The in vivo Transcriptional Response Towards Epigenetic Modulating Agents in Multiple Myeloma

Abstract Multiple myeloma (MM) is a hematological malignancy characterized by a plasma cell accumulation in the bone marrow (BM), for which novel treatment options are urgently needed. Epigenetic modulating agents such as histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) are under intense investigation for cancer therapy. As shown in numerous functional in vitro studies, HDACi and DNMTi affect various biological processes important for tumor control including tumor cell survival, proliferation, differentiation and DNA repair. Given the broad mechanisms of action of these agents, it remains important to continue pre-clinical evaluation to identify in vivo relevant mechanisms of action. This may lead to the identification of novel biologically relevant targets and predictive biomarkers allowing clinical trial optimization. Recently, we developed gene expression based risk scores after treating human MM cell lines with TSA (HA-score) or decitabine (DM-score). These scores were predictive for MM patient survival using two independent cohorts (Heidelberg-Montpellier (HM) and University of Arkansas for Medical Sciences-Total Therapy 2) and identified potential biomarkers predictive for drug sensitivity. However, the transcriptional response of MM cells in vivo may be influenced by the close contact with the BM-environment. Therefore, we here aimed to characterize the transcriptional response of MM cells after in vivo treatment with the HDACi JNJ-26481585 (quisinostat) or the DNMTi decitabine using the syngeneic immunocompetent murine 5T33MM model. 5T33MM mice (n=4/group) with established disease were treated with quisinostat or decitabine for 5 days after which tumor cells were isolated from the BM and subjected to microarray analysis. Using Significance Analysis of Microarray, we identified 574 and 180 probesets deregulated by respectively quisinostat and decitabine (of which 111 are in common). To assess the prognostic value of the deregulated genes, we performed MaxStat analysis in the HM cohort. JNJ-585 deregulated 31 genes associated with good prognosis and 31 associated with bad prognosis. Decitabine altered expression of 20 genes linked with poor prognosis while 5 genes were linked with good prognosis. The prognostic value of these genes was then implemented in a murine (Mu)-DM and Mu-HA score. The score values were significant higher in MM patients and human myeloma cell lines compared to MGUS and healthy bone marrow plasma cells. In addition, the scores were useful to separate patients of the 2 cohorts into a low risk and high risk group. Patients from the proliferation subgroup had a higher score compared to all other subgroups. In concordance, the scores were highest in patients with a high gene-expression based proliferation index. Using gene ontology (GO) tools (DAVID) and pathway tools (Reactome, STRING and Pathway-guide), we next explored the association of in vivo deregulated genes with biological processes and pathways. GO analysis showed that quisinostat-deregulated genes were mainly involved in immune modulation. Pathway analysis revealed associations with lymphocyte activation and proliferation, immune effector mechanisms and T-helper-1 development through processes like cytokine interactions, chemokine signaling and T-cell receptor- and NK-cell-signaling. In concordance, the signature represented elevated presence and signaling of interferon, tumor necrosis factor, interleukin-1 (IL-1), IL-2 and IL-12. The second most prominent alterations were genes linked with transcriptional misregulation in cancer. Pathways predicted to be affected by these alterations are linked with differentiation, resistance and cell survival. For decitabine, the gene list was substantially smaller and for more than half shared by JNJ-585. The pathway analysis also identified genes linked to immune system, gene expression regulation and metabolism pathways. In conclusion, in vivo treatment with epigenetic modulating agents identified a prognostic gene signature. In addition, HDACi (and to a lesser extent DNMTi) deregulated immunomodulatory genes and genes involved in transcriptional regulation. This indicates that immune regulation is an important in vivo anti-tumor property of HDACi and supports the rational to combine HDACi with immunomodulatory therapies such lenalidomide or cellular/peptide vaccination strategies. Disclosures Hose: Novartis: Research Funding. Seckinger:Novartis: Research Funding.

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Novel Murine Model To Study Modulation of Genes and Molecular Pathways Induced Following In Vivo Interaction between Multiple Myeloma Cells and Human BM Milieu.

Blood ◽

10.1182/blood.v108.11.3409.3409 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3409-3409

Author(s):

Paola Neri ◽

Pierfrancesco Tassone ◽

Masood Shammas ◽

Mariateresa Fulciniti ◽

Yu-Tzu Tai ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Bone Marrow ◽

Cell Growth ◽

Gene Expression Profile ◽

Expression Profile ◽

Murine Model ◽

Cell Signalling

Abstract Interaction between multiple myeloma (MM) cells and the bone marrow (BM) microenvironment plays a critical role in promoting MM cell growth, survival, migration and development of drug resistance. This interaction within the bone marrow milieu is unique and its understanding is important in evaluating effects of novel agents in vitro and in vivo. We here describe a novel murine model that allows us to study the expression changes in vivo in MM cells within the human BM milieu. In this model, the green fluorescent protein (INA-6 GFP+) transduced IL-6-dependent human MM cell line, INA-6, was injected in human bone chip implanted into SCID mice. At different time points the bone chip was retrieved, cells flushed out and GFP+ MM cells were purified by CD138 MACS microbeads. Similar isolation process was used on INA-6 GFP+ cells cultured in vitro and used as control. Total RNA was isolated from these cells and gene expression profile analyzed using the HG-U133 array chip (Affymetrix) and DChip analyzer program. We have identified significant changes in expression of several genes following in vivo interaction between INA-6 and the BM microenvironment. Specifically, we observed up-regulation of genes associated with cytokines (IL-4, IL-8, IGFB 2–5) and chemokines (CCL2, 5, 6, 18, 24, CCR1, 2, 4), implicated in cell-cell signalling. Moreover genes implicated in DNA transcription (V-Fos, V-Jun, V-kit), adhesion (Integrin alpha 2b, 7, cadherin 1 and 11) and cell growth (CDC14, Cyclin G2, ADRA1A) were also up-regulated and genes involved in apoptosis and cell death (p-57, BCL2, TNF1a) were down-regulated. Using the Ingenuity Pathway Analysis the most relevant pathways modulated by the in vivo interaction between MM cells and BMSCs were IL-6, IGF1, TGF-beta and ERK/MAPK-mediated pathways as well as cell-cycle regulation and chemokine signalling. These results are consistent with previously observed in vitro cell signalling studies. Taken together these results highlight the ability of BM microenvironment to modulate the gene expression profile of the MM cells and our ability to in vivo monitor the changes. This model thus provides us with an ability to study in vivo effects of novel agents on expression profile of MM cells in BM milieu, to pre-clinically characterize their activity.

