High Mobility Group A1 (HMGA1) Chromatin Remodeling Protein Mediates Crosstalk Between Acute Myeloid Leukemia Blasts & the Tumor Microenvironment

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3564-3564 ◽  
Author(s):  
Stuart A Rushworth ◽  
Lyubov Zaitseva ◽  
Lingling Xian ◽  
Kristian M Bowles ◽  
Linda M. S. Resar
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Lines ◽  
Chromatin Remodeling ◽  
High Mobility ◽  
Bone Marrow Microenvironment ◽  
High Mobility Group ◽  
Hematopoietic Stem ◽  
Knock Down ◽  
Acute Myeloid

Abstract Introduction: Acute myeloid leukemias (AMLs) are highly lethal hematologic malignancies that arise from diverse genetic abnormalities in hematopoietic progenitor cells. Unfortunately, most patients with AML will die of their disease due to failure of currently available cytotoxic chemotherapies. Accordingly, there is an urgent need to better understand the biologic interactions between AML blasts and signals from bone marrow stromal cells (BMSCs) within the niche that support their survival and protect them from exposure to chemotherapy. The high mobility group A1 (HMGA1) chromatin remodeling proteins are present at high levels during development and enriched in AML blasts, leukemic stem cells, diverse solid tumors, embryonic stem cells, and adult stem cells, such as hematopoietic stem cells (HSCs). HMGA1 proteins regulate gene expression by modulating chromatin structure and recruiting NF-κB and other transcription factor complexes to DNA. We discovered that HMGA1 acts as a potent oncogene in transgenic mouse and cultured cell models (Xu et. al, Cancer Research, 2004) by inducing stem cell transcriptional networks (Schuldenfrei et. al, BMC Genomics, 2011, Shah et. al, PLoS ONE, 2013). Here, we describe a novel role for HMGA1 in mediating crosstalk between AML blasts and BMSCs within the bone marrow microenvironment. Methods & Results: To investigate HMGA1 in regulating AML-niche signaling, we used potent lentiviruses to deliver short hairpin RNA and silence HMGA1 in AML blasts or BMSCs. We found that silencing HMGA1 rapidly halts proliferation and induces apoptotic cell death in 3 different AML cell lines. To determine how HMGA1 mediates survival in AML blasts, we assessed expression of pro-survival genes in AML cell lines and primary AML blasts, including those encoding NF-E2-related factor 2 (NRF2), cMYC, and the C-X-C chemokine receptor type 4 (CXCR4). CXCR4 is the receptor for stromal cell-derived factor 1 (SDF-1 or CXCL12), a growth factor secreted by BMSCs that also serves as a chemo-attractant for AML blasts or HSCs within the bone marrow microenvironment. We found that silencing HMGA1 represses expression of NRF2, cMYC, and CXCR4. This led us to hypothesize that HMGA1 regulates crosstalk between AML blasts and the leukemic cell niche via CXCR4 and SDF-1. To test this, we silenced HMGA1 in cultured AML cells and assessed migration in the presence of SDF-1. Strikingly, migration was significantly impaired in the AML cells with HMGA1 knock-down. Next, we silenced HMGA1 in primary, patient-derived BMSCs, which were co-cultured with primary AML blasts from the same patients to mimic the bone marrow microenvironment. We found that knock-down of HMGA1 in BMSCs also results in apoptosis in primary AML blasts. Conclusions: Together, our results demonstrate for the first time that HMGA1 mediates AML survival through cell-autonomous pathways in AML blasts and through non-cell-autonomous crosstalk from BMSCs within the bone marrow microenvironment. Studies are underway to determine if HMGA1 directly regulates expression of SDF-1 or other factors secreted by BMSCs within the hematopoietic niche. This knowledge should inform biologically rational strategies to enhance existing treatments and facilitate the design of novel therapies. Disclosures No relevant conflicts of interest to declare.

scholarly journals The leukemic stem cell niche: current concepts and therapeutic opportunities

Blood ◽  
2009 ◽  
Vol 114 (6) ◽  
pp. 1150-1157 ◽  
Author(s):  
Steven W. Lane ◽  
David T. Scadden ◽  
D. Gary Gilliland
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Bone Marrow Microenvironment ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Rational Development ◽  
Cell Niche ◽  
Acute Myeloid

