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 ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 157-157 ◽  
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.

Scavenger Receptor Type B1 Is Essential for High Density Lipoprotein Nanoparticle Induced B-Cell Lymphoma Cell Death

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2756-2756 ◽  
Author(s):  
Jonathan Scott Rink ◽  
Shuo Yang ◽  
Osman Cen ◽  
Fei Ying ◽  
Young Kwang Chae ◽  
...  
Keyword(s):  
Cell Death ◽  
High Density Lipoprotein ◽  
B Cell ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Density Lipoprotein ◽  
B Cell Lymphoma ◽  
High Density ◽  
Lymphoma Cell ◽  
B Cell Lymphomas

Abstract Introduction: We recently reported that biomimetic, synthetic high-density lipoprotein nanoparticles (HDL NP), similar to natural HDL in size, shape, charge, and composition potently induce apoptosis in human B cell lymphoma cell lines in vitro, and in vivo, without adversely affecting primary hepatocytes or macrophages (Yang et al. 2013. PNAS 110(7): 2511-6). We showed that HDL NPs bind to the high-affinity HDL receptor, scavenger receptor type B-1 (SR-B1), expressed by lymphoma cells, and may play a functional role in apoptosis of B cell lymphomas. Methods: We analyzed tissue microarrays (TMAs) from patients with non-Hodgkin's lymphoma (NHL) for SR-B1 expression. In silico analyses of gene microarray datasets from the publicly available database Oncomine were conducted to investigate SR-B1 expression in lymphoma at the mRNA level. The B cell lymphoma cell lines Ramos (Burkitt's lymphoma), SUDHL4 (diffuse large B cell lymphoma) and HF-1 (transformed follicular lymphoma) were used to investigate the requirement for SR-B1 in HDL NP induced cell death. A blocking antibody, and stably expressed shRNA targeting SR-B1 expression were used to inhibit HDL NP interactions with SR-B1. Results: SR-B1 was overexpressed in a subpopulation of NHL represented in available TMAs. At the mRNA level, SR-B1 was up-regulated in 20% of lymphoma data sets (6 of 30). These data further confirm SR-B1 as a potential target of therapeutic intervention in B cell lymphomas. Antibody blockade of SR-B1 in the SR-B1+ cell lines Ramos, SUDHL4, and HF-1 prevented HDL NP induced cell death in a dose dependent manner (Figure 1A). Stable knockdown of SR-B1 by shRNA in Ramos cells also protected against HDL NP induced cell death compared with wild type and scrambled shRNA controls (Figure 1B). HDL NP induced cholesterol efflux in Ramos, SUDHL4, and HF-1 cells was reduced by the SR-B1 blocking antibody, or SR-B1 knockdown, further supporting that the HDL NP binds SR-B1. Conclusion: SR-B1 is expressed in primary B cell lymphomas, and interference of HDL NP interaction with SR-B1, through antibody blockade or knockdown of SR-B1, abrogated HDL NP induced cell death in multiple B cell lymphoma cell lines. Taken together, our data demonstrate the requirement of SR-B1 in HDL NP induced lymphoma cell death, and provide a rationale to pursue HDL NPs as potent therapy for B cell lymphomas in cases that express SR-B1. Figure 1. Antibody blockade (A) and shRNA knockdown (B) of SR-B1 prevents HDL NP induce cell death. Figure 1. Antibody blockade (A) and shRNA knockdown (B) of SR-B1 prevents HDL NP induce cell death. Disclosures Gordon: Dr Leo I. Gordon: Patents & Royalties: Patent for gold nanoparticles pending; Northwestern University: Employment. Thaxton:Aurasense: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: High Density Lipoprotein Nanoparticles for Lymphoma.

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

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1757-1757
Author(s):  
Eiji Sugihara ◽  
Norisato Hashimoto ◽  
Satoru Osuka ◽  
Ueno Sayaka ◽  
Shinichiro Okamoto ◽  
...  
Keyword(s):  
B Cells ◽  
Mouse Model ◽  
B Cell ◽  
Cell Lines ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
Lymphoma Cells ◽  
Hodgkin's Lymphomas

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.

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

Blood ◽  
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.

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

Blood ◽  
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.

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

Blood ◽  
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.

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

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1401-1401 ◽  
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.).

