scholarly journals 941 Stromal cell sialylation suppresses T cells in inflammatory tumour microenvironments: a new tumour stromal cell immune checkpoint?

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A987-A987
Author(s):  
Oliver Treacy ◽  
Hannah Egan ◽  
Kevin Lynch ◽  
Niamh Leonard ◽  
Kim De Veirman ◽  
...  

BackgroundImmunosuppressive tumour microenvironments (TME) reduce the effectiveness of immune responses in cancer. Non-haematopoietic mesenchymal stromal cells, precursors to cancer-associated fibroblasts (CAFs), dictate tumour progression by enhancing immune cell suppression. Sialic acids, which exist as terminal sugars of glycans (known as sialoglycans), are highly expressed on cancer cells and hyper-sialylation of glycans is known to promote immune evasion in cancer. Sialoglycans are recognized by sialic acid-binding immunoglobulin-like lectins (Siglecs), a family of immunomodulatory receptors, which are analogous to the immune checkpoint inhibitor PD-1.1 The role of sialyation in stromal cell-mediated immunosuppression, however, is unknown. Using models of solid (colorectal cancer - CRC) and haematological (multiple myeloma - MM) stromal-rich tumours in both mouse and human, the aim of this study was to investigate if stromal cell sialylation contributes to enhanced immunosuppression in the TME.MethodsFlow cytometric analysis of sialic acid expression was performed initially on bone marrow-derived stromal cells isolated from healthy human donor bone marrow aspirates, from wild-type Balb/c mice or from 5T33 multiple myeloma mice. Stromal cells were also isolated and expanded from colorectal cancer patient tumour biopsies (CAFs) with matched controls isolated from tumour-adjacent non-cancerous tissue (normal-associated fibroblasts - NAFs) or from whole blood from primary multiple myeloma bone aspirates. Informed consent was obtained from all patients prior to sampling. Immunosuppression assays were performed using these stromal cells with or without exposure to the tumour cell secretome from the mouse and human CRC cell lines CT26 or HCT116 and HT29, respectively, co-cultured with either murine lymphocytes or healthy human donor-derived peripheral blood mononuclear cells (PBMCs).ResultsOur results showed that tumour conditioned stromal cells have increased levels of sialyltransferase gene expression, α2,3/α2,6-linked sialic acid and Siglec ligands. Co-culture assays revealed that CAFs induced significantly higher frequencies of Siglec 7 and Siglec 9-expressing CD8 T cells, as well as Tim-3 and PD-1-expressing CD8 T cells, compared to NAFs. Inhibition of sialyltransferase activity using the inhibitor 3FAXNeu5Ac reversed these CAF-induced effects. Interestingly, sialyltransferase inhibition had no observed effects on T cells co-cultured with NAFs.ConclusionsThese results demonstrate that targeting stromal cell sialylation can reverse immune cell suppression and reactivate exhausted T cells. These novel data support a rationale for the assessment of stromal cell sialylation and Siglec ligand expression in order to better stratify patients for immunotherapeutic combination treatments that aim to reactivate exhausted T cells in stromal-enriched tumour microenvironments.AcknowledgementsThe authors would like to thank the Blood Cancer Network of Ireland Biobank for providing bone marrow aspirates.ReferenceGray MA, Stanczak MA, Mantuano NR, Xiao H, Pijnenborg JFA, Malaker SA, Miller CL, Weidenbacher PA, Tanzo JT, Ahn G, Woods EC, Läubli H, Bertozzi CR. Targeted glycan degradation potentiates the anticancer immune response in vivo. Nat Chem Biol 2020;16:1376–1384.Ethics ApprovalColorectal tumor and adjacent normal mucosal tissue were obtained from patients undergoing colon tumor resection at University Hospital Galway under an ethically approved protocol (Clinical Research Ethics Committee, Ref: C.A. 2074). Samples were collected and isolated by the Blood Cancer Network of Ireland under an ethically approved protocol. Written informed explicit consent was obtained from all patients prior to sampling. Mice were housed and maintained following the conditions approved by the Animals Care Research Ethics Committee of the National University of Ireland, Galway (NUIG) and procedures were conducted under individual and project authorisation licenses from the Health Products Regulatory Authority (HPRA) of Ireland or from the Ethical Committee for Animal Experiments, Vrije Universiteit Brussel (license no. LA1230281, 16-281-6).