Abstract The genetic events that contribute to the pathogenesis of acute myeloid leukemia are among the best characterized of all human malignancies. However, with notable exceptions such as acute promyelocytic leukemia, significant improvements in outcome based on these insights have not been forthcoming. Acute myeloid leukemia is a paradigm of cancer stem (or leukemia initiating) cells with hierarchy analogous to that seen in hematopoiesis. Normal hematopoiesis requires complex bidirectional interactions between the bone marrow microenvironment (or niche) and hematopoietic stem cells (HSCs). These interactions are critical for the maintenance of normal HSC quiescence and perturbations can influence HSC self-renewal. Leukemia stem cells (LSCs), which also possess limitless self-renewal, may hijack these homeostatic mechanisms, take refuge within the sanctuary of the niche during chemotherapy, and consequently contribute to eventual disease relapse. We will discuss the emerging evidence supporting the importance of the bone marrow microenvironment in LSC survival and consider the physiologic interactions of HSCs and the niche that inform our understanding of microenvironment support of LSCs. Finally, we will discuss approaches for the rational development of therapies that target the microenvironment.

scholarly journals The Role of the Bone Marrow Microenvironment in the Response to Infection

2020 ◽  
Vol 11 ◽  
Author(s):  
Courtney B. Johnson ◽  
Jizhou Zhang ◽  
Daniel Lucas
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Immune Cells ◽  
Critical Role ◽  
Primary Source ◽  
Bone Marrow Microenvironment ◽  
Future Research ◽  
Multipotent Stem Cells ◽  
Hematopoietic Stem

Hematopoiesis in the bone marrow (BM) is the primary source of immune cells. Hematopoiesis is regulated by a diverse cellular microenvironment that supports stepwise differentiation of multipotent stem cells and progenitors into mature blood cells. Blood cell production is not static and the bone marrow has evolved to sense and respond to infection by rapidly generating immune cells that are quickly released into the circulation to replenish those that are consumed in the periphery. Unfortunately, infection also has deleterious effects injuring hematopoietic stem cells (HSC), inefficient hematopoiesis, and remodeling and destruction of the microenvironment. Despite its central role in immunity, the role of the microenvironment in the response to infection has not been systematically investigated. Here we summarize the key experimental evidence demonstrating a critical role of the bone marrow microenvironment in orchestrating the bone marrow response to infection and discuss areas of future research.

scholarly journals 7-Ketocholesterol Promotes Oxiapoptophagy in Bone Marrow Mesenchymal Stem Cell from Patients with Acute Myeloid Leukemia

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 482 ◽  
Author(s):  
Jessica Liliane Paz ◽  
Debora Levy ◽  
Beatriz Araujo Oliveira ◽  
Thatiana Correia de Melo ◽  
Fabio Alessandro de Freitas ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cholesterol Oxidation ◽  
Specific Cell ◽  
Hematopoietic Stem ◽  
Shh Pathway ◽  
Number Of Cells ◽  
Acute Myeloid

7-Ketocholesterol (7-KC) is a cholesterol oxidation product with several biological functions. 7-KC has the capacity to cause cell death depending on the concentration and specific cell type. Mesenchymal stem cells (MSCs) are multipotent cells with the ability to differentiate into various types of cells, such as osteoblasts and adipocytes, among others. MSCs contribute to the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases, such as leukemia, to a yet unknown extent. Here, we describe the effect of 7-KC on the death of bone marrow MSCs from patients with acute myeloid leukemia (LMSCs). LMSCs were less susceptible to the death-promoting effect of 7-KC than other cell types. 7-KC exposure triggered the extrinsic pathway of apoptosis with an increase in activated caspase-8 and caspase-3 activity. Mechanisms other than caspase-dependent pathways were involved. 7-KC increased ROS generation by LMSCs, which was related to decreased cell viability. 7-KC also led to disruption of the cytoskeleton of LMSCs, increased the number of cells in S phase, and decreased the number of cells in the G1/S transition. Autophagosome accumulation was also observed. 7-KC downregulated the SHh protein in LMSCs but did not change the expression of SMO. In conclusion, oxiapoptophagy (OXIdative stress + APOPTOsis + autophagy) seems to be activated by 7-KC in LMSCs. More studies are needed to better understand the role of 7-KC in the death of LMSCs and the possible effects on the SHh pathway.

scholarly journals Gpr44 Mediates the Selenium-Dependent Anti-Leukemic Effect in Acute Myeloid Leukemia

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1835-1835
Author(s):  
Fenghua Qian ◽  
Fenghua Qian ◽  
Diwakar Tukaramrao ◽  
Jiayan Zhou ◽  
Nicole Palmiero ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Murine Model ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Pparγ Agonist ◽  
Acute Myeloid

