The Critical Interaction Between Epstein-Barr Virus (EBV) Positive B-Cells and Tumor Associated Macrophages (TAMs)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2989-2989 ◽  
Author(s):  
Ai Sato ◽  
Natsuko Yamakawa ◽  
Kazuki Okuyama ◽  
Ai Kotani ◽  
Naoya Nakamura ◽  
...  
Keyword(s):  
B Cells ◽  
Tumor Microenvironment ◽  
Tumor Cells ◽  
B Cell Lymphoma ◽  
The Elderly ◽  
M2 Macrophages ◽  
Tumor Associated Macrophages ◽  
Lymphoma Cells ◽  
The Impact

Abstract Introduction: EBV positive diffuse large B-cell lymphoma of the elderly (EBV positive DLBCL, elderly) has been newly categorized in 2008 WHO classification. The incidence is higher in Asian countries than Western countries. The prognosis of DLBCL has been improved by the introduction of rituximab, while EBV positive DLBCL remains unknown. Recently we reported that EBV positive DLBCL of the elderly did have quit inferior prognosis than EBV negative DLBCL. The mechanism lying under the inferiority has yet been elucidated. We hypothesize that tumor microenvironment plays a role in the mechanism, as EBV related lymphoma are usually accompanied with massive infiltration of non-tumor cells. We have previously found that tumor secreted small RNAs were selectively taken by macrophages and dramatically change the character into tumor supporting phenotype in the EBV positive lymphoma. Accordingly, we focus the interaction between tumor cells and macrophages in EBV positive lymphoma microenvironment. Methods: We investigated the number of CD163-positive macrophage (CD163+M2) in the DLBCL specimen with and without EBV positivity. The effect of EBV positivity in the tumor cells on the macrophages infiltrated in the tumor were studied by use of the coculture system using human monocytic cell line (THP-1) and human Burkitt lymphoma cells lines (Akata) which has two subclones such as EBV positive and negative. PMA-induced macrophages from THP1 cells were cocultured with EBV positive or negative Akata, then the expression of the several cytokines such as TNF-a, IL-10, CXCL10, and VEGF were measured by real-time PCR. Finally, we tried to clarify the impact of the macrophages on tumor formation in vivo by using xeno-transplantation model. Hematopoietic humanized NOG mice were infected with EBV to induce EBV related lymphoproliferative disease (LPD). After the appearance of symptoms of the LPD such as body weight loss, mice were treated with Clodronate to deplete macrophages. Result: The multivariate analysis for DLBCL patients demonstrated the statistically significant association between both high scores of CD163+M2 macrophages (CD163-positive cell > 20%) and EBV positivity, and poor prognosis (p = 0.0084, 0.0020, respectively.), which implies that EBV affected the quantity of CD163+M2 macrophages in the tumor microenvironment. Co-culture of THP1 with EBV positive lymphoma cells significantly upregulated CXCL10 and VEGF, when compared with EBV negative cells. (p = 0.0073, 0.0161, respectively.). (Figure 1) Most surprisingly, EBER positive B cells almost completely disappeared by macrophage depletion by Clodronate treatment (Figure 2). These results suggest that the macrophages in the EBV positive tumor microenvironment are crucial for survival of EBV+ tumor cells. Conclusion: EBV status of the lymphoma cells affected on TAMs in the way such as up-regulation of CXCR10 and VGEF, angiogenetic factors which are presumed to support tumor survival. The in vivo depletion of macrophages by Clodronate also demonstrated that they were indispensable for EBV positive tumor cell survival. Taken together, the interaction of EBV positive tumor cells and tumor associated macrophages is of crucial importance in the biology and formation of EBV positive lymphoma. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Emetine Elicits Apoptosis of Intractable B-Cell Lymphoma Cells with MYC Rearrangement through Inhibition of Glycolytic Metabolism

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3019-3019
Author(s):  
Tomohiro Aoki ◽  
Kazuyuki Shimada ◽  
Akihiko Sakamoto ◽  
Keiki Sugimoto ◽  
Takanobu Morishita ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Glucose Metabolism ◽  
Tumor Cells ◽  
Drug Screening ◽  
Stromal Cells ◽  
Research Funding ◽  
B Cell Lymphoma ◽  
Lymphoma Cells