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

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2719-2719 ◽  
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.

scholarly journals Prosurvival and Chemoprotective Effects of Tumor-Associated Macrophages Reversed By Anti-CSF-1R Monoclonal Antibody in B-Cell Lymphomas

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 498-498
Author(s):  
Anupama Gopisetty ◽  
Myriam Foglietta ◽  
Min Zhang ◽  
Zhiqiang Wang ◽  
Nathan Fowler ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Line ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
B Cell Lymphomas ◽  
Lymphoma Cells ◽  
Tumor Survival

Abstract The results of gene expression profiling (GEP) and immunohistochemical studies indicate that survival is worsened by macrophages (MΦ) in the tumor microenvironment of various B-cell lymphomas including follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). Tumor-associated macrophages (TAMs) are known to be different from other types of MΦ, but the effects of TAMs that worsen prognosis in B-cell lymphoma are essentially unknown, as are the mechanisms of these effects. Here, we determined the phenotype and effects of TAMs on tumor survival, proliferation, and drug resistance in B-cell lymphomas and evaluated strategies to reverse their effects. As compared to peripheral blood monocytes (Mo) from normal donors (ND), Mo from FL patients were differentiated less into M1 MΦ (defined as CD68+CD163loCD206loCD86hi) by culture with CSF-1 for 5 days followed by IFN-g + LPS for 2 days more. In contrast, Mo from FL patients and ND were differentiated similarly into M2 MΦ (defined as CD68+CD163hiCD206hiCD86lo) by culture with CSF-1 followed by IL-4. Consistent with this, MΦ gene signatures from FL tumors were more similar to previously-described signatures of M2 rather than M1 MΦ (Martinez et al, J Immunol, 2006, 177(10):7303-11). In co-culture, primary FL tumor cells and lymphoma cell lines (including RL, a transformed FL cell line; Granta 519, a mantle cell lymphoma (MCL) cell line; and Raji, a Burkitt lymphoma cell line) induced differentiation of Mo into MΦ. Differentiation could be prevented by CS4 monoclonal antibody (mAb), a fully human IgG1 anti-human CSF-1R mAb (ImClone/Eli Lilly), but not isotype control Ab. Elevated levels of CSF-1 in culture supernatants after addition of CS4 mAb and real-time PCR of tumor cells suggested secretion of CSF-1 by lymphoma cells. Spontaneous apoptosis of primary FL and MCL tumor cells, determined by Annexin V and propidium iodide staining, was significantly reduced by co-culture with ND Mo (p<0.01), whether pre-differentiated into MΦ with CSF-1 or not, but this protection could be reversed by CS4 mAb. Mo and/or pre-differentiated MΦ protected primary FL and MCL tumor cells from cytotoxic effects of doxorubicin and/or bendamustine (p<0.01), but CS4 mAb reversed this effect. To assess effects of MΦ on proliferation, lymphoma cell lines (RL, Granta 519, and Raji) were CFSE-labeled prior to co-culture with Mo and doxorubicin, and proliferation assessed by CFSE dilution by flow cytometry in the presence or absence of CS4 or isotype control mAbs. MΦ promoted proliferation of all three cell lines, but this effect could be reversed by CS4 mAb. To further understand the mechanism by which MΦ promote tumor survival and growth, we performed phosflow analysis and found increased phosphorylation of STAT3 in co-cultured lymphoma cells. Consistent with this, we observed a correlation between an 11-gene STAT3 activation signature, described by Huang et al in DLBCL tumors (J Clin Oncol, 2013, 52.8414), and a MΦ gene signature in whole genome GEP studies of 191 FL tumors (Pearson correlation co-efficient=0.396, p<0.001). In conclusion, our results suggest that Mo from FL patients are predisposed to differentiate into an M2-like MΦ state. The interaction between lymphoma cells and Mo/MΦ is reciprocal: a change in Mo (MΦ differentiation) induced by interaction with lymphoma tumor cells leads to a change in the tumor cells (promotion of survival, proliferation, and chemoresistance). More importantly, our results demonstrate that targeting TAMs using CS4, an anti-CSF-1R mAb, can be an effective strategy to overcome the adverse effects of TAMs and reverse chemoresistance. Further studies are needed to determine whether STAT3 activation contributes to the protumor effects of TAMs. This may provide novel insights into the molecular mechanisms related to TAMs and lymphoma cells and offers additional targets for therapeutic development. In the long term, strategies targeting TAMs is especially appealing, as they should be able to be combined with existing therapies including chemotherapy, other immunotherapy, and targeted therapy, potentially improving their efficacy without increasing toxicity for FL, DLBCL, and other B-cell malignancies. Disclosures No relevant conflicts of interest to declare.

