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Journal ArticleDOI

Pathologic Correlates of Primary Central Nervous System Lymphoma Defined in an Orthotopic Xenograft Model

15 Mar 2009-Clinical Cancer Research (American Association for Cancer Research)-Vol. 15, Iss: 6, pp 1989-1997

TL;DR: Intracerebral implantation of Raji cells results in a reproducible and invasive xenograft model, which recapitulates the histopathology and molecular features of PCNSL, and is suitable for preclinical testing of novel agents.

AbstractPurpose: The prospect for advances in the treatment of patients with primary central nervous system lymphoma (PCNSL) is likely dependent on the systematic evaluation of its pathobiology. Animal models of PCNSL are needed to facilitate the analysis of its molecular pathogenesis and for the efficient evaluation of novel therapeutics. Experimental Design: We characterized the molecular pathology of CNS lymphoma tumors generated by the intracerebral implantation of Raji B lymphoma cells in athymic mice. Lymphoma cells were modified for bioluminescence imaging to facilitate monitoring of tumor growth and response to therapy. In parallel, we identified molecular features of lymphoma xenograft histopathology that are evident in human PCNSL specimens. Results: Intracerebral Raji tumors were determined to faithfully reflect the molecular pathogenesis of PCNSL, including the predominant immunophenotypic state of differentiation of lymphoma cells and their reactive microenvironment. We show the expression of interleukin-4 by Raji and other B lymphoma cell lines in vitro and by Raji tumors in vivo and provide evidence for a role of this cytokine in the M2 polarization of lymphoma macrophages both in the murine model and in diagnostic specimens of human PCNSL. Conclusion: Intracerebral implantation of Raji cells results in a reproducible and invasive xenograft model, which recapitulates the histopathology and molecular features of PCNSL, and is suitable for preclinical testing of novel agents. We also show for the first time the feasibility and accuracy of tumor bioluminescence in the monitoring of a highly infiltrative brain tumor.

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Citations
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Journal ArticleDOI
TL;DR: Progress in in vitro screening platforms as well as orthotopic and 'orthometastatic' xenograft mouse models has enabled comprehensive characterization of the impact of the tumour microenvironment on therapeutic efficacy, which can hopefully bridge the gap between preclinical studies and clinical trials of anticancer agents.
Abstract: The role of stromal cells and the tumour microenvironment in general in modulating tumour sensitivity is increasingly becoming a key consideration for the development of active anticancer therapeutics. Here, we discuss how these tumour-stromal interactions affect tumour cell signalling, survival, proliferation and drug sensitivity. Particular emphasis is placed on the ability of stromal cells to confer - to tumour cells - resistance or sensitization to different classes of therapeutics, depending on the specific microenvironmental context. The mechanistic understanding of these microenvironmental interactions can influence the evaluation and selection of candidate agents for various cancers, in both the primary site as well as the metastatic setting. Progress in in vitro screening platforms as well as orthotopic and 'orthometastatic' xenograft mouse models has enabled comprehensive characterization of the impact of the tumour microenvironment on therapeutic efficacy. These recent advances can hopefully bridge the gap between preclinical studies and clinical trials of anticancer agents.

343 citations


Journal ArticleDOI
TL;DR: This review will focus on PCNSL in the immunocompetent host, an uncommon variant of extranodal non-Hodgkin lymphoma that has been challenging to study and an effective standard of care has been difficult to establish.
Abstract: Primary central nervous system (CNS) lymphoma (PCNSL), an uncommon variant of extranodal non-Hodgkin lymphoma (NHL), can affect any part of the neuraxis including the eyes, brain, leptomeninges, or spinal cord. It accounts for approximately 3% of all the primary CNS tumors diagnosed each year in the United States. Congenital or acquired immunodeficiency is the only established risk factor for PCNSL, and individuals with human immunodeficiency virus (HIV) infection are at greater risk for developing this tumor. Infection with HIV likely accounted for the increased incidence in PCNSL observed from 1970 to 2000, but over the last decade the number of cases of PCNSL has stabilized or decreased to about 0.47 cases per 100 000 persons. Owing to the rarity of PCNSL, the disease has been challenging to study and an effective standard of care has been difficult to establish. Unfortunately, although durable remissions may be achieved for some patients with PCNSL, the tumor relapses in most cases. In this review, we will focus on PCNSL in the immunocompetent host.