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A918-A918
Author(s):  
Hannah Egan ◽  
Oliver Treacy ◽  
Kevin Lynch ◽  
Niamh Leonard ◽  
Amir Nader ◽  
...  

BackgroundImmunosuppressive tumour microenvironments (TME) inhibit the effectiveness of cancer immunotherapies. Sialic acids, which exist as terminal sugars of glyco-conjugates, are highly expressed on cancer cells and are involved in various pathological processes including increased immune evasion, tumour invasiveness and tumour cell metastasis.1 Siglecs (Sialic acid-binding immunoglobulin-type lectins) are expressed on immune cell surfaces and bind sialic acid. Siglec binding to hypersialylated tumour glycans blocks immune cell activation to promote immunosuppression.1 2Intestinal stromal cells (iSCs), precursors to cancer-associated fibroblasts (CAFs), are a key component of the TME and play a vital role in tumour progression by enhancing a tumour-promoting microenvironment. The aim of this study was therefore to investigate if iSC/CAF sialylation contributes to enhanced immunosuppression in the TME.Methods iSCs were isolated from colorectal cancer patient biopsies and cultured ex vivo. Informed consent was obtained from all patients prior to sampling. Tumour-derived iSCs were termed CAFs while control iSCs, isolated from tumour-adjacent non-cancerous tissue, were termed normal-associated fibroblasts (NAFs). NAFs/CAFs were then co-cultured with healthy allogeneic PBMCs and their immunosuppressive properties were assessed by flow cytometry.ResultsCAFs significantly supressed the proliferation of CD8+ and CD4+ T-cells and induced a more exhausted T-cell phenotype as evidenced by increased expression of the exhaustion markers TIM-3, LAG-3 and PD-1 when compared to co-culture with control NAFs, thereby demonstrating their potent immunosuppressive properties. Strikingly, CAFs also induced significantly higher expression of both Siglec-7 and Siglec-9 receptors on CD8+ T-cells specifically.To elucidate the role of sialylation on CAF-mediated immunosuppression, NAFs/CAFs were treated with the sialyltransferase inhibitor (SI) P-3FAX-Neu5Ac prior to co-culture. Reduction of sialic acid expression on NAFs/CAFs was confirmed by flow cytometry and the SI-treated NAFs/CAFs were then co-cultured with allogeneic T-cells to assess the functional consequences of reduced NAF/CAF sialylation. SI-treated CAFs induced significantly less CD4+TIM-3+ and both CD4+LAG-3+ and CD8+LAG-3+ T-cells compared to their untreated counterparts. Interestingly, SI-treated CAFs also induced significantly less Siglec-7 and -9 receptor-expressing CD8+ T-cells.ConclusionsThese results demonstrate that non-haematopoietic stromal cells in the tumour-microenvironment can suppress activated T-cells and that this immunosuppressive effect can be significantly reversed through the modulation of sialylation on the stromal cell surface. These results support the hypothesis that stromal cell sialylation plays a role in their immunosuppressive properties. Understanding how sialylation of stromal cells is regulated and functions to enhance immunosuppression in the TME could uncover novel immune checkpoints to reactivate anti-tumour immunity, allowing for tumour cell clearance.Ethics ApprovalThis study was approved by Galway University Hospitals’ Clinical Research Ethics Committee, approval number C.A 2074.ConsentN/AReferencesWang L, Liu Y, Wu L, Sun XL. Sialyltransferase inhibition and recent advances. Biochim Biophys Acta 2016 Jan; 1864(1):143-53.Munkley J, Scott E. Targeting aberrant sialylation to treat cancer. Medicines (Basel) 2019 Oct 13;6(4):102.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2508-2508
Author(s):  
Michael Kline ◽  
Kathleen Donovan ◽  
Linda Wellik ◽  
Christopher Lust ◽  
Wendy Jin ◽  
...  

