Tumor Microenvironment Proteomics: Lessons From Multiple Myeloma

Although the “seed and soil” hypothesis was proposed by Stephen Paget at the end of the 19th century, where he postulated that tumor cells (seeds) need a propitious medium (soil) to be able to establish metastases, only recently the tumor microenvironment started to be more studied in the field of Oncology. Multiple myeloma (MM), a malignancy of plasma cells, can be considered one of the types of cancers where there is more evidence in the literature of the central role that the bone marrow (BM) microenvironment plays, contributing to proliferation, survival, migration, and drug resistance of tumor cells. Despite all advances in the therapeutic arsenal for MM treatment in the last years, the disease remains incurable. Thus, studies aiming a better understanding of the pathophysiology of the disease, as well as searching for new therapeutic targets are necessary and welcome. Therefore, the present study aimed to evaluate the protein expression profiling of mononuclear cells derived from BM of MM patients in comparison with these same cell types derived from healthy individuals, in order to fill this gap in MM treatment. Proteomic analysis was performed using the mass spectrometry technique and further analyses were done using bioinformatics tools, to identify dysregulated biological pathways and/or processes in the BM microenvironment of patients with MM as a result of the disease. Among the pathways identified in this study, we can highlight an upregulation of proteins related to protein biosynthesis, especially chaperone proteins, in patients with MM. Additionally, we also found an upregulation of several proteins involved in energy metabolism, which is one of the cancer hallmarks. Finally, with regard to the downregulated proteins, we can highlight mainly those involved in different pathways of the immune response, corroborating the data that has demonstrated that the immune system of MM is impaired and, therefore, the immunotherapies that have been studied recently for the treatment of the disease are extremely necessary in the search for a control and a cure for these patients who live with the disease.

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High Dimensional Immune Profiling in Smoldering Multiple Myeloma Identifies Novel Organizing Features of the Tumor Microenvironment

Blood ◽

10.1182/blood-2019-130554 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4384-4384

Author(s):

Hearn Jay Cho ◽

Deepak Perumal ◽

Adeeb H Rahman ◽

Seunghee Kim-Schultze ◽

Jennifer Yesil ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Microenvironment ◽

Tumor Cells ◽

Research Funding ◽

Mononuclear Cells ◽

Plasma Cells ◽

High Dimensional ◽

Integrated Analysis ◽

Symptomatic Disease

Multiple myeloma (MM) is a malignancy of plasma cells that arises from premalignant Monoclonal Gammopathy of Undetermined Significance (MGUS) and often progresses through an asymptomatic Smoldering (SMM) phase lasting months or years before manifesting clinical symptoms warranting therapy. Current research indicates that the tumor microenvironment (TME) in the bone marrow may play a significant role in governing progression to symptomatic disease. Therefore, understanding of the interactions between malignant plasma cells and the TME in early disease states is critical in the pursuit of therapies that will prevent progression to symptomatic disease. We performed high dimensional genomic and immunologic analysis of bone marrow specimens from 73 subjects with SMM. We performed RNA-seq on the malignant plasma cells isolated by anti-CD138 magnetic bead positive selection, mass cytometry (CyTOF) and T cell receptor sequencing (TCR Seq) of CD138-depleted bone marrow mononuclear cells, and proteomics, seromic, and grand serology analysis of bone marrow plasma. These samples and assays provided a broad view of the tumor cells and the cellular and soluble components of the TME. Each of these assays identified self-organizing clusters of subjects, indicating that subgroups of SMM patients shared common characteristics in the tumor or TME populations. We then applied novel bioinformatic methods to compare data from pairs, trios, quartets, and quintets of assays to identify communities of subjects with similar immunologic and genomic characteristics. Integrated analysis of CyTOF, proteomic, and TCR Seq resolved three distinct communities with a high degree of significance. These communities shared distinct cellular and proteomic features that suggested early adaptive, activated adaptive, or innate immune characteristics. These results suggest that the continuum from MGUS to MM does not consist of a single pathway in either the tumor cells or the TME, and that complex interactions ultimately determine progression. This suite of assays (CyTOF, proteomics, and TCR Seq) may be applicable in translational and clinical studies to understand key tumor and immune determinants of SMM and lead to rationally designed therapy to replicate these conditions to prevent progression to symptomatic disease. Disclosures Cho: Genentech: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; The Multiple Myeloma Research Foundation: Employment; Takeda: Research Funding; BMS: Consultancy; Agenus: Research Funding; GSK: Consultancy. Adams:Janssen Pharmaceuticals R&D: Employment, Other: Own Stock. Parekh:Foundation Medicine Inc.: Consultancy; Celgene Corporation: Research Funding; Karyopharm Inc.: Research Funding.