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The New CXCR4 Inhibitor MDX-1338 Exerts Anti-Tumor Activity in Multiple Myeloma

Blood ◽

10.1182/blood.v118.21.1844.1844 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1844-1844 ◽

Cited By ~ 1

Author(s):

Aldo M Roccaro ◽

Antonio Sacco ◽

Michelle Kuhne ◽

AbdelKareem Azab ◽

Patricia Maiso ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Cells ◽

Mouse Models ◽

Research Funding ◽

Therapeutic Agents ◽

Dependent Manner ◽

Apoptotic Pathways ◽

Dose Dependent

Abstract Abstract 1844 Background. We have previously shown the SDF1/CXCR4 axis plays a major role in homing and trafficking of multiple myeloma (MM) to the bone marrow (BM), and disruption of the interaction of tumor cells with the BM leads to enhanced sensitivity to therapeutic agents. We hypothesize that the novel anti-CXCR4 antibody, BMS936564/MDX-1338, may prevent the homing and adhesion of MM cells to the BM and will sensitize them to therapeutic agents. Methods. Primary MM cells (CD138+); MM cell lines (MM.1S, RPMI.8226); and primary MM bone marrow stromal cells (BMSCs) were used. Migration towards SDF-1 and BMSCs has been evaluated. Cytotoxicity and DNA synthesis were measured by MTT and thymidine uptake, respectively. Cell signaling and apoptotic pathways were studied by Western Blot. Synergism was calculated using the Chou-Talalay method. In vivo MM tumor growth was evaluated with xenograft mouse models. Results. MDX-1338 inhibited migration of MM cells toward SDF-1a and primary MM BMSCs, in a dose-dependent manner. Adhesion of primary MM cells to BMSCs was also inhibited by BMS936564/MDX-1338 in a dose-dependent manner, while also inducing cytotoxicity on primary BM-derived CD138+ cells. BMS936564/MDX-1338 targeted MM cells in the context of BM milieu by overcoming BMSC-induced proliferation of tumor cells. In addition, BMS936564/MDX-1338 synergistically enhanced bortezomib-induced cytotoxicity in MM cells. BMS936564/MDX-1338-dependent activation of apoptotic pathways in MM cells was documented, as shown by cleavage of caspase-9 and PARP. SDF-1a-induced ERK-, Akt-, and Src-phosphorilation was inhibited by BMS936564/MDX-1338 in a dose-dependent manner. Importantly, BMS936564/MDX-1338 inhibited MM cell proliferation in vivo in xenograft mouse models. Conclusion. These studies therefore show that targeting CXCR-4 in MM by using BMS936564/MDX-1338 represents a valid therapeutic strategy in this disease. Disclosures: Roccaro: Roche:. Kuhne:BMS: Employment. Pan:Bristol-Myers Squibb: Employment. Cardarelli:Bristol-Myers Squibb: Employment. Ghobrial:Noxxon: Research Funding; Bristol-Myers Squibb: Research Funding; Millennium: Research Funding; Noxxon:; Millennium:; Celegene:; Novartis:.

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Stress Erythropoiesis Is Associated with Changes in the Transcriptome of Central Macrophages

Blood ◽

10.1182/blood.v124.21.1404.1404 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1404-1404

Author(s):

Ritama Gupta ◽

Bart Crielaard ◽

Piali Mukherjee ◽

Igor Theurl ◽

Carla Casu ◽

...

Keyword(s):

