scholarly journals A pilot study of 3D tissue-engineered bone marrow culture as a tool to predict patient response to therapy in multiple myeloma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kinan Alhallak ◽  
Amanda Jeske ◽  
Pilar de la Puente ◽  
Jennifer Sun ◽  
Mark Fiala ◽  
...  

AbstractCancer patients undergo detrimental toxicities and ineffective treatments especially in the relapsed setting, due to failed treatment attempts. The development of a tool that predicts the clinical response of individual patients to therapy is greatly desired. We have developed a novel patient-derived 3D tissue engineered bone marrow (3DTEBM) technology that closely recapitulate the pathophysiological conditions in the bone marrow and allows ex vivo proliferation of tumor cells of hematologic malignancies. In this study, we used the 3DTEBM to predict the clinical response of individual multiple myeloma (MM) patients to different therapeutic regimens. We found that while no correlation was observed between in vitro efficacy in classic 2D culture systems of drugs used for MM with their clinical efficacious concentration, the efficacious concentration in the 3DTEBM were directly correlated. Furthermore, the 3DTEBM model retrospectively predicted the clinical response to different treatment regimens in 89% of the MM patient cohort. These results demonstrated that the 3DTEBM is a feasible platform which can predict MM clinical responses with high accuracy and within a clinically actionable time frame. Utilization of this technology to predict drug efficacy and the likelihood of treatment failure could significantly improve patient care and treatment in many ways, particularly in the relapsed and refractory setting. Future studies are needed to validate the 3DTEBM model as a tool for predicting clinical efficacy.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2690-2690
Author(s):  
Kinan Alhallak ◽  
Amanda Jeske ◽  
Pilar De La Puente ◽  
Jennifer Sun ◽  
Mark A. Fiala ◽  
...  

Abstract Introduction: Multiple myeloma (MM) is the cancer of plasma cells within the bone marrow (BM) and represents the second most common hematologic malignancy. Although therapeutic options have broadened over the years, the disease is challenged by frequent relapses. Relapsed/refractory MM (RRMM) often becomes non-responsive to previous lines of treatment and has significantly poorer survival outcome. Physicians are faced with a difficult task to choose a right treatment regimen. Thus, a precision medicine tool that predicts the clinical response of individual patients to therapy is greatly desired. We have previously developed a novel 3D tissue-engineered BM (3DTEBM) culture model, which is patient derived, closely recapitulates the pathophysiological conditions in the BM, and allows ex vivo proliferation of primary cells of various hematologic malignancies. In this study, we conducted a retrospective study that tests the ability of the ex vivo 3DTEBM platform to predict the clinical response in individual MM patients, to help decision-making process for RRMM. We hypothesized that the 3DTEBM will be able to predict clinical responses of RRMM patients. Methods: We first performed a literature search to examine the clinical efficacious concentrations (Css) for 10 MM drugs. We then experimentally determined the in vitro efficacious concentrations (IC50) of these drugs in MM cell lines, in both 2D and 3DTEBM cultures. The IC50 values were then correlated with their respective clinical Css values to evaluate how well each culture system reproduce drug efficacy. For the retrospective trial, we used viably frozen whole BM samples from 19 RRMM patients with known clinical responsiveness to the regimen they received. 3DTEBM cultures were developed for each patient with BM biopsies obtained prior to the start of clinical regimen. Cultures were treated ex vivo with the same treatment regimen each patient received clinically, at increasing concentrations (0X, 3X and 10X of Css of individual drugs). After 4 days, cultures were digested and cells were retrieved for flow cytometry analysis. Primary cells were stained Leukocyte-/CD38+ and counted against counting beads. Survival was determined as % of untreated control, and ex vivo responsiveness was analyzed by ANOVA. Finally, the clinical team correlated the ex vivo response with the clinical response for each patient. Results: To demonstrate this discrepancy between drug efficacy in laboratory settings and clinical outcomes, we compared the in vitro IC50 to the clinical Css of 10 drugs used for the treatment of MM. We found that there was no correlation between the IC50 in classic 2D culture systems and the clinical Css (R 2=0.019) (Figure 1A). In contrast, the IC50 in the 3DTEBM directly correlated with the clinical Css (R 2=0.993) (Figure 1B). We then conducted a retrospective clinical trial to determine if the 3DTEBM platform is able to predict each patient's clinical response by recreating the same treatment regimen ex vivo (Figure 1C). The 3DTEBM was able to predict the response in 89% of the MM patient cohort across multiple treatment regimens, with no false positives (Figure 1D). Conclusions: Our retrospective clinical trial demonstrated that the 3DTEBM technology is a feasible platform for predicting therapeutic responses in MM with a high predictive accuracy within a clinically actionable time frame. Such platforms can provide precise clinical insight about the efficacy of different treatment plans and assist physicians to propose the best choice of therapy for their individual patients. Future prospective studies are needed to validate these significant findings by testing prospective prediction ability of 3DTEBM to improve therapy response in hematologic malignancies. Figure 1 Figure 1. Disclosures De La Puente: Cellatrix LLC: Other: Co-founder. Azab: Cellatrix LLC: Current Employment. Vij: BMS: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; BMS: Honoraria; GSK: Honoraria; Oncopeptides: Honoraria; Karyopharm: Honoraria; CareDx: Honoraria; Legend: Honoraria; Biegene: Honoraria; Adaptive: Honoraria; Harpoon: Honoraria. Azab: Cellatrix, LLC: Current Employment, Current holder of individual stocks in a privately-held company.