PRDM11 Is a Novel Putative Tumor Suppressor In Aggressive B Cell Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1002-1002
Author(s):  
Fazila Asmar ◽  
Cathrine Kolster Fog ◽  
Klaus Jensen ◽  
Linda Jacobsen ◽  
Elisabeth Ralfkiær ◽  
...  
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
B Cell ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
Expression Levels ◽  
Immunohistochemistry Staining ◽  
Pr Domain

Abstract Abstract 1002 Introduction and Aim: Deregulation of epigenetic factors contributes together with genetic alterations to the development of cancer. The PR domain proteins (PRDMs) constitute a sub-family of the SET domain family of histone methyl transferases and consist of 17 family members. Several of the PRDMs have been characterized as tumorsuppressors, including PRDM2, PRDM3, PRDM5 and PRDM16, but the mechanisms are largely unknown. In a functional screen with overexpressed MYC, we found that shRNA mediated down regulation of PRDM11 facilitates oncogenic transformation. Given the importance of MYC in lymphoma development it is essential to understand the genetic settings that facilitate MYC-induced transformation. We thus set out to investigate the function of PRDM11 in lymphomagenesis. Methods: To identify PR/SET proteins collaborating with MYC in cellular transformation a retroviral vector based library of shRNA targeting 61 SET and PR domain genes from mice and humans was generated. Primary mouse embryo fibroblasts (MEFs) were transduced with the library and with the Myc overexpression vector. A conditional Prdm11 knockout (KO) mouse strain and crosses to the Eμ-Myc tumor prone strain were generated to evaluate the tumorsuppressor potential of Prdm11 in vivo. The expression levels of PRDM11 in B cell lymphoma cell lines were evaluated by RT-qPCR and immunohistochemistry staining. PRDM11 expression level in Diffuse Large B Cell Lymphoma (DLBCL) patients was assessed by immunohistochemistry staining of DLBCL tissue microarrays (TMAs) according to the H-score. In order to investigate whether the PRDM11 expression was regulated by epigenetic mechanisms we performed H3K27me3 and H3K4me3 ChIP analysis and DNA methylation specific melting curve analysis. DGGE mutation scanning was applied to analyze 17 lymphoma cell lines and 77 DLBCL patients for point mutations. Results: We found that overexpression of Prdm11 in MEFs diminished growth and induced apoptosis in a manner independent of p53 and the intrinsic apoptotic pathway. Furthermore, Prdm11 (KO) MEFs grew faster than their wildtype (WT) littermate controls and transformed in the presence of oncogenic Myc. Prdm11 KO mice were viable and fertile with no apparent phenotype. The Eμ-Myc mice selectively express the Myc transgene in the B-cell lineage and develop malignant lymphomas with a mean latency of 100–120 days. Importantly, we found that loss of Prdm11 potently accelerated lymphomagenesis in the Eμ-Myc mouse (p<0,0006) and induced the incidence time from 111 to 75 days. To investigate the function if PRDM11 in humans, PRDM11 expression levels were evaluated in a panel of human DLBCL and Mantle Cell Lymphoma (MCL) cell lines. Compared to normal B-cells and reactive lymph nodes, PRDM11 mRNA expression levels were significantly lower or absent in 16/19 lymphoma cell lines. PRDM11 immunohistochemistry staining of DLBCL TMAs showed lower levels compared to reactive lymph nodes. PRDM11 immunohistochemistry staining in reactive lymph nodes was mainly localized to the activated B cells in the germinal centres. Interestingly, low or absent PRDM11 expression is associated with significantly worse overall survival (p = 0,011, univariate analysis of 22 patients). We are currently in the process of investigating the prognostic significance of PRDM11 expression in another 100 patients with DLBCL. These data will be presented at the meeting. We have found an inverse correlation between the expression level of PRDM11 and the presence of the repressive chromatin mark H3K27me3 at the PRDM11 promoter by ChIP analysis. H3K27me3 is less enriched at the promoter of PRDM11 in normal B cells as well as in cell lines with EZH2 missense mutation. DNA methylation was not detected in 17 lymphoma cell lines or 77 DLBCL patients and 3 PRDM11 sequence variants were also present in the germ line. In conclusion: PRDM11 is a novel putative tumor suppressor in mice and men, whose downregulation may be associated with poor prognosis in DLBCL. H3K27 trimethylation of the PRDM11 promoter may be a novel target for therapy in DLBCL. Disclosures: No relevant conflicts of interest to declare.

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