scholarly journals Glutamine Depletion By Addicted Myeloma Cells Inhibits Osteoblastic Differentiation of Bone Marrow Mesenchymal Stromal Cells Limiting Asparagine Availability: A Possible New Mechanism for Myeloma Bone Disease

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4339-4339
Author(s):  
Martina Chiu ◽  
Denise Toscani ◽  
Emanuela Vicario ◽  
Roberta Andreoli ◽  
Giuseppe Taurino ◽  
...  

Metabolic alterations of cancer cells, aimed at sustaining their growth, may also influence the behavior of the tumor microenvironment. Our group has recently demonstrated that multiple myeloma (MM) is a highly glutamine(Gln)-addicted tumor that utilize huge amounts of Gln to fuel its metabolism through the enzyme glutaminase (GLS). For this reason, MM cells exhibits increased Gln uptake, mainly through the ASCT2 transporter. Interestingly, lower bone marrow (BM) plasma Gln concentration (down to a median value of 0.4 mM vs. a median value of 0.6 mM) was found in MM patients as compared with smoldering MM (SMM) and Monoclonal Gammopathy of Uncertain Significance (MGUS). The main feature of MM BM microenvironment is the suppression of osteoblastic (OB) differentiation leading to the development of osteolytic bone lesions, the hallmark of MM. Most recently, it has been demonstrated that Gln metabolism is needed to sustain bone mass formation in murine models and that GLS inhibition decreases OB differentiation of human mesenchymal stromal cells (hMSCs). However, no information is yet available on the role of Gln depletion imposed by MM cell metabolism on OB differentiation into the BM. This topic has been investigated in the present study. Firstly, human MM cells were co-cultured with BM hMSCs, and Gln medium concentration was evaluated with mass spectrometry (MS), demonstrating a MM-induced depletion of the amino acid. Upon Gln depletion, MSC exhibited a sustained induction of Glutamine Synthetase (GS). On the contrary, when differentiated in osteogenic medium (D-MEM + 5% Fetal Bovine Serum, supplemented with 2 mM Gln, ascorbic acid and dexamethasone), GS was suppressed. Conversely, GLS (both KGA and GAC isoforms) and SLC38A2, the gene for the concentrative Gln transporter SNAT2, were induced. These data suggest that hMSCs differentiation in OBs is associated with an increased dependence upon extracellular Gln. Consistent with this conclusion, the activity of SNAT2 was absent in undifferentiated hMSCs but well detectable after 14 days of OB differentiation, when total Gln uptake was also increased. Under the same conditions, OB differentiation markers (RUNX2, COL1A1, ALPL expression and ALPL activity or staining) were significantly induced but their expression was blunted by incubation in low-Gln (0.4 mM) medium or in the presence of the SNAT2 inhibitor MeAIB. The incubation in Gln-free D-MEM suppressed the induction of GLS and SLC38A2 along with OB differentiation, which was restored by the supplementation of Non-Essential Amino Acids (NEAA). Among NEAA, only asparagine (Asn) was able to rescue OB differentiation in the absence of Gln. The determination of intracellular amino acids with MS indicated that OB differentiation was associated with the increase of cell Asn, without significant changes of Gln, glutamate (Glu) or aspartate (Asp). Asparagine Synthetase (ASNS), the Gln-dependent enzyme that accounts for Asn synthesis, was also found induced during OB differentiation of hMSCs. Gene Expression Profiles of primary BM hMSCs and OBs from bone biopsies of both healthy donors (n=7) and MM patients (n=16) indicated that GLS, ASNS, and SLC38A2 are more expressed in OBs, while the expression of GLUL, the gene for GS, is higher in undifferentiated hMSCs from healthy donors. Overall, these results indicate that (1) OB differentiation of hMSCs is Gln-dependent; (2) the partial Gln depletion, imposed by Gln-addicted MM cells in the BM microenvironment, contributes to the impairment of osteoblastic differentiation of hMSCs; (3) hindrance of differentiation may depend on the limited availability of intracellular Asn derived from Gln-dependent ASNS. These results support the evidence that Gln addiction of MM cells affects bone microenvironment leading to the inhibition of OB differentiation and, consequently, to the development of MM bone disease. Disclosures Giuliani: Janssen: Research Funding.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3816-3816
Author(s):  
Manja Wobus ◽  
Gwendolin Dünnebier ◽  
Silvia Feldmann ◽  
Gerhard Ehninger ◽  
Martin Bornhauser ◽  
...  