168 citations


Cites background from "Pathologic Correlates of Primary Ce..."

  • ...Recently, the first mouse model of PCNSL was developed; it could potentially be used to test new therapeutic agents that target these molecular abnormalities including the IL-4 signaling pathway.(4)...

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Journal ArticleDOI
06 Jun 2013-Blood
TL;DR: It is demonstrated for the first time that elevated CXCL13 concentration in cerebrospinal fluid (CSF) is prognostic and that CXC chemokine ligand and IL-10 mediate chemotaxis of lymphoma cells isolated from CNS lymphoma lesions.
Abstract: Establishing the diagnosis of focal brain lesions in patients with unexplained neurologic symptoms represents a challenge The goal of this study is to provide evidence supporting functional roles for CXC chemokine ligand (CXCL)13 and interleukin (IL)-10 in central nervous system (CNS) lymphomas and to evaluate the utility of each as prognostic and diagnostic biomarkers We demonstrate for the first time that elevated CXCL13 concentration in cerebrospinal fluid (CSF) is prognostic and that CXCL13 and CXCL12 mediate chemotaxis of lymphoma cells isolated from CNS lymphoma lesions Expression of the activated form of Janus kinase 1 supported a role for IL-10 in prosurvival signaling We determined the concentration of CXCL13 and IL-10 in CSF of CNS lymphoma patients and control cohorts including inflammatory and degenerative neurologic disease in a multicenter study involving 220 patients Bivariate elevated CXCL13 plus IL-10 was 993% specific for primary and secondary CNS lymphoma, with sensitivity significantly greater than reference standard CSF tests These results identify CXCL13 and IL-10 as potentially important biomarkers of CNS lymphoma that merit further evaluation and support incorporation of CXCL13 and IL-10 into diagnostic algorithms for the workup of focal brain lesions in which lymphoma is a consideration

148 citations


Cites methods from "Pathologic Correlates of Primary Ce..."

  • ...To enable the generation of adequate numbers of cells for in vitro assays, patient-derived lymphoma cells were implanted into the cerebrum of NOD-SCID g mice whereupon they expanded to form visible tumors within 4 weeks, according to an Institutional Animal Care and Use Committee–approved protocol.(17) At necropsy, intracranial lymphoma xenografts were isolated, and malignant B cells purified by CD191 selection by MACS (Miltenyi Biotech) for in vitro migration assays....

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Journal ArticleDOI
TL;DR: The cell lines and murine models used to study lymphomagenesis, the lymphoma microenvironment, and the efficacy of new therapies are summarized to improve understanding of the molecular and cellular mechanisms of tumor genesis and development as well as the fundamental processes governing the interaction of tumors and their host tissues.
Abstract: Human B-cell lymphomas, the fourth most common hematologic malignancy, are currently the subject of extensive research. The limited accessibility of biopsies, the heterogeneity among patients, and the subtypes of lymphomas have necessitated the development of animal models to decipher immune escape mechanisms and design new therapies. Here, we summarize the cell lines and murine models used to study lymphomagenesis, the lymphoma microenvironment, and the efficacy of new therapies. These data allow us to understand the role of the immune system in the fight against tumors. Exploring the advantages and limitations of immunocompetent versus immunodeficient models improves our understanding of the molecular and cellular mechanisms of tumor genesis and development as well as the fundamental processes governing the interaction of tumors and their host tissues. We posit that these basic preclinical investigations will open up new and promising approaches to designing better therapies.