Abstract Background: Despite remarkable advances of initial treatment in diffuse large B-cell lymphoma (DLBCL), the prognosis of the disease with MYC rearrangement remains poor with a median overall survival of less than 1 year. The application of intensive or targeting treatment failed to show a benefit for the disease, an innovative approach should be thus required to overcome the obstacle of MYC rearrangement. Recent findings revealed that the close interaction of tumor cells with stromal cells in its microenvironment is involved in resistance to chemotherapy, and that tumor microenvironment has been shed light on a potential attractive therapeutic target. Purpose: To overcome poor prognoses of intractable DLBCL with MYC rearrangement, we explored an effective drug targeting tumor microenvironment through the high-throughput drug screening (Sugimoto et al. Sci Rep. 2015). Material and methods: Allpatient samples were experimentally used with written informed consent. To perform drug screening against primary patient lymphoma cells with intractable clinical course,we firstly developed co-culture system of lymphoma cells and stromal cells, which allowed us to culture them in vitro.For this, isolated stromal cells derived from human lymph node were prepared. Then 3,440 compounds mainly containing known pharmacologically active substance or off-patent drugs were screened to identify effective drugs for patient lymphoma cells. The efficacy and mechanism of action of the drug were confirmed by subsequent in vitro and in vivo analyses. Results: Two patient tumor cells with MYC/BCL2 rearrangement were used for the drug screening. Both patients developed refractory diseases within 1 year after diagnosis. In the screening analyses, primary lymphoma cells obtained from lymph node for patient (Pt) #1 were used, and tumor cells from PDX mouse model for Pt #2 were used to validate the result of Pt #1. The both tumor cells could not survive in in vitro monoculture, while the both lymphoma cells could remarkably survive longer in co-culture with stromal cells. Then we performed drug screening against primary tumor cells from Pt #1. Ninety-nine compounds with the viability of tumor cells less than 0.5 were identified, and we validated cell death of these 99 compounds against the other lymphoma cells from Pt #2. Among 10 compounds identified as potentially effective for the both tumor cells, we picked out emetine, which induced cell death against the both cells with an IC50 of 312 nM and 506 nM, respectively. Regarding the effect of emetine on stromal cells, the proliferation and survival was not affected in the concentration of 2 µM emetine whose concentration was used for the screening. However, stromal cells pretreated 0.5 µM emetine decreased a support potential to tumor cells resulting from decreased ATP production and glutathione in tumor cells. In terms of the effect of emetine on tumor cells, the drug induced a G2/M arrest in tumor cells, which resulted in induction of apoptosis. Based on previous finding that emetine suppresses HIF-1a expression, which is one of key regulators glucose metabolisms, we investigated the expression in tumor cells under the treatment of emetine. HIF-1a expression was suppressed in tumor cells as expected; we subsequently analyzed the status of glucose metabolism in tumor cells. The expression of key enzymes including HK2, PDK1, and LDHA were suppressed and ATP production and GLUT1 expression were also suppressed. The serial cascade of the alteration of glucose metabolism including the decreased mitochondrial membrane potential, the alteration of pentose phosphate pathway, and the reduction of NADPH and glutathione leading to the accrual of reactive oxygen species (ROS) was observed under the presence of emetine. In in vivo analyses, significant growth inhibition was observed under the emetine treatment (Figure A and B). Conclusions: Emetine identified by the drug screening is clearly effective for patient lymphoma cells with intractable clinical course in vitro and in vivo. Subsequent analyses regarding the mechanism of action of emetine revealed that the drug affected the both tumor cells and stromal cells in tumor microenvironment through the inhibition of glucose metabolism. Further investigations of the translation to clinic should be warranted. Disclosures Sugimoto: Otsuka Pharmaceutical Co., Ltd.: Employment. Kiyoi:Nippon Shinyaku Co., Ltd.: Research Funding; Fujifilm Corporation: Patents & Royalties, Research Funding; Eisai Co., Ltd.: Research Funding; Astellas Pharma Inc.: Consultancy, Research Funding; Phizer Japan Inc.: Research Funding; Yakult Honsha Co.,Ltd.: Research Funding; Takeda Pharmaceutical Co., Ltd.: Research Funding; MSD K.K.: Research Funding; Alexion Pharmaceuticals: Research Funding; Novartis Pharma K.K.: Research Funding; Mochida Pharmaceutical Co., Ltd.: Research Funding; Toyama Chemikal Co.,Ltd.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; AlexionpharmaLLC.: Research Funding; JCR Pharmaceutlcals Co.,Ltd.: Research Funding; Nippon Boehringer Ingelheim Co., Ltd.: Research Funding; Celgene Corporation: Consultancy; Zenyaku Kogyo Co.LTD.: Research Funding; Kyowa-Hakko Kirin Co.LTD.: Research Funding; Chugai Pharmaceutical Co. LTD.: Research Funding.

