Development of a New Mouse Model for Mature B Cell Lymphoma and Resistance to Fas Restoration-Triggered Apoptosis

Abstract Non-Hodgkin's lymphomas (NHLs) include mature B cell lymphomas such as Burkitt lymphoma (BL) and diffuse large B cell lymphoma (DLBCL), which are derived from germinal center (GC) B cells. The pro-apoptotic receptor Fas (CD95) is normally expressed in GC B cells and has been considered to be implicated in the pathogenesis of lymphomas. However, little is known about how Fas is regulated during lymphomagenesis. In this study, we developed a new ex vivo-based simple mouse model for mature B cell lymphoma by the transplantation of Ink4a/Arf (Cdkn2a)-deficient GC B cells that were retrovirally transduced with c-Myc. We found that Fas expression was downregulated at protein and mRNA levels in all formed lymphomas. To determine the role of Fas downregulation in lymphomagenesis and established lymphoma cells, we performed shRNA-mediated knockdown of Fas in c-Myc-GC B cells and retroviral transduction of Fas in lymphoma cells. As a result of transplantations, Fas downregulation was critical for both lymphomagenesis and maintenance of lymphoma cell survival, suggesting that GC-derived lymphomas require sustained Fas downregulation, probably to escape immune surveillance. We further found that CD40 signal activation in mouse lymphoma cells restored Fas expression thorough multiple signaling pathways including NFkB, PI3K and MAPKs (SAPK, MEK and p38). Restored Fas expression significantly induced apoptosis after FasL treatment, suggesting that Fas restoration is a potential therapeutic strategy for lymphomas. Similarly, human BL and DLBCL cell lines mostly demonstrated Fas downregulation, which was restored by CD40L stimulation. While half of the lymphoma cell lines exhibited sensitivity to FasL treatment upon Fas restoration, the other cell lines were resistant to it. We identified that Livin, a member of IAP family, is highly expressed in these resistant cell lines and is a poor prognostic factor for BL and DLBCL patients. Knockdown of Livin by shRNA and an inhibitor targeting Livin sensitized the resistant cells to Fas restoration-triggered cell death. Thus, the resistant lymphoma cells may acquire Livin during lymphoma development. Correctively, these findings suggest that Fas can be restored in lymphoma cells and thereby induce apoptosis with FasL treatment, and that Livin is a promising therapeutic target for NHLs resistant to Fas restoration-triggered apoptosis. Disclosures Okamoto: Otsuka Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Nippon Shinyaku Co., Ltd.: Research Funding; Bristol-Myers Squibb K.K.: Honoraria, Research Funding; Kyowa Hakko Kirin Co., Ltd.: Research Funding; Asahi Kasei Pharma Corp.: Research Funding; Astellas Pharma Inc.: Research Funding; Alexion Pharmaceuticals, Inc.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Shionogi & Co., Ltd.: Research Funding; Toyama Chemical Co., Ltd.: Research Funding; Teijin Pharma Limited: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Pfizer Inc.: Honoraria, Research Funding; JCR Pharmaceuticals Co., Ltd.: Research Funding. Saya:Daiichi Sankyo Co., Ltd.: Research Funding; Aqua Therapeutics Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Nihon Nohyaku Co., Ltd.: Research Funding.

Download Full-text

Biomimetic Synthetic High Density Lipoprotein Nanostructures Target the SR-B1 Receptor and Differentially Manipulate Cellular Cholesterol Flux in Lymphoma Cells: A Novel Treatment Paradigm

Blood ◽

10.1182/blood.v120.21.157.157 ◽

2012 ◽

Vol 120 (21) ◽

pp. 157-157 ◽

Cited By ~ 1

Author(s):

Shuo Yang ◽

Marina G Damiano ◽

Heng Zhang ◽

Sushant Tripathy ◽

Andrey Ugolkov ◽

...

Keyword(s):

