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Sample records for hematopoietic microenvironment origin

  1. Hematopoietic microenvironment. Origin, lineage, and transplantability of the stromal cells in long-term bone marrow cultures from chimeric mice

    SciTech Connect

    Perkins, S.; Fleischman, R.A.

    1988-04-01

    Studies of bone marrow transplant patients have suggested that the stromal cells of the in vitro hematopoietic microenvironment are transplantable into conditioned recipients. Moreover, in patients with myeloproliferative disorders, all of the stromal cells, which include presumptive endothelial cells, appear to be derived from hematopoietic precursors. To confirm these findings, we have constructed two chimeric mouse models: (a) traditional radiation chimeras, and (b) fetal chimeras, produced by placental injection of bone marrow into genetically anemic Wx/Wv fetuses, a technique that essentially precludes engraftment of nonhematopoietic cells. Using two-color indirect immunofluorescence, the stromal cells in long-term bone marrow culture derived from these chimeras were analyzed for donor or host origin by strain-specific H-2 antigens, and for cell lineage by a variety of other specific markers. 75-95% of the stromal cells were shown to be hematopoietic cells of the monocyte-macrophage lineage, based upon donor origin, phagocytosis, and expression of specific hematopoietic surface antigens. The remaining 5-25% of the stromal cells were exclusively host in origin. Apart from occasional fat cells, these cells uniformly expressed collagen type IV, laminin, and a surface antigen associated with endothelial cells. Since these endothelial-like cells are not transplantable into radiation or fetal chimeras, they are not derived from hematopoietic stem cells. The contrast between our findings and human studies suggests either unexpected species differences in the origin of stromal lineages or limitations in the previous methodology used to detect nonhematopoietic stromal cells.

  2. [Hematopoietic microenvironment: cellular and extracellular matrix elements].

    PubMed

    Minguell, J J; Fernández, M; Tetas, M; Martínez, J; Bruzzone, M; Rodríguez, J P

    1988-06-01

    In bone marrow, cellular stroma together with extracellular matrix (EM) provide an adequate microenvironment for the proliferation and differentiation of hemopoietic progenitor cells. In this article we describe studies on the cell characteristics of a main stromal phenotype, a fibroblast-like cell and its ability to produce in vitro EM components. Comparative studies were performed in fibroblast cultures derived from normal and acute lymphoblastic leukemic (ALL) bone marrow. The grow characteristics of fibroblasts from ALL marrow as well as its capacity to synthetize collagen, fibronectin and GAGs are impaired when compared to fibroblast from normal marrow. Thus, in ALL the impaired production of EM biomolecules by a transient damaged population of stromal cells, may contribute to the development of a defective microenvironment for hemopoiesis. PMID:3154858

  3. Minireview: Complexity of Hematopoietic Stem Cell Regulation in the Bone Marrow Microenvironment

    PubMed Central

    Hoffman, Corey M.

    2014-01-01

    Hematopoiesis in vertebrates is sustained over the duration of an organism's lifetime due to strict regulation of the highly hierarchical hematopoietic system, where a few immature hematopoietic stem cells (HSCs) continuously regenerate the entire blood supply, which is constantly being replaced. Although HSCs self-regulate through cell-autonomous processes, they also receive a variety of signals from their microenvironment or niche. Within the microenvironment, HSCs are regulated through both cell-cell interactions and secreted signals, including hormones. HSCs at the apex of the blood supply integrate these signals to produce progeny to support hematopoiesis while simultaneously maintaining a stem cell pool. In the past 10 years, advances in genetic models and flow cytometry have provided the tools to test how the microenvironment regulates HSCs. This review is organized in 3 main parts and will focus on cellular components of the HSC niche that are potential targets for hormonal signals, then review critical regulatory signals in the HSC niche, and finally highlight the emerging role of hormonal and paracrine signals in the bone marrow. PMID:25083740

  4. In vivo hematopoietic Myc activation directs a transcriptional signature in endothelial cells within the bone marrow microenvironment.

    PubMed

    Franke, Katharina; Vilne, Baiba; Prazeres da Costa, Olivia; Rudelius, Martina; Peschel, Christian; Oostendorp, Robert A J; Keller, Ulrich

    2015-09-01

    Cancer pathogenesis involves tumor-intrinsic genomic aberrations and tumor-cell extrinsic mechanisms such as failure of immunosurveillance and structural and functional changes in the microenvironment. Using Myc as a model oncogene we established a conditional mouse bone marrow transduction/transplantation model where the conditional activation of the oncoprotein Myc expressed in the hematopoietic system could be assessed for influencing the host microenvironment. Constitutive ectopic expression of Myc resulted in rapid onset of a lethal myeloproliferative disorder with a median survival of 21 days. In contrast, brief 4-day Myc activation by means of the estrogen receptor (ER) agonist tamoxifen did not result in gross changes in the percentage/frequency of hematopoietic lineages or hematopoietic stem/ progenitor cell (HSPC) subsets, nor did Myc activation significantly change the composition of the non-hematopoietic microenvironment defined by phenotyping for CD31, ALCAM, and Sca-1 expression. Transcriptome analysis of endothelial CD45- Ter119- cells from tamoxifen-treated MycER bone marrow graft recipients revealed a gene expression signature characterized by specific changes in the Rho subfamily pathway members, in the transcription-translation-machinery and in angiogenesis. In conclusion, intra-hematopoietic Myc activation results in significant transcriptome alterations that can be attributed to oncogene-induced signals from hematopoietic cells towards the microenvironment, e. g. endothelial cells, supporting the idea that even pre-leukemic HSPC highjack components of the niche which then could protect and support the cancer-initiating population. PMID:26308666

  5. Bone Marrow Cells in Acute Lymphoblastic Leukemia Create a Proinflammatory Microenvironment Influencing Normal Hematopoietic Differentiation Fates

    PubMed Central

    Vilchis-Ordoñez, Armando; Contreras-Quiroz, Adriana; Dorantes-Acosta, Elisa; Reyes-López, Alfonso; Quintela-Nuñez del Prado, Henry Martin; Venegas-Vázquez, Jorge; Mayani, Hector; Ortiz-Navarrete, Vianney; López-Martínez, Briceida; Pelayo, Rosana