62 citations


Journal ArticleDOI
05 Aug 2013-PLOS ONE
TL;DR: POM is a promising therapeutic agent for CNS lymphoma with excellent CNS penetration, significant preclinical therapeutic activity, and a major impact on the tumor microenvironment.
Abstract: Primary CNS lymphoma carries a poor prognosis. Novel therapeutic agents are urgently needed. Pomalidomide (POM) is a novel immunomodulatory drug with anti-lymphoma activity. CNS pharmacokinetic analysis was performed in rats to assess the CNS penetration of POM. Preclinical evaluation of POM was performed in two murine models to assess its therapeutic activity against CNS lymphoma. The impact of POM on the CNS lymphoma immune microenvironment was evaluated by immunohistochemistry and immunofluorescence. In vitro cell culture experiments were carried out to further investigate the impact of POM on the biology of macrophages. POM crosses the blood brain barrier with CNS penetration of ~ 39%. Preclinical evaluations showed that it had significant therapeutic activity against CNS lymphoma with significant reduction in tumor growth rate and prolongation of survival, that it had a major impact on the tumor microenvironment with an increase in macrophages and natural killer cells, and that it decreased M2-polarized tumor-associated macrophages and increased M1-polarized macrophages when macrophages were evaluated based on polarization status. In vitro studies using various macrophage models showed that POM converted the polarization status of IL4-stimulated macrophages from M2 to M1, that M2 to M1 conversion by POM in the polarization status of lymphoma-associated macrophages is dependent on the presence of NK cells, that POM induced M2 to M1 conversion in the polarization of macrophages by inactivating STAT6 signaling and activating STAT1 signaling, and that POM functionally increased the phagocytic activity of macrophages. Based on our findings, POM is a promising therapeutic agent for CNS lymphoma with excellent CNS penetration, significant preclinical therapeutic activity, and a major impact on the tumor microenvironment. It can induce significant biological changes in tumor-associated macrophages, which likely play a major role in its therapeutic activity against CNS lymphoma. POM should be further evaluated in clinical trials.

57 citations


Cites background from "Pathologic Correlates of Primary Ce..."

  • ...When they were treated with IL4 followed by POM, they expressed pSTAT1 and iNOS, and did not express pSTAT6 and YM1/FXIIIA, indicating conversion of their polarization from M2 to M1 via activation of STAT1 signalling and inactivation of STAT6 signalling....

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  • ...These cells expressed pSTAT6 and YM1/FXIIIA [12] on treatment with IL4 followed by DMSO, indicating M2 polarization via IL4/STAT6 signalling pathway....

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  • ...In experiments in which IL-4 was used to induce M2 polarization of macrophages, cells were treated with IL-4 (20ng/ml) for 48 hours followed by treatment with POM (10ug/ml) or DMSO control for 48 hours....

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  • ...It has been shown that macrophages in PCNSL are M2 polarized related to upregulation of IL4 in CNS lymphoma [12,13]....

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  • ...POM converted the IL-4-induced M2 polarization of macrophages as indicated by FXIII A and pSTAT6 expression to M1 polarization as indicated by iNOS and pSTAT1 expression....

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References
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Abstract: The classical pathway of interferon-gamma-dependent activation of macrophages by T helper 1 (T(H)1)-type responses is a well-established feature of cellular immunity to infection with intracellular pathogens, such as Mycobacterium tuberculosis and HIV. The concept of an alternative pathway of macrophage activation by the T(H)2-type cytokines interleukin-4 (IL-4) and IL-13 has gained credence in the past decade, to account for a distinctive macrophage phenotype that is consistent with a different role in humoral immunity and repair. In this review, I assess the evidence in favour of alternative macrophage activation in the light of macrophage heterogeneity, and define its limits and relevance to a range of immune and inflammatory conditions.

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TL;DR: Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylation of theMGMT promoter did notHave such a benefit and were assigned to only radiotherapy.
Abstract: background Epigenetic silencing of the MGMT (O 6 -methylguanine–DNA methyltransferase) DNArepair gene by promoter methylation compromises DNA repair and has been associated with longer survival in patients with glioblastoma who receive alkylating agents. methods We tested the relationship between MGMT silencing in the tumor and the survival of patients who were enrolled in a randomized trial comparing radiotherapy alone with radiotherapy combined with concomitant and adjuvant treatment with temozolomide. The methylation status of the MGMT promoter was determined by methylation-specific polymerase-chain-reaction analysis. results The MGMT promoter was methylated in 45 percent of 206 assessable cases. Irrespective of treatment, MGMT promoter methylation was an independent favorable prognostic factor (P<0.001 by the log-rank test; hazard ratio, 0.45; 95 percent confidence interval, 0.32 to 0.61). Among patients whose tumor contained a methylated MGMT promoter, a survival benefit was observed in patients treated with temozolomide and radiotherapy; their median survival was 21.7 months (95 percent confidence interval, 17.4 to 30.4), as compared with 15.3 months (95 percent confidence interval, 13.0 to 20.9) among those who were assigned to only radiotherapy (P=0.007 by the log-rank test). In the absence of methylation of the MGMT promoter, there was a smaller and statistically insignificant difference in survival between the treatment groups. conclusions Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylated MGMT promoter did not have such a benefit.