scholarly journals Melanoma-specific bcl-2 promotes a protumoral M2-like phenotype by tumor-associated macrophages

2020 ◽  
Vol 8 (1) ◽  
pp. e000489 ◽  
Author(s):  
Marta Di Martile ◽  
Valentina Farini ◽  
Francesca Maria Consonni ◽  
Daniela Trisciuoglio ◽  
Marianna Desideri ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Tumor Cells ◽  
Macrophage Polarization ◽  
Melanoma Cells ◽  
Response To Therapy ◽  
Major Constituent ◽  
M2 Macrophage ◽  
Tumor Associated Macrophages

BackgroundA bidirectional crosstalk between tumor cells and the surrounding microenvironment contributes to tumor progression and response to therapy. Our previous studies have demonstrated that bcl-2 affects melanoma progression and regulates the tumor microenvironment. The aim of this study was to evaluate whether bcl-2 expression in melanoma cells could influence tumor-promoting functions of tumor-associated macrophages, a major constituent of the tumor microenvironment that affects anticancer immunity favoring tumor progression.MethodsTHP-1 monocytic cells, monocyte-derived macrophages and melanoma cells expressing different levels of bcl-2 protein were used. ELISA, qRT-PCR and Western blot analyses were used to evaluate macrophage polarization markers and protein expression levels. Chromatin immunoprecipitation assay was performed to evaluate transcription factor recruitment at specific promoters. Boyden chamber was used for migration experiments. Cytofluorimetric and immunohistochemical analyses were carried out to evaluate infiltrating macrophages and T cells in melanoma specimens from patients or mice.ResultsHigher production of tumor-promoting and chemotactic factors, and M2-polarized activation was observed when macrophages were exposed to culture media from melanoma cells overexpressing bcl-2, while bcl-2 silencing in melanoma cells inhibited the M2 macrophage polarization. In agreement, the number of melanoma-infiltrating macrophages in vivo was increased, in parallel with a greater expression of bcl-2 in tumor cells. Tumor-derived interleukin-1β has been identified as the effector cytokine of bcl-2-dependent macrophage reprogramming, according to reduced tumor growth, decreased number of M2-polarized tumor-associated macrophages and increased number of infiltrating CD4+IFNγ+and CD8+IFNγ+effector T lymphocytes, which we observed in response to in vivo treatment with the IL-1 receptor antagonist kineret. Finally, in tumor specimens from patients with melanoma, high bcl-2 expression correlated with increased infiltration of M2-polarized CD163+macrophages, hence supporting the clinical relevance of the crosstalk between tumor cells and microenvironment.ConclusionsTaken together, our results show that melanoma-specific bcl-2 controls an IL-1β-driven axis of macrophage diversion that establishes tumor microenvironmental conditions favoring melanoma development. Interfering with this pathway might provide novel therapeutic strategies.

scholarly journals The impact of tumor stromal architecture on therapy response and clinical progression