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Clinical and Prognostic Impact of (11;14)(q13;q32) Translocation on Patients with Multiple Myeloma

Blood ◽

10.1182/blood-2019-130809 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5507-5507

Author(s):

Daisuke Miura ◽

Kentaro Narita ◽

Ayumi Kuzume ◽

Rikako Tabata ◽

Toshiki Terao ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Cells ◽

Clinical Characteristics ◽

Mononuclear Cells ◽

Plasma Cells ◽

Stage Iii ◽

Prognostic Impact ◽

Cd20 Expression ◽

The Impact

Introduction. Translocations involving chromosome 14 at band q32, the immunoglobulin heavy chain (IgH) locus, are considered to be the most important initiating events for the development of multiple myeloma (MM). Among the IgH translocations in MM, t(11;14)(q13;q32) is the most frequently reported, and associated with a lymphoplasmacytic morphology. This translocation have been traditionally considered as standard-risk chromosomal abnormality compared to other translocations such as t(4;14) or t(14;16), although some controversies on the prognostic impact of this translocation still remain. This study aimed to clarify the clinical and prognostic impact of t(11;14) in Japanese patients in relation to other clinical variables such as immunophenotype of the tumor cells, other cytogenetic abnormalities, and use of stem cell transplantation (SCT). Patients and methods. Among the 244 consecutive patients with newly diagnosed MM, treated at Kameda Medical Center between April 2009 and July 2019, 234 patients, having cytogenetic analysis data (including t(11;14), t(4;14), t(14;16), and del(17p) by interphase fluorescence in situ hybridization (iFISH)) fully available, were included in this study. Data regarding the patients' clinical and laboratory characteristics, including the International Staging System (ISS), immunophenotype of the tumor cells, baseline circulating plasma cells (CPCs), treatment responses, disease progression, and survival status, were collected. iFISH was performed with CD138-purified bone marrow plasma cells, and the cut off values for translocation were ≥ 10% and for del(17p) ≥ 20%. Using multicolor flow cytometry, surface marker analysis of bone marrow samples and quantification of pre-treatment CPCs on peripheral blood mononuclear cells were simultaneously performed. CPCs were reported as the percentage of total mononuclear cells. Patients were considered to be negative for clonal CPCs at a sensitivity of 10−4 (0.01%) clonal plasma cells for all events evaluated. Results. The incidence of patients harboring t(11;14) was 24.4% (n = 57); t(11;14) was detected significantly high in light-chain-only subtypes (P < 0.001). We compared clinical characteristics of patients carrying t(11;14) with others. Myeloma cells with t(11;14) were associated with negative expression of CD56 (P < 0.001), CD117 (P = 0.046), and CD200 (P = 0.006), and positive expression of CD20 (P = 0.01) and CD81 (P = 0.035). Patients with t(11;14) were associated with positive CPCs (P = 0.011). In order to focus on the impact of t(11;14), we divided the patients into 4 groups: (A) no specific cytogenetic abnormality listed above (n = 137), (B) t(11;14) group (n = 57), (C) t(4;14) or t(14;16) group (n = 29), and (D) del(17p) only (n = 10), and the clinical characteristics and survival of the patients were compared across the three groups (A), (B), and (C). Almost all the patients (> 95%) in this cohort received bortezomib-based therapy. Median progression-free survival (PFS) and overall survival (OS) of patients in (A), (B), and (C) groups were 55.6, 34.2, and 30.2 months (m) (A vs. B, P = 0.036, and A vs. C, P = 0.031), and not reached, 51.2, and 79.8 m (A vs. B, P = 0.11, and A vs. C, P = 1.00), respectively. However, patients harboring t(11;14) were further divided into CD20-positive and -negative groups, the latter having poor prognosis (36.1 vs. 26.7, P = 1.0 for median PFS, and not reached vs. 44.2, P = 0.029 for median OS). Compared to other groups, patients without CD20 expression had significantly shorter OS (vs. A, vs. B, P = 0.024, 0.035, respectively), whereas those with CD20 expression tended to have longer OS, without statistical significance (Figure 1).Univariate analysis revealed ISS stage III, creatinine > 2.0 mg/dL, use of SCT, t(11;14) without CD20 expression, and age ≥ 70 years to be associated with shorter OS, whereas multivariate analysis demonstrated ISS stage III, use of SCT, and t(11;14) without expression CD20 (HR 1.88; 95% CI 1.10-3.21; P = 0.021) to be independent prognostic factors for poor OS. Conclusions. Our findings demonstrated that patients harboring t(11;14) had distinct clinical and immunophenotypic characteristics, two subsets of the disease entities with a clearly different survival according to CD20 expression. Disclosures Matsue: Ono Pharmaceutical: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; Novartis Pharma K.K: Honoraria; Celgene: Honoraria; Takeda Pharmaceutical Company Limited: Honoraria.