Abstract Abstract 3816 Poster Board III-752 Introduction Recent studies in patients with MDS have clearly demonstrated the clinical efficacy of lenalidomide. However, its exact mechanisms of action have not been elucidated yet. Myelosuppression is the most common adverse event and seems to be dependent on dose as well MDS subtype, being rather infrequent in patients other than del5q. The aim of this study was to investigate whether lenalidomide affects the bone marrow microenvironment. Therefore, we analyzed in-vitro characteristics of isolated mesenchymal stromal cells (MSCs) from MDS patients and from healthy controls. Methods Bone marrow samples were collected from healthy donors (n=5) and patients with MDS (del5q MDS n=3, RA n=2, RAEB1/2 n=3). MSCs were isolated according to the standard adhesion protocol and cultured in the presence or absence of lenalidomide. Results Lenalidomide treatment of MSCs caused no morphological changes but proliferation was slightly increased. Typical surface molecules as CD73, CD90, CD105 and CD166 were expressed in MSCs from MDS patients at comparable levels to healthy controls. Lenalidomide treatment caused an upregulation of CD29 by 17.8 ± 4.4% and of CD73 by 24 ± 5.7% (mean fluorescence intensity). Investigating the cytokine production, we found lower IL-8 mRNA and protein levels in MSCs from MDS patients (mean in MDS MSC: 138.1 pg/ml vs. mean in healthy MSC: 1177 pg/ml). Interestingly, the IL-8 production can be increased by approximately 40% under lenalidomide treatment. MDS MSCs retained the capacity for adipogenic and osteogenic differentiation as well as their supportive function towards hematopoietic cells in long term culture-initiating assays (LTC-IC). However, the LTC-IC frequency was lower on MSC which had been preincubated with lenalidomide compared to controls. Lenalidomide also slightly accelerated osteogenic differentiation because mineralization started as early as on day 5 with lenalidomide whereas in the control cells first calcium deposits were visible after 7 days. Other samples showed augmented lipid vacuoles after adipogenic differentiation under lenalidomide treatment. Conclusion In conclusion, lenalidomide modulates the phenotype of MSC and leads to an increase of their IL-8 secretion by a yet unknown mechanism. Whether these in-vitro effects are associated with the clinical efficacy of this compound in patients with MDS remains to be investigated. Disclosures: Platzbecker: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


2011 ◽  
Vol 112 (7) ◽  
pp. 1817-1821 ◽  
Author(s):  
Valentina Achille ◽  
Melissa Mantelli ◽  
Giulia Arrigo ◽  
Francesca Novara ◽  
Maria Antonietta Avanzini ◽  
...  

Author(s):  
Martina Chiu ◽  
Giuseppe Taurino ◽  
Erica Dander ◽  
Donatella Bardelli ◽  
Alessandra Fallati ◽  
...  

Mechanisms underlying the resistance of Acute Lymphoblastic Leukemia (ALL) blasts to L-asparaginase are still incompletely known. Here we demonstrate that human primary bone marrow mesenchymal stromal cells (MSCs) successfully adapt to L-asparaginase and markedly protect leukemic blasts from the enzyme-dependent cytotoxicity through an amino acid trade-off. ALL blasts synthesize and secrete glutamine, thus increasing extracellular glutamine availability for stromal cells. In turn, MSCs use glutamine, either synthesized through Glutamine Synthetase (GS) or imported, to produce asparagine, which is then extruded to sustain asparagine-auxotroph leukemic cells. GS inhibition prevents mesenchymal cells adaptation to L-asparaginase, lowers glutamine secretion by ALL blasts, and markedly hinders the protection exerted by MSCs on leukemic cells. The pro-survival amino acid exchange is hindered by the inhibition or silencing of the asparagine efflux transporter SNAT5, which is induced in mesenchymal cells by ALL blasts. Consistently, primary MSCs from ALL patients express higher levels of SNAT5 (p < 0.05), secrete more asparagine (p < 0.05), and protect leukemic blasts (p < 0.05) better than MSCs isolated from healthy donors. In conclusion, ALL blasts arrange a pro-leukemic amino acid trade-off with bone marrow mesenchymal cells, which depends on GS and SNAT5 and promotes leukemic cell survival during L-asparaginase treatment.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1873-1873
Author(s):  
Christophe Martinaud ◽  
Christophe Desterke ◽  
Johanna Konopacki ◽  
Lisa Pieri ◽  
Rachel Golub ◽  
...  