2018 ◽  
Author(s):  
Philipp M. Altrock ◽  
Nara Yoon ◽  
Joshua A. Bull ◽  
Hao Wu ◽  
Javier Ruiz-Ramírez ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Targeted Therapies ◽  
Therapeutic Interventions ◽  
Clinical Samples ◽  
Main Question ◽  
Breast Cancers ◽  
Oncology Research ◽  
The Impact

Abstract— Advances in molecular oncology research culminated in the development of targeted therapies that act on defined molecular targets either on tumor cells directly (such as inhibitors of oncogenic kinases), or indirectly by targeting the tumor microenvironment (such as anti-angiogenesis drugs). These therapies can induce strong clinical responses, when properly matched to patients. Unfortunately, most targeted therapies ultimately fail as tumors evolve resistance. Tumors consist not only of neoplastic cells, but also of stroma, whereby “stroma” is the umbrella term for non-tumor cells and extracellular matrix (ECM) within the tumor microenvironment, possibly excluding immune cells1. We know that tumor stroma is an important player in the development of resistance. We also know that stromal architecture is spatially complex, differs from patient to patient and changes with therapy. However, to this date we do not understand the link between spatial and temporal changes in stromal architecture and response of tumors to therapy, in space and time. In this project we sought to address this gap of knowledge using a combination of mathematical and statistical modeling, experimental in vivo studies, and analysis of clinical samples in therapies that target tumor cells directly (in lung and breast cancers) and indirectly (in kidney cancer). This knowledge will inform therapy choices and offer new angles for therapeutic interventions. Our main question is: how does spatial architecture of stroma impact the emergence or evolution of resistance to targeted therapies, and how can we use this knowledge clinically?

scholarly journals Tumor-Associated Macrophages in Tumor Immunity

2020 ◽  
Vol 11 ◽  
Author(s):  
Yueyun Pan ◽  
Yinda Yu ◽  
Xiaojian Wang ◽  
Ting Zhang
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Immune Cell ◽  
Malignant Tumors ◽  
Treatment Strategies ◽  
Cell Types ◽  
Therapeutic Interventions ◽  
M2 Macrophages ◽  
Tumor Associated Macrophages ◽  
Mediate Cytotoxicity

Tumor-associated macrophages (TAMs) represent one of the main tumor-infiltrating immune cell types and are generally categorized into either of two functionally contrasting subtypes, namely classical activated M1 macrophages and alternatively activated M2 macrophages. The former typically exerts anti-tumor functions, including directly mediate cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC) to kill tumor cells; the latter can promote the occurrence and metastasis of tumor cells, inhibit T cell-mediated anti-tumor immune response, promote tumor angiogenesis, and lead to tumor progression. Both M1 and M2 macrophages have high degree of plasticity and thus can be converted into each other upon tumor microenvironment changes or therapeutic interventions. As the relationship between TAMs and malignant tumors becoming clearer, TAMs have become a promising target for developing new cancer treatment. In this review, we summarize the origin and types of TAMs, TAMs interaction with tumors and tumor microenvironment, and up-to-date treatment strategies targeting TAMs.

Apoptotic Lymphoma Cells Evoke a Pro-Senescent Stromal Signal That Limits Lymphoma Development.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2392-2392
Author(s):  
Maurice Reimann ◽  
Soyoung Lee ◽  
Christoph Loddenkemper ◽  
Jan Dörr ◽  
Vedrana Tabor ◽  
...  
Keyword(s):  
B Cell ◽  
Tumor Cells ◽  
Transgenic Mouse ◽  
Cellular Senescence ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cells ◽  
Anti Cancer ◽  
Mouse Lymphoma