Abstract Background: Multiple myeloma (MM) is an incurable hematological malignancy characterized by the expansion of a plasma cell clone that localizes to the bone marrow. Stromal cells residing in the bone marrow respond to signals from MM cells and other cell types by producing cytokines and other proteins that stimulate tumor cell growth, survival, adhesion, migration, and drug resistance. We have examined the proteins produced by stromal cells in response to stimulation by bone marrow from patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and MM. Furthermore, we have begun analyzing the properties of one of these proteins, the pro-angiogenic chemokine IL-8, in MM. Methods: Bone marrow aspirates from patients with MGUS (n=3), SMM (n=7), and MM (n=6) were cultured for 48 hours, and the culture supernatants were incubated with stromal cells for an additional 48 hours. Protein levels were analyzed using antibody array and ELISA. Microvessel density (MVD) was determined as a measure of angiogenesis in patient bone marrow samples using CD34 staining. Flow cytometry analysis of MM cell lines and patient bone marrow samples was performed using monoclonal antibodies against IL-8 receptors CXCR1 and CXCR2. Results and Conclusion: We observed a significant increase in stromal cell IL-8 production stimulated by bone marrow cells from patients with active myeloma and a subset of SMM patients (16.67 ± 9.82 ng/ml) in comparison to bone marrow of patients with MGUS and all other SMM patients (0.55 ± 0.17 ng/ml; P=0.0004). Use of an IL-1 inhibitor and recombinant IL-1β demonstrated that IL-8 production was dependent upon IL-1β signaling. Increased BM microvessel density correlated with stimulation of stromal cell IL-8 production (P=0.0005). Furthermore, the majority of MM cell lines (7/9) and MM patient plasma cells were found to express IL-8 receptors CXCR1 and CXCR2. In addition to its function as a pro-angiogenic factor, IL-8 may directly influence MM cells through its CXCR1 and CXCR2 receptors. We conclude that stromal cell IL-8 production parallels MM disease activity, is IL-1β induced, correlates with bone marrow angiogenesis, and may influence MM disease via impact upon both the microenvironment and tumor cells.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1689-1689
Author(s):  
Jichun Chen ◽  
Neal S. Young