Gene Expression ◽

Bone Marrow ◽

Chronic Stress ◽

Stock Options ◽

Research Funding ◽

Acute Stress ◽

Cellular Adhesion ◽

Biological Processes ◽

Stress Erythropoiesis ◽

Splenic Macrophages

Abstract Macrophages have been implicated in erythropoiesis historically as a mediator of iron recycling and a key component of the erythroblastic island-consisting of a central macrophage surrounded by erythroid cells in different stages of differentiation. Recently we and others have shown that macrophages contribute to stress erythropoiesis, and such contributions extend beyond the known macrophage function of iron recycling. This finding necessitates the investigation of processes within a macrophage itself that might facilitate stress erythropoiesis and the characterization of macrophage transcriptome signatures associated with the same. Macrophages in the bone marrow have been identified previously as CD115LowGR1LowF4/80High cells. Extending this to the spleen, we sorted and sequenced singlet macrophages in the bone marrow and spleen of two mice models of stress erythropoiesis: acute stress induced by retro orbital phlebotomy and chronic stress by bone marrow transplanted Polycythemia Vera. We found that splenic macrophages show more significant changes upon induction of stress (both acute and chronic) in comparison of macrophages in the bone marrow. The mean of normalized count of each gene when plotted against fold change (Figure 1) show that the acute and chronically stressed splenic macrophages differ significantly over non stressed macrophages but not over each other. Fig 1: Acute over non stressed Chronic over non stressed Acute over non stressed Fig 1:. Acute over non stressed Chronic over non stressed Acute over non stressed We further found that stressed splenic macrophages have a characteristic gene expression profile associated with erythropoietic stress, common to both models of induced and chronic stress. There were a total of 2602 genes showing significant changes in expression upon induction of acute stress and a total of 2196 genes showing significant changes in expression upon chronic stress. Out of these, 1529 genes common to both acute and chronically stressed splenic macrophages showed an expression profile common to both acute and induced stress. (Fig 2) Fig 2. Fig 2. We used the open bioinformatics resource DAVID and Ingenuity Pathway Analysis (IPA) to look at biological processes encompassing our significantly up regulated candidates (FDR 10%), upstream analysis of our candidates and further network analysis. Some biological processes of highest significance were cellular growth and proliferation, hematological system development and function, inflammatory response, response to infection, cellular adhesion, cellular movement and immune cell trafficking. We validated some of our key candidates under these biological processes by flow cytometry, such as the iron exporter ferroportin, the receptor for the anti inflammatory cytokine, IL-10 and the cellular adhesion molecule ICAM-1. Some transcription factors significantly upregulated were Hes1, Nfkb1A, RelB, Bcl3 to mention a few. Upstream analysis using IPA predicted activation of transcription factors such as Notch1, Jun, RelA etc. Along with further validation of our key candidates, we are currently investigating macrophage gene expression in another model of chronic stress, beta thalassemia and how this profile associated with the physiological condition of erythropoietic stress compares to those under in vivo models of classical and alternative macrophage activation. Disclosures Casu: Merganser Biotech: Research Funding; Isis Pharmaceuticals Inc.: Research Funding. Rivella:Merganser Biotech: Consultancy, Research Funding, Stock options, Stock options Other; Bayer: Consultancy, Research Funding; Isis Pharmaceuticals. Inc.: Consultancy, Research Funding.

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Baseline and on-Treatment Bone Marrow Microenvironments Predict Myeloma Patient Outcomes and Inform Potential Intervention Strategies

Blood ◽

10.1182/blood-2018-99-113169 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1882-1882 ◽

Cited By ~ 1

Author(s):

Samuel A Danziger ◽

Mark McConnell ◽

Jake Gockley ◽

Mary Young ◽

Adam Rosenthal ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Expression Profiles ◽

Cell Types ◽

Employment Equity ◽

Advisory Committees ◽

Equity Ownership

Abstract Introduction The multiple myeloma (MM) tumor microenvironment (TME) strongly influences patient outcomes as evidenced by the success of immunomodulatory therapies. To develop precision immunotherapeutic approaches, it is essential to identify and enumerate TME cell types and understand their dynamics. Methods We estimated the population of immune and other non-tumor cell types during the course of MM treatment at a single institution using gene expression of paired CD138-selected bone marrow aspirates and whole bone marrow (WBM) core biopsies from 867 samples of 436 newly diagnosed MM patients collected at 5 time points: pre-treatment (N=354), post-induction (N=245), post-transplant (N=83), post-consolidation (N=51), and post-maintenance (N=134). Expression profiles from the aspirates were used to infer the transcriptome contribution of immune and stromal cells in the WBM array data. Unsupervised clustering of these non-tumor gene expression profiles across all time points was performed using the R package ConsensusClusterPlus with Bayesian Information Criterion (BIC) to select the number of clusters. Individual cell types in these TMEs were estimated using the DCQ algorithm and a gene expression signature matrix based on the published LM22 leukocyte matrix (Newman et al., 2015) augmented with 5 bone marrow- and myeloma-specific cell types. Results Our deconvolution approach accurately estimated percent tumor cells in the paired samples compared to estimates from microscopy and flow cytometry (PCC = 0.63, RMSE = 9.99%). TME clusters built on gene expression data from all 867 samples resulted in 5 unsupervised clusters covering 91% of samples. While the fraction of patients in each cluster changed during treatment, no new TME clusters emerged as treatment progressed. These clusters were associated with progression free survival (PFS) (p-Val = 0.020) and overall survival (OS) (p-Val = 0.067) when measured in pre-transplant samples. The most striking outcomes were represented by Cluster 5 (N = 106) characterized by a low innate to adaptive cell ratio and shortened patient survival (Figure 1, 2). This cluster had worse outcomes than others (estimated mean PFS = 58 months compared to 71+ months for other clusters, p-Val = 0.002; estimate mean OS = 105 months compared with 113+ months for other clusters, p-Val = 0.040). Compared to other immune clusters, the adaptive-skewed TME of Cluster 5 is characterized by low granulocyte populations and high antigen-presenting, CD8 T, and B cell populations. As might be expected, this cluster was also significantly enriched for ISS3 and GEP70 high risk patients, as well as Del1p, Del1q, t12;14, and t14:16. Importantly, this TME persisted even when the induction therapy significantly reduced the tumor load (Table 1). At post-induction, outcomes for the 69 / 245 patients in Cluster 5 remain significantly worse (estimate mean PFS = 56 months compared to 71+ months for other clusters, p-Val = 0.004; estimate mean OS = 100 months compared to 121+ months for other clusters, p-Val = 0.002). The analysis of on-treatment samples showed that the number of patients in Cluster 5 decreases from 30% before treatment to 12% after transplant, and of the 63 patients for whom we have both pre-treatment and post-transplant samples, 18/20 of the Cluster 5 patients moved into other immune clusters; 13 into Cluster 4. The non-5 clusters (with better PFS and OS overall) had higher amounts of granulocytes and lower amounts of CD8 T cells. Some clusters (1 and 4) had increased natural killer (NK) cells and decreased dendritic cells, while other clusters (2 and 3) had increased adipocytes and increases in M2 macrophages (Cluster 2) or NK cells (Cluster 3). Taken together, the gain of granulocytes and adipocytes was associated with improved outcome, while increases in the adaptive immune compartment was associated with poorer outcome. Conclusions We identified distinct clusters of patient TMEs from bulk transcriptome profiles by computationally estimating the CD138- fraction of TMEs. Our findings identified differential immune and stromal compositions in patient clusters with opposing clinical outcomes and tracked membership in those clusters during treatment. Adding this layer of TME to the analysis of myeloma patient baseline and on-treatment samples enables us to formulate biological hypotheses and may eventually guide therapeutic interventions to improve outcomes for patients. Disclosures Danziger: Celgene Corporation: Employment, Equity Ownership. McConnell:Celgene Corporation: Employment. Gockley:Celgene Corporation: Employment. Young:Celgene Corporation: Employment, Equity Ownership. Schmitz:Celgene Corporation: Employment, Equity Ownership. Reiss:Celgene Corporation: Employment, Equity Ownership. Davies:MMRF: Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; TRM Oncology: Honoraria; Abbvie: Consultancy; ASH: Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria. Copeland:Celgene Corporation: Employment, Equity Ownership. Fox:Celgene Corporation: Employment, Equity Ownership. Fitch:Celgene Corporation: Employment, Equity Ownership. Newhall:Celgene Corporation: Employment, Equity Ownership. Barlogie:Celgene: Consultancy, Research Funding; Dana Farber Cancer Institute: Other: travel stipend; Multiple Myeloma Research Foundation: Other: travel stipend; International Workshop on Waldenström's Macroglobulinemia: Other: travel stipend; Millenium: Consultancy, Research Funding; European School of Haematology- International Conference on Multiple Myeloma: Other: travel stipend; ComtecMed- World Congress on Controversies in Hematology: Other: travel stipend; Myeloma Health, LLC: Patents & Royalties: : Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC. Trotter:Celgene Research SL (Spain), part of Celgene Corporation: Employment, Equity Ownership. Hershberg:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Dervan:Celgene Corporation: Employment, Equity Ownership. Ratushny:Celgene Corporation: Employment, Equity Ownership. Morgan:Takeda: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Research Funding.

