selinexor (KPT-330) Is Not Cross-Resistant with Chemotherapy and Demonstrates Strong Synergy with Targeted Therapy in DLBCL

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4503-4503
Author(s):  
Jingda Xu ◽  
R Eric Davis ◽  
Zhiqiang Wang ◽  
Jason R. Westin
Keyword(s):  
Gene Expression ◽  
Targeted Therapy ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Cell Lines ◽  
Expression Profiling ◽  
Single Agent ◽  
B Cell Lymphoma ◽  
Dose Titration ◽  
Ic50 Values

Abstract Introduction: XPO1 (CRM1, Exportin 1) is the sole transporter of many tumor suppressor proteins (including MYC, BCL2, BCL6, BTK, IkB) and is elevated in non-Hodgkin Lymphoma. Selinexor (Sel, KPT-330) is an oral covalent inhibitor of XPO1, the first clinical molecule of the Selective Inhibitors of Nuclear Export drug class. The phase I clinical trial of Sel in hematologic malignancies showed promising early single-agent efficacy with modest toxicity in relapsed Diffuse Large B-cell Lymphoma (DLBCL, Gutierrez et al, ASCO 2014). DLBCL, the most common lymphoid malignancy, is currently cured in only 10% of relapsed patients, and consists of 2 subtypes based on putative cell of origin (COO): activated B-cell (ABC) and germinal center B-cell (GCB). We performed preclinical studies of Sel, modeling its single-agent efficacy in frontline and relapsed DLBCL and its potential synergy with other clinically relevant therapeutics. Methods: To model drug resistant DLBCL, resistant subpopulations of 12 patient-derived DLBCL cell lines were created by in vitro intermittent exposure to active congeners of cyclophosphamide, doxorubicin, and vincristine (ivCHOP), approximating clinical practice. To determine if CHOP-resistant DLBCL is also resistant to other agents, we determined single-agent dose response curves and IC50 values for both parental and ivCHOP resistant (CHOP-res) subclones of 4 of these lines at submission (HBL1 & TMD8 of ABC subtype, OCI-Ly7 & HT of GCB subtype, with 8 lines in progress) with Sel, chemotherapy (CT, ivCHOP, DHAP, and ICE), and targeted therapy (TT, ibrutinib, ABT-199, idelalisib, everolimus, MLN0128, alisertib, lenalidomide, bortezomib, I-BET151, and ONC201). Viability was assessed with CellTiter-Glo (Promega) after a 3 day cell culture. IC50 values were determined using GraphPad Prism. Based on these results, we evaluated the ability of Sel to synergize with other agents or restore sensitivity in CHOP-res with a combination “checkerboard” (orthogonal dose titration for each drug). The Combination Index (CI) for pairs at all concentrations was calculated with ComboSyn, with CI values <1 indicating synergy. Gene expression profiling with Illumina HT12v4 arrays will compare parental and CHOP-res of 12 DLBCL lines. Results: All CHOP-res lines of both COO types had higher IC50 for both ivCHOP (mean, 3.7x) and DHAP (4.5x) as compared to parental cells (Table 1). In contrast, the IC50 of Sel is unchanged between parental and CHOP-res, for both COO types. Other targeted agents displayed variable activity between parental and CHOP-res and between COO types, with the IC50 of ibrutinib being nearly 2 log lower in ABC lines. CI values showed that Sel was generally a strong synergizer (Table 1), especially with TT and in ABC lines. Sel had lower CI values with CT, but restored sensitivity to ivCHOP in HBL1 (Figure 1). Bortezomib and Sel were moderately antagonistic, although further tests are ongoing. Gene expression profiling, comparing parental vs. CHOP-res and Sel synergizing vs. non-synergizing lines, is ongoing. Conclusions: Our data suggest that Sel: 1) is equally active, and thus not cross-resistant, in cell lines made resistant to standard chemotherapeutics, 2) is a potent, broadly active synergizer with targeted therapy against lines modeling relapsed DLBCL, and 3) has greater synergy in ABC DLBCL, in which it may be able to reverse acquired resistance to frontline therapy. This behavior fits with the broad effects of XPO1 inhibition. The cross-resistance of CHOP-res lines to DHAP models clinical outcomes, and re-sensitization of CHOP-res lines with Sel suggests the potential for relapsed and frontline clinical trials. Further work with our model may discover more synergies of Sel, suggesting future clinical combinations and biomarkers associated with response. Table 1HBL1TMD8OCI-Ly7HTABCGCBIC50SR ΔSR ΔSR ΔSR ΔivCHOP2E-62.31E-75.51E-63.78E-63.2DHAP6E-73.65E-85.52E-73.71E-75.2Selinexor5E-80.66E-81.57E-80.94E-71.3Ibrutinib8E-81.02E-70.43E-60.92E-61.0ABT-1992E-60.53E-61.23E-60.38E-940.3Bortezomib4E-100.61E-101.03E-102.84E-100.9MLN01282E-71.22E-89.44E-85.42E-73.4CI with selinexorivCHOP 0.27 0.27 1.26 3.24DHAP 0.65 0.65 2.23 0.49Ibrutinib 0.06 0.06 0.02 0.95ABT-199 0.47 0.47 0.26 0.89Bortezomib 3.23 3.23 3.53 10Dexamethasone 0.19 0.19 0.39 2.09MLN0128 0.11 0.35 0.47 0.09 ivCHOP sensitive=S, Resistant=R, Δ fold change from S to R Disclosures No relevant conflicts of interest to declare.