Abstract Objectives The relapse of acute myeloid leukemia (AML) remains a significant concern due to persistent leukemia stem cells (LSCs) that are not targeted by existing therapies. LSCs show sensitivity to endogenous cyclopentenone prostaglandin J (CyPG) metabolites that are increased by dietary trace element selenium (Se), which is significantly decreased in AML patients. We investigated the anti-leukemic effect of Se supplementation in AML via mechanisms involving the activation of the membrane-bound G-protein coupled receptor 44 (Gpr44) and the intracellular receptor, peroxisome proliferator-activated receptor gamma (PPARγ), by endogenous CyPGs. Methods A murine model of AML generated by transplantation of hematopoietic stem cells (HSCs- WT or Gpr44−/−) expressing human MLL-AF9 fusion oncoprotein, in the following experiments: To investigate the effect of Se supplementation on the outcome of AML, donor mice were maintained on either Se-adequate (Se-A; 0.08–0.1 ppm Se) or Se-supplemented (Se-S; 0.4 ppm Se) diets. Complete cell counts in peripheral blood were analyzed by hemavet. LSCs in bone marrow and spleen were analyzed by flow cytometry. To determine the role of Gpr44 activation in AML, mice were treated with Gpr44 agonists, CyPGs. LSCs in bone marrow and spleen were analyzed. Mice transplanted with Gpr44−/- AML cells were compared with mice transplanted with wild type AML cells and the progression of the disease was followed as above. To determine the role of PPARγ activation in AML, PPARγ agonist (Rosiglitazone, 6 mg/kg, i.p, 14 d) and antagonist (GW9662, 1 mg/kg, i.p. once every other day, 7 injections) were applied to Se-S mice transplanted with Gpr44−/- AML cells and disease progression was followed. Results Se supplementation at supraphysiological levels alleviated the disease via the elimination of LSCs in a murine model of AML. CyPGs induced by Se supplementation mediate the apoptosis in LSCs via the activation of Gpr44 and PPARγ. Conclusions Endogenous CyPGs produced upon supplementation with Se at supraphysiological levels improved the outcome of AML by targeting LSCs to apoptosis via the activation of two receptors, Gpr44 and PPARg. Funding Sources NIH DK 07,7152; CA 175,576; CA 162,665. Office of Dietary Supplements, USDA Hatch funds PEN04605, Accession # 1,010,021 (KSP, RFP).

Lentivirus-based vectors transduce mouse hematopoietic stem cells with similar efficiency to Moloney murine leukemia virus–based vectors

Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3385-3391 ◽  
Author(s):  
Stephane Barrette ◽  
Janet L. Douglas ◽  
Nancy E. Seidel ◽  
David M. Bodine
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Lines ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Lentivirus Vector ◽  
Hematopoietic Stem ◽  
Lentivirus Vectors ◽  
Murine Leukemia

Abstract The low levels of transduction of human hematopoietic stem cells (HSCs) with Moloney murine leukemia virus (MLV) vectors have been an obstacle to gene therapy for hematopoietic diseases. It has been demonstrated that lentivirus vectors are more efficient than MLV vectors at transducing nondividing cell lines as well as human CD34+ cells and severe combined immunodeficiency disease repopulating cells. We compared transduction of cell lines and Lin− bone marrow cells, using a vesicular stomatitis virus G (VSV-G)-pseudotyped lentivirus or MLV vectors carrying a green fluorescent protein marker gene. As predicted, the lentivirus vector was more efficient at transducing mouse and human growth-inhibited cell lines. The transduction of mouse HSC by lentivirus vectors was compared directly to MLV vectors in a co-transduction assay. In this assay, transduction by ecotropic MLV is a positive internal control for downstream steps in retrovirus transduction, including cell division. Both the VSV-G lentivirus and MLV vectors transduced mouse HSCs maintained in cytokine-free medium at very low frequency, as did the ecotropic control. The lentivirus vector and the MLV vector were equally efficient at transducing bone marrow HSCs cultured in interleukin 3 (IL-3), IL-6, and stem cell factor for 96 hours. In conclusion, although lentivirus vectors are able to transduce growth-inhibited cell lines, the cell cycle status of HSCs render them resistant to lentivirus-mediated transduction, and it is hypothesized that entry into cycle, not necessarily division, may be a requirement for efficient lentivirus-mediated transduction.

scholarly journals Rb Regulates Interactions between Hematopoietic Stem Cells and Their Bone Marrow Microenvironment

Cell ◽  
2007 ◽  
Vol 129 (6) ◽  
pp. 1081-1095 ◽  
Author(s):  
Carl R. Walkley ◽  
Jeremy M. Shea ◽  
Natalie A. Sims ◽  
Louise E. Purton ◽  
Stuart H. Orkin
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Bone Marrow Microenvironment ◽  
Hematopoietic Stem