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Minimal Residual Disease in Autografts and Bone Marrow of Patients with Multiple Myeloma: 8-Color Multiparameter Flow Cytometry (EuroFlow-NGF) Vs. Next-Generation Sequencing

Blood ◽

10.1182/blood-2020-137014 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 22-23

Author(s):

Hiroyuki Takamatsu ◽

Naoki Takezako ◽

Takeshi Yoroidaka ◽

Takeshi Yamashita ◽

Ryoichi Murata ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Flow Cytometry ◽

Research Funding ◽

Prognostic Value ◽

Residual Disease ◽

Multiparameter Flow Cytometry ◽

Next Generation ◽

Generation Sequencing ◽

Minimal Residual

Background: Autologous stem cell transplantation (ASCT) in conjunction with novel therapeutic drugs can dramatically improve response rates and the prognoses of patients with multiple myeloma (MM). However, most patients with MM ultimately relapse due to minimal residual disease (MRD). Next-generation multiparameter flow cytometry (MFC) (EuroFlow-NGF) and next-generation sequencing (NGS) are currently the standard methods to assess MRD. Aims: To compare the prognostic value of MRD detection in autografts and bone marrow (BM) cells using 8-color MFC (EuroFlow-NGF) and NGS (Adaptive Biotechnologies), and also MRD levels between fresh and cryopreserved autografts using NGF. Methods: The study enrolled 52 newly-diagnosed MM patients who underwent ASCT. The median age ASCT was 61 (range 41-69) years and included 29 males and 23 females at ISS I (n = 17), II (n = 23), and III (n = 12). Of these, 18 patients harbored high-risk chromosomal abnormalities including t(4;14) (n = 15), del17p and t(4;14) (n = 2), and complex (n = 1). Bortezomib-based chemotherapy was used for induction together with melphalan at 140 mg/m2 (n = 1) and 200 mg/m2 (n = 51) for conditioning before ASCT. 39 of 52 (75%) patients received maintenance therapy until progressive disease. The best responses achieved post-ASCT included 30 sCR, 4 CR, 15 VGPR, and 3 PR. Forty autografts, one from each MM patient, were analyzed using NGF and NGS protocols, and BM cells at pre/post-ASCT and autografts derived from 16 patients were analyzed using NGS. The EuroFlow-NGF method uses standard sample preparation; large numbers of cells are evaluated using an optimized 8-color antibody panel that facilitates accurate identification of discrimination between phenotypically aberrant plasma cells (aPCs) and their normal counterparts (Flores-Montero et al., Leukemia 2017). NGS-based MRD assessment was performed using Adaptive's standardized NGS-MRD Assay (Seattle, WA) (Martinez-Lopez et al., Blood 2014). Eight additional autografts were used to assess MRD in both fresh and cryopreserved samples by NGF. Results: MRD was evaluated in 48 of 52 autografts (92%) using NGF and in 44 of 52 autografts (85%) using NGS. We identified aPCs in autografts based on multivariate analysis of individual cell populations (e.g., CD56+, CD19−, CyIgκ+, and CD117+). As the results of NGF revealed a strong correlation with respect to MRD in fresh vs. thawed autografts (r = 0.999, P < 0.0001), MRD was subsequently evaluated in thawed autografts. The sensitivity of NGF was 1 × 10−5-2 × 10−6; the sensitivity of NGS was 1 × 10−6. 28 of 48 (58%) of the autografts were MRD-positive by NGF; 30 of 44 (68%) of the autografts were MRD-positive by NGS. MRD levels in autografts using NGF and NGS correlated with one another (r = 0.69, P < 0.0001; Fig. 1A). MRD negative in autografts by NGF cases (MRDNGF (-)) and MRDNGS (-) tended to show better progression-free survival (PFS) than MRDNGF (+) (P = 0.195) and MRDNGS (+) (P = 0.156), respectively. Furthermore, MRDNGS (-) showed significantly better overall survival (OS) than MRDNGS (+) (P = 0.03) (Fig. 1C) while MRDNGF (-) showed better OS than MRDNGF (+) (P = 0.09) (Fig. 1B). Our data revealed only a minimal correlation between MRD in the autografts (median 1.1 × 10−5,range 0-7.29 × 10−4) and in the BM cells at pre-ASCT (median 5.05 × 10−3,range 6 × 10−6-2.64 × 10−1; r = 0.09, P = 0.7) or at post-ASCT (median 2.11 × 10−4,range 0-9.09 × 10−3; r = 0.14, P = 0.6); MRD detected in the autografts was > 27 times lower than that detected in pre-ASCT BM cells, and MRD detected in the post-ASCT BM cells was > 3 times lower than that detected in pre-ASCT BM cells except for one case in which the ratio was increased by two times. Interestingly, while MRD was detected in all BM cells at pre-ASCT (n = 16), 4 of 16 (25%) of these autografts were MRDNGS-negative. The median of MRD levels of the 4 cases in pre-ASCT and post-ASCT BM cells were 4.14 × 10−4 (range 6-583 × 10−6)and 1.8 × 10−5 (range 0-27 × 10−6), respectively. Conclusion: Although EuroFlow-NGF is a rapid and accurate method for detecting MRD, NGS was more sensitive and provided greater prognostic value than EuroFlow-NGF. Disclosures Takamatsu: Adaptive Biotechnologies: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Janssen Pharmaceutical: Consultancy, Honoraria, Research Funding; Ono pharmaceutical: Honoraria, Research Funding; SRL: Consultancy, Research Funding. Takezako:Bristol-Myers Squibb: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Research Funding; Abbvie: Research Funding. Nakao:Symbio: Consultancy; Kyowa Kirin: Honoraria; Alexion: Research Funding; Novartis: Honoraria.