Leukemia ◽  
2016 ◽  
Vol 31 (8) ◽  
pp. 1743-1751 ◽  
Author(s):  
S Hipp ◽  
Y-T Tai ◽  
D Blanset ◽  
P Deegen ◽  
J Wahl ◽  
...  

Abstract B-cell maturation antigen (BCMA) is a highly plasma cell-selective protein that is expressed on malignant plasma cells of multiple myeloma (MM) patients and therefore is an ideal target for T-cell redirecting therapies. We developed a bispecific T-cell engager (BiTE) targeting BCMA and CD3ɛ (BI 836909) and studied its therapeutic impacts on MM. BI 836909 induced selective lysis of BCMA-positive MM cells, activation of T cells, release of cytokines and T-cell proliferation; whereas BCMA-negative cells were not affected. Activity of BI 836909 was not influenced by the presence of bone marrow stromal cells, soluble BCMA or a proliferation-inducing ligand (APRIL). In ex vivo assays, BI 836909 induced potent autologous MM cell lysis in both, newly diagnosed and relapsed/refractory patient samples. In mouse xenograft studies, BI 836909 induced tumor cell depletion in a subcutaneous NCI-H929 xenograft model and prolonged survival in an orthotopic L-363 xenograft model. In a cynomolgus monkey study, administration of BI 836909 led to depletion of BCMA-positive plasma cells in the bone marrow. Taken together, these results show that BI 836909 is a highly potent and efficacious approach to selectively deplete BCMA-positive MM cells and represents a novel immunotherapeutic for the treatment of MM.


2020 ◽  
Vol 4 (8) ◽  
pp. 1628-1639
Author(s):  
Zachary J. Walker ◽  
Michael J. VanWyngarden ◽  
Brett M. Stevens ◽  
Diana Abbott ◽  
Andrew Hammes ◽  
...  

Abstract The oncogenic drivers and progression factors in multiple myeloma (MM) are heterogeneous and difficult to target therapeutically. Many different MM drugs have emerged, however, that attack various phenotypic aspects of malignant plasma cells. These drugs are administered in numerous, seemingly interchangeable combinations. Although the availability of many treatment options is useful, no clinical test capable of optimizing and sequencing the treatment regimens for an individual patient is currently available. To overcome this problem, we developed a functional ex vivo approach to measure patients’ inherent and acquired drug resistance. This method, which we termed myeloma drug sensitivity testing (My-DST), uses unselected bone marrow mononuclear cells with a panel of drugs in clinical use, followed by flow cytometry to measure myeloma-specific cytotoxicity. We found that using whole bone marrow cultures helped preserve primary MM cell viability. My-DST was used to profile 55 primary samples at diagnosis or at relapse. Sensitivity or resistance to each drug was determined from the change in MM viability relative to untreated control samples. My-DST identified progressive loss of sensitivity to immunomodulatory drugs, proteasome inhibitors, and daratumumab through the disease course, mirroring the clinical development of resistance. Prospectively, patients’ ex vivo drug sensitivity to the drugs subsequently received was sensitive and specific for clinical response. In addition, treatment with <2 drugs identified as sensitive by My-DST led to inferior depth and duration of clinical response. In summary, ex vivo drug sensitivity is prognostically impactful and, with further validation, may facilitate more personalized and effective therapeutic regimens.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4504-4504
Author(s):  
Quanhong Sun ◽  
Peng Zhang ◽  
Juraj Adamik ◽  
Konstantinos Lontos ◽  
Valentina Marchica ◽  
...  