B Cells ◽

High Density Lipoprotein ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

Density Lipoprotein ◽

B Cell Lymphoma ◽

High Density ◽

Lymphoma Cell ◽

Lymphoma Cells

Abstract Abstract 157 We report a nanoparticle-enabled therapeutic approach to B cell lymphoma using synthetic, high-density lipoprotein nanoparticles (HDL-NP). Like natural HDLs, biomimetic HDL-NPs target scavenger receptor type B-1 (SR-B1), a high-affinity HDL receptor expressed by lymphoma cells. Functionally, and unlike natural HDL, a gold nanoparticle template used to control HDL-NP synthesis enables differential manipulation of cellular cholesterol flux through SR-B1. Recent evidence in lymphoblasts and myeloblasts from patients with acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML) demonstrates enhanced uptake of cholesterol through high-density lipoprotein (HDL) carriers, which may result in increased cell proliferation. We therefore hypothesized that by targeting SR-B1, we could manipulate cholesterol flux in lymphoma cells thereby targeting cellular signaling pathways that would lead to cell death and offer an innovative approach to the treatment of lymphoma and other cancers. Methods: To accomplish this, we developed a biomimetic spherical nanoparticle (HDL-NP) with surface chemical properties similar to natural HDL, including the ability to sequester cholesterol. Biomimetic HDL-NPs are synthesized using a 5 nm diameter gold (Au) nanoparticle (NP) as a size- and shape-restrictive template on which to assemble the surface chemical components of natural HDLs, including phospholipids and the HDL-defining apolipoprotein A1 (Apo A1). Importantly, the core AuNP template occupies the real estate in natural cholesterol-rich HDLs reserved for esterified cholesterol, which inherently limits the ability of HDL-NPs to deliver cholesterol. We incubated the HDL-NPs with various lymphoma cell lines, and similarly tested the HDL-NPs in a xenograft model. Results: We first examined gene expression profiles of diffuse large B-cell lymphoma (DLBCL), Burkitt Lymphoma (BL) and normal B cells from patient samples in a database generated using Affymetrix U133plus 2.0 arrays in order to establish the prevalence of SR-B1 expression. We compared the expression of SR-B1 in BL cases (n=20), and DLBCL cases (n=40) that were further subdivided as activated B-cell (ABC)-like DLBCL (n=20), and germinal center (GC)-like DLBCL (n=20) to normal naive (n=3) and memory (n=3) B cells obtained from healthy donors. We found that SR-B1 was expressed at two to four-fold higher levels in the lymphomas (ABC and GC) compared with normal B cells. Next, we determined the expression of SR-B1 in lymphoma cell lines and normal peripheral lymphocytes by immunoblotting, and we found that SR-B1 is expressed in multiple B cell lymphoma cell lines, but not in Jurkat, a T-cell line, and is not expressed by normal human lymphocytes. Incubation of HDL-NP with Ramos, LY-3 and SUDHL-4 resulted in a dose-dependent decrease in cell viability and apoptosis (Figure 1) of the Ramos and SUDHL-4 cells, less so in LY-3 cells, and not in the Jurkat line. This required the nanoparticle construct and could not be duplicated by individual components of that construct, and was reversible with addition of acetylated low-density lipoprotein, indicating that the SR-B1 receptor was targeted. Xenograft experiments with SCID beige mice (C.B-Igh-1b/GbmsTac-Prkdcscid-Lystbg N7) bearing Ramos and Jurkat flank tumor xenografts confirmed the activity of the HDL-NP (Figure 2). Conclusion: We report a template-directed and bio-functional therapeutic nanostructure that could shift the paradigm for treating lymphoma and other cancers. A combination of SR-B1 binding and manipulation of cholesterol flux is responsible for selective induction of apoptosis in B cell lymphoma. Disclosures: Thaxton: Aurasense: Employment, Equity Ownership.

Download Full-text

HDAC6 Inhibition Increases CD20 Level and Improves The Efficacy Of Anti-CD20 Monoclonal Antibodies

Blood ◽

10.1182/blood.v122.21.4406.4406 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4406-4406

Author(s):

Malgorzata Bobrowicz ◽

Michal Dwojak ◽

Kamil Bojarczuk ◽

Magdalena Winiarska ◽

Jakub Golab

Keyword(s):

Monoclonal Antibodies ◽

B Cells ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphoma Cell ◽

Cd20 Antigen ◽

Anti Cd20 ◽

Hodgkin's Lymphomas

Abstract CD20, an integrate membrane protein expressed on the surface of normal and malignant B-cells is widely used as a molecular target for monoclonal antibodies (mAbs) in the therapy of non-Hodgkin’s lymphomas and chronic lymphocytic leukemia (CLL). Accumulating evidence indicates that CD20 can be modulated at several levels, both transcriptional and posttranscriptional and its up-regulation would result in increased efficacy of anti-CD20 mAbs. CD20 antigen has been reported to be regulated epigenetically e.g. by histone deacetylases (HDACs). The results of our preliminary experiments show that use of non-selective HDAC inhibitors as well as blocking the activity of a single HDAC isoform - HDAC6 leads to up-regulation of CD20 protein in B-cell lymphoma cell lines and increase of the efficacy of therapy with anti-CD20 mAbs. Since HDAC6 is engaged mainly in the acetylation of non-histone substrates and the observed up-regulation of CD20 molecule does not seem to rely on transcriptional mechanisms we postulate that HDAC6 is engaged in processes of CD20 trafficking or/and degradation. CD20 being a membrane bound protein is most probably undergoing endocytosis. However, this process and the role of HDAC6 in its regulation has not been explored so far. The aim of this study was to understand how the inhibition of HDAC6 activity influences CD20 level in normal and malignant B-cells. We wanted to determine the mechanisms underlying this phenomena. This study required use of B-cell lymphoma cell lines as well as lymphocytes infected with Epstein-Barr virus and normal B- lymphocytes. Several HDAC pan-inhibitors and HDAC6 inhibitors were tested. To assess the membrane level of CD20 antigen, FITC-anti-CD20 staining was performed followed by cytometric analysis. The influence of HDACi on total level of CD20 protein was assessed in Western blotting. The complement-dependent cytotoxicity (CDC) assay was performed using rituximab and ofatumumab as well as human serum as a source of complement. Cell cytotoxicity was assessed by propidium iodide staining followed by cytometric analysis. The influence of HDAC inhibition on the transcription of CD20 was examined by qRT-PCR using SyBR Green and hydrolysis probes. The activity of CD20 promoter after inhibition of HDAC was assessed in Dual Luciferase Assay. The colocalisation of CD20 with other proteins that may influence its trafficking/degradation was assessed using immunocytochemistry with specific antibodies and observed under confocal microscope. The results of our study strongly suggest that combining HDACi with anti-CD20 antibodies can be an effective therapeutic modality for patients suffering from B-cell malignancies. Extensive experiments aiming at determining what factors are engaged in the regulation of CD20 by HDAC6 are planned. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Anti-CD45 Mediated Cytolysis of Human T-Cell Lymphoma Cells.