Gene Expression Profiling Comparison between the Major Mature B-Cell Neoplasms and Their Normal Cellular and Anatomic Counterparts: Identification of Candidate Genes Potentially Involved in Lymphomagenesis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2375-2375
Author(s):  
Nicolas Blin ◽  
Celine Bossard ◽  
Jean-Luc Harousseau ◽  
Catherine Charbonnel ◽  
Wilfried Gouraud ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
B Cells ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Germinal Center ◽  
Expression Profiling ◽  
Marginal Zone ◽  
Cell Lymphoma ◽  
B Cell Lymphoma

Abstract Gene expression profiling has provided new insights into the understanding of mature B cell neoplasms by relating each one to its normal counterpart, so that they can be to some extent classified according to the corresponding normal B-cell stage. Thus, diffuse large B cell (DLBCL) and follicular lymphoma (FL) have been related to a germinal center precursor whereas mantle cell lymphoma (MCL) or marginal zone lymphoma (MZL) are more likely to derive from naïve and memory B cell, respectively. However, little is still known about the physiopathology of B-cell lymphomas and particularly the deregulated pathways involved in their oncogenesis. To further investigate that point, we performed laser capture microdissection (LCM) of the three anatomic lymphoid compartments (i.e germinal center, mantle zone and marginal zone) taken from nine normal spleens and lymph nodes and magnetic cell separation of the four normal B cell subpopulations (i.e naïve B cells, centroblasts, centrocytes and memory B cells) purified from twelve normal tonsils for gene expression profiling by cDNA microarray. These molecular profiles have been compared to those of the four most frequent mature B cell neoplasms in adult (i.e DLBCL, FL, MZL and MCL), each one isolated from five previously untreated patients. Unsupervised analysis by hierarchical clustering of the normal anatomic and cellular populations could discriminate the germinal from the extra-germinal populations by genes involved in cell proliferation (e.g. E2F5, CCNB2, BUB1B and AURKB), DNA repair (e.g. PCNA and EXO1), cytokine secretion (e.g. IL8, IL10RB, IL4R and TGFBI) and apoptosis (e.g. CASP8, CASP10, BCL2 and FAS). Supervised analysis of the comparison between each B-cell lymphoma and its anatomic and cellular physiologic equivalent identified molecular deregulations concerning several genes’families characterizing the different histologic subtypes. Genes associated with cellular adhesion and ubiquitin cycle were significantly up-regulated in MCL (FCGBP, ITGAE, USP7, VCAM1) and MZL (CTGF, CDH1, ITGAE) whereas germinal center derived lymphomas (i.e. DLBCL and FL) mainly showed up-regulation of genes involved in cell proliferation (TNFRSF17, SEPT8) and immune response (FCER1G, XBP1, IL1RN). Few deregulated genes were common to the four subtypes, principally associated with cell proliferation (CYR61, GPNMB), cytosqueleton organization (EPB41L3) and carbohydrates metabolism (GNPDA1), suggesting potential similar oncogenic pathways. Those preliminary results are compatible with both subtype-specific and overall mechanisms of lympomagenesis and should be verified in a wider range of samples to confirm the oncogenic events involved in this heterogeneous disease.