Abstract Abstract 2392 Poster Board II-369 Introduction: Cancer entities frequently exhibiting constitutive Myc expression, such as aggressive B-cell lymphomas, typically display significant amounts of apoptotic cell death. So far, cellular senescence as another cell-autonomous oncogene-inducible safeguard program has been recognized in RAS/BRAF-driven scenarios but not as a bona fide Myc-evoked anti-cancer mechanism. Understanding how oncogenic Myc may provoke not only apoptosis but cellular senescence as a failsafe mechanism to counter tumor development has broad implications for the clinical presentation and therapeutic strategies in frequently Myc-driven lymphoma entities such as Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL). Results: Using the Burkitt's like Eμ-myc transgenic mouse lymphoma model, we show here that cellular senescence serves as another crucial anti-neoplastic barrier during Myc-driven tumorigenesis in addition to apoptosis. Eμ-myc lymphomas harbor a substantial fraction of senescent tumor cells, that stain positive for histone H3 lysine 9 (H3K9)-trimethylation. Lymphomas lacking the H3K9 methyltransferase Suv39h1 display no senescence and develop significantly faster, although apoptosis is not affected by Suv39h1 deficiency. While Myc, unlike other Ras-type oncogenes, shows rather modest pro-senescent activity in vitro, we identified the cytostatic cytokine TGF-β as the main paracrine senescence trigger in vivo. When neutralizing TGF-β action during Myc-driven lymphomagenesis utilizing a secretable TGF-β receptor II ecto-domain, senescence is completely blunted and tumor latency is significantly shortened. We identify macrophages, but not lymphoma cells, as the main source of exogenous TGF-β, that is secreted upon phagocytosis of apoptotic lymphoma cells. Lymphomas harboring a Bcl2-mediated apoptotic block presented with a much lower frequency of both infiltrating macrophages and senescent cells in vivo, suggesting that there is a functional link between cell-autonomous Myc-triggered apoptosis and non-cell-autonomous, macrophage-induced senescence. Both pharmacological suppression of TGF-β production in macrophages via the angiotensin-converting enzyme (ACE) inhibitor lisinopril and depletion of macrophages in Eμ-myc lymphoma-harboring mice by systemic exposure to clodronate resulted in a profound reduction of senescence, thereby underscoring the important role for tumor-infiltrating macrophages in TGF-β-mediated senescence in vivo. We recapitulated components of such a mechanism in human aggressive B-cell lymphomas, a frequently Myc-activated entity where TGF-β1 signaling has previously been identified as a component of the prognostically favourable “stromal-1” signature (Lenz-G et al., NEJM, 2008). A panel of 30 DLBCL samples was sub-divided based on Ki67 immunoreactivity into a very high proliferation (Ki67hi; ≥80% Ki67-positive cells) and a lower proliferation (Ki67lo; <80% Ki67-positive cells) group. Ki67lo samples exhibited a higher frequency of H3K9me3-positive cells, indicative of cellular senescence. Importantly, the Ki67lo group also presented with a higher fraction of apoptotic cells, more lymphoma-infiltrating macrophages, and a stronger reactivity for the TGF-β signaling mediator Smad3-P, thereby representing a subgroup in DLBCL that displays features highly reminiscent of the macrophage-derived mechanism of senescence induction. Conclusions: Our study expands the relevance of oncogene-induced senescence to Myc-driven cancers and demonstrates that different tumor suppressor programs - such as apoptosis and senescence - are enforced in an interdependent fashion between the tumor- and non-malignant stroma cells during lymphomagenesis. Utilizing the Eμ-myc transgenic mouse lymphoma model and furthermore supported by evidence from human aggressive B-cell lymphoma samples, this study establishes a novel network of heterotypic cell-cell interactions within a tumor in which apoptotic tumor cells induce a paracrine response in non-malignant bystander cells that limits lymphomagenesis by cellular senescence. Given the anti-cancer relevance of senescence and the demonstrated inducibility of senescence by a non-DNA damaging cytokine, such as TGF-β, these findings open the exciting perspective to utilize Suv39h1/H3K9me3-mimicking approaches for future cancer therapies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Dendritic cells loaded with apoptotic antibody-coated tumor cells provide protective immunity against B-cell lymphoma in vivo

Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1504-1511 ◽  
Author(s):  
Suzanne N. Franki ◽  
Kristopher K. Steward ◽  
David J. Betting ◽  
Kamran Kafi ◽  
Reiko E. Yamada ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Tumor Antigens ◽  
B Cell Lymphoma ◽  
Lymphoma Cells ◽  
Term Survival ◽  
Dc Vaccine