Blood ◽

10.1182/blood.v104.11.4637.4637 ◽

2004 ◽

Vol 104 (11) ◽

pp. 4637-4637

Author(s):

Gerald G. Wulf ◽

Anita Boehnke ◽

Bertram Glass ◽

Lorenz Truemper

Keyword(s):

T Cell ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Cytolytic Activity ◽

T Cell Lymphoma ◽

Lymphoma Cell ◽

Lymphoma Cells ◽

Human T Cell

Abstract Anti-CD45 mediated cytoreduction is an effective means for T-cell depletion in rodents and humans. In man, the CD45-specific rat monoclonal antibodies YTH24 and YTH54 are IgG2b subclass, exert a predominantly complement-dependent cytolytic activity against normal T-lymphocytes, and have been safely given to patients as part of conditioning therapies for allogeneic stem cell transplantation. The efficacy of such antibodies against human lymphoma is unknown. Therefore, we evaluated the cytolytic activity of YTH24 and YTH54 by complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), as well as by direct apoptotic and antiproliferative effects, against a panel of Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) cell lines, and against primary specimens. Significant CDC activity (>50% cytolysis) of the antibodies YTH54 and YTH24 was observed against three of five T-cell lymphoma lines, but against only one of nine B-cell lymphoma lines and none of four HD cell lines. The combination of YTH54 and YTH24 induced ADCC in all T-cell lymphoma cell lines and three primary leukemic T-cell lymphoma specimens, but were ineffective in B-cell lymphoma and HD cell lines.There were only minor effects of either antibody or the combination on lymphoma cell apoptosis or cell cycle arrest. In summary, anti-CD45 mediated CDC and ADCC via the antibodies YTH24 and YTH54 are primarily effective against lymphoma cells with T-cell phenotype, and may be an immunotherapeutic tool for the treatment of human T-cell lymphoma.

Download Full-text

Micro-RNA Gene Deregulation by Chromosome Translocations with Fragile Genomic Regions in B-Cell Lymphoma Cells

Blood ◽

10.1182/blood.v112.11.786.786 ◽

2008 ◽

Vol 112 (11) ◽

pp. 786-786

Author(s):

Bjoern Schneider ◽

Stefan Nagel ◽

Maren Kaufmann ◽

Hans G. Drexler ◽

Roderick A.F. MacLeod

Keyword(s):

Multiple Myeloma ◽

B Cells ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Micro Rna ◽

Lymphoma Cell ◽

Chromosome Rearrangements ◽

Causal Connection

Abstract Micro-RNA (miR) genes posttranscriptionally modulate target gene expression via imperfect 3′-UTR matching sequences and play key roles in development, homeostasis and cancer. Little is known how miR genes are themselves regulated, or deregulated in cancer. Chief paradigm for neoplastic miR deregulation concerns miR-17/92 cluster members subject to genomic amplification in B-cell lymphoma. While the repeated occurrence of oncogenic miR genes at or near chromosomal breakpoints in cancer links chromosome fragility to oncogenic miR deregulation, direct evidence of a causal connection remains tenuous. We found that t(3;7)(q27;q32) in a B-cell lymphoma cell line joins 5′-BCL6 to a noncoding region of chromosome 7 inside a common chromosomal fragile site (FRA7H). In these cells hybrid mRNA was absent, unlike canonical BCL6 translocations which involve promoter exchange yielding hybrid mRNA. Affected cells instead showed downregulation of miR-29b-1, the only gene located within FRA7H - a recurrent transcriptional feature of B-cell lymphoma subsets. In another BCL6 translocation, t(3;13)(q27;q31)t(13;12)(q31;p11), which 5′-RACE also showed to be non-fusogenic, long distance inverse (LDI)-PCR revealed junction of 5′-BCL6 to chromosome 13 sequences inside the miR-17/92 host gene MIRH1 (alias c13orf25). FISH using a sensitive tyramide amplification protocol with c13orf25 clones confirmed the presence of a cryptic BCL6-MIRH1 rearrangement. Surprisingly, reverse transcriptase quantitative (q) PCR assay revealed weak MIRH1 expression using 3′-primers. In contrast, repeating the assay using more central primers covering the miR-17/92 coding region showed massive upregulation. 3′-RACE confirmed a novel high level MIRH1 transcript truncated by 3.1 kbp. Quantitative genomic PCR and FISH excluded miR-17/92 genomic copy number alteration, while LDI-PCR analysis showed that formation of truncated MIRH1 involved multiple DNA cuts at 3q27 (x1), 12p11 (x1), and 13q31 (x5) – the last including a complex excision/inversion/insertion rearrangement. Stress induced DNA duplex destabilization (SIDD) analysis revealed that 6 of 7 breaks precisely coincided with fragility peaks. Taken together, these data suggest a novel role for BCL6 translocations in the deregulation of miR genes near sites of chromosome or DNA instability. BCL6 has been shown to suppress p53 in germinal center B-cells thus protecting B-cells from apoptosis induced by DNA damage, offering a possible explanation for chromosome rearrangements associated with genomic fragility therein. Chromosomal MIRH1 dysregulation is not limited to BCL6 expressing lymphomas, however: cytogenetic investigations performed on diverse leukemia-lymphoma cell lines, including those derived from multiple myeloma and plasma cell leukemia, showed 11/50 with cytogenetic rearrangements at or near MIRH1. In sister cell lines sequentially established at diagnosis and relapse of multiple myeloma, only the latter showed miR-17/92 chromosomal rearrangement and upregulation. Interestingly miR overexpression was limited to miR-92, while miR-17/18 were barely expressed. FISH analysis and qPCR showed that discrepant expression was associated with rearrangement upstream of MIRH1. In brief, our data show that like other cancer genes, oncogenic miRs are subject to dysregulation mediated by structural chromosome rearrangements.