Abstract Immune-mediated bone marrow (BM) failure has been modeled in the mouse by infusion of lymph node cells from allogeneic C57BL/6 (B6) donors into major or minor histocompatibility antigen-mismatched recipients (Chen et al., Blood 2004; Bloom et al., Exp Hematol 2004, Chen et al., J Immunol 2007). Co-infusion of limited numbers of CD4+CD25+ regulatory T lymphocytes (Tregs) can alleviate clinical manifestations by suppressing the expansion of pathogenic T cells (Chen et al., J Immunol 2007). In the current study, we investigated the effectiveness of Tregs and suppressor cells contained in BM stroma in this fatal disease. Infusion of fewer than 3 × 103 Tregs to each recipient mouse had only a minor effect in preserving BM cells and did not prevent pancytopenia. Fifteen-50 × 103 thymic Tregs was moderately protective: blood WBC, RBC, platelet and BM cell counts at three weeks after cell infusion were 197%, 116%, 155% and 158% of those of control animals that did not receive Treg infusion; 5–10 × 103 B6 splenic Tregs produced the largest effect as WBC, RBC, platelet and BM cell counts were 275%, 143%, 276%, and 198% of controls. Overall, Treg therapy was helpful but its effectiveness was limited and variable among individual recipients as no antigen-specific Tregs can be identified for the treatment of BM failure. Learned about the immunosuppressive effects of mesenchymal stem cells (MSCs), we went on to test the effectiveness of stromal cells as another therapeutic modality for BM failure, since stromal cells contain MSCs. These cells were derived from B6 BM by culture in α-modified Eagle medium at 33°C with 5% CO2 for two weeks. After separating the non-adherent cells, we detached the adherent stromal cells and infused them into TBI + B6 LN-infused C.B10 mice. Injection of 106 stromal cells at the time of LN cell infusion effectively preserved WBCs (3.09 ± 0.51 vs 0.61 ± 0.18), RBCs (8.72 ± 0.14 vs 3.52 ± 0.46), platelets (924 ± 93 vs 147 ± 25) and BM cells (186.6 ± 8.7 vs 52.7 ± 7.8) when compared to LN-cell-infused mice without stromal cell addition. Delayed stromal cell injection at day 9 after LN cell infusion had only a mild effect on the preservation of RBCs (147%), platelets (276%) and BM cells (223%) and no effect on WBCs (64%), and infusion of non-adherent cells from the same stromal cell culture had no therapeutic effect. Stromal cell-infused mice had higher proportion of FoxP3+CD4+ cells in the peripheral blood (59.7 ± 10.7% vs 29.8 ± 5.4%) and more Lin−CD117+CD34− hematopoietic stem and progenitor cells in the BM (591 ± 95 vs 60 ± 43, thousand) in comparison to LN cell infused mice without stromal cell treatment. Mitigation of pathogenic T cells, including both CD4 and CD8 T lymphocytes, is the potential mechanism for the effectiveness of Treg and stromal cell therapies that helped to protect hematopoietic stem and progenitor cells in the BM of affected animals. Figure Figure


Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 619-629 ◽  
Author(s):  
Abdel Kareem Azab ◽  
Feda Azab ◽  
Simona Blotta ◽  
Costas M. Pitsillides ◽  
Brian Thompson ◽  
...  

Abstract The interaction of multiple myeloma (MM) cells with the bone marrow (BM) milieu plays a crucial role in MM pathogenesis. Stromal cell–derived factor-1 (SDF1) regulates homing of MM cells to the BM. In this study, we examined the role of RhoA and Rac1 GTPases in SDF1-induced adhesion and chemotaxis of MM. We found that both RhoA and Rac1 play key roles in SDF1-induced adhesion of MM cells to BM stromal cells, whereas RhoA was involved in chemotaxis and motility. Furthermore, both ROCK and Rac1 inhibitors reduced SDF1-induced polymerization of actin and activation of LIMK, SRC, FAK, and cofilin. Moreover, RhoA and Rac1 reduced homing of MM cells to BM niches. In conclusion, we characterized the role of RhoA and Rac1 GTPases in SDF1-induced adhesion, chemotaxis, and homing of MM cells to the BM, providing the framework for targeting RhoA and Rac1 GTPases as novel MM therapy.


2021 ◽  
Vol 8 ◽  
Author(s):  
Haipeng Jia ◽  
Xiaofen Zhang ◽  
Xinxin Liu ◽  
Ruifang Qiao ◽  
Yan Liu ◽  
...  

Objective: Multiple myeloma is an incurable hematological malignancy. It is imperative to identify immune markers for early diagnosis and therapy. Here, this study analyzed immune-related mRNAs and assessed their prognostic value and therapeutic potential.Methods: Abnormally expressed immune-related mRNAs were screened between multiple myeloma and normal bone marrow specimens in the GSE47552 and GSE6477 datasets. Their biological functions were then explored. Survival analysis was presented for assessing prognosis-related mRNAs. CIBERSORT was utilized for identifying 22 immune cell compositions of each bone marrow specimen. Correlation between FABP5 mRNA and immune cells was then analyzed in multiple myeloma.Results: Thirty-one immune-related mRNAs were abnormally expressed in multiple myeloma, which were primarily enriched in B cells-related biological processes and pathways. Following validation, FABP5 mRNA was a key risk factor of multiple myeloma. Patients with its up-regulation usually experienced unfavorable outcomes. There were distinct differences in the infiltration levels of B cells naïve, B cells memory, plasma cells, T cells CD4 naïve, resting memory CD4 T cells, activated memory CD4 T cells, Tregs, resting NK cells, M0 macrophages, M1 macrophages, M2 macrophages, and neutrophils between multiple myeloma and normal samples. FABP5 mRNA had correlations to B cells memory, B cells naïve, dendritic cells activated, macrophages M0, macrophages M1, macrophages M2, neutrophils, activated NK cells, resting memory CD4 T cells, CD8 T cells and Tregs.Conclusion: Collectively, our data showed that FABP5 mRNA was related to immune microenvironment, which could be a target of immunotherapy and prognostic marker for multiple myeloma.