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Tumor cell heterogeneity in multiple myeloma: antigenic, morphologic, and functional studies of cells from blood and bone marrow

Blood ◽

10.1182/blood.v73.7.1925.bloodjournal7371925 ◽

1989 ◽

Vol 73 (7) ◽

pp. 1925-1935

Author(s):

MA King ◽

DS Nelson

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Cell ◽

Tumor Cells ◽

B Lymphocytes ◽

Plasma Cells ◽

Bone Marrow Cells ◽

Cell Types ◽

Pokeweed Mitogen

Tumor cells from six patients with immunoglobulin G (IgG) multiple myeloma were analyzed for surface antigens, cytoplasmic paraprotein, morphology, and response to various culture conditions. The tumor marker was the paraprotein idiotype. Low numbers of tumor cells were found in the blood of most of the patients. In some patients, the circulating tumor cells were solely B lymphocytes, whereas in other patients, they were lymphoid, lymphoplasmacytoid, and plasmacytoid. Dual surface antigen analysis of blood and bone marrow cells confirmed that the tumor may be composed of a spectrum of cell types. Thus, cells may range from surface-idiotype+,CD19+,CD20+, PCA-1-,cytoplasmic- idiotype- lymphocytes, to CD19-,PCA-1+,cytoplasmic-idiotype+ plasma cells that are surface-idiotype- or weakly surface-idiotype+. In one patient, some of the tumor cells co-expressed surface idiotype and CD10. The tumor B lymphocytes were activated in vitro to synthesize paraprotein by pokeweed mitogen (PWM), and by low molecular weight B cell growth factor (BCGF). In contrast, spontaneous synthesis of paraprotein by more mature tumor cells was inhibited by agents that also inhibit nonmyeloma plasma cells. These agents included PWM, gamma interferon, and phorbol ester. The results demonstrate that in multiple myeloma there exist different tumor cell types that are similar, by a variety of criteria, to normal B lineage cells at different stages of differentiation. Thus, further evidence is provided for the hypothesis of myeloma cell differentiation.