    2015-01-01

    B-cell acute lymphoblastic leukemia (B-ALL) is a serious public health problem in the pediatric population worldwide, contributing to 85% of deaths from childhood cancers. Understanding the biology of the disease is crucial for its clinical management and the development of therapeutic strategies. In line with that observed in other malignancies, chronic inflammation may contribute to a tumor microenvironment resulting in the damage of normal processes, concomitant to development and maintenance of neoplastic cells. We report here that hematopoietic cells from bone marrow B-ALL have the ability to produce proinflammatory and growth factors, including TNFα, IL-1β, IL-12, and GM-CSF that stimulate proliferation and differentiation of normal stem and progenitor cells. Our findings suggest an apparently distinct CD13+CD33+ population of leukemic cells contributing to a proinflammatory microenvironment that may be detrimental to long-term normal hematopoiesis within B-ALL bone marrow. PMID:26090405

  6. Modeling the Pro-inflammatory Tumor Microenvironment in Acute Lymphoblastic Leukemia Predicts a Breakdown of Hematopoietic-Mesenchymal Communication Networks

    PubMed Central

    Enciso, Jennifer; Mayani, Hector; Mendoza, Luis; Pelayo, Rosana

    2016-01-01

    Lineage fate decisions of hematopoietic cells depend on intrinsic factors and extrinsic signals provided by the bone marrow microenvironment, where they reside. Abnormalities in composition and function of hematopoietic niches have been proposed as key contributors of acute lymphoblastic leukemia (ALL) progression. Our previous experimental findings strongly suggest that pro-inflammatory cues contribute to mesenchymal niche abnormalities that result in maintenance of ALL precursor cells at the expense of normal hematopoiesis. Here, we propose a molecular regulatory network interconnecting the major communication pathways between hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs) within the BM. Dynamical analysis of the network as a Boolean model reveals two stationary states that can be interpreted as the intercellular contact status. Furthermore, simulations describe the molecular patterns observed during experimental proliferation and activation. Importantly, our model predicts instability in the CXCR4/CXCL12 and VLA4/VCAM1 interactions following microenvironmental perturbation due by temporal signaling from Toll like receptors (TLRs) ligation. Therefore, aberrant expression of NF-κB induced by intrinsic or extrinsic factors may contribute to create a tumor microenvironment where a negative feedback loop inhibiting CXCR4/CXCL12 and VLA4/VCAM1 cellular communication axes allows for the maintenance of malignant cells. PMID:27594840

  7. Modeling the Pro-inflammatory Tumor Microenvironment in Acute Lymphoblastic Leukemia Predicts a Breakdown of Hematopoietic-Mesenchymal Communication Networks.

    PubMed

    Enciso, Jennifer; Mayani, Hector; Mendoza, Luis; Pelayo, Rosana

    2016-01-01

    Lineage fate decisions of hematopoietic cells depend on intrinsic factors and extrinsic signals provided by the bone marrow microenvironment, where they reside. Abnormalities in composition and function of hematopoietic niches have been proposed as key contributors of acute lymphoblastic leukemia (ALL) progression. Our previous experimental findings strongly suggest that pro-inflammatory cues contribute to mesenchymal niche abnormalities that result in maintenance of ALL precursor cells at the expense of normal hematopoiesis. Here, we propose a molecular regulatory network interconnecting the major communication pathways between hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs) within the BM. Dynamical analysis of the network as a Boolean model reveals two stationary states that can be interpreted as the intercellular contact status. Furthermore, simulations describe the molecular patterns observed during experimental proliferation and activation. Importantly, our model predicts instability in the CXCR4/CXCL12 and VLA4/VCAM1 interactions following microenvironmental perturbation due by temporal signaling from Toll like receptors (TLRs) ligation. Therefore, aberrant expression of NF-κB induced by intrinsic or extrinsic factors may contribute to create a tumor microenvironment where a negative feedback loop inhibiting CXCR4/CXCL12 and VLA4/VCAM1 cellular communication axes allows for the maintenance of malignant cells. PMID:27594840

  8. Quantitative Imaging of Hematopoietic Stem and Progenitor Cell localization and hypoxic status in the Bone Marrow microenvironment

    PubMed Central

    Nombela-Arrieta, César; Pivarnik, Gregory; Winkel, Beatrice; Canty, Kimberly J.; Harley, Brendan; Mahoney, John E.; Park, Shin-Young; Lu, Jiayun; Protopopov, Alexei; Silberstein, Leslie E.

    2014-01-01

    The existence of a hematopoietic stem cell niche as a spatially confined regulatory entity relies on the notion that hematopoietic stem and progenitor cells (HSPCs) are strategically positioned in unique bone marrow (BM) microenvironments with defined anatomical and functional features. Here, we employ a powerful imaging cytometry platform to perform a comprehensive quantitative analysis of HSPC distribution in BM cavities of femoral bones. We find that HSPCs preferentially localize in endosteal zones, where the majority closely interacts with sinusoidal and non-sinusoidal BM microvessels, which form a distinctive circulatory system. In situ tissue analysis reveals that HSPCs exhibit a hypoxic profile, defined by strong retention of pimonidazole and expression of HIF-1α, regardless of localization throughout the BM, adjacency to vascular structures or cell cycle status. These studies argue that the characteristic hypoxic state of HSPCs is not solely the result of a minimally oxygenated niche but may be partially regulated by cell-specific mechanisms. PMID:23624405

  9. The construction of an in vitro three-dimensional hematopoietic microenvironment for mouse bone marrow cells employing porous carriers.