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ASXL2 Is Recurrently Mutated in t(8;21) AML and Regulates Hematopoietic Development

Blood ◽

10.1182/blood.v128.22.1051.1051 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1051-1051

Author(s):

Vikas Madan ◽

Lin Han ◽

Norimichi Hattori ◽

Anand Mayakonda ◽

Qiao-Yang Sun ◽

...

Keyword(s):

Gene Expression ◽

Bone Marrow ◽

Research Funding ◽

Hematopoietic Differentiation ◽

Wild Type ◽

Flow Cytometric ◽

Deficient Mice

Abstract Chromosomal translocation t(8;21) (q22;q22) leading to generation of oncogenic RUNX1-RUNX1T1 fusion is a cytogenetic abnormality observed in about 10% of acute myelogenous leukemia (AML). Studies in animal models and recent next generation sequencing approaches have suggested cooperativity of secondary genetic lesions with t(8;21) in inducing leukemogenesis. In this study, we used targeted and whole exome sequencing of 93 cases (including 30 with matched relapse samples) to profile the mutational landscape of t(8;21) AML at initial diagnosis and post-therapy relapse. We identified recurrent mutations of KIT, TET2, MGA, FLT3, NRAS, DHX15, ASXL1 and KMT2Dgenes in this subtype of AML. In addition, high frequency of truncating alterations in ASXL2 gene (19%) also occurred in our cohort. ASXL2 is a member of mammalian ASXL family involved in epigenetic regulation through recruitment of polycomb or trithorax complexes. Unlike its closely related homolog ASXL1, which is mutated in several hematological malignancies including AML, MDS, MPN and others; mutations of ASXL2 occur specifically in t(8;21) AML. We observed that lentiviral shRNA-mediated silencing of ASXL2 impaired in vitro differentiation of t(8;21) AML cell line, Kasumi-1, and enhanced its colony forming ability. Gene expression analysis uncovered dysregulated expression of several key hematopoiesis genes such as IKZF2, JAG1, TAL1 and ARID5B in ASXL2 knockdown Kasumi-1 cells. Further, to investigate implications of loss of ASXL2 in vivo, we examined hematopoiesis in Asxl2 deficient mice. We observed an age-dependent increase in white blood cell count in the peripheral blood of Asxl2 KO mice. Myeloid progenitors from Asxl2 deficient mice possessed higher re-plating ability and displayed altered differentiation potential in vitro. Flow cytometric analysis of >1 year old mice revealed increased proportion of Lin-Sca1+Kit+ (LSK) cells in the bone marrow of Asxl2 deficient mice, while the overall bone marrow cellularity was significantly reduced. In vivo 5-bromo-2'-deoxyuridine incorporation assay showed increased cycling of LSK cells in mice lacking Asxl2. Asxl2 deficiency also led to perturbed maturation of myeloid and erythroid precursors in the bone marrow, which resulted in altered proportions of mature myeloid populations in spleen and peripheral blood. Further, splenomegaly was observed in old ASXL2 KO mice and histological and flow cytometric examination of ASXL2 deficient spleens demonstrated increased extramedullary hematopoiesis and myeloproliferation compared with the wild-type controls. Surprisingly, loss of ASXL2 also led to impaired T cell development as indicated by severe block in maturation of CD4-CD8- double negative (DN) population in mice >1 year old. These findings established a critical role of Asxl2 in maintaining steady state hematopoiesis. To gain mechanistic insights into its role during hematopoietic differentiation, we investigated changes in histone marks and gene expression affected by loss of Asxl2. Whole transcriptome sequencing of LSK population revealed dysregulated expression of key myeloid-specific genes including Mpo, Ltf, Ngp Ctsg, Camp and Csf1rin cells lacking Asxl2 compared to wild-type control. Asxl2 deficiency also caused changes in histone modifications, specifically H3K27 trimethylation levels were decreased and H2AK119 ubiquitination levels were increased in Asxl2 KO bone marrow cells. Global changes in histone marks in control and Asxl2 deficient mice are being investigated using ChIP-Sequencing. Finally, to examine cooperativity between the loss of Asxl2 and RUNX1-RUNX1T1 in leukemogenesis, KO and wild-type fetal liver cells were transduced with retrovirus expressing AML1-ETO 9a oncogene and transplanted into irradiated recipient mice, the results of this ongoing study will be discussed. Overall, our sequencing studies have identified ASXL2 as a gene frequently altered in t(8;21) AML. Functional studies in mouse model reveal that loss of ASXL2 causes defects in hematopoietic differentiation and leads to myeloproliferation, suggesting an essential role of ASXL2 in normal and malignant hematopoiesis. *LH and NH contributed equally Disclosures Ogawa: Takeda Pharmaceuticals: Consultancy, Research Funding; Sumitomo Dainippon Pharma: Research Funding; Kan research institute: Consultancy, Research Funding.