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Tumor cell heterogeneity in multiple myeloma: antigenic, morphologic, and functional studies of cells from blood and bone marrow

Blood ◽

10.1182/blood.v73.7.1925.1925 ◽

1989 ◽

Vol 73 (7) ◽

pp. 1925-1935 ◽

Cited By ~ 32

Author(s):

MA King ◽

DS Nelson

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Cell ◽

Tumor Cells ◽

B Lymphocytes ◽

Plasma Cells ◽

Bone Marrow Cells ◽

Cell Types ◽

Pokeweed Mitogen

Abstract Tumor cells from six patients with immunoglobulin G (IgG) multiple myeloma were analyzed for surface antigens, cytoplasmic paraprotein, morphology, and response to various culture conditions. The tumor marker was the paraprotein idiotype. Low numbers of tumor cells were found in the blood of most of the patients. In some patients, the circulating tumor cells were solely B lymphocytes, whereas in other patients, they were lymphoid, lymphoplasmacytoid, and plasmacytoid. Dual surface antigen analysis of blood and bone marrow cells confirmed that the tumor may be composed of a spectrum of cell types. Thus, cells may range from surface-idiotype+,CD19+,CD20+, PCA-1-,cytoplasmic- idiotype- lymphocytes, to CD19-,PCA-1+,cytoplasmic-idiotype+ plasma cells that are surface-idiotype- or weakly surface-idiotype+. In one patient, some of the tumor cells co-expressed surface idiotype and CD10. The tumor B lymphocytes were activated in vitro to synthesize paraprotein by pokeweed mitogen (PWM), and by low molecular weight B cell growth factor (BCGF). In contrast, spontaneous synthesis of paraprotein by more mature tumor cells was inhibited by agents that also inhibit nonmyeloma plasma cells. These agents included PWM, gamma interferon, and phorbol ester. The results demonstrate that in multiple myeloma there exist different tumor cell types that are similar, by a variety of criteria, to normal B lineage cells at different stages of differentiation. Thus, further evidence is provided for the hypothesis of myeloma cell differentiation.

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The oxidative stress response regulates DKK1 expression through the JNK signaling cascade in multiple myeloma plasma cells

Blood ◽

10.1182/blood-2006-11-056747 ◽

2007 ◽

Vol 109 (10) ◽

pp. 4470-4477 ◽

Cited By ~ 61

Author(s):

Simona Colla ◽

Fenghuang Zhan ◽

Wei Xiong ◽

Xiaosong Wu ◽

Hongwei Xu ◽

...

Keyword(s):

Oxidative Stress ◽

Multiple Myeloma ◽

Wnt Signaling ◽

Plasma Cells ◽

Cell Types ◽

Signaling Cascade ◽

Jnk Pathway ◽

Jnk Signaling ◽

Dkk1 Expression

Abstract Multiple myeloma (MM) plasma cells, but not those from healthy donors and patients with monoclonal gammopathy of undetermined significance or other plasma cell dyscrasias involving the bone marrow, express the Wnt-signaling antagonist DKK1. We previously reported that secretion of DKK1 by MM cells likely contributes to osteolytic lesions in this disease by inhibiting Wnt signaling, which is essential for osteoblast differentiation and survival. The mechanisms responsible for activation and regulation of DKK1 expression in MM are not known. Herein, we could trace DKK1 expression changes in MM cells to perturbations in the JNK signaling cascade, which is differentially modulated through oxidative stress and interactions between MM cells with osteoclasts in vitro. Despite its role as a tumor suppressor and mediator of apoptosis in other cell types including osteoblasts, our data suggest that DKK1, a stress-responsive gene in MM, does not mediate apoptotic signaling, is not activated by TP53, and its forced overexpression could not inhibit cell growth or sensitize MM cells to apoptosis following treatment with thalidomide or lenalidomide. We conclude that specific strategies to modulate persistent activation of the JNK pathway may be beneficial in preventing disease progression and treating myeloma-associated bone disease by inhibiting DKK1 expression.