Abstract Multiple myeloma (MM) is the most frequent cancer to involve the skeleton and remains incurable for most patients, thus novel therapies are needed. MM bone disease is characterized by osteolytic lesions that contribute significantly to patient morbidity and mortality. We showed that TBK1 signaling is a novel pathway that increases osteoclast (OCL) formation in Paget's disease, an inflammatory bone disease. Therefore, we hypothesized that TBK1 plays a similar role in MM induction of OCL. We found that MM conditioned media (MM-CM) dose-dependently increased bone marrow monocyte (BMM) expression of activated TBK1 protein and enhanced RANKL-driven OCL formation. TBK1 knockdown by shRNA transduction into BMM significantly attenuated the ability of MM-CM to increase OCL differentiation without altering OCL differentiation in control media. We found that the TBK1/IKKε inhibitor Amlexanox (Amlx) blocked normal and MM-enhanced OCL formation. Importantly, TBK1 mRNA expression in CD138+ plasma cells (PC) isolated from MM or PC leukemia patients is significantly higher as compared to PC from Monoclonal Gammopathy of Undetermined Significance (MGUS) patients. Therefore, we tested whether targeting the TBK1/ IKKε signaling pathways would also affect MM cells. We found that Amlx strongly decreased the viability of several MM cell lines and primary MM cells via induction of apoptosis. Amlx treatment of MM cell lines also induced a G1/S blockade, decreased activated ERK1/2, and increased translation of the dominant-negative C/EBPb-LIP isoform in several MM cell lines. The positive-acting C/EBPb-LAP isoform was previously shown to be a critical transcription factor for MM viability. Importantly, Amlx also enhanced the effectiveness of the proteasome inhibitors bortezomib and carfilzomib to kill MM cells in culture. Further, Amlx sensitized MM1.S cells to the induction of apoptosis by the autophagic inhibitor Bafilomycin A. Amlx dose-dependently inhibited tumor growth in a syngeneic MM mouse model in which 5TGM1 MM cells expressing secreted GLuc were injected subcutaneously into immunocompetent C57Bl/KaLwRij. Tumor growth was assessed by measuring tumor volumes and by the levels of secreted GLuc in the blood. Further, OCL formation ex vivo from bone marrow monocytes obtained from AMLX-treated mice versus controls was decreased. Amlx did not affect the viability of primary BMM, bone marrow stromal cells (BMSC), or splenocytes. Further, Amlx treatment of primary BMSC from MM patients or normal donors decreased expression of TNFα, IL-6 and RANKL, thereby decreasing BMSC support of MM survival and OCL differentiation. Amlx pretreatment of BMSC and murine pre-osteoblast MC4 cells also decreased VCAM1 expression and reduced MM cell adhesion, another mechanism for Amlx reduction of bone microenvironmental MM support. These data suggest that targeting TBK1/IKKε signaling may decrease MM bone disease by slowing MM growth, directly and indirectly, and preventing MM-induced osteolysis. Disclosures Giuliani: Janssen Pharmaceutica: Other: Avisory Board, Research Funding; Celgene Italy: Other: Avisory Board, Research Funding; Takeda Pharmaceutical Co: Research Funding. Roodman:Amgen Denosumab: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4988-4988
Author(s):  
Inger S. Nijhof ◽  
Jeroen Lammerts van Bueren ◽  
Berris van Kessel ◽  
Michel de Weers ◽  
Joost M Bakker ◽  
...  