    PubMed

    Tomimori, Y; Takagi, M; Yoshida, T

    2000-10-01

    Spatial development of mouse bone marrow cellsemploying porous carriers was investigated in order todesign a bioreactor with a three-dimensionalhematopoietic microenvironment. Three types of porouscarriers were used for examining the spatialdevelopment of anchorage-dependent primary stromalcells as feeder cells. Stromal cells were found tospread well at a high density on a polyester nonwovendisc carrier (Fibra cel (FC)) under a scanningelectron microscope, while cells on porous cellulosebeads (Microcube (MC), 500 mum pore diameter)spread at a low density; cells on another type ofcellulose porous beads (CPB, 100 mum pore diameter)were globular. Mouse bone marrow cells wereinoculated to dishes containing three types of porouscarriers which shared more than 30% of the bottomsurface in a dish. The concentration of stromal cellsin the well containing FC was lower than that on theother two carriers. However, the weekly output oftotal hematopoietic cell (suspension cells) increasedbetween day 21 and 28 in the culture using FC while itdecreased monotonously in the cultures by use of theother two carriers. The proportion of progenitorcells (BFU-E, CFU-GM) in the total hematopoietic cellpopulation, after showing an initial decrease,increased after 1 week in the culture using FC whilethe proportion decreased monotonously to zero in thecultures using MC and CPB. PMID:19003386

  10. Studies on the organization and regeneration of bone marrow: origin, growth, and differentiation of endocloned hematopoietic colonies

    SciTech Connect

    Lambertsen, R.H.; Weiss, L.

    1983-04-01

    Hematopoietic colonies were studied by light microscopy in the marrow of alternate fraction x-irradiated mice (C576J/B1) to investigate the microenvironmental organization of marrow and identify early hematopoietic cell-stromal cell interactions. Undifferentiated colonies (UC) were detected at 3 days postirradiation, showed a marked predilection for bone surfaces, and disappeared as differentiated colonies developed. Some UC occurred along marrow arteries. Neutrophilic granulocyte colonies (GC) occurred in all areas at 3 days but grew rapidly only subosteally. Few eosinophilic colonies (GCe) occurred. Erythrocytic colonies (EC) appeared at 4 days as dispersed populations of motile cells within a localized area of marrow; these tended to proliferate initially in intermediate and central marrow zones. Macrophage colonies (M phi C) of two ''subtypes'' were detected, peaking in relative frequency at 4 days. These appeared active in stromal repair and monocytopoiesis. Megakaryocyte colonies (MC) originated along bone and differentiated away from bone. These results were interpreted as evidence that in x-irradiated marrow: (1) hematopoietic microenvironments (HMs) for stem-cell proliferation and commitment to differentiation, with the possible exception of HMs determining erythroid differentiation, occur in endosteal and periarterial regions; (2) a proliferative and/or chemotactic stimulus to erythroid progenitors exists in intermediate and central marrow regions; and (3) some subosteal regions may exclude erythropoiesis, or preferentially support nonerythroid differentiation. Elaborate associations occurred between macrophages and early UC, GC, and EC, but not MC hematopoietic cells. UC and GC often associated with osteoclasts. Reticular and other fibroblastic cells associated with the cells of all colony types.

  11. [Origin of Hematopoietic Stem Cells in Bone Marrow--Endothelial to Hematopoietic Transition (EHT)?].

    PubMed

    Wang, Fen; Yuan, Yan; Chen, Tong

    2015-06-01

    In contrast to primitive hematopoiesis, during embryonic definitive hematopoiesis, it has been demonstrated that multilineage hematopoietic stem/progenitor cells (HSPCs) arise from hemogenic endothelium, and the endothelial to hematopoietic transition (EHT) exists within the yolk sac, placenta, AGM, mouse head vascular and extraembryonic vessels. However, whether hemogenic endothelial cells contribute to blood cell development at other sites of definitive hematopoiesis, including fetal liver and bone marrow, remains largely unknown. Recently, more and more researches showed that hematopoiesis within bone marrow had a close relationship with vascular endothelium development, too. This review summarizes the mechanism of EHT during embryo development, and discuss whether EHT exists in adult hematopoiesis. PMID:26117052

  12. Specially modified stromal and immune microenvironment in injected bone marrow following intrabone transplantation facilitates allogeneic hematopoietic stem cell engraftment.

    PubMed

    Chen, Chen; Su, Yingjun; Chen, Jianwu; Song, Yajuan; Zhuang, Ran; Xiao, Bo; Guo, Shuzhong

    2016-07-01

    For allogeneic hematopoietic stem cell transplantation (HSCT), the first key step is the engraftment of hematopoietic stem cells (HSCs) across the major histocompatibility complex (MHC) barrier. Intrabone bone marrow transplantation (IBBMT) could replace more recipient stromal cells with donor cells and facilitate allogeneic organ transplantation compared with the conventional intravenous approach. However, it remains unknown whether and how IBBMT reconstructs the immune microenvironment for allogeneic HSCs. We explored where the BM microenvironment changes by determining BM stromal cell chimerism and measuring the change in CXCL-12 expression and regulatory T cells in recipient BM. We found that most stromal cells were replaced by allogeneic cells in the injected BM, with higher expression of immune regulatory cytokines (interleukin-10) compared with the contralateral BM and the intravenous group BM. This difference was independent of injury caused by intrabone injection. Consistent with the microenvironment modification, the allogeneic the engraftment rate and reconstitution capacity of HSCs were enhanced in the injected BM compared with the contralateral BM and intravenous group BM. Surgical removal of the injected bone at 7 days rather than 21 days reduced the levels of allogeneic granulocytes and HSCs in the peripheral blood. In conclusion, IBBMT specially modifies stromal cells in the injected BM which provide immune protective cues that improve the engraftment of allogeneic HSCs in an early period. PMID:27090963

  13. Increased Type 1 Immune Response in the Bone Marrow Immune Microenvironment of Patients with Poor Graft Function after Allogeneic Hematopoietic Stem Cell Transplantation.