Abstract The in vitro priming of tumor-specific T cells by dendritic cells (DCs) phagocytosing killed tumor cells can be augmented in the presence of antitumor monoclonal antibody (mAb). We investigated whether DCs phagocytosing killed lymphoma cells coated with tumor-specific antibody could elicit antitumor immunity in vivo. Irradiated murine 38C13 lymphoma cells were cocultured with bone marrow–derived DCs in the presence or absence of tumor-specific mAb. Mice vaccinated with DCs cocultured with mAb-coated tumor cells were protected from tumor challenge (60% long-term survival), whereas DCs loaded with tumor cells alone were much less effective. The opsonized whole tumor cell–DC vaccine elicited significantly better tumor protection than a traditional lymphoma idiotype (Id) protein vaccine, and in combination with chemotherapy could eradicate preexisting tumor. Moreover, the DC vaccine protected animals from both wild-type and Id-negative variant tumor cells, indicating that Id is not a major target of the induced tumor immunity. Protection was critically dependent upon CD8+ T cells, with lesser contribution by CD4+ T cells. Importantly, opsonized whole tumor cell–DC vaccination did not result in tissue-specific autoimmunity. Since opsonized whole tumor cell–DC and Id vaccines appear to target distinct tumor antigens, optimal antilymphoma immunity might be achieved by combining these approaches.

A CD47xCD19 Bispecific Antibody That Remodels the Tumor Microenvironment for Improved Killing and Provokes a Memory Immune Response to Cancer B Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 44-44
Author(s):  
Walter G. Ferlin ◽  
Xavier Chauchet ◽  
Vanessa Buatois ◽  
Susana Salgado-Pires ◽  
Limin Shang ◽  
...  
Keyword(s):  
B Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
B Cell ◽  
Cell Lymphoma ◽  
Treatment Strategies ◽  
B Cell Lymphoma ◽  
Tumor Killing

Abstract Up-regulation of CD47 in hematological and solid cancers correlates with poor clinical prognosis. CD47 interaction with SIRPα provides a ‘don't eat me’ signal that allows healthy cells to limit elimination by immune cells, in particular macrophages. Although tumor-associated macrophages (TAMs) are often considered pro-tumorigenic, several studies report a high phagocytic potential and tumoricidal function in the presence of therapeutic antibodies (Ab). Therefore, targeting the CD47-SIRPα pathway in the tumor microenvironment is an attractive approach to maximize the tumor killing potential of TAMs to boost tumor destruction. However, clinical development of monoclonal Abs to CD47 is likely to be hindered by the ubiquitous expression of CD47 leading to rapid drug elimination and toxicity including anemia. To address these concerns, we have created NI-1701, a bispecific Ab that drives efficacious binding only to CD19+B cells by pairing a high affinity anti-CD19 targeting arm to an anti-CD47 arm of optimized affinity.. In addition to in vitro data demonstrating that the bispecific Ab, NI-1701, effectively kills CD19+ human tumor B cells through ADCP (antibody-dependent cellular phagocytosis) and antibody-dependent cell-mediated cytotoxicity (ADCC), we have observed significant tumor killing in vivo, as either a monotherapy or in a combination approach. NI-1701 controlled