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A Novel Role For Histone Deacetylase 11 (HDAC11) In Plasma Cell Differentation and Survival

Blood ◽

10.1182/blood.v122.21.1907.1907 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1907-1907

Author(s):

Eva Sahakian ◽

Jason B. Brayer ◽

John Powers ◽

Mark Meads ◽

Allison Distler ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Bone Marrow ◽

B Cells ◽

Plasma Cell ◽

Research Funding ◽

Plasma Cells ◽

Myeloma Cells ◽

Peripheral Blood Plasma

Abstract The role of HDACs in cellular biology, initially limited to their effects upon histones, is now appreciated to encompass more complex regulatory functions that are dependent on their tissue expression, cellular compartment distribution, and the stage of cellular differentiation. Recently, our group has demonstrated that the newest member of the HDAC family of enzymes, HDAC11, is an important regulator of IL-10 gene expression in myeloid cells (Villagra A Nat Immunol. 2009). The role of this specific HDAC in B-cell development and differentiation is however unknown. To answer this question, we have utilized a HDAC11 promoter-driven eGFP reporter transgenic mice (TgHDAC11-eGFP) which allows the monitoring of the dynamic changes in HDAC11 gene expression/promoter activity in B-cells at different maturation stages (Heinz, N Nat. Rev. Neuroscience 2001). First, common lymphoid progenitors are devoid of HDAC11 transcriptional activation as indicated by eGFP expression. In the bone marrow, expression of eGFP moderately increases in Pro-B-cells and transitions to the Pre- and Immature B-cells respectively. Expression of eGFP doubles in the B-1 stage of differentiation in the periphery. Of note, examination of both the bone marrow and peripheral blood plasma cell compartment demonstrated increased expression of eGFP/HDAC11 mRNA at the steady-state. These results were confirmed in plasma cells isolated from normal human subjects in which HDAC11 mRNA expression was demonstrated. Strikingly, analysis of primary human multiple myeloma cells demonstrated a significantly higher HDAC11 mRNA expression in malignant cells as compared to normal plasma cells. Similar results were observed in 4/5 myeloma cell lines suggesting that perhaps HDAC11 expression might provide survival advantage to malignant plasma cells. Support to this hypothesis was further provided by studies in HDAC11KO mice in which we observed a 50% decrease in plasma cells in both the bone marrow and peripheral blood plasma cell compartments relative to wild-type mice. Taken together, we have unveiled a previously unknown role for HDAC11 in plasma cell differentiation and survival. The additional demonstration that HDAC11 is overexpressed in primary human myeloma cells provide the framework for specifically targeting this HDAC in multiple myeloma. Disclosures: Alsina: Millennium: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Baz:Celgene Corporation: Research Funding; Millenium: Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding.

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An APRIL Based Chimeric Antigen Receptor to Simultaneously Target BCMA and TACI in Multiple Myeloma (MM) Has Potent Activity in Vitro and in Vivo

Blood ◽

10.1182/blood.v128.22.379.379 ◽

2016 ◽

Vol 128 (22) ◽

pp. 379-379 ◽

Cited By ~ 3

Author(s):