Download Full-text

Protein arginine methyltransferase 5 represses tumor suppressor miRNAs that down-regulate CYCLIN D1 and c-MYC expression in aggressive B-cell lymphoma

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.008742 ◽

2019 ◽

Vol 295 (5) ◽

pp. 1165-1180 ◽

Cited By ~ 1

Author(s):

Vrajesh Karkhanis ◽

Lapo Alinari ◽

Hatice Gulcin Ozer ◽

Jihyun Chung ◽

Xiaoli Zhang ◽

...

Keyword(s):

B Cell ◽

Cyclin D1 ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphoma Cell ◽

Lymphoma Cells ◽

Protein Arginine Methyltransferase ◽

Arginine Methyltransferase ◽

Hodgkin's Lymphomas ◽

Protein Arginine Methyltransferase 5

Protein arginine methyltransferase-5 (PRMT5) is overexpressed in aggressive B-cell non-Hodgkin's lymphomas, including mantle cell lymphoma and diffuse large B-cell lymphoma, and supports constitutive expression of CYCLIN D1 and c-MYC. Here, we combined ChIP analysis with next-generation sequencing to identify microRNA (miRNA) genes that are targeted by PRMT5 in aggressive lymphoma cell lines. We identified enrichment of histone 3 dimethylation at Arg-8 (H3(Me2)R8) in the promoter regions of miR33b, miR96, and miR503. PRMT5 knockdown de-repressed transcription of all three miRNAs, accompanied by loss of recruitment of epigenetic repressor complexes containing PRMT5 and either histone deacetylase 2 (HDAC2) or HDAC3, enhanced binding of co-activator complexes containing p300 or CREB-binding protein (CBP), and increased acetylation of specific histones, including H2BK12, H3K9, H3K14, and H4K8 at the miRNA promoters. Re-expression of individual miRNAs in B-cell lymphoma cells down-regulated expression of PRMT5, CYCLIN D1, and c-MYC, which are all predicted targets of these miRNAs, and reduced lymphoma cell survival. Luciferase reporter assays with WT and mutant 3′UTRs of CYCLIN D1 and c-MYC mRNAs revealed that binding sites for miR33b, miR96, and miR503 are critical for translational regulation of the transcripts of these two genes. Our findings link altered PRMT5 expression to transcriptional silencing of tumor-suppressing miRNAs in lymphoma cells and reinforce PRMT5's relevance for promoting lymphoma cell growth and survival.

Download Full-text

B Cell Lymphomas Are Resistant towards Bone Morphogenetic Protein (BMP) Induced Growth Inhibition.

Blood ◽

10.1182/blood.v108.11.2381.2381 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2381-2381

Author(s):

Kanutte Huse ◽

Marianne B. Eide ◽

Christian Kersten ◽

Erlend B. Smeland ◽

June H. Myklebust

Keyword(s):

Growth Inhibition ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphoma Cell ◽