    PubMed

    Wang, Yu-Tong; Kong, Yuan; Song, Yang; Han, Wei; Zhang, Yuan-Yuan; Zhang, Xiao-Hui; Chang, Ying-Jun; Jiang, Zheng-Fan; Huang, Xiao-Jun

    2016-08-01

    Poor graft function (PGF) is a severe complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The question of whether the bone marrow (BM) immune microenvironment is involved in the pathogenesis of PGF remains unresolved. In total, 10 patients with PGF, 30 matched patients with good graft function after allo-HSCT, and 15 healthy donors were enrolled in this nested case-control study. The Th1, Th2, Tc1, Tc2, and active phenotypes were analyzed by flow cytometry. IFN-γ and IL-4 levels in BM plasma were evaluated using cytometric beads assay. Relative to other subjects, patients with PGF had significantly higher proportions of stimulated CD4(+) and CD8(+) T cells that produced IFN-γ (Th1 and Tc1 cells) but notably decreased proportions of IL-4-producing T cells (Th2 and Tc2 cells), resulting in a shift of the IFN-γ/IL-4 ratio towards a type 1 response and an elevated percentage of activated CD8(+) T cells. Changes in IFN-γ and IL-4 levels in BM plasma were consistent with the cellular results. Our results suggest that dysregulated T cell responses may contribute to the occurrence of PGF after HSCT. PMID:27131864

  14. Cell of origin and microenvironment contribution for NF1-associated dermal neurofibromas

    PubMed Central

    Le, Lu Q.; Shipman, Tracey; Burns, Dennis K.; Parada, Luis F.

    2009-01-01

    SUMMARY The tumor predisposition disorder Neurofibromatosis type I (NF1) is one of the most common genetic disorders of the nervous system. It is caused by mutation in the Nf1 tumor suppressor gene, which encodes a GTPase Activating Protein (GAP) that negatively regulates p21-RAS. The development of malignant nerve tumors and neurofibromas, the most frequent tumors in NF1, is a serious complication of the disease. However, little is known about the molecular mechanisms mediating the initiation and progression of these complex tumors, as well as the identity of the specific cell type that gives rise to dermal or cutaneous neurofibromas. In this study, we identify a population of stem/progenitor cells residing in the dermis termed Skin Derived Precursors (SKPs) that, through loss of Nf1, form neurofibromas. We propose that SKPs, or their derivatives, are the cell of origin of dermal neurofibroma. We also provide evidence that additional signals from the non-neoplastic cells in the tumor microenvironment play essential roles in neurofibromagenesis. PMID:19427294

  15. Hematopoietic Stem Cell Origin of BRAFV600E Mutations in Hairy Cell Leukemia

    PubMed Central

    Chung, Young Rock; Lito, Piro; Teruya-Feldstein, Julie; Hu, Wenhuo; Beguelin, Wendy; Monette, Sebastien; Duy, Cihangir; Rampal, Raajit; Telis, Leon; Patel, Minal; Kim, Min Kyung; Huberman, Kety; Bouvier, Nancy; Berger, Michael F.; Melnick, Ari M.; Rosen, Neal; Tallman, Martin S.

    2014-01-01

    Hairy cell leukemia (HCL) is a chronic lymphoproliferative disorder characterized by somatic BRAFV600E mutations. The malignant cell in HCL has immunophenotypic features of a mature B cell, but no normal counterpart along the continuum of developing B lymphocytes has been delineated as the cell of origin. We find that the BRAFV600E mutation is present in hematopoietic stem cells (HSCs) in HCL patients, and that these patients exhibit marked alterations in hematopoietic stem/progenitor cell (HSPC) frequencies. Quantitative sequencing analysis revealed a mean BRAFV600E-mutant allele frequency of 4.97% in HSCs from HCL patients. Moreover, transplantation of BRAFV600E-mutant HSCs from an HCL patient into immunodeficient mice resulted in stable engraftment of BRAFV600E-mutant human hematopoietic cells, revealing the functional self-renewal capacity of HCL HSCs. Consistent with the human genetic data, expression of BRafV600E in murine HSPCs resulted in a lethal hematopoietic disorder characterized by splenomegaly, anemia, thrombocytopenia, increased circulating soluble CD25, and increased clonogenic capacity of B lineage cells—all classic features of human HCL. In contrast, restricting expression of BRafV600E to the mature B cell compartment did not result in disease. Treatment of HCL patients with vemurafenib, an inhibitor of mutated BRAF, resulted in normalization of HSPC frequencies and increased myeloid and erythroid output from HSPCs. These findings link the pathogenesis of HCL to somatic mutations that arise in HSPCs and further suggest that chronic lymphoid malignancies may be initiated by aberrant HSCs. PMID:24871132

  16. Reactive Oxygen Species Regulate Hematopoietic Stem Cell Self-Renewal, Migration and Development, As Well As Their Bone Marrow Microenvironment

    PubMed Central

    Ludin, Aya; Gur-Cohen, Shiri; Golan, Karin; Kaufmann, Kerstin B.; Itkin, Tomer; Medaglia, Chiara; Lu, Xin-Jiang; Ledergor, Guy; Kollet, Orit

    2014-01-01

    Abstract Significance: Blood forming, hematopoietic stem cells (HSCs) mostly reside in the bone marrow in a quiescent, nonmotile state via adhesion interactions with stromal cells and macrophages. Quiescent, proliferating, and differentiating stem cells have different metabolism, and accordingly different amounts of intracellular reactive oxygen species (ROS). Importantly, ROS is not just a byproduct of metabolism, but also plays a role in stem cell state and function. Recent Advances: ROS levels are dynamic and reversibly dictate enhanced cycling and myeloid bias in ROShigh short-term repopulating stem cells, and ROSlow quiescent long-term repopulating stem cells. Low levels of ROS, regulated by intrinsic factors such as cell respiration or nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) activity, or extrinsic factors such as stem cell factor or prostaglandin E2 are required for maintaining stem cell self-renewal. High ROS levels, due to stress and inflammation, induce stem cell differentiation and enhanced motility. Critical Issues: Stem cells need to be protected from high ROS levels to avoid stem cell exhaustion, insufficient host immunity, and leukemic transformation that may occur during chronic inflammation. However, continuous low ROS production will lead to lack of stem cell function and opportunistic infections. Ultimately, balanced ROS levels are crucial for maintaining the small stem cell pool and host immunity, both in homeostasis and during stress situations. Future Directions: Deciphering the signaling pathway of ROS in HSC will provide a better understanding of ROS roles in switching HSC from quiescence to activation and vice versa, and will also shed light on the possible roles of ROS in leukemia initiation and development. Antioxid. Redox Signal. 21, 1605–1619. PMID:24762207

  17. Breast cancer cells compete with hematopoietic stem and progenitor cells for intercellular adhesion molecule 1-mediated binding to the bone marrow microenvironment.