Abstract Abstract 4988 To date, multiple myeloma (MM) remains an incurable malignancy of antibody-producing clonal plasma cells. The introduction of a new generation of immunomodulatory agents, such as lenalidomide (LEN), and the potent proteasome inhibitor bortezomib (BORT), used alone or in combination with steroids (dexamethasone; DEX or prednisone; PRED) has significantly improved the overall survival of MM patients. Nonetheless, all chemotherapy strategies are eventually hampered by the development of drug-resistance. Towards a novel and effective targeted immunotherapy for MM, we have developed daratumumab (DARA), a CD38 human antibody with broad-spectrum killing activity. In vitro, DARA induces substantial anti-MM effects mainly via ADCC (antibody dependent cellular cytotoxicity) and CDC (complement dependent cytotoxicity). In ex vivo assays, which allowed us to address killing of MM cells in bone marrow aspirates isolated from MM patients, enhanced or even synergistic MM cell killing was observed when DARA was combined with LEN, or with cocktails of LEN/BORT/DEX and melphalan/BORT/DEX. We now extended these ex vivo analyses to evaluate whether DARA in combination with LEN, BORT and DEX could improve the lysis of MM cells in bone marrow aspirates derived from 22 patients of whom 9 became refractory for LEN and 6 for LEN and BORT. DARA significantly enhanced the lysis of MM cells when combined with LEN or BORT in virtually all patients, including the LEN- and LEN/BORT-refractory patients. The combination of DARA+BORT and DARA+DEX induced additive killing, suggestive of lysis by independent mechanisms. When combined with LEN, DARA improved the lysis of MM cells in a synergistic manner in both non-refractory and LEN-refractory patients. This is suggestive of killing by at least partly complementary mechanisms. Synergistic activity of LEN and DARA was attributable to LEN-induced activation of effector cells that were involved in DARA-mediated ADCC. In addition, enhanced/synergistic direct killing of MM cells was observed. Experiments are under way to further investigate the mechanism underlying synergistic activity of DARA and LEN. In conclusion, our results provide a rationale for clinical evaluation of DARA in combination with LEN, BORT and DEX including in patients refractory to these drugs. Disclosures: van Bueren: genmab: Employment. de Weers:genmab: Employment. Bakker:genmab: Employment. Parren:genmab: Employment. Lokhorst:genmab: Consultancy, Research Funding. Mutis:genmab: Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1987-1987
Author(s):  
Amanda Jeske ◽  
Feda Azab ◽  
Pilar De La Puente ◽  
Barbara Muz ◽  
Justin King ◽  
...  

Abstract Background: Multiple Myeloma (MM) is the second most common hematological malignancy, and continues to be a fatal disease even with the development of novel therapies. Despite promising preclinical data in standard tissue culture models, most drugs fail in clinical trials and show lower efficacy in patients. This highlights the discrepancy between the current in vitro models, the pathophysiology of the disease in the patients, and the urgent need for better in vitro models for drug development and improved prediction of efficacy in patients. We have previously developed a patient-derived 3D-Tissue Engineered Bone Marrow (3DTEBM) culture model, which showed superior properties for proliferation of primary MM cells ex vivo, and better recapitulated drug resistance. The long-term goal of this study is to use the 3DTEBM model as a tool to perform drug screens on BM aspirates of MM patients and prospectively predict the efficacy of different therapies in individual patients, and help treatment providers develop personalized treatment plans for each individual patient. In the current study, we used the 3DTEBM model to, retrospectively, predict clinical responses of MM patients to therapy, as a proof of concept. Methods: We used whole-BM, viably frozen tissue banked samples from 20 MM patients with clear clinical response patterns of complete remission, and either very good partial response (sensitive) or progressive disease (non-sensitive). The BM aspirates were used to develop a 3DTEBM that represents each individual patient. The patient-derived 3DTEBM cultures were treated ex vivo with the same therapeutic regimen that the patient received in the clinic for 3 days. The treatment ex vivo was based on combinations at different concentrations which mimic the steady state concentrations (Css) of each drug. The efficacy of the treatment ex vivo was evaluated by digestion of the 3DTEBM matrix, extraction of the cells, and analysis for prevalence of MM cells in the treatment groups compared to the non-treated controls. Patients were defined "sensitive" if the effect reached 50% killing in the range of 10xCss. The ex vivo sensitivity data was then correlated with the clinical response outcomes. Results: We found that the 3DTEBM was predictive in approximately 80% of the cases (in about 85% of the combination therapy cases, and in about 70% of the single therapy cases). Broken down by individual drug, it was predictive in 80% of the cases treated with Bortezomib, 78% Lenalidomide, 84% Dexamethasone, 100% Daratumumab, 50% Carfilzomib, 50% Pomalidomide, and 100% Doxorubicin. Conclusions: The 3DTEBM is a more pathophysiologically relevant model which predicts clinical efficacy of drugs in multiple myeloma patients, retrospectively. This data provides the bases for future studies which will examine the ability of the 3DTEBM model to predict treatment efficacy, prospectively, for development of personalized treatment plans in individual multiple myeloma patients. Disclosures Jeske: Cellatrix LLC: Employment. Azab:Cellatrix LLC: Employment. De La Puente:Cellatrix LLC: Other: Co-founder. Vij:Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansson: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Azab:Ach Oncology: Research Funding; Cellatrix LLC: Equity Ownership, Other: Founder and owner; Glycomimetics: Research Funding; Targeted Therapeutics LLC: Equity Ownership, Other: Founder and owner.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4798-4798
Author(s):  
Shannon L. Winski ◽  
Stefan D. Gross ◽  
Suzy A. Brown ◽  
Deborah Anderson ◽  
Augusta Garrison ◽  
...  