Lymphoma Cells ◽

Bmp Receptors ◽

Induced Apoptosis

Abstract Bone morphogenetic proteins (BMPs) belong to the TGF-β superfamily, and mediate their effects mainly through the Smad signalling pathway. Whereas TGF-β is well established as one of the most potent negative regulators in hematopoietic cells, the role of BMPs remains more elusive. We have previously shown that BMP-6 inhibits the growth of naïve and memory human B cells. As high BMP-6 mRNA expression is associated with poor outcome in diffuse large B cell lymphoma (DLBCL; Rosenwald et al, N Engl J Med 2002), we hypothesized that resistance towards BMP-induced growth inhibition is a possible mechanism for lymphomagenesis. In the current study, 7 B cell lymphoma cell lines (representing Burkitt lymphoma (BL) and DLBCL) and tumour material from lymphoma patients were investigated to unravel the role of BMPs in lymphomas. We analyzed the expression of BMP receptors by FACS analysis, and found variable expression of the BMP receptor type I (Alk2, Alk3 and Alk6) and type II (BMP RII, Activin RIIA and RIIB) among the cell lines and in primary lymphoma cells, suggesting variable binding of BMPs. We next investigated the effect of BMP-2, BMP-4, BMP-6 and BMP-7 on proliferation and survival of B lymphoma cell lines, and found 2 of 7 cell lines to be resistant towards BMP-2 and BMP-4 induced growth inhibition. In contrast, 4 of 7 and 7 of 7 cell lines were resistant to BMP-6 and BMP-7 induced growth inhibition, respectively. In Sudhl6 cells that were highly sensitive to BMP-2 and BMP-6 induced apoptosis and inhibition of proliferation, we demonstrated that the cytokines IL-10, CD40 Ligand and BLyS were able to counteract the negative effects induced by BMPs, while IL-2 and IL-4 were not. On the contrary, both BMP-2 and BMP-6 greatly increased anti-IgM activation induced apoptosis. In resistant lymphoma cells, the BMPs were not able to induce detectable levels or induced low levels of phosphorylated SMAD1/5/8 compared to sensitive cell lines. Low or no increase in phosphorylation of SMAD1/5/8 induced by BMPs could only partly be explained by low/ undetectable expression of BMP receptors. Hence, upregulation of inhibitory Smads (Smad6, Smad7) or mutations in receptors or Smads represent other possible mechanisms for resistance to BMPs in lymphomas, and this is currently under investigation. We also investigated if the lymphoma cells produced BMPs themselves and found that 5 of 7 cell lines and 3 of 5 primary lymphomas produced significant amounts of BMP-7. Some lymphoma cells also had detectable levels of BMP-4 and BMP-6. Our findings that lymphoma cells are resistant towards BMP-7 and to some degree BMP-6 induced growth inhibition, whereas they produce these cytokines, suggest that resistance towards BMP induced signalling in B cell lymphomas can contribute to increased tumour growth.

Download Full-text

RNA Sequencing of Hodgkin Lymphoma Reed-Sternberg Cells Uncovers a Plasma Cell Signature and Escape from NK Cell Recognition

Blood ◽

10.1182/blood-2019-131163 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 549-549 ◽

Cited By ~ 1

Author(s):

Ethel Cesarman ◽

Mikhail Roshal ◽

Jonathan Reichel ◽

Wagner Florian ◽

Bhavneet Binder ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Rna Sequencing ◽

Cell Lines ◽

Plasma Cell ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Provision Of Services ◽

Slam Family

Introduction: Previous gene expression profiling studies of classical Hodgkin lymphoma (cHL) have been confined to cell lines and microdissected HRS cells from tissue biopsies given the difficulty of isolating sparse Hodgkin and Reed-Sternberg (HRS) cells from reactive background tissue. We previously used flow sorting to separate HRS cells from fresh or viably frozen cHL biopsies, and performed the first full exome sequencing of HRS cells. Here we report use of the same cell separation approach to examine the HRS cell transcriptome using RNA sequencing. Methods: We used flow cytometric cell sorting and low-input RNA sequencing to generate full transcriptome data from viable primary HRS cells, along with intratumor B cells. Nine primary cases of cHL and four cell lines were assessed for RNA expression, expressed mutations, cell type of origin, signaling pathways, gene fusions and pathogen identification. We used immunohistochemistry to evaluate expression of PDIA6 and CD48 in the 9 cases sequenced and a tissue microarray containing 16 additional cases of cHL. Flow cytometry for CD48 was performed in two cell lines and 5 primary cases. Results: Clustering show that primary HRS cells have a transcriptional profile that is unique, and different from that of intratumoral B cells, as well as cHL cell lines. Comparison of HRS cells with normal cellular subsets indicated plasma cell differentiation, suggesting that the cell of origin is a B cell on its way to becoming a plasma cell. Clustering with B cells showed much lower similarity. Consistent with plasma cell differentiation, we uncovered an unfolded protein response UPR) signature, shared with plasma cell neoplasms and, to a lesser extent, activated B cell (ABC) diffuse large B cell lymphoma, but not other B cell lymphoma types, including primary mediastinal B cell lymphoma (PMBCL). Among other UPR response genes, PDIA6 showed strong downregulation at the RNA level (2.4 logFC, p=9.4E-17). This finding was validated by immunohistochemistry for PDIA6, which showed strong positivity in the HRS cells of all 25 cases examined, confirming that this is a common feature of cHL, including nodular sclerosis and mixed cellularity subtypes. Top upregulated genes included those involved in oncogenesis (HGF/MET, NFkB/apoptosis inhibition), stem cell differentiation (homeobox genes MEIS1 and PBX1), and mitotic checkpoints, mitotic spindle formation and DNA repair, possibly explaining the unique nuclear morphology of HRS cells. Downregulation of MHC-1 and MHC-2 driven antigen processing and presentation was confirmed, and so was overexpression of PDL1 (CD274). Importantly, we detected loss of SLAM family receptors, which serve as activation signals for NK cells providing an additional mechanism for tumor immune evasion. One of these is CD48 (-2.63 logFC, p=1.56E-05), which was confirmed to be strongly downregulated. This finding was confirmed by immunohistochemistry (25 cases) and flow cytometry (2 cell lines and 5 primary cases) on the expanded sample set. Given that only some cHL cases are associated with EBV infection, it has been speculated that other viruses are involved in negative cases. However, our analysis did not reveal additional viruses in the HRS cells. Conclusions: Our data indicate that cHL more closely resembles plasma cells than B cells, and plasma cell malignancies than other lymphomas. The salient feature of plasmacytic differentiation is a UPR, which is seen in HRS cells and multiple myeloma. In contrast, UPR is not a feature of primary mediastinal B cell lymphoma, which is thought to be the DLBCL most similar to cHL clinically, immunophenotypically and in terms of gene expression patterns. We also provide an integrated view of potential immune evasion mechanisms by HRS cells that potentially explain lack of anti-tumor T or innate response. These include lack of antigen presentation due to B2M mutations, overexpression of PDL1 and PDL2, immunosuppressive cytokine secretion and, for the first time, a demonstration of lack of NK activating receptors of the SLAM family. Lack of SLAM family receptors may explain lack of NK cells clearance of HRS cells in the face of MHC-I downregulation. It has long been suspected that cHL is a tumor where there likely exists a previously undiscovered virus in addition to EBV, but RNA sequencing failed to reveal additional infectious transcripts in the HRS cells. Disclosures Roshal: Celgene: Other: Provision of Services; Auron Therapeutics: Equity Ownership, Other: Provision of services; Physicians' Education Resource: Other: Provision of services. Brody:Kite Pharma: Research Funding; Celldex Therapeutics: Research Funding; Genentech: Research Funding; Acerta Pharma: Research Funding; Oncovir, Inc.: Research Funding; BMS: Research Funding; Merck: Research Funding. Dave:Data Driven Bioscience: Equity Ownership.