    PubMed

    Dhawan, Abhishek; Friedrichs, Jens; Bonin, Malte von; Bejestani, Elham Peshali; Werner, Carsten; Wobus, Manja; Chavakis, Triantafyllos; Bornhäuser, Martin

    2016-08-01

    Adhesion-based cellular interactions involved in breast cancer metastasis to the bone marrow remain elusive. We identified that breast cancer cells directly compete with hematopoietic stem and progenitor cells (HSPCs) for retention in the bone marrow microenvironment. To this end, we established two models of competitive cell adhesion-simultaneous and sequential-to study a potential competition for homing to the niche and displacement of the endogenous HSPCs upon invasion by tumor cells. In both models, breast cancer cells but not non-tumorigenic cells competitively reduced adhesion of HSPCs to bone marrow-derived mesenchymal stromal cells (MSCs) in a tumor cell number-dependent manner. Higher adhesive force between breast cancer cells and MSCs, as compared with HSPCs, assessed by quantitative atomic force microscopy-based single-cell force spectroscopy could partially account for tumor cell mediated reduction in HSPC adhesion to MSCs. Genetic inactivation and blockade studies revealed that homophilic interactions between intercellular adhesion molecule 1 (ICAM-1) expressed on tumor cells and MSCs, respectively, regulate the competition between tumor cells and HSPCs for binding to MSCs. Moreover, tumor cell-secreted soluble ICAM-1(sICAM-1) also impaired HSPC adhesion via blocking CD18-ICAM-1 binding between HSPCs and MSCs. Xenotransplantation studies in NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ mice revealed reduction of human HSPCs in the bone marrow via metastatic breast cancer cells. These findings point to a direct competitive interaction between disseminated breast cancer cells and HSPCs within the bone marrow micro environment. This interaction might also have implications on niche-based tumor support. Therefore, targeting this cross talk may represent a novel therapeutic strategy. PMID:27207667

  18. Characterization of purified intraembryonic hematopoietic stem cells as a tool to define their site of origin

    PubMed Central

    Bertrand, Julien Y.; Giroux, Sébastien; Golub, Rachel; Klaine, Michèle; Jalil, Abdelali; Boucontet, Laurent; Godin, Isabelle; Cumano, Ana

    2005-01-01

    Little is known about hematopoietic stem cell (HSC) development from mesoderm. To gain more information on the intraembryonic HSC site of origin, we purified multipotent hematopoietic progenitors from the aorta–gonads–mesonephros (AGM) of mice. This population, expressing c-Kit, AA4.1, CD31, and CD41, but not Flk1, and mainly negative for CD45, proved capable of long-term reconstitution in sublethally irradiated Rag2γc-/- recipients. We assigned the expression of GATA-2, GATA-3, and lmo2 to AGM-HSC, whereas erythromyeloid progenitors express only GATA-2. This unique combination of surface markers and transcription factors could be allocated in the AGM to the intraaortic clusters and the subaortic patches underlying aortic endothelial cells. Taken together, those data indicate that embryonic HSCs (i) differ from their fetal liver and adult counterpart by the low expression of CD45, (ii) do not colocalize with aortic endothelial cells as previously thought, and (iii) are localized, at 10.5 days postcoïtum, in the splanchnic mesoderm underlying aortic endothelial cells, within GATA-3+CD31+ cell clusters. PMID:15623562

  19. Hair follicle: a reliable source of recipient origin after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Hong, Y C; Liu, H M; Chen, P S; Chen, Y J; Lyou, J Y; Hu, H Y; Yi, M F; Lin, J S; Tzeng, C-H

    2007-11-01

    Blood, buccal swab and hair follicles are among the most commonly used sources for forensic science, parentage testing and personal identification. A total of 29 patients who have had a sustained engraftment from 15 months to 21.5 years after allogeneic hematopoietic stem cell transplantation (HSCT) without rejection, relapse or chronic GVHD involving oral mucosa were enrolled for a chimerism study. PCR-amplified short tandem repeat analyses were conducted per patient every 3 months for at least three consecutive times. The results for blood were all donor type except one who had a mixed chimerism, 14.5 years after receiving a transplant for lymphoma. As for buccal swab, mixed chimerism ranging from 10 to 96% donor origin was noted for 28 recipients except the one who had mixed chimerism of blood and retained total recipient type. In contrast, hair follicles were 100% recipient type for the entire group. It is concluded that the hair follicle is devoid of adult stem cell plasticity and may serve as a reliable source of recipient's origin when pre-transplant DNA fingerprinting or reference DNA is not available for people who have successfully received allogeneic HSCT while in need of a personal identification. PMID:17704789

  20. Characterization of two distinct liver progenitor cell subpopulations of hematopoietic and hepatic origins

    SciTech Connect

    Corcelle, V.; Stieger, B.; Gjinovci, A.; Wollheim, C.B.; Gauthier, B.R. . E-mail: Benoit.Gauthier@medecine.unige.ch

    2006-09-10

    Despite extensive studies, the hematopoietic versus hepatic origin of liver progenitor oval cells remains controversial. The aim of this study was to determine the origin of such cells after liver injury and to establish an oval cell line. Rat liver injury was induced by subcutaneous insertion of 2-AAF pellets for 7 days with subsequent injection of CCl{sub 4}. Livers were removed 9 to 13 days post-CCl{sub 4} treatment. Immunohistochemistry was performed using anti-c-kit, OV6, Thy1, CK19, AFP, vWF and Rab3b. Isolated non-parenchymal cells were grown on mouse embryonic fibroblast, and their gene expression profile was characterized by RT-PCR. We identified a subpopulation of OV6/CK19/Rab3b-expressing cells that was activated in the periportal region of traumatized livers. We also characterized a second subpopulation that expressed the HSCs marker c-kit but not Thy1. Although we successfully isolated both cell types, OV6/CK19/Rab3b{sup +} cells fail to propagate while c-kit {sup +}-HSCs appeared to proliferate for up to 7 weeks. Cells formed clusters which expressed c-kit, Thy1 and albumin. Our results indicate that a bona fide oval progenitor cell population resides within the liver and is distinct from c-kit {sup +}-HSCs. Oval cells require the hepatic niche to proliferate, while cells mobilized from the circulation proliferate and transdifferentiate into hepatocytes without evidence of cell fusion.