Lydia Sarah Hui Lee ◽

Benjamin Owen Draper ◽

Neil Chaplin ◽

Brian Philip ◽

Melody Chin ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Cell Death ◽

Chimeric Antigen Receptor ◽

Research Funding ◽

Antigen Receptor ◽

Facs Analysis ◽

Equity Ownership ◽

Low Levels

Abstract Immune based strategies have shown early promise in multiple myeloma (MM), and are likely to prove a valuable addition to the therapeutic platforms for these patients. B cell maturation antigen (BCMA) is a promising therapeutic target with selective expression on plasma cells, including MM cells. In the first report of BCMA targeting therapies, an anti-BCMA scFv-based chimeric antigen receptor (CAR) had clinical activity, albeit with short lived responses (Ali et al, 2016). Observed challenges included low expression level of BCMA, shedding of BCMA and potential loss of expression. In addition to BCMA, MM cells also express transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) which functions in plasma cell survival and differentiation. TACI is selectively expressed within lymphoid tissue and at reduced levels compared to BCMA, as measured by RT-PCR on normal tissues. TACI and BCMA share a common ligand called a proliferating ligand (APRIL), a compact self-protein forming a trimer and binding with nanomolar affinity to TACI and BCMA. The natural trimerization of APRIL would serve to enhance cell binding, especially important in the case of low levels of target antigen. Concurrent targeting of two tumour antigens, by increasing antigen density, would improve efficacy as well as reducing the risk of antigen negative disease escape. We quantified APRIL targets on primary MM cells by flow cytometry and observed BCMA expression in all of 41 patients tested (median 1051, range 105-8323 antibodies bound per cell, ABC) with most patients (78%) also expressing TACI (333, 0-21301 ABC). We designed an APRIL based 3rd generation chimeric antigen receptor (APRIL-CAR) comprising an engineered APRIL protein as antigen-binding domain. Peripheral blood mononuclear cells (PBMCs) were activated, transduced with APRIL-CAR and CD56-depleted before testing against cell lines expressing a wide range of BCMA and TACI (1005-1.5x10^5 and 2200-1.6x10^5 ABC respectively). We confirmed the cytolytic capability of APRIL-CAR against engineered targets, even at the low antigen levels observed in primary cells. Using standard chromium release, there was significant cytolysis of the lowest antigen expressers, with 40.9±3.8% (mean±SEM) and 42.6±5.7% cell death in SUPT1BCMAlo and SUPT1TACIlo respectively cf 15.0±5.8% for control SUPT1NT targets, at an E:T ratio of 4:1 (n=4, p<0.01 and p<0.05). When we lowered the E:T ratio, APRIL-CAR continued to show potent activity, with cytolysis of SUPT1BCMAlo/ SUPT1TACIlo targets at 1:10 (71.7±3.8% and 70.4±6.3% cell death respectively cf 21.6±5.8% for SUPT1NT, n=4, p<0.001 for both) and human myeloma cell lines at 1:32 (MM.1s and U266, 56.2±3.9% and 25.1±3.9% target cytolysis by APRIL-CAR and 4.7±11.6% and 6.6±3.9% by PBMCs NT respectively, n=5, p<0.01 for both). We confirmed cytolytic activity of APRIL-CAR against primary MM cells. Allogeneic PBMCs transduced with APRIL-CAR and CD56-depleted were co-cultured 1:1 with CD138+ bone marrow MM cells from 5 patients. Despite variable BCMA and TACI expression between patient samples (BCMA 1224-7728 and TACI 563-1213 ABC), tumour cytolysis was evident in all cases (APRIL-CAR 72.9±12.2% specific cell death cf media control 2.8±15.3%; p<0.05). Finally we tested the in vivo activity of APRIL-CAR in an intramedullary model established with tail vein injection of MM.1s.Fluc cells into NOD scid gamma (NSG) mice. Animals were analysed by bioluminescent imaging and FACS analysis of bone marrow for tumour cells. Complete clearance of established intramedullary disease was seen 5 days after infusion of 5x10^6 APRIL-CAR positive PBMCs in 12/12 animals. Elimination of tumour cells was confirmed in the bone marrow (p<0.01) with concurrent detection of APRIL-CAR T cells by FACS analysis. In summary we report for the first time a 3rd generation CAR utilising a natural ligand to simultaneously target two antigens found on MM cells. Our APRIL-based CAR demonstrated potent activity at the low levels of BCMA and TACI found in primary MM cells, at low (physiological) E:T ratios, and in an intramedullary MM model. This APRIL based CAR holds particular promise and deserves testing in clinical studies. Disclosures Lee: Bloodwise: Research Funding; Autolus Ltd: Patents & Royalties: APRIL based chimeric antigen receptor. Draper:Autolus Ltd: Equity Ownership, Patents & Royalties: APRIL based CAR. Chaplin:Autolus Ltd: Equity Ownership. Philip:Autolus: Equity Ownership. Thomas:Autolus Ltd: Employment. Kokalaki:Autolus Ltd: Employment. Francis:Autolus Ltd: Employment. Yong:Autolus Ltd: Equity Ownership, Patents & Royalties: APRIL based chimeric antigen receptor; Janssen: Research Funding. Pule:Autolus Ltd: Employment, Equity Ownership, Research Funding; UCL Business: Patents & Royalties; Amgen: Honoraria; Roche: Honoraria.

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Citron Rho Interacting Kinase (CRIK) Regulates Survival in IL-6 Dependent Multiple Myeloma Cells.

Blood ◽

10.1182/blood.v114.22.1825.1825 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1825-1825

Author(s):

Hai T. Ngo ◽

Alexey A. Leontovich ◽

Aldo M. Roccaro ◽

Abdel Kareem Azab ◽

Judith M. Runnels ◽

...

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Multiple Myeloma ◽

Bone Marrow ◽

Protein Expression ◽

Board Of Directors ◽

Research Funding ◽

Protein Microarray ◽

Advisory Committees ◽

Inhibition Of Proliferation

Abstract Abstract 1825 Poster Board I-851 Purpose Recent advances in understanding of the molecular alterations that occur at the genetic and epigenetic levels in Multiple Myeloma (MM) have led to major leaps in identifying molecular pathways that regulate progression and resistance to therapeutic agents. However, despite great scientific advances at the genomic level, studies to identify signaling pathways deregulated at the functional proteomic level in MM are limited. We have previously demonstrated that Citron Rho Interacting Kinase (CRIK) is overexpressed in primary multiple myeloma (MM) cells, as compared to the normal plasma cell counterpart, using an antibody-based protein microarray technique. We therefore sought to investigate the functional role of CRIK in MM cells. Methods We determined the protein expression level of 512 polypeptides in 12 samples of newly diagnosed patients with MM using high-throughput proteomic analysis with antibody-based protein microarray. Primary CD138+ sorted MM cells were obtained from the bone marrow of patients after informed consent. MM.1S, RPMI8226, and INA6 MM cell lines were used in this study. Protein expression has been studied by immunoblotting. Gene expression analysis has been assessed using the Affymetrix U133A platform. Lentivirus was used to knockdown CRIK in MM cell lines (MM.1S, RPMI8226, INA6). DNA synthesis, cell survival, cell cycle profiling and apoptosis were assessed by thymidine uptake, MTT, PI and Annexin/PI staining and flow cytometric analysis, respectively. Results Overexpression of CRIK has been confirmed in primary CD138+ tumor cells isolated from bone marrow of 12 patients with MM, as compared to normal plasma cells obtained from healthy donors. We found that CRIK-knockdown exerted an anti-proliferative and pro-apoptotic effect only in IL-6-dependent MM cell line INA6; in contrast, no effect on proliferation and survival was observed in MM1.S and RPMI8226. Indeed, INA6 CRIK-knockdown cells were characterized by a reduction in the proliferation rate, associated with decreased S-phase and G2/M phase cell cycle arrest. Moreover, induction of cytotoxicity was also demonstrated in CRIK knockdown cells compared to scramble probe transfected or non-transfected cells. We also showed that CRIK knockdown led to cytokinesis in INA6, indicating a possible mechanism for inhibition of proliferation of these cells. We next correlated CRIK gene expression level (CIT) with prognosis using previously published gene expression datasets and found that CRIK correlated with poor prognosis. Conclusion In this study, we show that MM cells express a high level of CRIK, and that inhibition of this protein leads to significant inhibition of proliferation and survival of IL-6 dependent MM cells. Moreover, CRIK protein expression correlated with poor survival in patients with MM. Disclosures Anderson: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghobrial:Millennium: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