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Mesenchymal Stem Cells and Cancer Stem Cells: An Overview of Tumor-Mesenchymal Stem Cell Interaction for therapeutic interventions

Current Drug Targets ◽

10.2174/1389450122666210824142247 ◽

2021 ◽

Vol 22 ◽

Author(s):

Soheila Montazersaheb ◽

Ezzatollah Fathi ◽

Ayoub Mamandi ◽

Raheleh Farahzadi ◽

Hamid Reza Heidari

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Tumor Microenvironment ◽

Cancer Stem Cells ◽

Tumor Cells ◽

Cell Types ◽

Cell Interaction ◽

Therapeutic Interventions ◽

Tumorigenic Potential ◽

Different Types

: Tumors are made up of different types of cancer cells that contribute to tumor heterogeneity. Among these cells, cancer stem cells (CSCs) have a significant role in the onset of cancer and development. Like other stem cells, CSCs are characterized by the capacity for differentiation and self-renewal. A specific population of CSCs is constituted by mesenchymal stem cells (MSCs) that differentiate into mesoderm-specific cells. The pro-or anti-tumorigenic potential of MSCs on the proliferation and development of tumor cells has been reported as contradictory results. Also, tumor progression is specified by the corresponding tumor cells like the tumor microenvironment. The tumor microenvironment consists of a network of reciprocal cell types such as endothelial cells, immune cells, MSCs, and fibroblasts as well as growth factors, chemokines, and cytokines. In this review, recent findings related to the tumor microenvironment and associated cell populations, homing of MSCs to tumor sites, and interaction of MSCs with tumor cells will be discussed.

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Assessment of phagocytic activity in live macrophages-tumor cells co-cultures by Confocal and Nomarski Microscopy

Biology Methods and Protocols ◽

10.1093/biomethods/bpx002 ◽

2017 ◽

Vol 2 (1) ◽

Cited By ~ 5

Author(s):

Dalia Martinez-Marin ◽

Courtney Jarvis ◽

Thomas Nelius ◽

Stéphanie Filleur

Keyword(s):

Tumor Microenvironment ◽

Tumor Cells ◽

Phagocytic Activity ◽

Molecular Mechanisms ◽

Cell Types ◽

Functional Assay ◽

Loss Of Function ◽

Multiple Cancer

Abstract Macrophages have been recognized as the main inflammatory component of the tumor microenvironment. Although often considered as beneficial for tumor growth and disease progression, tumor-associated macrophages have also been shown to be detrimental to the tumor depending on the tumor microenvironment. Therefore, understanding the molecular interactions between macrophages and tumor cells in relation to macrophages functional activities such as phagocytosis is critical for a better comprehension of their tumor-modulating action. Still, the characterization of these molecular mechanisms in vivo remains complicated due to the extraordinary complexity of the tumor microenvironment and the broad range of tumor-associated macrophage functions. Thus, there is an increasing demand for in vitro methodologies to study the role of cell–cell interactions in the tumor microenvironment. In the present study, we have developed live co-cultures of macrophages and human prostate tumor cells to assess the phagocytic activity of macrophages using a combination of Confocal and Nomarski Microscopy. Using this model, we have emphasized that this is a sensitive, measurable, and highly reproducible functional assay. We have also highlighted that this assay can be applied to multiple cancer cell types and used as a selection tool for a variety of different types of phagocytosis agonists. Finally, combining with other studies such as gain/loss of function or signaling studies remains possible. A better understanding of the interactions between tumor cells and macrophages may lead to the identification of new therapeutic targets against cancer.

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Myeloma Cell Associated Therapeutic Protein Discovery Using Single Cell RNA-Seq Data

Blood ◽

10.1182/blood-2020-142205 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 4-5

Author(s):