2021 ◽  
Author(s):  
Hannah Egan ◽  
Oliver Treacy ◽  
Kevin Lynch ◽  
Niamh A Leonard ◽  
Grace O'Malley ◽  
...  

Immunosuppressive tumour microenvironments (TME) reduce the effectiveness of immune responses in cancer. Non-haematopoietic mesenchymal stromal cells (MSC), the precursor to cancer associated fibroblasts (CAFs), dictate tumour progression by enhancing immune cell suppression. Hyper-sialylation of glycans promotes immune evasion in cancer, but the role of sialyation in stromal cell-mediated immunosuppression is unknown. Here we study changes in sialyltransferase (ST) enzymes and associated surface expressed sialic acid in stromal cells following inflammatory and tumour secretome conditioning. We show that tumour conditioned stromal cells have increased levels of sialyltransferases, α2,3/6 linked sialic acid and siglec ligands. In tumour models of solid (colorectal cancer) and haematological (multiple myeloma) stromal rich tumours, stromal cell sialylation is associated with enhanced immunosuppression. Using datasets and patient samples, we confirm that targeting sialylation in tumour stromal cells reverses immune cell exhaustion. Targeting stromal cell sialylation may represent a novel immune checkpoint to reactivate anti-tumour immunity.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 690-690
Author(s):  
Madelon M.E. de Jong ◽  
Zoltan Kellermayer ◽  
Natalie Papazian ◽  
M Duin ◽  
Annemiek Broyl ◽  
...  