  1. Infectious hematopoietic necrosis virus: Monophyletic origin of European isolates from North American Genogroup M

    USGS Publications Warehouse

    Enzmann, P.-J.; Kurath, G.; Fichtner, D.; Bergmann, S.M.

    2005-01-01

    Infectious hematopoietic necrosis virus (IHNV) was first detected in Europe in 1987 in France and Italy, and later, in 1992, in Germany. The source of the virus and the route of introduction are unknown. The present study investigates the molecular epidemiology of IHNV outbreaks in Germany since its first introduction. The complete nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes from 9 IHNV isolates from Germany have been determined, and this has allowed the identification of characteristic differences between these isolates. Phylogenetic analysis of partial G gene sequences (mid-G, 303 nucleotides) from North American IHNV isolates (Kurath et al. 2003) has revealed 3 major genogroups, designated U, M and L. Using this gene region with 2 different North American IHNV data sets, it was possible to group the European IHNV strains within the M genogroup, but not in any previously defined subgroup. Analysis of the full length G gene sequences indicated that an independent evolution of IHN viruses had occurred in Europe. IHN viruses in Europe seem to be of a monophyletic origin, again most closely related to North American isolates in the M genogroup. Analysis of the NV gene sequences also showed the European isolates to be monophyletic, but resolution of the 3 genogroups was poor with this gene region. As a result of comparative sequence analyses, several different genotypes have been identified circulating in Europe. ?? Inter-Research 2005.

  2. The Role of Population Origin and Microenvironment in Seedling Emergence and Early Survival in Mediterranean Maritime Pine (Pinus pinaster Aiton)

    PubMed Central

    Vizcaíno-Palomar, Natalia; Revuelta-Eugercios, Bárbara; Zavala, Miguel A.; Alía, Ricardo; González-Martínez, Santiago C.

    2014-01-01

    Understanding tree recruitment is needed to forecast future forest distribution. Many studies have reported the relevant ecological factors that affect recruitment success in trees, but the potential for genetic-based differences in recruitment has often been neglected. In this study, we established a semi-natural reciprocal sowing experiment to test for local adaptation and microenvironment effects (evaluated here by canopy cover) in the emergence and early survival of maritime pine (Pinus pinaster Aiton), an emblematic Mediterranean forest tree. A novel application of molecular markers was also developed to test for family selection and, thus, for potential genetic change over generations. Overall, we did not find evidence to support local adaptation at the recruitment stage in our semi-natural experiment. Moreover, only weak family selection (if any) was found, suggesting that in stressful environments with low survival, stochastic processes and among-year climate variability may drive recruitment. Nevertheless, our study revealed that, at early stages of recruitment, microenvironments may favor the population with the best adapted life strategy, irrespectively of its (local or non-local) origin. We also found that emergence time is a key factor for seedling survival in stressful Mediterranean environments. Our study highlights the complexity of the factors influencing the early stages of establishment of maritime pine and provides insights into possible management actions aimed at environmental change impact mitigation. In particular, we found that the high stochasticity of the recruitment process in stressful environments and the differences in population-specific adaptive strategies may difficult assisted migration schemes. PMID:25286410

  3. Aberrant Notch Signaling in the Bone Marrow Microenvironment of Acute Lymphoid Leukemia Suppresses Osteoblast-Mediated Support of Hematopoietic Niche Function.

    PubMed

    Wang, Weihuan; Zimmerman, Grant; Huang, Xiaoran; Yu, Shuiliang; Myers, Jay; Wang, Yiwei; Moreton, Stephen; Nthale, Joseph; Awadallah, Amad; Beck, Rose; Xin, Wei; Wald, David; Huang, Alex Y; Zhou, Lan

    2016-03-15

    More than half of T-cell acute lymphoblastic leukemia (T-ALL) patients harbor gain-of-function mutations in the intracellular domain of Notch1. Diffuse infiltration of the bone marrow commonly occurs in T-ALL and relapsed B-cell acute lymphoblastic leukemia patients, and is associated with worse prognosis. However, the mechanism of leukemia outgrowth in the marrow and the resulting biologic impact on hematopoiesis are poorly understood. Here, we investigated targetable cellular and molecular abnormalities in leukemia marrow stroma responsible for the suppression of normal hematopoiesis using a T-ALL mouse model and human T-ALL xenografts. We found that actively proliferating leukemia cells inhibited normal hematopoietic stem and progenitor cell (HSPC) proliferation and homing to the perivascular region. In addition, leukemia development was accompanied by the suppression of the endosteum-lining osteoblast population. We further demonstrated that aberrant Notch activation in the stroma plays an important role in negatively regulating the expression of CXLC12 on osteoblasts and their differentiation. Notch blockade reversed attenuated HSPC cycling, leukemia-associated abnormal blood lineage distribution, and thrombocytopenia as well as recovered osteoblast and HSPC abundance and improved the hematopoietic-supportive functions of osteoblasts. Finally, we confirmed that reduced osteoblast frequency and enhanced Notch signaling were also features of the marrow stroma of human ALL tissues. Collectively, our findings suggest that therapeutically targeting the leukemia-infiltrated hematopoietic niche may restore HSPC homeostasis and improve the outcome of ALL patients. PMID:26801976