Download Full-text

Analysis of Adct-602 Pre-Clinical Activity in B-Cell Lymphoma Models and Identification of Potential Biomarkers for Its Activity

Blood ◽

10.1182/blood-2020-134664 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 10-11

Author(s):

Eugenio Gaudio ◽

Chiara Tarantelli ◽

Luciano Cascione ◽

Filippo Spriano ◽

Gaetanina Golino ◽

...

Keyword(s):

B Cell ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphoma Cell ◽

Advisory Committees ◽

Travel Grant

Introduction. CD22 is a cell surface marker expressed by the vast majority of normal and neoplastic B-cells. ADCT-602 is an antibody drug conjugate (ADC) composed of Emab-C220, an engineered version of the anti-CD22 humanized IgG1 antibody epratuzumab, site-specifically conjugated to SG3249, which includes the DNA minor groove crosslinking pyrrolobenzodiazepine (PBD) dimer SG3199 linked to the antibody via a protease-cleavable linker (Zammarchi et al, ASH 2016). ADCT-602 is currently being tested in a phase I/II clinical trial (NCT03698552) in recurrent or refractory B-cell acute lymphoblastic leukemia (B-ALL) patients. Here, we assessed its in vitro anti-lymphoma activity, also exploring for potential biomarkers and mechanisms of resistance. Methods. Fifty-seven human lymphoma cell lines were exposed to ADCT-602, an isotype-control ADC and the PBD dimer SG3199 as single agents for 96h, followed by MTT proliferation assay and IC50 calculation. Quantum Simply Cellular (QSC) microspheres were used for the quantitative determination of cellular CD22 antigen expression (Bangs Laboratories. Inc). Differences in IC50 values among lymphoma subtypes were calculated using the Wilcoxon rank-sum test. Statistical significance was defined by P values of 0.05 or less. Sensitivity analysis to ADCT-602 was performed by integrating different omics data, such as Illumina HT-12 microarray data (GSE94669), HTG EdgeSeq Oncology Biomarker Panel data (GSE103934) and DNA copy number variations. Results. The median IC50 for ADCT-602 was 200 pM (95%C.I, 90-400 pM) in 48 B-cell lymphoma lines (including three Hodgkin lymphoma cell lines), and 1850 pM in nine T-cell lymphoma lines (95%C.I, 700-15000 pM). ADCT-602 was more active in B- than in T-cell lymphomas, as expected based on the pattern of CD22 expression (P < 0.005). Focusing on B-cell lymphomas, ADCT-602 in vitro activity was not correlated with its target expression measured both at the cell surface protein level (absolute quantitation, n=48, r=0.06 P=ns) and at the RNA level (Illumina HT-12 arrays, n=42, r=0.28, P=ns; HTG EdgeSeq Oncology Biomarker Panel, n=36, r=0.24, P=ns). In vitro activity was stronger in marginal zone lymphoma (MZL) cell lines than other B-cell lymphoma models (median IC50s 62.5 vs 312.5 pM; P = 0.03) as well as in diffuse large B-cell lymphoma (DLBCL) cell lines with BCL2 and MYC translocations (DHT DLBCL) versus DLBCL with none or a single translocation (median IC50s 25 vs 400 pM, P = 0.03). No associations were seen with TP53 status or other histology (mantle cell lymphoma, DLBCL, DLBCL cell of origin). We then exploited the gene expression profiling data using the Illumina HT-12 microarray gene expression technology. Within all the B-cell lymphoma cell lines (sensitive, n= 25; resistant, n= 23) we identified 1.207 genes down-regulated (FC-) and 1,104 genes up-regulated (FC+) in resistant cell lines. To delineate the pathways associated with the different degrees of sensitivity to ADCT-602, we performed a gene set enrichment analysis (GSEA; GSEA hallmarks and c2.common pathways) on the pre-ranked limma data. Transcripts up-regulated in resistant cell lines were enriched of genes coding for proteins involved in respiratory electron transport, oxidative phosphorylation and proteasome. Conversely, transcripts up-regulated in the sensitive cell lines were enriched of genes coding for proteins involved in inflammation, chemokine signaling, p53 response, IL2/STAT5 signaling, hypoxia, TGF-beta and interferon response. Similar gene signatures were picked up using the HTG platform, which can be applied to formalin-fixed paraffin-embedded clinical specimens, despite the smaller number of investigated genes. Conclusion. ADCT-602 showed in vitro anti-tumor activity across