Mesenchymal Stem Cells Self-Regulate Their Differentiation To Maintain the Bone Marrow Stromal System.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2335-2335
Author(s):  
Iekuni Oh ◽  
Akira Miyazato ◽  
Hiroyuki Mano ◽  
Tadashi Nagai ◽  
Kazuo Muroi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Expression Profiles ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Steady Level

Abstract Mesenchymal stem cells (MSCs) account for a very small population in bone marrow stroma as a non-hematopoietic component with multipotency of differentiation into adipocytes, osteocytes and chondrocytes. MSC-derived cells are known to have hematopoiesis-supporting and immunomodulatory abilities. Although clinical applications of MSCs have already been conducted for the suppression of graft versus host disease in allogeneic stem cell transplantation and for tissue regeneration, underlying mechanisms of the biological events are still obscure. Previously, we established a differentiation model of MSCs using a mouse embryo fibroblast cell line, C3H10T1/2 (10T1/2) (Nishikawa M et al: Blood81:1184–1192, 1993). Preadipocyte (A54) and myoblast (M1601) cell lines were cloned by treatment with 5-azacytidine. A54 cells and M1601 cells can terminally differentiate into adipocytes and myotubes, respectively, under appropriate conditions, while parent 10T1/2 cells remain undifferentiated. Moreover, A54 cells show a higher ability to support hematopoiesis compared with the other cell lines. In this study, we analyzed gene expression profiles of the three cell lines by using DNA microarray and real-time PCR to investigate molecular mechanisms for maintaining immaturity of parent 10T1/2 cells. In A54 cells, 202 genes were up-regulated, including those encoding critical factors for hematopoiesis such as SCF, Angiopoietin-1, and SDF-1 as well as genes known to be involved in adipocyte differentiation such as C/EBPα, C/EBPδ and PPAR-γ genes. These data are consistent with the hematopoiesis-supporting ability of A54 cells. During adipocyte differentiation, SCF and SDF-1 expression levels decreased in A54 cells while C/EBPα expression showed a steady level. Recently, osteoblasts have been reported to play crucial roles in “niche” for self-renewal of hematopoietic stem cells. Our results also implicate that precursor cells of non-hematopoietic components may have important roles for hematopoiesis in bone marrow. Meanwhile, in parent 10T1/2 cells, 105 genes were up-regulated, including CD90, Dlk, Wnt5α and many functionally unknown genes. Although C/EBPα expression was induced in 10T1/2 cells without differentiation under the adipocyte differentiation conditions, CD90 expression decreased, Dlk showed a steady level and Wnt5α was up-regulated. Assuming that some regulatory mechanisms are needed to keep an immature state of parent 10T1/2 cells even under the differentiation-inducible conditions, we performed following experiments. First, enforced Dlk expression in A54 cells did not inhibit terminal differentiation to adipocytes under the differentiation conditions. Second, when we cultured A54 cells in the conditioned media of parent 10T1/2 cells under the differentiation-inducible conditions, adipocyte differentiation was inhibited, suggesting that 10T1/2 cells produce some soluble molecules that can inhibit adipocyte differentiation. Since Wnt family is known to be involved in the regulation of self-renewal of several stem cells, Wnt5α may be one candidate for maintenance of “stemness” of MSCs. Taken together, the data of 10T1/2 cells suggest that MSCs can self-regulate their differentiation in the bone marrow stromal system. This concept may be important to investigate the fatty change of bone marrow in aging and in aplastic anemia.

Human Hematopoietic Stem Cells and Leukemic Cells Form Cadherin-Catenin Based Junctional Complexes with Mesenchymal Stromal Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1367-1367 ◽  
Author(s):  
Patrick Wuchter ◽  
Rainer Saffrich ◽  
Wolfgang Wagner ◽  
Frederik Wein ◽  
Mario Stephan Schubert ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Leukemia Cells ◽  
Feeder Layer ◽  
Hematopoietic Stem ◽  
Knock Down ◽  
Junctional Complexes