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Induction of a Leukemic Bone Marrow Niche Mediated By TGFB1 of Leukemic Blasts in Pediatric Acute Mekaryoblastic Leukemia: Results of an in Vitro and In Vivo Analysis

Blood ◽

10.1182/blood-2019-126536 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3734-3734

Author(s):

Theresa Hack ◽

Stefanie Bertram ◽

Guntram Büsche ◽

Helmut Hanenberg ◽

Ludger Klein-Hitpass ◽

...

Keyword(s):

Gene Expression ◽

Bone Marrow ◽

Research Funding ◽

Expression Profiles ◽

Adipogenic Differentiation ◽

Bone Marrow Niche ◽

Differentiation Potential ◽

Advisory Boards

Background: An increasing knowledge about the bone marrow niche demonstrates the high complexity of leukemogenesis. Mesenchymal stromal cells (MSC) are important members of the bone marrow niche and source of fibrosis. Further, the microenvironment seems to be regulated by megakaryocytes and platelets via cytokines, such as transforming growth factor beta 1 (TGFB1). Despite extensive research, the pathogenesis of the bone marrow niche in childhood leukemia and the therapeutic potential is still unclear. We focus on acute childhood megakaryoblastic leukemia (AMKL) as a disease model and include patients with (ML-DS) and without Down syndrome. Based on similar clinical progressions - myelofibrosis occurs as a side-effect of both leukemia subtypes; these two diseases suit to characterize the leukemic bone marrow niche. Methods: We performed a comprehensive characterisation of MSC from ML-DS (n=9), AMKL patients (n=5) and healthy donors (HD; n=6) via e.g. differentiation assays (adipogenic, osteogenic), gene expression profiles and western blot analysis. In addition, we established an in vivo model with humanized ossicles, representing a human bone marrow microenvironment (as described by Chen et al. 2012; Reinisch et al. 2015): We injected MSC mixed with pooled human umbilical vein endothelial cells (HUVEC) and Matrigel subcutaneously into NOD scid gamma (NSG) mice. After 8 weeks, the engrafted ossicles were injected with megakaryoblastic cells (CMK cell line); injected ossicles (n=16); uninjected ossicle (n=27), MSC from ML-DS (n=19 ossicles), AML M1 (n=15 ossicles) and HD (n=9 ossicles). After 4 more weeks, histopathology evaluation of fibrosis in the ossicles was performed in accordance with the European Consensus on Grading Bone Marrow criteria from an independent pathologist. Results: The detailed characterisation of MSC with ML-DS and AMKL demonstrated a high similarity to MSC of HD: morphology, osteogenic differentiation potential, colony forming unit-fibroblast assay, proliferation and gene expression profiles. However, two differences emerged in our analysis: MSC showed a decreased adipogenic differentiation potential in ML-DS and AMKL compared to HD (ML-DS vs. HD=0.26-fold, p<0.05; AMKL vs. HD=0.50-fold). Gene expression profiling identified an upregulation of IGF2BP3, an oncofetal RNA binding protein, in MSC of ML-DS compared to HD confirmed by qRT-PCR (2.6-fold, p<0.05). IGF2BP3 is known to be highly expressed in many cancers and seems to be associated with proliferation. The increased level of IGF2BP3 (protein: IF2B3) was confirmed at protein-level detected by western blot analysis (ML-DS vs HD: 37.3-fold, p<0.05 and AMKL-MSC vs HD: 13.1-fold, p<0.05). TGFB1 - known to be secreted by leukemic megakaryoblasts - induced a fibrotic state in MSC regardless of their origin indicated by decreased adipogenic differentiation potential (treated vs. untreated: ML-DS 0.22-fold; AMKL 0.08-fold; HD 0.06-fold, p<0.05) and increased expression of collagen genes (qRT-PCR; COL1A1: ML-DS=1.63-fold, AMKL=1.80-fold (p<0.01), HD=1.66-fold (p<0.05); COL3A1: ML-DS=1.31-fold, AMKL=1.52-fold (p<0.05), HD=1.24-fold). The humanized bone marrow niche in our mouse model demonstrated a development of myelofibrosis after injection of the megakaryoblastic cell line (CMK): Grade 1 or 2 in 81% of the ossicles. The induction was independent of the MSC entity (HD/ML-DS). Of note, a monocytic subpopulation, which engrafted unexpectedly in ossicle from HD-MSC (n=3 ossicle), did not induce fibrotic fibers. Conclusion: Our data impressively illustrate the mutual influence between MSC and leukemic blasts that leads to a fibrotic microenvironment. This correlation has been observed in vitro but also in a unique mouse model. The interaction of MSC and leukemic blasts seems to be the key factor for the development of the leukemic niche in AMKL mediated inter alia by the TGFB pathway. However, we could identify several disease specific characteristics of MSC. Our model offers a unique opportunity to fundamentally examine of the leukemic niche in order to subsequently evaluate the potential therapeutic use in further studies. Disclosures Reinhardt: Novartis: Other: Participation in Advisory Boards; CSL Behring: Research Funding; Jazz: Other: Participation in Advisory Boards, Research Funding; Roche: Research Funding.

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