Loss of the B-lineage–specific gene expression program in Hodgkin and Reed-Sternberg cells of Hodgkin lymphoma

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1505-1512 ◽  
Author(s):  
Ines Schwering ◽  
Andreas Bräuninger ◽  
Ulf Klein ◽  
Berit Jungnickel ◽  
Marianne Tinguely ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Hodgkin Lymphoma ◽  
Cell Lines ◽  
Expression Profiles ◽  
Specific Gene ◽  
Mrna Levels ◽  
Study Gene Expression ◽  
B Lineage

Hodgkin and Reed-Sternberg (HRS) cells represent the malignant cells in classical Hodgkin lymphoma (HL). Because their immunophenotype cannot be attributed to any normal cell of the hematopoietic lineage, the origin of HRS cells has been controversially discussed, but molecular studies established their derivation from germinal center B cells. In this study, gene expression profiles generated by serial analysis of gene expression (SAGE) and DNA chip microarrays from HL cell lines were compared with those of normal B-cell subsets, focusing here on the expression of B-lineage markers. This analysis revealed decreased mRNA levels for nearly all established B-lineage–specific genes. For 9 of these genes, lack of protein expression was histochemically confirmed. Down-regulation of genes affected multiple components of signaling pathways active in B cells, including B-cell receptor (BCR) signaling. Because several genes down-regulated in HRS cells are positively regulated by the transcriptional activator Pax-5, which is expressed in most HRS cells, we studied HL cell lines for mutations in the Pax-5gene. However, no mutations were found. We propose that the lost B-lineage identity in HRS cells may explain their survival without BCR expression and reflect a fundamental defect in maintaining the B-cell differentiation state in HRS cells, which is likely caused by a novel, yet unknown, pathogenic mechanism.

Expression of FOXP1 in a Poor Prognostic Sub-Group of DLBCL Is Associated with Deregulated Expression of AID.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2034-2034
Author(s):  
James A.L. Fenton ◽  
Sharon L. Barrans ◽  
Andrew S. Jack
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Expression Profiles ◽  
Ectopic Expression ◽  
B Cell Lymphoma ◽  
Cell Development ◽  
B Cell Development ◽  
Germinal Centre ◽  
Cell Phenotype

Abstract We have previously shown that strong, uniform expression of the transcription factor FOXP1 is associated with a poor outcome in a sub-group of activated (non-germinal centre) diffuse large B-cell lymphoma (DLBCL). To further define this poor prognostic group we have compared gene expression profiles of 10 cases which had either FOXP1 uniform, positive expression (n=6) or were FOXP1 negative (n=4). For all cases, a non-Germinal Centre (GC) B cell phenotype, namely CD10 negative, BCL6 negative, MUM1 positive, BCL2 positive, was matched as closely as possible between the two groups, with FOXP1 expression being the solitary differential factor. Gene expression profiling using Affymetrix U133 plus 2.0 chips was performed with RNA extracted from the 10 patient samples and differentially expressed genes were identified between the 2 groups following normalisation of the results. FOXP1 positive lymphoma cells were associated with a distinct expression pattern with activation-induced deaminase (AID) being the gene determined as having the biggest difference in expression, namely an approximately 60-fold increase in expression in FOXP1 positive samples. AID is associated with both the somatic hypermutation and class switch recombination processes of immunoglobulin heavy chain (IgH) genes of normal B-cells, being primarily expressed at the GC stage of B-cell development. An RT-PCR undertaken for AID expression of the 8 cases, where further RNA was still available, confirmed that AID expression was present in FOXP1 positive cases (n=5) but either absent or very weakly expressed in FOXP1 negative cases (n=3). PCR amplification of the IgH variable (V) gene of the sample from RNA, where successful was followed by sequence analysis which showed expected levels of mutation of at least 5% variation from germline IgH V genes. Intraclonal variation of the IgH V region genes was also examined in both FOXP1 positive and negative samples, there was no correlation between the expression of AID and the occurrence of SHM or even evidence of ongoing mutation. Reports have variably suggested that AID expression is confined to GC-type DLBCL, or is heterogeneous between GC and non GC-type (activated) DLBCL. Here we have demonstrated expression of AID in association with over-expression of FOXP1 in cases that are of post-GC origin. This would suggest that AID is deregulated, being expressed beyond the normal GC stage of B-cell differentiation. We hypothesise that FOXP1 positive DLBCL arise from cells at a specific phase of B-cell development. Normal B-cells expressing FOXP1 are found predominately in the mantle zone with a small number of cells in the GC. Ectopic expression of AID has been linked with tumour formation in mice, implying AID has oncogenic potential. Continued (or post-GC) deregulated expression of AID in these DLBCL cells may be a significant pathogenic event associated with these tumours. Normally AID is tightly regulated in B-cells, one vital function of this regulation may be to prevent lymphomagenesis. It is therefore conceivable that overexpression of FOXP1 in this poor prognostic subgroup of DLBCL results in deregulated expression of AID and is therefore a major contributing factor to lymphomagenesis.