sub-cutaneously implanted Raji cell tumor growth in NOD/SCID mice in a manner dependent on the co-ligation of both CD19 and CD47. Examination of the excised tumors revealed that NI-1701 reshaped the tumor microenvironment by enhancing the tumoricidal activity of macrophages (i.e., more macrophages engulfing tumor cells), by promoting an antitumor M1-like phenotype, and reducing the proportion of CD11b+Gr1+myeloid-derived suppressor cells (MDSCs). Extending these findings to a disseminated in vivo model, NI-1701 eliminated tumor cells from the peripheral blood, bone marrow and liver in mice transplanted either with the B-Acute Lymphocytic Leukemia (B-ALL) cell line NALM-6 or with primary cells from B-ALL patients. Furthermore, NI-1701 also abrogated tumor growth more efficiently than the BTK inhibitor ibrutinib in a Diffuse Large B-Cell Lymphoma (DLBCL) patient-derived xenograft (PDX) mouse model. As combination therapies are gaining traction as successful treatment strategies in the clinic, we next tested the effect of blocking CD47 biology in combination with clinically validated molecules. Interestingly, in NOD/SCID mice implanted with Raji cells, NI-1701 was shown to be more efficacious at controlling tumor cell growth than Rituximab. A combination of NI-1701 and Rituximab was shown to act synergistically at controlling tumor growth and leading to tumor regression in some mice. Finally, in a syngeneic re-challenge model, using bispecific reagents targeting CD47 blockade to the A20 murine B-cell lymphoma, we observed the induction of a durable and protective anti-tumor response when combined with a single administration of cyclophosphamide. Importantly, in vitro safety studies demonstrate a favorable binding profile of NI-1701 to B cells compared with erythrocytes, no evidence of platelet activation or aggregation and no haemagglutination at and above anticipated therapeutic concentrations. Single and multiple dose studies in non-human primates demonstrated favorable elimination kinetics and no effects on hematological parameters (e.g., red blood cell and platelet counts) up to 100mg/kg, the highest dose tested. Taken together, we describe a novel bispecific approach that balances a safe yet effective blockade of CD47 with a high selectivity for a B cell associated antigen resulting in impressive tumor cell killing in a range of preclinical models. The effects on both the reshaping of the tumor microenvironment and the induction of long term tumor immunity provide further evidence that manipulation of myeloid lineage cells (e.g., macrophages and dendritic cells) is a promising approach for the next frontier in immune-oncology treatment strategies. NI-1701 is in preclinical enabling studies in preparation for a Phase I clinical study in patients with CD19+ B cell malignancies, planned for early 2017. Disclosures Ferlin: Novimmune S.A.: Employment, Equity Ownership. Chauchet:Novimmune S.A.: Employment. Buatois:Novimmune S.A.: Employment. Salgado-Pires:Novimmune S.A.: Employment. Shang:Novimmune S.A.: Employment. Dheilly:Novimmune S.A.: Employment. Masternak:Novimmune S.A.: Employment. Johnson:Novimmune S.A.: Employment. DiPersio:Incyte Corporation: Research Funding. Kosco-Vilbois:Novimmune S.A.: Employment. Fischer:Novimmune S.A.: Employment.