a large panel of B-cell lymphoma models of various histology. Expression signatures and other features (MZL or DHT DLBCL histology), but not the expression levels of its target, were associated with different sensitivity to the ADC. Our data supports the clinical evaluation of ADCT-602 in patients with B-cell lymphoma in addition to B-ALL. Disclosures Zucca: Kite: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Beigene: Membership on an entity's Board of Directors or advisory committees; Abbvie: Other: Travel Grants; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel Grants, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Research Funding; Celltrion Healthcare: Membership on an entity's Board of Directors or advisory committees. Stathis:PharmaMar: Other: Travel Grant; Member of the steering committee of the trial of this abstract: Other; Loxo: Honoraria, Other, Research Funding; Cellestia: Research Funding; Roche: Other, Research Funding; Novartis: Other, Research Funding; Bayer: Other, Research Funding; Merck: Other, Research Funding; Pfizer: Other, Research Funding; MEI Pharma: Other, Research Funding; ADC Therapeutcis: Other, Research Funding; Abbvie: Other: Travel Grant. Van Berkel:ADC-Therapeutics: Current Employment, Current equity holder in publicly-traded company. Zammarchi:ADC-Therapeutics: Current Employment, Current equity holder in publicly-traded company. Bertoni:ADC-Therapeutics: Research Funding; Bayer AG: Research Funding; Helsinn: Research Funding; Menarini Ricerche: Consultancy, Research Funding; NEOMED Therapeutics 1: Research Funding; Nordic Nanovector ASA: Research Funding; Astra Zeneca: Other: travel grant; Amgen: Other: travel grant.

Download Full-text

Anti-CD20 Antibody Rituximab and Anti-CD23 Antibody IDEC-152 Induce Apoptosis of Malignant B-Cells in Combination with Chemical Antagonists of XIAP.

Blood ◽

10.1182/blood.v104.11.1401.1401 ◽

2004 ◽

Vol 104 (11) ◽

pp. 1401-1401 ◽

Cited By ~ 1

Author(s):

Massimo Mangiola ◽

Kate Welsh ◽

Shinichi Kitada ◽

Irene M. Pedersen ◽

Nuzhat Pathan ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

Annexin V ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Lymphoma Cell ◽

Efficient Induction ◽

Anti Cd20

Abstract We tested the effects of Rituximab (anti-CD20) and IDEC-152 (anti-CD23) on apoptosis of B-cell malignancies, using established non-Hodgkin’s B-Cell lymphoma cell lines and freshly isolated Chronic Lymphocytic Leukemia (CLL) B-cells. We used monolayers of stably transfected CHO-cells expressing FcRγIII-A to present antibody to B-cells and promote crosslinking. Established B-cell lymphomas (n = 3) were cultured in the presence of FcRγIIIA-expressing CHO monolayer with or without MAbs and apoptosis was measured by annexin V/propidium iodide staining at various times thereafter. Both antibodies induced time-dependent apoptosis of B-cell lymphoma cell lines. After 48 hrs of treatment with either Rituximab or IDEC-152, the majority of the malignant B-cells were apoptotic (remaining viable cells = 28.7% ± 0.2137% for Rituximab and 30.87% ± 0.7332% for IDEC-152). Rituximab and IDEC-152 also induced marked increases in caspase activity in B-cell lymphoma cell lines, with fold-increases above baseline control cells of 25 ± 0.9031 and 24 ± 0.3839, respectively. In contrast, neither Rituximab nor IDEC-152 induced striking effects on primary CLL B-cells (n = 6). We therefore tested the combination of Rituximab or IDEC-152 with other agents that target anti-apoptotic proteins, exploring whether more efficient induction of apoptosis can be achieved. We cultured lymphoma cell lines and primary CLL specimens with chemical antagonists of XIAP (Schimmer, et al. Cancer Cell5: 25, 2004), an anti-apoptotic protein that inhibits effector caspases. When used at concentrations where XIAP antagonists alone were non-apoptotic (approximately 2.5 μM), a significant increase in apoptosis was achieved in cultures of lymphoma and CLL cells treated with either Rituximab or IDEC-152. These findings suggest that Rituximab or IDEC-152 may more efficiently induce apoptosis of malignant B-cells when combined with an apoptosis-sensitizing agent. (Supported by CA-81534; CA-78040; and an unrestricted grant from Genentech, Inc.).