Abstract The interaction between human hematopoietic stem cells (HSC) and their niche plays a key role in regulating maintenance of “stemness” and differentiation. We have demonstrated that a feeder layer of human mesenchymal stromal cells (MSC) can serve as a surrogate model for the niche for human HSC. We could also show, MSC are intimately connected to one another by a novel kind of adhering junction, consisting of villiformto-vermiform cell projections (processus adhaerentes). With this background, we have analyzed the intercellular junctional complexes between HSC and MSC. In comparison, we also studied the cell-cell contacts between leukemia cells (LC) and MSC. MSC were derived from bone marrow aspirates from healthy voluntary donors. HSC were isolated from umbilical cord blood. Leukemia cells that were CD34+ were obtained from bone marrow aspirates from patients suffering from acute myeloid leukemia at the time point of initial diagnosis. After 24–48 hours of co-cultivation, we stained the cellular contacts with a panel of antibodies specific for various components of tight, gap and adherens junctions. Using advanced confocal laser scanning microscopy in combination with deconvolution and volume rendering software, we were able to produce 3D-images of intercellular junctions between HSC/MSC as well as between LC/MSC. To examine the specific function of N-cadherin, we analyzed the effect of siRNA knock down of N-cadherin in MSC upon co-cultures of HSC and MSC. Intercellular connections between HSC and MSC are mainly characterized by podia formation of the HSC linking to the adjacent MSC. At the intimate contact zone to the MSC, we have identified the cytoplasmic plaque proteins alpha- and beta-catenin, co-localized with the transmembrane glycoprotein N-cadherin. Additionally, we compared these findings with a similar setting consisting of human LC co-cultured with feeder-layer of MSC. Our results demonstrated that in comparison to HSC, the proportion of leukemia cells adherent to the feeder-layer is significantly lower and podia formation is less frequent (ratio 1:3). However, the mechanism of adhesion through cadherin-catenin-complex has remained the same. At a functional level, we found that siRNA knock down of N-cadherin in MSC resulted in decreased adhesion of HSC to MSC and in a reduction of cell divisions of HSC. These results confirm that direct cellular contact via N-cadherin-based junctions is essential for homing and adhesion of HSC to the cellular niche and subsequently for the regulation of self-renewal versus differentiation in HSC.

Mtss1 Suppresses BCR-ABL Induced Cell Migration and Is Downregulated in CML Stem Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1077-1077
Author(s):  
Mirle Schemionek ◽  
Shuchi Agrawal ◽  
Martin Stehling ◽  
Daniel G. Tenen ◽  
Ashley Hamilton ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Migration ◽  
Tumor Suppressor ◽  
Transgenic Mice ◽  
Cell Lines ◽  
Actin Binding ◽  
Bone Marrow Niche ◽  
Hematopoietic Stem ◽  
Retroviral Transduction

Abstract Migration and adhesion properties of hematopoietic stem cells (HSC) are disrupted in chronic myeloid leukemia (CML). Egression of these cells from the bone marrow is associated with cytoskeletal changes including actin remodeling. In a microarray screen of differentially regulated genes in HSC from BCR-ABL positive transgenic mice, we found downregulation of multiple genes involved in actin-associated changes of cell structure, adhesion, and migration (i.e. intersectin-1, cortactin, Mtss1, synaptopodin, and Gem GTPase). Mtss1 was further studied since it has been described to be a binding partner of Rac, which is essential for BCR-ABL mediated transformation, and a potential tumor suppressor. Using quanitative RT-PCR, Mtss1 downregulation (6-fold) was confirmed in HSC and unfractionated bone marrow and spleen cells from SCLtTA/BCR-ABL transgenic mice after 3 weeks of BCR-ABL induction as well as in human BCR-ABL positive cell lines. Treatment of BCR-ABL positive (32D/BCR-ABL, K562, KYO-1) but not BCR-ABL negative (32D, U937) cell lines with 5μ M Imatinib led to upregulation of Mtss1 mRNA (5- to 10-fold) and protein, suggesting that downregulation of Mtss1 is dependent on BCR-ABL kinase activity. Retroviral transduction of Mtss1 into 32D/BCR-ABL cells almost completely inhibited BCR-ABL induced cell motility of individual cells seeded on murine bone marrow stromal cells in time-lapse video experiments over the course of two hours. Interestingly, we found that retroviral transduction of Mtss1 into 32D/BCR-ABL cells completely suppressed migration of these cells to extra-hematopoietic sites in vivo upon intravenous transplantation into syngeneic C3H mice. Moreover, when Mtss1-transduced cells were injected subcutaneously, the size of the tumors was significantly decreased as compared to empty vector-transduced 32D/BCR-ABL cells (p<0.05), confirming that Mtss1 may be a tumor suppressor. These results demonstrate that Mtss1 antagonizes BCR-ABL induced cell migration and is downregulated by BCR-ABL in CML stem cells, suggesting that downregulation of Mtss1 and other cytoskeletal adaptor proteins may be required for egression of CML stem cells from the bone marrow niche. Since the same Mtss1 protein domain is responsible for both Rac and actin binding, Mtss1 may interfere with Rac function and thereby inhibit the effects of Rac on migration and cytoskeletal dynamics of HSC.

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