Lijun Yao ◽

Reyka G Jayasinghe ◽

Tianjiao Wang ◽

Julie O'Neal ◽

Ruiyang Liu ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Cell Surface ◽

B Cell ◽

Tumor Cells ◽

Plasma Cell ◽

Tissue Specificity ◽

Plasma Cells ◽

Expression Data ◽

Intracellular Proteins

Multiple myeloma (MM) is a hematological cancer of the antibody-secreting plasma cells. Despite therapeutic advancements, MM remains incurable due to high incidence of drug-resistant relapse. In recent years, targeted immunotherapies, which take advantage of the immune system's cytotoxic defenses to specifically eliminate tumor cells expressing certain cell surface and intracellular proteins have shown promise in combating this and other B cell hematologic malignancies. A major limitation in the development of these therapies lies in the discovery of optimal candidate targets, which require both high expression in tumor cells as well as stringent tissue specificity. In an effort to identify potential myeloma-specific target antigens, we performed an unbiased search for genes with specific expression in plasma and/or B cells using single-cell RNA-sequencing (scRNAseq) of 53 bone marrow samples taken from 42 patients. By comparing >40K plasma cells to >97K immune cells across our cohort, we were able to identify a total of 181 plasma cell-associated genes, including 65 that encode cell-surface proteins and 116 encoding intracellular proteins. Of particular interest is that the plasma cells from each patient were shown to be transcriptionally distinct with unique sets of genes expressed defining each patient's malignant plasma cells. Using pathway enrichment analysis, we found significant overrepresentation of cellular processes related to B-Cell receptor (BCR) signaling, protein transport, and endoplasmic reticulum (ER) stress, involving genes such as DERL3, HERPUD1, PDIA4, PDIA6, RRBP1, SSR3, SSR4, TXNDC5, and UBE2J1. To note, our strategy successfully captured several of the most promising MM therapeutic targets currently under pre-clinical and clinical trials, including TNFRSF17(BCMA), SLAMF7, and SDC1 (CD138). Among these, TNFRSF17 showed very high plasma cell expression, with concomitant sharp exclusion of other immune cell types. To ascertain tissue specificity of candidate genes outside of the bone marrow, we analyzed gene and protein expression data from the Genotype-Tissue Expression (GTEx) portal and Human Protein Atlas (HPA). We found further support for several candidates (incl. TNFRSF17,SLAMF7, TNFRSF13B (TACI), and TNFRSF13C) as being both exclusively and highly expressed in lymphoid tissues. While several surface candidates were not found to be lymphocyte-restricted at the protein level, they remain relevant considerations as secondary targets for bi-specific immunotherapy approaches currently under development. To further investigate potential combinatorial targeting, we examine sample-level patterns of candidate co-expression and mutually-exclusive expression using correlation analysis. As the majority of our detected plasma cell-specific genes encode intracellular proteins, we investigated the potential utility of these epitopes as therapeutic targets via MHC presentation. Highly expressed candidates include MZB1, SEC11C, HLA-DOB, POU2AF1, and EAF2. We analyzed protein sequences using NetMHC and NETMHCII to predict high-affinity peptides for common class-I and class-II HLA alleles. To correlate MHC allelic preference with candidate expression in our cohort, we performed HLA-typing for 29 samples using Optitype. To support our scRNAseq-driven findings, we cross-referenced gene expression data with 907 bulk RNA-sequencing samples, including 15 from internal studies and 892 from the Multiple Myeloma Research Foundation (MMRF), as well as bulk global proteomics data from 4 MM cell lines (TIB.U266, RPMI8226, OPM2, MM1ST) and 4 patients. We see consistent trends across both cohorts, with high positive correlation (Pearson R ranging between 0.60 and 0.99) for a majority of genes when comparing scRNA and bulk RNA expression in the same samples. Our experimental design and analysis strategies enabled the efficient discovery of myeloma-associated therapeutic target candidates. In conclusion, this study identified a set of promising myeloma CAR-T targets, providing novel treatment options for myeloma patients. Disclosures Goldsmith: Wugen Inc.: Consultancy. DiPersio:Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees.

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Patient-derived micro-organospheres recapitulate tumor microenvironment and heterogeneity for precision oncology.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.3076 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 3076-3076

Author(s):

Shengli Ding ◽

Zhaohui Wang ◽

Marcos Negrete Obando ◽

Grecia rivera Palomino ◽

Tomer Rotstein ◽

...