Download Full-text

Combination of NVP-BEZ235 and Enzastaurin on B-Cell Lymphoma Cell Lines: An Effective Therapeutic Strategy

Blood ◽

10.1182/blood.v118.21.2719.2719 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2719-2719 ◽

Cited By ~ 2

Author(s):

Monica Civallero ◽

Maria Cosenza ◽

Samantha Pozzi ◽

Stefano Sacchi

Keyword(s):

Bone Marrow ◽

B Cell ◽

Cell Lines ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphoid Cells ◽

Lymphoma Cell ◽

Lymphoma Cells ◽

Apoptosis Pathways ◽

Extrinsic Apoptosis

Abstract Abstract 2719 Non-Hodgkin's lymphoma is the most common hematologic neoplasm in adults. Chemotherapy combined with CD-20 monoclonal antibodies has improved survival in both indolent and aggressive B-NHL. However, a substantial subset of patients does not achieve a cure or long disease remission. This has promoted the identification of new targeted treatments and new agents that have shown promising efficacy for future B-NHL therapies. The phosphatidylinositol 3-kinase (PI3K) mammalian target of rapamicin (mTOR) pathway mediates proliferation, survival and drug resistance in lymphoma cells. NVP-BEZ235 (BEZ235) is a new, orally bio available inhibitor of PI3K and mTOR and a representative of a new class of anti-tumour agents. In the current study, the efficacy of the combination of two orally available inhibitor to PI3K/mTOR (BEZ235) and PKCbeta/AKT (enzastaurin) was evaluated in B-cell lymphoma cell lines (RL, WSH-NHL, Jeko and Granta). First, we tested the anti-lymphoma activity of BEZ235 alone and in combination with enzastaurin, everolimus and perifosine. Results using MTT assay were expressed as fraction of cells killed by the individual drug or the combination in the drug-treated versus untreated cells. The interaction between drugs was analyzed by isobologram analysis using the STACorp8.2 software program based upon the Chou-Talalay method to determine if the combination were additive or synergistic. We found that enzastaurin, everolimus and perifosine enhanced the cytotoxicity triggered by BEZ235; a clear synergistic interaction (CI<1) appeared after 48 hours using low concentrations of the all compounds. We examined the functional effects of BEZ235 alone and in combination on apoptosis in lymphoma cells. We demonstrated that BEZ235 (20nM) alone after 24 hours induces an increase of 8–10% of apoptotic cells versus untreated, instead BEZ235 (20nM) in combination with enzastaurin (5microM) after 24 hours induces an increase of 25%. We next defined mechanisms whereby BEZ235 alone and in combination induce apoptosis in lymphoid cells. In particular, BEZ235 combined with enzastaurin induces both intrinsic and extrinsic apoptosis pathways with caspase 3, caspase 9, caspase 8 cleavage. We also showed that the combination of BEZ235 and enzastaurin decreases viability and induce apoptosis in B-cell lymphoma cell lines and peripheral blood mononuclear cells (PBMCs) from lymphoma patients. The combination has no effect on normal PBMCs and suppresses cell prolipheration of B-cell lymphoma cell lines (RL and Jeko) when co-cultured with bone marrow stromal cells in a system that mimics the bone marrow microenvironment. BEZ235, enzastaurin, everolimus and perifosine are inhibitors of intracellular pathways, thought we investigated effects of BEZ235 alone and in combinations with the other compounds in targeting p-AKT, p-mTOR, p-GSK3beta, p-p70, p-p90, p-MAPK, p-4EBP1 and cyclin D1 pathways by Western Blot. In addition, we demonstrated that BEZ235 plus enzastaurin resulted in increased expression of pro-apoptotic Bim, and in decrease expression of anti-apoptotic Bcl-2, which could not be abrogated by BEZ235 alone. In conclusion, our data suggest that in B cell lymphoma cell lines, BEZ235 in combination with enzastaurin elicits its antitumor effect better that combinated with perifosine and everolimus. Our data reveals that the drug combination targets phosphorilation of PI3K/Akt/mTOR pathways and induces both intrinsic and extrinsic apoptosis pathways. Furthermore, inhibition of Bcl-2 anti-apoptosis family members may, in part, explain the efficacy of signalling blockade in lymphoma cells and suggests an additional therapeutic targeting strategy. Therefore, these preclinical data support the potential use of BEZ235 in patients with NHL, and in particular provide rationale for combination with enzastaurin. Disclosures: No relevant conflicts of interest to declare.

Download Full-text