scholarly journals Mechanisms of Therapeutic Response to Tipifarnib in a Mouse Model of Angioimmunoblastic T-Cell Lymphoma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Jose Rodriguez Cortes ◽  
Anisha Cooke ◽  
Aidan Quinn ◽  
Bobby B Shih ◽  
Ioan Filip ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
Tumor Cells ◽  
Cell Lymphoma ◽  
Cell Populations ◽  
Lymphoma Cells ◽  
Mouse Lymphoma

Angioimmunoblastic T-cell lymphomas (AITLs) are aggressive non-Hodgkin lymphomas arising from malignant transformation of follicular helper T-cells (Tfh) and are associated with limited response to intensified chemotherapy and poor prognosis. The genomic landscape of AITL is characterized by loss of function mutations in epigenetic regulators, including TET2, and the highly prevalent RHOA G17V mutation identified in almost 70% of AITL cases (Palomero et al., 2014). Using a combination of loss of TET2 and expression of RHOA G17V in CD4+ T-cells, our group developed a new mouse model of AITL, which accurately recapitulates the features of the human disease (Cortes et al., 2018). Our model constitutes a relevant platform for studying AITL pathogenesis and developing experimental therapeutic approaches for the treatment of this disease. Tipifarnib is a farnesyltransferase inhibitor that has been linked to reduced cell proliferation and increased apoptosis in a variety of solid tumors and leukemias (Alsina et al., 2004; Kirschbaum et al., 2011). Interestingly, a phase II study of tipifarnib in patients with relapsed/refractory lymphoma indicated that, while tipifarnib had a modest anti-lymphoma activity within the whole cohort, it elicited an overall response rate of 31% within the Peripheral T-cell Lymphoma cases, particularly AITL (Witzig et al, 2011). However, the molecular bases for the therapeutic activity of tipifarnib in AITL are still unknown. To understand the role and the mechanisms of action of tipifarnib in AITL, we have used our TET2-/-RHOA G17V mouse AITL lymphoma model. Using this model, we first identified that treatment in vitro with increasing doses of tipifarnib showed limited effect on the viability of AITL lymphoma cells; however, when mouse lymphoma cells were co-cultured in the presence of splenocytes as supporting cells, tipifarnib induced a strong decrease in cell viability and proliferation, suggesting that tipifarnib might be exerting its therapeutic effects not only on the tumor cells, but also indirectly by regulating the tumor microenvironment. Indeed, tipifarnib treatment in a lymphoma model in vivo led to significantly decreased tumor load and substantial reduction of lymphoma cell infiltration in solid organs, demonstrating a consistent and strong anti-tumor effect of tipifarnib in AITL in vivo. Mechanistic analysis of signaling pathways regulated by tipifarnib indicated that tipifarnib induced downregulation of surface expression of the CXCR4 receptor in tumor cells and increased the circulating levels of its ligand, CXCL12, resulting in an effective increase of the CXCL12/CXCR4 ratio. In addition, our data revealed a significant tipifarnib-induced decrease in the levels of IFN-G, TNF-A, IL-10 and IL-17 cytokines. We also performed gene expression profiling in sorted AITL lymphoma cells and sorted stroma splenocytes from mice that had been treated with tipifarnib or vehicle control. Interestingly, most of the genes specifically affected by tipifarnib were expressed in stromal cells, where we detected an upregulation of Fas-L and, more notably, of multiple genes associated with NK cell function and differentiation (CD226, CD244a, Klre1, Xcl1 and Eomes). CYBERSORT analysis of hematopoietic cell populations indicated that treatment with tipifarnib in our mouse lymphoma model is associated with enrichment in NK signatures and a potential decrease of monocytes and neutrophils within the tumor microenvironment. In summary, we have demonstrated that tipifarnib has a strong anti-lymphoma effect on a mouse model of AITL and that this effect might be mediated by the recruitment and/or activation of different hematopoietic cell populations in the tumor microenvironment that can alter the survival and proliferation of lymphoma cells. Disclosures Palomero: Kura Onclology: Research Funding.

scholarly journals Tumor-associated macrophages: potential therapeutic strategies and future prospects in cancer

2021 ◽  
Vol 9 (1) ◽  
pp. e001341
Author(s):  
Chunxiao Li ◽  
Xiaofei Xu ◽  
Shuhua Wei ◽  
Ping Jiang ◽  
Lixiang Xue ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Poor Prognosis ◽  
Tumor Immunotherapy ◽  
Therapeutic Strategies ◽  
Preclinical Studies ◽  
Future Prospects ◽  
Tumor Associated Macrophages

Macrophages are the most important phagocytes in vivo. However, the tumor microenvironment can affect the function and polarization of macrophages and form tumor-associated macrophages (TAMs). Usually, the abundance of TAMs in tumors is closely associated with poor prognosis. Preclinical studies have identified important pathways regulating the infiltration and polarization of TAMs during tumor progression. Furthermore, potential therapeutic strategies targeting TAMs in tumors have been studied, including inhibition of macrophage recruitment to tumors, functional repolarization of TAMs toward an antitumor phenotype, and other therapeutic strategies that elicit macrophage-mediated extracellular phagocytosis and intracellular destruction of cancer cells. Therefore, with the increasing impact of tumor immunotherapy, new antitumor strategies to target TAMs are now being discussed.

scholarly journals Differentiated glioblastoma cells accelerate tumor progression by shaping the tumor microenvironment via CCN1-mediated macrophage infiltration

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Atsuhito Uneda ◽  
Kazuhiko Kurozumi ◽  
Atsushi Fujimura ◽  
Kentaro Fujii ◽  
Joji Ishida ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Tumor Cells ◽  
In Silico ◽  
Tumor Tissue ◽  
The Cancer Genome Atlas ◽  
Macrophage Infiltration ◽  
Macrophage Migration

AbstractGlioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.

Sign in / Sign up

Export Citation Format

Share Document