MicroRNAs Distinguish Burkitt Lymphoma from the Molecular Subsets of Diffuse Large B Cell Lymphoma.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3353-3353
Author(s):  
Cassandra L. Jacobs ◽  
Anand S. Lagoo ◽  
Raj C Dash ◽  
Adekunle Raji ◽  
Andrew M Evens ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Germinal Center ◽  
Burkitt Lymphoma ◽  
Expression Profiling ◽  
B Cell Lymphoma ◽  
Microrna Expression ◽  
Leave One Out

Abstract Background: Burkitt lymphoma (BL) is a highly aggressive lymphoma that can be cured in up to 80% of patients when treated with intensive multi-agent chemotherapy. The distinction between BL and diffuse large B-cell lymphoma (DLBCL) is critical because there are important differences in their clinical management. However, the distinction can be difficult because of an overlap between DLBCL and BL in morphology, immunophenotype and cytogenetics. Previous work has shown that gene expression profiling can distinguish these entities with a high degree of certainty. Our previous work has demonstrated that microRNAs play a direct role in regulating key transcription factors in normal and malignant B cells. We investigated whether microRNA expression could be used to reliably distinguish BL from DLBCL. Methods: Biopsy samples were collected from 104 patients with a diagnosis of either sporadic BL (N=25) or DLBCL (N=79). All cases were reviewed for pathology diagnosis and profiled for microRNA expression using microarrays. Using the 30 most highly differentially expressed microRNAs with the highest t-statistic, we applied singular value decomposition to identify the 10 most predictive microRNAs. Using those 10 microRNAs, we constructed a Bayesian predictor to distinguish BL from DLBCL. The predictor performance was tested using leave-one-out cross-validation. We further applied gene expression profiling to 52 cases of DLBCL to identify the molecular subsets of DLBCL: activated B cell type and germinal center B cell type DLBCL. We constructed a Bayesian predictor to distinguish these molecular subsets based upon their gene expression. A separate predictor was created from the microRNA profiles of these DLBCL subsets and tested using leave-one-out cross-validation. In order to understand the effects of lineage-specific microRNAs in B cell lymphomas, we applied FACS-sorting to isolate mature B cell subsets including naïve B cells, germinal center B cells, plasma cells and memory cells. We compared the microRNAs involved in germinal center differentiation to those expressed highly in Burkitt lymphoma. Results: The predictor constructed based on microRNA expression was 90% accurate in distinguishing Burkitt lymphoma from DLBCL, using pathology diagnosis as the standard. The microRNA-based predictor was also over 90% accurate in the distinction of the molecular subsets of DLBCL, compared to the gold standard of gene expression-profiling. Further, we found that the Burkitt lymphoma cases consistently expressed microRNAs related to normal germinal center B cell differentiation, suggesting that they also maintain expression of B cell stage-specific microRNAs. Conclusion: This study demonstrates that the microRNA expression profiles can be used to accurately distinguish Burkitt lymphoma from DLBCL. The ability of the predictor to identify the molecular subsets of patients with DLBCL and those with BL suggests that it will be useful in the diagnosis and management of patients with Burkitt lymphoma. Further, the patterns of microRNA expression and their target genes suggests a role for microRNAs in the pathophysiology of these tumors.

Pharmacogenetic Approaches Identify ANTXR1 As a Potential Mediator of Response to Therapeutic NF-κB Inhibition in Diffuse Large B Cell Lymphoma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 234-234
Author(s):  
Soham D. Puvvada ◽  
Cassandra L Love ◽  
Vladimir Grubor ◽  
Jenny Zhang ◽  
Jason Smith ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Exome Sequencing ◽  
Cell Lines ◽  
Expression Profiling ◽  
B Cell Lymphoma ◽  
Lymphoid Malignancies ◽  
Whole Exome