  4. Epithelial Tumors Originate in Tumor Hotspots, a Tissue-Intrinsic Microenvironment.

    PubMed

    Tamori, Yoichiro; Suzuki, Emiko; Deng, Wu-Min

    2016-09-01

    Malignant tumors are caused by uncontrolled proliferation of transformed mutant cells that have lost the ability to maintain tissue integrity. Although a number of causative genetic backgrounds for tumor development have been discovered, the initial steps mutant cells take to escape tissue integrity and trigger tumorigenesis remain elusive. Here, we show through analysis of conserved neoplastic tumor-suppressor genes (nTSGs) in Drosophila wing imaginal disc epithelia that tumor initiation depends on tissue-intrinsic local cytoarchitectures, causing tumors to consistently originate in a specific region of the tissue. In this "tumor hotspot" where cells constitute a network of robust structures on their basal side, nTSG-deficient cells delaminate from the apical side of the epithelium and begin tumorigenic overgrowth by exploiting endogenous Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling activity. Conversely, in other regions, the "tumor coldspot" nTSG-deficient cells are extruded toward the basal side and undergo apoptosis. When the direction of delamination is reversed through suppression of RhoGEF2, an activator of the Rho family small GTPases, and JAK/STAT is activated ectopically in these coldspot nTSG-deficient cells, tumorigenesis is induced. These data indicate that two independent processes, apical delamination and JAK/STAT activation, are concurrently required for the initiation of nTSG-deficient-induced tumorigenesis. Given the conservation of the epithelial cytoarchitecture, tumorigenesis may be generally initiated from tumor hotspots by a similar mechanism. PMID:27584724

  5. Extrinsic allospecific signals of hematopoietic origin dictate iNKT cell lineage-fate decisions during development

    PubMed Central

    Strong, Beverly S. I.; Newkold, Tess J.; Lee, Amanda E.; Turner, Lucas E.; Alhajjat, Amir M.; Heusel, Jonathan W.; Shaaban, Aimen F.

    2016-01-01

    Invariant NKT (iNKT) cells are critical to the maintenance of tolerance toward alloantigens encountered during postnatal life pointing to the existence of a process for self-education. However, the impact of developmentally encountered alloantigens in shaping the phenotype and function of iNKT cells has not been described. To better understand this process, the current report examined naïve iNKT cells as they matured in an allogeneic environment. Following the prenatal transfer of fetal hematopoietic cells between age-matched allogeneic murine fetuses, cell-extrinsic signals appeared to dictate allospecific patterns of Ly49 receptor expression and lineage diversity in developing iNKT cells. Regulation for this process arose from cells of hematopoietic origin requiring only rare exposure to facilitate broad changes in developing iNKT cells. These findings highlight surprisingly asymmetric allospecific alterations in iNKT cells as they develop and mature in an allogeneic environment and establish a new paradigm for study of the self-education of iNKT cells. PMID:27354027

  6. Involvement of cells of hematopoietic origin in genetically determined resistance of Syrian hamsters to vesicular stomatitis virus.

    PubMed Central

    Fultz, P N; Shadduck, J A; Kang, C Y; Streilein, J W

    1981-01-01

    Susceptibility of Syrian hamsters of the inbred LSH and MHA strains to injection of as few as 10 plaque-forming units of vesicular stomatitis virus (VSV) was shown to occur only after intraperitoneal and intrapleural injection and not after injection of VSV intravenously, intranasally, or in the footpads. Despite the fact that fewer LSH hamsters died when VSV was injected via the latter routes, the histopathology of the VSV-induced disease at early times after infection was identical irrespective of the route of virus administration. Histological examination of tissues at various times after administration of VSV by the various routes revealed that VSV exhibited tropism for lymphoreticular tissue, with the greatest amount of necrosis in the splenic periarteriolar lymphoid sheath. A similar pattern also was observed in VSV-infected tissues from genetically resistant UT1 hamsters. Infectivity titrations of various tissues at different times after intraperitoneal injection of VSV revealed that resistant UT1 hamsters began to clear virus from tissues between 40 and 48 h postinfection, whereas virus titers remained high in susceptible animals. Resistance of UT1 hamsters appeared to require an intact spleen since survival of splenectomized animals was less than that of sham-splenectomized UT1 controls. Sublethal whole-body irradiation was also able to reduce resistance of UT1 hamsters (survival was reduced from 100 to 50%). Bone marrow cells from resistant (UT1 X LSH) F1 females were transferred into lethally irradiated susceptible LSH hamsters, and hematopoietic chimeras were produced. After intraperitoneal injection of 100 plaque-forming units of VSV, all of the female chimeras survived, but only 33% of male chimeras survived. These data indicate that resistance to VSV in Syrian hamsters is mediated, at least partially, by cells of hematopoietic origin. Images PMID:6273320

  7. Targeting hypoxia in the leukemia microenvironment

    PubMed Central

    Benito, Juliana; Zeng, Zhihong; Konopleva, Marina; Wilson, William R

    2013-01-01

    SUMMARY The bone marrow (BM) microenvironment regulates survival and maintenance of normal hematopoietic stem cells. Within the endosteal niche, hypoxia has an essential role in maintenance of the primitive quiescent hematopoietic stem cell. We and others have demonstrated that in the context of hematologic malignancies the BM is highly hypoxic, and that progression of the disease is associated with expansion of hypoxic niches and stabilization of the oncogenic HIF-1α. This review will provide an overview of the normal and leukemic BM microenvironment with a special emphasis on pathological hypoxia including the development of hypoxia-activated prodrugs and their applicability in hematological malignancies. PMID:24490034

  8. Targeting the Microenvironment in Acute Myeloid Leukemia

    PubMed Central

    Rashidi, Armin; Uy, Geoffrey L.