Keyword(s):

Drug Discovery ◽

Tumor Microenvironment ◽

Single Cell ◽

Stromal Cells ◽

Mononuclear Cells ◽

Immune Cell ◽

Tumor Biology ◽

Cell Types ◽

Precision Oncology ◽

Original Tumor

3076 Background: Preclinical models that can recapitulate patients’ intra-tumoral heterogeneity and microenvironment are crucial for tumor biology research and drug discovery. In particular, the ability to retain immune and other stromal cells in the microenvironment is vital for the development of immuno-oncology assays. However, current patient-derived organoid (PDO) models are largely devoid of immune components. Methods: We first developed an automated microfluidic and membrane platform that can generate tens of thousands of micro-organospheres from resected or biopsied clinical tumor specimens within an hour. We next characterized growth rate and drug response of micro-organospheres. Finally, extensive single-cell RNA-seq profiling were performed on both micro-organospheres and original tumor samples from lung, ovarian, kidney, and breast cancer patients. Results: Micro-organospheres derived from clinical tumor samples preserved all original tumor and stromal cells, including fibroblasts and all immune cell types. Single-cell analysis revealed that unsupervised clustering of tumor and non-tumor cells were identical between original tumors and the derived micro-organospheres. Quantification showed similar cell composition and percentages for all cell types and also preserved functional intra-tumoral heterogeneity.. An automated, end-to-end, high-throughput drug screening pipeline demonstrated that matched peripheral blood mononuclear cells (PBMCs) from the same patient added to micro-organospheres can be used to assess the efficacy of immunotherapy moieties. Conclusions: Micro-organospheres are a rapid and scalable platform to preserve patient tumor microenvironment and heterogeneity. This platform will be useful for precision oncology, drug discovery, and immunotherapy development. Funding sources: NIH U01 CA217514, U01 CA214300, Duke Woo Center for Big Data and Precision Health

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Anti-CD38-blocked ricin: an immunotoxin for the treatment of multiple myeloma [see comments]

Blood ◽

10.1182/blood.v84.9.3017.3017 ◽

1994 ◽

Vol 84 (9) ◽

pp. 3017-3025 ◽

Cited By ~ 52

Author(s):

VS Goldmacher ◽

LA Bourret ◽

BA Levine ◽

RA Rasmussen ◽

M Pourshadi ◽

...

Keyword(s):

Multiple Myeloma ◽

Tumor Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Tumor Cell Line ◽

Covalent Attachment ◽

Myeloma Cells ◽

Colony Forming Units

Abstract We report the development of a potent anti-CD38 immunotoxin capable of killing human myeloma and lymphoma cell lines. The immunotoxin is composed of an anti-CD38 antibody HB7 conjugated to a chemically modified ricin molecule wherein the binding sites of the B chain have been blocked by covalent attachment of affinity ligands (blocked ricin). Conjugation of blocked ricin to the HB7 antibody has minimal effect on the apparent affinity of the antibody and no effect on the ribosome-inactivating activity of the ricin A-chain moiety. Four to six logs of CD38+ tumor cell line kill was achieved at concentrations of HB7-blocked ricin in the range of 0.1 to 3 nmol/L. Low level of toxicity for normal bone marrow (BM) granulocyte-macrophage colony- forming units (CFU-GM), burst-forming units-erythroid (BFU-E), colony- forming units-granulocyte/erythroid/monocyte/macrophage (CFU-GEMM) cells was observed. Greater than two logs of CD38+ multiple myeloma cells were depleted from a 10-fold excess of normal BM mononuclear cells (BMMCs) after an exposure to HB7-blocked ricin under conditions (0.3 nmol/L) that were not very toxic for the normal BM precursors. HB7- blocked ricin was tested for its ability to inhibit protein synthesis in fresh patients' multiple myeloma cells and in normal BMMCs isolated from two healthy volunteers; tumor cells from four of five patients were 100-fold to 500-fold more sensitive to the inhibitory effect of HB7-blocked ricin than the normal BM cells. HB7 antibody does not activate normal resting peripheral blood lymphocytes, and HB7-blocked ricin is not cytotoxic toward these cells at concentrations of up to 1 nmol/L. The potent killing of antigen-bearing tumor cells coupled with a lack of effects on peripheral blood T cells or on hematopoietic progenitor cells suggests that HB7-blocked ricin may have clinical utility for the in vivo or in vitro purging of human multiple myeloma cells.

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