Abstract Multiple Myeloma (MM) is a malignancy characterized by the clonal expansion of plasma cells within the bone marrow microenvironment. Within this compartment, the proliferative capacity of MM cells is enhanced by pro-inflammatory cytokines, and there is growing recognition that bone marrow stromal cells play an important role in the support of MM growth and chemo-resistance. We have identified a series of compounds, of which ARRY-614 is representative, that are potent inhibitors (EC50<10 nM) of cytokine synthesis through the inhibition of p38 MAPK. This compound is also a potent inhibitor of Abl tyrosine kinases and Tie2/Tek receptor tyrosine kinase. ARRY-614 is active against all of these targets on both the isolated enzymes and in cells. To confirm these activities, ARRY-614 was evaluated in relevant in vitro and in vivo models. ARRY-614 inhibited p38α in ex vivo stimulated human whole blood (EC50=2 nM) and the release of IL-6 and TNFα from SEA- or LPS-challenged mice (ED50<10 mg/kg). Further, ARRY-614 administered as a single agent was efficacious at inhibiting bFGF-driven angiogenesis in an in vivo matrigel invasion assay as well as inhibiting tumor growth in subcutaneous K562 (BCR-Abl dependent) and RPMI 8226 (multiple myeloma) tumor xenografts in mice, at doses ranging from 30 to 100 mg/kg qd, PO. In regulated safety studies, this compound was well-tolerated at doses up to 100 mg/kg qd and 30 mg/kg qd in rats and cynomolgus, respectively. Together, these data support the advancement of this agent into clinical trials for hematologic malignancies.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2006
Author(s):  
Konstantinos Papadimitriou ◽  
Ioannis V. Kostopoulos ◽  
Anastasia Tsopanidou ◽  
Nikolaos Orologas-Stavrou ◽  
Efstathios Kastritis ◽  
...  

Multiple myeloma (MM) remains incurable despite the abundance of novel drugs. As it has been previously shown, preclinical 2D models fail to predict disease progression due to their inability to simulate the microenvironment of the bone marrow. In this review, we focus on 3D models and present all currently available ex vivo MM models that fulfil certain criteria, such as development of complex 3D environments using patients’ cells and ability to test different drugs in order to assess personalized MM treatment efficacy of various regimens and combinations. We selected models representing the top-notch ex vivo platforms and evaluated them in terms of cost, time-span, and feasibility of the method. Finally, we propose where such a model can be more informative in a patient’s treatment timeline. Overall, advanced 3D preclinical models are very promising as they may eventually offer the opportunity to precisely select the optimal personalized treatment for each MM patient.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4389-4389
Author(s):  
Melania Carlisi ◽  
Salvatrice Mancuso ◽  
Marco Pio La Manna ◽  
Valentina Orlando ◽  
Nadia Caccamo ◽  
...  