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TL;DR: Recent studies have shown that monocyte heterogeneity is conserved in humans and mice, allowing dissection of its functional relevance: the different monocyte subsets seem to reflect developmental stages with distinct physiological roles, such as recruitment to inflammatory lesions or entry to normal tissues.
Abstract: Heterogeneity of the macrophage lineage has long been recognized and, in part, is a result of the specialization of tissue macrophages in particular microenvironments. Circulating monocytes give rise to mature macrophages and are also heterogeneous themselves, although the physiological relevance of this is not completely understood. However, as we discuss here, recent studies have shown that monocyte heterogeneity is conserved in humans and mice, allowing dissection of its functional relevance: the different monocyte subsets seem to reflect developmental stages with distinct physiological roles, such as recruitment to inflammatory lesions or entry to normal tissues. These advances in our understanding have implications for the development of therapeutic strategies that are targeted to modify particular subpopulations of monocytes.

4,500 citations


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TL;DR: These functionally polarized cells, and similarly oriented or immature dendritic cells present in tumors, have a key role in subversion of adaptive immunity and in inflammatory circuits that promote tumor growth and progression.
Abstract: Mononuclear phagocytes are versatile cells that can express different functional programs in response to microenvironmental signals. Fully polarized M1 and M2 (or alternatively activated) macrophages are the extremes of a continuum of functional states. Macrophages that infiltrate tumor tissues are driven by tumor-derived and T cell-derived cytokines to acquire a polarized M2 phenotype. These functionally polarized cells, and similarly oriented or immature dendritic cells present in tumors, have a key role in subversion of adaptive immunity and in inflammatory circuits that promote tumor growth and progression.

4,126 citations


Journal ArticleDOI
TL;DR: It is demonstrated that Fc-receptor-dependent mechanisms contribute substantially to the action of cytotoxic antibodies against tumors and indicate that an optimal antibody against tumors would bind preferentially to activation Fc receptors and minimally to the inhibitory partner FcγRIIB.
Abstract: Inhibitory receptors have been proposed to modulate the in vivo cytotoxic response against tumor targets for both spontaneous and antibody-dependent pathways. Using a variety of syngenic and xenograft models, we demonstrate here that the inhibitory FcgammaRIIB molecule is a potent regulator of antibody-dependent cell-mediated cytotoxicity in vivo, modulating the activity of FcgammaRIII on effector cells. Although many mechanisms have been proposed to account for the anti-tumor activities of therapeutic antibodies, including extended half-life, blockade of signaling pathways, activation of apoptosis and effector-cell-mediated cytotoxicity, we show here that engagement of Fcgamma receptors on effector cells is a dominant component of the in vivo activity of antibodies against tumors. Mouse monoclonal antibodies, as well as the humanized, clinically effective therapeutic agents trastuzumab (Herceptin(R)) and rituximab (Rituxan(R)), engaged both activation (FcgammaRIII) and inhibitory (FcgammaRIIB) antibody receptors on myeloid cells, thus modulating their cytotoxic potential. Mice deficient in FcgammaRIIB showed much more antibody-dependent cell-mediated cytotoxicity; in contrast, mice deficient in activating Fc receptors as well as antibodies engineered to disrupt Fc binding to those receptors were unable to arrest tumor growth in vivo. These results demonstrate that Fc-receptor-dependent mechanisms contribute substantially to the action of cytotoxic antibodies against tumors and indicate that an optimal antibody against tumors would bind preferentially to activation Fc receptors and minimally to the inhibitory partner FcgammaRIIB.

2,705 citations


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