Background: In multiple myeloma, tumor cell survival, disease progression and therapy response are influenced by signals derived from the non-malignant bone marrow niche. This notwithstanding, a detailed in-vivo definition of the cells that define the multiple myeloma niche is lacking. Mesenchymal stromal cells are important niche constituents. Recent progress made with single cell transciptomics suggests that mesenchymal stromal cells are a dynamic population of cells that can exist as several subsets with functionally distinct activation and differentiation profiles. Aim: To identify mesenchymal stromal cell subsets specific for the multiple myeloma bone marrow niche, by comparing stromal cells from myeloma patients to non-cancer controls. Methods: The non-hematopoietic bone marrow niche was isolated from viably frozen bone marrow aspirates from 10 newly diagnosed multiple myeloma patients (6 hyperdiploid, 3 t(11;14) and 1 with deletion of 17p) and 2 non-cancer controls using high speed cell sorting. The purified cells were analyzed by 10X Genomics single cell sequencing directly post-thawing, without prior cell culture. From 10 multiple myeloma patients we generated single cell transcriptomes with an average read-depth of 20,000 reads per cell of in total 12,000 niche cells and from the 2 non-cancer controls a total of 3,500 niche cells. Transcriptomes were pooled and subjected to clustering analyses using the Seurat package for R to identify genetically distinct clusters of niche cells and changes in these clusters associated specifically with multiple myeloma. Results: The bioinformatical analyses generated 10 distinct clusters of niche cells, all of which were present in both non-cancer and multiple myeloma bone marrow. One of these clusters contained CDH5+ endothelial cells while the remaining 9 clusters were subsets of CXCL12+LEPR+ mesenchymal stromal cells. Because samples were taken from the central marrow by aspiration, peripheral endosteal or neuronal lineage cells were not represented in these clusters. Gene Set Enrichment Analysis (GSEA) of the stromal cell clusters from myeloma versus non-cancer controls revealed two significantly altered pathways: TNF signaling via NF-kB and Inflammatory response. Detailed analyses of the individual stromal cell clusters identified two clusters that were responsible for the inflammatory changes identified by GSEA. Both clusters were present in all myeloma patients, constituted on average 20% of total stromal cells and were defined by transcription of the inflammatory chemokines CXCL2, CXCL3 and CXCL8 the cytokine IL6. All these transcripts were absent from the equivalent clusters in control bone marrow. The presence of inflammatory stroma in the multiple myeloma niche indicates either the appearance of a novel stromal cell subset, or activation of pre-existing stromal cells. GSEA analyses suggested inflammatory signaling, and to functionally confirm this, we tested whether activation of stromal cells would induce the inflammatory stromal phenotype. Stimulation of primary human stromal cells in vitro with recombinant TNF was sufficient to induce transcription of CXCL2, CXCL3 and CXCL8, recapitulating the inflammatory transcriptome. Moreover, manual removal of these TNF target genes from the in-silico clustering analyses led to a merging of the inflammatory clusters with non-inflammatory clusters. This indicates that the major distinguishing feature of the myeloma-specific stromal cells are genes induced upon stromal cell activation. Conclusion: Through single cell transcriptomic analyses we have identified the presence of activated inflammatory stromal cells associated with TNF signaling in the multiple myeloma stromal niche. These inflammatory stromal cells are reminiscent of pathogenic cancer-associated fibroblasts found in solid tumors, where these cells create a pro-tumorigenic niche that favors tumor survival and proliferation while simultaneously inhibiting anti-cancer immunity. These findings represent the first description of myeloma-specific stromal cell subsets, and provide novel cellular targets for interventions aimed at disrupting the pro-tumorigenic microenvironment in multiple myeloma. Disclosures Broyl: Celgene, amgen, Janssen,Takeda: Honoraria. Sonneveld:Amgen: Honoraria, Research Funding; BMS: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; SkylineDx: Research Funding; Takeda: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 329-329
Author(s):  
David G. Coffey ◽  
Francesco Maura ◽  
Edgar Gonzalez-Kozlova ◽  
Javier Diaz-Mejia3 ◽  
Ping Luo ◽  
...  