Abstract Primary myelofibrosis (PMF) is myeloproliferative neoplasm characterized by clonal myeloproliferation, dysmegakaryopoiesis, extramedullary hematopoiesis associated with myelofibrosis and altered stroma in bone marrow and spleen. Mesenchymal stromal cells (MSCs) are reported to play a pivotal role in fibrosis and stromal changes are considered as a reactive counterpart of the cytokine production by clonal hematopoietic cells. The present study shows that MSCs from patients demonstrate functional abnormalities that are unexpectedly maintained ex-vivo, in culture. Material and Methods: we studied MSCs and bone marrow sections from PMF patients (n=12) as compared to healthy donors (HDs) (n=6). We tested their proliferation, immunophenotype, hematopoiesis supporting capacities, differentiation abilities, in-vivo osteogenic assays, and performed secretome and transcriptome analysis. Results: We found that PMF-MSCs exhibit similar proliferative capacity and long-term hematopoiesis supporting abilities as compare to healthy donors. They overproduce interleukin 6, VEGF, RANTES, PDGF, BMP-2 and surprisingly TGF-beta1. MSCs from fibrotic PMF patients express high levels of glycosaminoglycans. Adipocytes and chondrocytes differentiation abilities were not different as compared to HDs but PMF-MSCs exhibit an increased in vitro potential. Implementation on scaffold in nude mice confirmed, in vivo, this increased osteogenic potential. We then looked into gene expression and discovered that PMF-MSCs show an original transcriptome signature related to osteogenic lineage and TGF-beta1. Indeed, osteogenic genes such as Runx2, Dlx5, Twist1, Noggin, Sclerostin, GDF5 and Serpine1 are deregulated and suggest a potential osteoprogenitor priming of PMF-MSCs. These molecular results also advocated for a TGF-beta1 impregnation that prompted us to study its impact on PMF-MSCs osteogenic differentiation. First, we then showed that Smad2 is intrinsically over-activated in PMF-MSC and that stimulation by TGF-beta1 is associated with an increase phospho-Smad2 level and an enhancement of bone master gene regulator Runx2 expression. Then, we inhibited TGF-beta1 pathway by by SB-431542 and evidenced a specific behavior of osteogenic MSCs differentiation in patients, suggesting involvement of TGF-beta1 in osteogenic impairment. Conclusion: Altogether, our results identify a signature of PMF-MSCs and suggest that they participate in PMF osteogenic dysregulation independently from in vivo local stimulation by clonal hematopoietic cells Disclosures No relevant conflicts of interest to declare.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Sarah M. Churchman ◽  
Sally A. Boxall ◽  
Dennis McGonagle ◽  
Elena A. Jones

Background and Objectives. Culture expanded multipotential stromal cells (MSCs) have considerable potential for bone regeneration therapy but their wider use is constrained by the lack of simple and predictive assays of functional potency. Extended passaging leads to loss of multipotency but speed of decline depends on MSC donor age. The aim of this study was to develop an assay predictive of MSC culture longevity applicable to a broad donor age range. Materials and Methods. Bone marrow (BM, n=7) was obtained from a diverse range (2–72 years) of healthy donors. MSCs were culture expanded to senescence and their osteoprogenitor content, gene expression profiles, epigenetic signature, and telomere behaviour were measured throughout. Output data was combined for modelling purposes. Results. Regardless of donor age, cultures’ osteoprogenitor content correlated better with remaining lifespan (population doublings before senescence, PD-BS) than proliferative history (accrued PDs). Individual gene’s expression or telomere length did not predict PD-BS but methylation of individual CpG islands did, PRAMEF2 in particular (r=0.775). Coupling the steep relationship of relative SPARC expression with PD-BS (r=-0.753) the formula SPARC × 1/PREMEF2 gave an improved correlation (r=-0.893). Conclusion. A formula based on SPARC mRNA and PRAMEF2 methylation may be used to predict remaining BM-MSC longevity and related loss of multipotentiality independent of donor age.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Antonio Garcia-Gomez ◽  
Tianlu Li ◽  
Carlos de la Calle-Fabregat ◽  
Javier Rodríguez-Ubreva ◽  
Laura Ciudad ◽  
...  

AbstractMultiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2694-2694
Author(s):  
Ladan Kobari ◽  
Martine Auclair ◽  
Olivier Piau ◽  
Nathalie Ferrand ◽  
Maurice Zaoui ◽  
...  

Abstract Introduction: Myeloma is characterized by bone lesions, which are related to both an increased osteoclast activity and a defect in the differentiation of medullary mesenchymal stem cells (MSCs) into osteoblasts. Outside the medullary environment, adipocyte-derived MSCs (ASCs) could represent a source of functional osteoblasts. However, we recently found a defect in the osteoblastic differentiation of ASCs from myeloma patients (MM-ASCs). We therefore examined the effects of plasma from myeloma patients at diagnosis (MM-plasmas) and in complete remission (CR-plasmas) and from healthy donors on the osteoblastic differentiation of healthy donor-derived ASCs (HD-ASCs) and healthy donor-bone marrow derived MSCs (HD-BM-MSCs). Materials and Methods: We studied 11 MM-ASCs, 5 HD-ASCs and 3 HD-BM-MSCs. The plasmas were from myeloma patients with bone lesions at diagnosis (n=12), in complete remission (n=8) and from 5 pools of 100 healthy donors (HD-plasmas). HD-ASCs were differentiated into osteoblasts and adipocytes and HD-BM-MSCs into osteoblasts with the three types of plasmas as well as newly discovered cytokines. Results: Osteoblastogenesis in HD-ASCs was suppressed by MM-plasmas. Alizarin red coloration and alkaline phosphatase activity were strongly decreased along with a decreased RUNX2 and osteocalcin expression. However, adipocyte differentiation was unaltered. The osteoblastic differentiation deficiency was reversible once the plasma-derived factors were removed. Using cytokine array and comparing MM-plasmas with HD-plasmas, we identified seven cytokines (ANG1, ENA-78, EGF, PDGF-AA/AB/BB and TARC), besides DKK1, highly increased in MM-plasmas which was confirmed by ELISA (Figure). They separately inhibited the osteoblastic differentiation of HD-ASCs. In contrast, myeloma patients in remission had a cytokine plasma level almost normal with barely no osteoblastic differentiation inhibition. In addition, the mixture of the 7 cytokines with and without DKK1 inhibited not only the HD-ASCs but also the HD-BM-MSCs. Concomittantly, we observed that MM-plasmas enhanced adipogenesis-related gene expression. Comparison of MM-ASCs and HD-ASCs by RNA sequencing showed that two master genes characterizing adipocyte differentiation, CD36 and PPARγ, were upregulated in MM-ASCs as compared to HD-ASCs. Moreover, we demonstrated a significant increase in CD36 and PPARγ expression in HD-ASCs in the presence of MM-plasmas or the seven cytokines individually, similarly as in MM-ASCs. Finally, we tried to identify the origin of these cytokines. When myeloma patients were in remission, the cytokines levels were strongly decreased suggesting a malignant plasmocyte secretion. This was reinforced by the detection of the 7 cytokines in three different myeloma cell lines with an especially high secretion of PDGF-AA. We conclude that specific cytokines in MM-plasmas, besides the well-known DKK1, inhibit the osteoblastic differentiation of MM- and HD-ASCs with a skewing towards adipocyte differentiation. Of note, this inhibition by the cytokines were also observed on HD-BM-MSCs suggesting that this could also be the case on myeloma-BM-MSCs. Legend to figure: Cytokine expression in MM, CR and HD-plasmas (A) Representative images of cytokine array blots probed with the plasma samples. The red boxes identify the cytokines significantly dysregulated in MM- as compared to HD- or CR-plasmas and further analyzed by ELISA. The blue boxes identified the cytokines similarly expressed in MM-/CR-/HD-plasmas. (B) Cytokine concentrations in the HD-plasmas (n=5), MM-plasmas (n=11) and CR-plasmas (n=8) were measured by ELISA. * p < 0.05, ** p < 0.01, *** p < 0.001, ns (not significant). Figure 1 Figure 1. Disclosures Delhommeau: Novartis: Consultancy; BMS: Consultancy; Celgene: Consultancy. Garderet: Celgene: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Takeda: Consultancy.


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