Abstract Abstract 234 Background: NF-κB is a family of transcription factors known to play an essential role in the development & survival of lymphocytes. In recent years, it has been clear that aberrant NF-κB activation is a hallmark of various lymphoid malignancies and appears to be associated with chemotherapy resistance and adverse prognosis. The canonical NF-κB pathway is frequently engaged in lymphoid malignancies wherein activated IKK phosphorylates IκB proteins inducing IκB polyubiquination and subsequent proteasomal proteolytic degradation; this allows for release and nuclear translocation of NF-κB dimers to activate target gene transcription. Gene Expression Profiling (GEP) has identified two distinct sub groups of Diffuse Large B cell Lymphoma (DLBCL). While the Activated B cell (ABC) type shows constitutive activation of NF-κB, the role for NF-κB activation in Germinal Center B Cell (GCB) DLBCL is currently unclear. Since NF-κB inhibition has been identified as a therapeutic possibility in DLBCLs, it is important to define the role of this pathway and its modulators. In this study, we sought to investigate key regulators of the NF-κB pathway that might mediate a therapeutic response to IKKβ inhibition of NF-κB in DLBCL including the GCB subtype. Through GEP and Exome Sequencing, we demonstrate that ANTXR1 is a key mediator of response to IKKβ inhibition in DLBCL. Methods/Results: We obtained a novel selective inhibitor of IKKβ, TLX-2001 that has been found to be safe in animal models. IC50 were obtained on 61 cell lines representing various lymphomas including DLBCL (N=25) using cell viability MTT assays. The drug showed efficacy in both ABC and GCB DLBCL cell lines at physiologically achievable concentrations. These results were unsurprising in ABC DLBCLs which are known to depend on NF-κB activation, but the lethality of this selective drug in GCB DLBCLs was unexpected. To better understand the role of individual genes in the response in GCB DLBCLs, gene expression profiling was performed on 61 cell lines using Human Gene 1.0 ST Array. We found that ANTXR1 expression significantly correlated with NF-κB resistance (p = 0.035). Additionally, we sequenced the exomes of DLBCL tumors (N=95) and matched normal tissue (N=34). 95 cases of DLBCLs consisted of 73 cases of primary human DLBCLs and 22 DLBCL cell lines. Whole exome sequencing was performed using the Agilent solution-based system of exon capture to sequence all protein coding exons in the CCDS database. We identified 465 recurrently somatically mutated genes in these DLBCL cases, and found that mutation status of ANTXR1 was associated with high sensitivity to IKKβ inhibition (p =0.015) of NF-κB. Cell lines with non-synonymous mutations in ANTXR1 had over 3-fold lower IC50 (mean= 2.39 μM) compared to cell lines with no mutation in ANTXR1 (mean IC50 = 8.72μM). Discussion/Conclusion: ANTXR1 is the docking receptor for bacillus anthracis toxin, and anti-tumor responses have been observed in mice injected with recombinant engineered anthrax toxin. It is also known as TEM8 and maps to chromosome 2p13.1. Increased levels of TEM8 (tumor endothelial marker 8) have been noted in various malignancies including melanoma. Our data suggest that pharmacogenetic approaches that combine gene expression profiling and whole exome sequencing are useful tools for identifying novel genes that modulate therapeutic responses in lymphoma. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Molecular Diagnosis of Primary Mediastinal B Cell Lymphoma Identifies a Clinically Favorable Subgroup of Diffuse Large B Cell Lymphoma Related to Hodgkin Lymphoma

2003 ◽  
Vol 198 (6) ◽  
pp. 851-862 ◽  
Author(s):  
Andreas Rosenwald ◽  
George Wright ◽  
Karen Leroy ◽  
Xin Yu ◽  
Philippe Gaulard ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Gene Expression Profiling ◽  
Hodgkin Lymphoma ◽  
Molecular Diagnosis ◽  
Expression Profiling ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Using current diagnostic criteria, primary mediastinal B cell lymphoma (PMBL) cannot be distinguished from other types of diffuse large B cell lymphoma (DLBCL) reliably. We used gene expression profiling to develop a more precise molecular diagnosis of PMBL. PMBL patients were considerably younger than other DLBCL patients, and their lymphomas frequently involved other thoracic structures but not extrathoracic sites typical of other DLBCLs. PMBL patients had a relatively favorable clinical outcome, with a 5-yr survival rate of 64% compared with 46% for other DLBCL patients. Gene expression profiling strongly supported a relationship between PMBL and Hodgkin lymphoma: over one third of the genes that were more highly expressed in PMBL than in other DLBCLs were also characteristically expressed in Hodgkin lymphoma cells. PDL2, which encodes a regulator of T cell activation, was the gene that best discriminated PMBL from other DLBCLs and was also highly expressed in Hodgkin lymphoma cells. The genomic loci for PDL2 and several neighboring genes were amplified in over half of the PMBLs and in Hodgkin lymphoma cell lines. The molecular diagnosis of PMBL should significantly aid in the development of therapies tailored to this clinically and pathogenetically distinctive subgroup of DLBCL.

Sign in / Sign up

Export Citation Format

Share Document