Abstract Background: The progression of multiple myeloma (MM) during ongoing therapy is driven by a complex interplay between tumor cells and their surrounding immune microenvironment. We were motivated to conduct a comprehensive and orthogonal investigation of the cellular and humoral immunity of patients with MM treated with lenalidomide maintenance therapy. We compared patients who achieved sustained minimal residual disease (MRD) negativity during the first year of maintenance therapy to those who lost or were unable to attain an MRD negative state. Methods: As part of our prospective phase II clinical trial designed to investigate the MRD dynamics and the efficacy of continuous lenalidomide maintenance in MM (NCT02538198, Lancet Haematology 2021; 8:e422-32), we conducted a pre-planned correlative investigation to elucidate the roles of cellular and humoral immunity. We leveraged single-cell RNA sequencing (scRNAseq) coupled with V(D)J sequencing of peripheral blood mononuclear cells and CyTOF mass cytometry of bone marrow samples collected before and approximately one year after starting maintenance therapy (median 342 days). Proteomic analysis of 92 immuno-oncology related proteins within bone marrow plasma was performed using Olink. Reference-based mapping was used to perform automated cell classification of 31 immune cell subtypes using scRNAseq. A custom 38-marker panel enabled the identification of 21 immune cell subtypes by CyTOF. A total of 40 peripheral blood samples from 20 patients were analyzed by scRNAseq, 28 bone marrow aspirates from 14 patients were analyzed by CyTOF, and 34 plasma samples from 16 patients were analyzed by Olink. Results: Prior to maintenance therapy, 11 (46%) patients completed planned induction therapy and high-dose melphalan (HDM) followed by autologous stem cell transplantation (ASCT); 13 (54%) received planned induction therapy without HDM-ASCT. Through the integration of scRNAseq and CyTOF by bioinformatic analyses, we were able to characterize the cellular composition and phenotypic states of the immune microenvironment before maintenance therapy and after exposure to lenalidomide. Profound and sustained immunosuppression was observed among patients exposed to HDM-ASCT, which associated with accelerated seeding of MM recurrence (Nature Communications 2020;11:3617). Independent of prior exposure to HDM-ASCT, we found differential abundance of immune cell composition to be associated with sustained versus unsustained MRD negativity. Additionally, patients who achieved and sustained MRD negativity (compared to patients with unsustained MRD negativity) had increased frequency of circulating naïve CD8+ T cells in their baseline sample, as well as elevated levels of circulating naïve CD4+ T cells during therapy. When investigating the dynamics of the immune microenvironment longitudinally, circulating regulatory T cells were found to increase during maintenance therapy among patients who had early progression. In the bone marrow, NK cells were more abundant in patients who achieved but could not sustain MRD negativity while vascular endothelial growth factor (VEGF) levels were increased in patients with sustained MRD negativity. We compared our results to a separate report describing the immune microenvironment in patients with MM and healthy donors (Zavidij et al. Nature Cancer 2020;1:493-506) and found the immune landscape of MM patients with sustained MRD negativity to gradually normalize. In contrast, immunosuppression remained present at baseline and during follow-up in MM patients with unsustained MRD negativity. Conclusions: Our findings represent the first detailed characterization of the longitudinal dynamics of the immune microenvironment in relation to low-burden disease in patients with MM treated with lenalidomide maintenance therapy. As expected, HDM-ASCT exposure translated into long-term cellular and humoral immunosuppression, which correlated with dynamics of MM recurrence. Independent of the profound impact of HDM-ASCT on host immunity, the composition of the immune microenvironment varied according to the depth of response. Patients with unsustained MRD negativity had hallmarks of immune dysregulation at baseline and during lenalidomide maintenance, while those who achieved and sustained MRD negativity showed gradual normalization of the immune microenvironment. Disclosures Maura: Medscape: Consultancy, Honoraria; OncLive: Honoraria. Smith: BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: CAR T cells for MM; Sanofi: Patents & Royalties: GPRC5D antibody based therapies; Novarits: Consultancy; Chimeric Therapeutics: Consultancy; Fate Therapeutics: Research Funding; Eureka Therapeutics: Consultancy. Lesokhin: bristol myers squibb: Research Funding; Genetech: Research Funding; Trillium Therapeutics: Consultancy; pfizer: Consultancy, Research Funding; Janssen: Honoraria, Research Funding; Serametrix, Inc: Patents & Royalties; Behringer Ingelheim: Honoraria; Iteos: Consultancy. Kazandjian: Arcellx: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees. Green: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Cellectar Biosciences: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; JANSSEN Biotech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno Therapeutics: Patents & Royalties, Research Funding; Legend Biotech: Consultancy; Neoleukin Therapeutics: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; SpringWorks Therapeutics: Research Funding. Landgren: Celgene: Research Funding; Janssen: Other: IDMC; Janssen: Honoraria; Janssen: Research Funding; Amgen: Honoraria; Amgen: Research Funding; Takeda: Other: IDMC; GSK: Honoraria.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 444-444
Author(s):  
Sabrina Manni ◽  
Denise Toscani ◽  
Anna Colpo ◽  
Alessandra Brancalion ◽  
Fortunato Zaffino ◽  
...  