Background: CD8+ T cell responses are an essential component of the adaptive immune system. After resolution of infection a small population of memory cells is formed. In relation to circulatory patterns, different subsets of memory CD8+ T cells can be identified: the central memory (CM) and the effector memory T cells (EM) (Martin MD, et al., Front Immunol. 2018). In addition, it has been described a subset of resident memory T cells (TRM) permanently living in peripheral tissues, including the bone marrow (BM) (Di Rosa F., et al., Nat Rev Immunol. 2016). It is conceivable that these cells can contribute to the defence toward haematological tumours infiltrating the BM. Therefore, we performed a study to evaluate the frequency and the phenotype of BM CD8+ TRM in patients with multiple myeloma (MM). Moreover, to evaluate the contribution that the microenvironment can have on the homeostatic and functional maintenance of these cells, we performed in vitro experiments of BM-derived mononucleate cells of MM patients cultured in the presence of different homeostatic cytokines. Patients and Methods: we prospectively analysed 21 patients, 16 with a new diagnosis of IgA, IgG and light chain multiple myeloma (MM) and 5 with IgA and IgG smoldering myeloma (SM). At the time of the bone marrow assessment, we collected a sample for the flow cytometry analysis and in vitro cell culture. The ex vivo evaluation of CD8+ TRM frequency and phenotype in BM samples was performed using anti-human mAbs to CD3, CD103, CD69, CD45, CD8, CD45RA and CCR7 (CD197). The sequential gating strategy was: gate on lymphocytes population with CD45 vs. SSC, 7AAD negative cells, exclusion of doublets with FSC-H vs. FSC-A, CD8+CD3+ and evaluation of percentage of CD103+CD69+ cells. Was also established the subsets using CCR7 and CD45RA. Moreover, to evaluate the role of the microenvironment on maintenance of these cells, we performed in vitro experiments of BM-derived mononucleate cells of MM patients cultured in the presence of homeostatic cytokines in maintaining these cells for a long time. BM derived mononucleate cells from patients were then cultured in vitro in complete RPMI with 10% of human serum for 4 days with IL15 (25 ng/ml), IL7 (25 ng/ml) and TGF-β (2 ng/ml), in different combination and in RPMI alone. After culture, we analyzed the frequency of CD8+ TRM and the proliferating fraction with intracellular staining with anti human Ki67 APC. Non parametric Mann-Whitney and Kruskall-wallis tests were performed to determine statistical differences in the distribution of the results using GraphPad Prism 7.00. Values of * p<0.05 were considered significant. Results: the ex vivo average frequency of CD8+ TRM in 16 MM patients was of 0.48% and the phenotype was represented mainly by TEM (72,9%) followed by TEMRA (12.3%) and (7,6%) of naïve cells and (7,2%) of TCM (Fig. A). The comparison with the ex vivo frequency of CD8 TRM in SM patients did not show any significant difference between two groups (data not showed). To evaluate factors capable of maintaining or to induce the expansion of these cells in vitro, we maintained BM-derived mononucleate cells from MM patients for 4 days in presence of homeostatic cytokines, IL-15, IL-7 plus IL-15 and IL-7 together with IL-15 and TGF-β. The result showed an increase of the percentage of CD8+ TRM in all conditions tested, especially in presence of all cytokines (Fig. B), with a percentage of CD8 TRM of 2,74%. Regarding the phenotype distribution, we observed an expansion of CM compared to the other subsets (Fig. C). We also analysed the percentage of CD8+ TRM proliferating through the identification of Ki67 positive cells. Data highlight that IL-15 gives the strongest proliferative input, but also other cytokines contribute to the homeostatic maintenance of these cells (Fig. D). Conclusions: we evaluated the frequency and the phenotype of CD8 TRM in BM of MM patients compared to SM patients with the conclusion that these cells do not differ significantly in percentage and phenotypic distribution in both conditions. In MM patients, the increase of CD8+ TRM cells with a CM phenotype after in vitro culture with the three cytokines could have an anti-tumor role in the control of MM. Further studies are needed to investigate the cytotoxic capacity of these cells against myeloma cells, in order to study their functional role, also in the perspective of a possible use in future therapeutic programs. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Marina Ferrarini ◽  
Magda Marcatti ◽  
Fabio Ciceri ◽  
Elisabetta Ferrero

Multiple Myeloma (MM) develops almost exclusively within the Bone Marrow (BM), highlighting the critical role of the microenvironment in conditioning disease progression and resistance to drugs. Indeed, while the therapeutic armamentarium for MM has significantly improved over the past 20 years, the disease remains ultimately incurable. This failure may depend on the high phenotypic and genetic heterogeneity of MM, but also on the paucity and inadequacy of two-dimensional (2D) conventional preclinical models in reproducing MM within the BM. In the present paper, we provide a brief updated overview on MM BM microenvironment. We then discuss newly developed preclinical models mimicking MM/microenvironment interactions, including three-dimensional (3D), gel-based, in vitro models and a novel ex vivo system of isolated tumor and stromal cells cultured in bioreactor. Potential applications of each model, relative to investigation of MM pathogenic mechanisms and prediction of the best drug/combination for each individual patient will be also evaluated.


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