Abstract Abstract 444 Background. Multiple myeloma (MM) plasma cell growth in the bone marrow (BM) microenvironment is fueled by survival signals delivered by the surrounding non-malignant cells (stromal and other types) and through contacts with the extracelllar matrix. Interactions of MM cells with osteoclasts and osteoblasts generate a milieu, in which bone resorption and bone loss occur more rapidly than bone deposition. Novel agents, such as bortezomib and lenalidomide, which target the MM BM microenvironment, have shown unprecedented anti-myeloma efficacy in part due to their ability to somewhat revert these microenvironmental alterations. However, often resistance occurs also to novel drugs and the disease progresses. We have described that targeting protein kinase CK2 with chemical inhibitors or RNA interference causes MM cell death, increases the sensitivity to chemotherapeutics and compromises the NF-κB and STAT3 activity (Piazza FA et al. 2006, Blood; 108: 1698). We also found that CK2 inhibitors synergize with Hsp90 inhibitors (Manni S et al. 2012, Clinical Cancer Res; 18: 1888) and bortezomib (Manni S et al., Blood (2011 ASH Annual Meeting Abstracts); 118; 1849) in inducing MM cell death. Moreover, a phase I clinical trial is ongoing in USA (ID: NCT01199718) testing the oral CK2 inhibitor CX4945 (Cylene Pharmaceuticals, CA, USA) in MM patients. Purpose. We investigated whether and how CK2 inhibition with ATP-competitive CX4945 and tTBB inhibitors could affect the growth of MM cells and of osteoprogenitors in models of BM microenvironemnt. The aim of the study was to provide further insights into the mechanism of action of CK2 inhibitors also in the MM microenvironment, in particular on the stromal cell-mediated MM cell survival and on the unbalanced bone metabolism. We ultimately aimed at generating original data useful for the design of novel rational combination therapies incorporating CK2 inhibitors in the therapy of MM and of MM-bone disease. Methods. MM plasma cells from patients and MM cell lines were cultured in the presence of BM stromal cells obtained from MM patients or BM stromal cell lines or in the presence of osteoclasts. ATP-competitive CK2 inhibitors were added to the co-cultures or to cultures of osteoblast cell lines or progenitors. Cell growth was evaluated with different means and signaling pathways were studied in MM plasma cells and in the stromal cells. NF-κB target gene expression and DNA binding was tested with microplate arrays. For osteoclast generation, CD14+ peripheral blood monocytes were stimulated in alpha-MEM medium with 10% FBS plus RANKL (60ng/ml) plus M-CSF (25ng/ml) for 28 days; early-osteoblasts colonies were obtained from BM cells stimulated under appropriate conditions. Results. CK2 inhibition with CX4945 or tTBB caused apoptosis of MM cells (either freshly isolated from patients or cell lines) cultured on patient-derived mesenchymal stromal cells (MSC) or on the BM stromal cell line HS-5. The inhibitors did not significantly affect MSC viability. A reduction of NF-κB activity evaluated in MM cells was found upon CK2 inhibition, with a parallel reduction of the production of NF-κB-dependent cytokines. When assayed on osteoprogenitors, CX4945 displayed an inhibitory effect on osteoclast formation from CD14+ monocytes even at low concentrations (1 μM up to 7 μM, comparable with the effects of zolendronate 1 μM), whereas it inhibited the formation of osteoblasts from BM colonies at day 14 at fairly higher concentrations (>5 μM). Moreover, CX4945 inhibited osteoblast proliferation at even higher concentration (>7.5 μM). The anti-myeloma effect of CK2 inhibitors was present also when MM cells (INA-6 cell line) were cultured in the presence of osteoclasts generated from CD14+ monocytes. Conclusions. Our study shows that inhibition of CK2 could profoundly affect the growth of MM cells in models of BM microenvironment while substantially sparing the normal cellular stromal counterparts and osteoblasts and suggests that CK2 inhibitors could be exploited to target the hyperactivity of osteoclast seen in MM bone disease. Disclosures: Giuliani: Celgene: Research Funding.


2021 ◽  
pp. clincanres.2188.2020
Author(s):  
Lisa C. Holthof ◽  
Jort J. van der Schans ◽  
Afroditi Katsarou ◽  
Renee Poels ◽  
Anne T. Gelderloos ◽  
...  

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