    2015-01-01

    The bone marrow microenvironment plays a critical role in the development, progression, and relapse of acute myeloid leukemia (AML). Similar to normal hematopoietic stem cells, AML blasts express receptors on their surface, allowing them to interact with specific components of the marrow microenvironment. These interactions contribute to both chemotherapy resistance and disease relapse. Preclinical studies and early phase clinical trials have demonstrated the potential for targeting the tumor-microenvironment interactions in AML. Agents currently under investigation include hypoxia-inducible agents and inhibitors of CXCR4 and adhesion molecules such as VLA-4 and E-selectin. PMID:25921388

  9. Formation of gullies on Mars: link to recent climate history and insolation microenvironments implicate surface water flow origin.

    PubMed

    Head, James W; Marchant, David R; Kreslavsky, Mikhail A

    2008-09-01

    Features seen in portions of a typical midlatitude Martian impact crater show that gully formation follows a geologically recent period of midlatitude glaciation. Geological evidence indicates that, in the relatively recent past, sufficient snow and ice accumulated on the pole-facing crater wall to cause glacial flow and filling of the crater floor with debris-covered glaciers. As glaciation waned, debris-covered glaciers ceased flowing, accumulation zones lost ice, and newly exposed wall alcoves continued as the location for limited snow/frost deposition, entrapment, and preservation. Analysis of the insolation geometry of this pole-facing crater wall, and similar occurrences in other craters at these latitudes on Mars, shows that they are uniquely favored for accumulation of snow and ice, and a relatively more rapid exposure to warmer summer temperatures. We show that, after the last glaciation, melting of residual snow and ice in alcoves could have formed the fluvial channels and sedimentary fans of the gullies. Recent modeling shows that top-down melting can occur in these microenvironments under conditions similar to those currently observed on Mars, if small amounts of snow or frost accumulate in alcoves and channels. Accumulation and melting is even more favored in the somewhat wetter, relatively recent geological past of Mars, after the period of active glaciation. PMID:18725636

  10. Formation of gullies on Mars: Link to recent climate history and insolation microenvironments implicate surface water flow origin

    PubMed Central

    Head, James W.; Marchant, David R.; Kreslavsky, Mikhail A.

    2008-01-01

    Features seen in portions of a typical midlatitude Martian impact crater show that gully formation follows a geologically recent period of midlatitude glaciation. Geological evidence indicates that, in the relatively recent past, sufficient snow and ice accumulated on the pole-facing crater wall to cause glacial flow and filling of the crater floor with debris-covered glaciers. As glaciation waned, debris-covered glaciers ceased flowing, accumulation zones lost ice, and newly exposed wall alcoves continued as the location for limited snow/frost deposition, entrapment, and preservation. Analysis of the insolation geometry of this pole-facing crater wall, and similar occurrences in other craters at these latitudes on Mars, shows that they are uniquely favored for accumulation of snow and ice, and a relatively more rapid exposure to warmer summer temperatures. We show that, after the last glaciation, melting of residual snow and ice in alcoves could have formed the fluvial channels and sedimentary fans of the gullies. Recent modeling shows that top-down melting can occur in these microenvironments under conditions similar to those currently observed on Mars, if small amounts of snow or frost accumulate in alcoves and channels. Accumulation and melting is even more favored in the somewhat wetter, relatively recent geological past of Mars, after the period of active glaciation. PMID:18725636

  11. A 54-Year-Old Woman with Donor Cell Origin of Multiple Myeloma after Allogeneic Hematopoietic Stem Cell Transplantation for the Treatment of CML

    PubMed Central

    Maestas, Erika; Jain, Shikha; Stiff, Patrick

    2016-01-01

    Chronic myeloid leukemia is a myeloproliferative disorder that may be treated with hematopoietic stem cell transplantation (HSCT). While posttransplantation relapse of disease resulting from a failure to eradicate the patient's original leukemia could occur, patients may also rarely develop a secondary malignancy or myelodysplastic syndrome (MDS) of donor origin termed donor cell leukemia (DCL). Cases of donor-derived acute myeloid leukemia (AML) or MDS after HSCT or solid tumor transplantation have been published. However, very few cases of donor-derived multiple myeloma (MM) exist. We describe a patient who developed a donor-derived MM following allogeneic HSCT from a sibling donor. PMID:26989529

  12. Origin of osteoclasts: Mature monocytes and macrophages are capable of differentiating into osteoclasts under a suitable microenvironment prepared by bone marrow-derived stromal cells

    SciTech Connect

    Udagawa, Nobuyuki; Takahashi, Naoyuki; Akatsu, Takuhiko; Tanaka, Hirofumi; Sasaki, Takahisa; Suda, Tatsuo ); Nishihara, Tatsuji; Koga, Toshihiko ); Martin, T.J. )

    1990-09-01

    The authors previously reported that osteoclast-like cells were formed in cocultures of a mouse marrow-derived stromal cell line (ST2) with mouse spleen cells in the presence of 1{alpha},25-dihydroxyvitamin D{sub 3} and dexamethasone. In this study, they developed a new coculture system to determine the origin of osteoclasts. When relatively small numbers of mononuclear cells obtained from mouse bone marrow, spleen, thymus, or peripheral blood were cultured for 12 days on the ST2 cell layers, they formed colonies with a linear relationship between the number of colonies formed and the number of hemopoietic cells inoculated. Tartrate-resistant acid phosphatase (TRAPase)-positive monoculear and multinucleated cells appeared in the colonies (TRAPase-positive colonies) in response to 1{alpha},25-dihydroxyvitamin D{sub 3} and dexamethasone. When hemopoietic cells suspended in a collagen-gel solution were cultured on the ST2 cell layers to prevent their movement, TRAPase-positive colonies were similarly formed, indicating that each colony originated from a single cell. Salmon {sup 125}I-labeled calcitonin specifically bound to the TRAPase-positive cells. Resorption lacunae were formed on dentine slices on which cocultures were performed. These results indicate that osteoclasts are also derived from the mature monocytes and macrophages when a suitable microenvironment is provided by bone marrow-derived stromal cells.

  13. Hematopoietic stem cells: multiparameter regulation.

    PubMed

    Song, Kedong; Li, Liying; Wang, Yiwei; Liu, Tianqing

    2016-04-01

    Hematopoietic stem cells (HSCs) are capable to self-renew with multi-potency which generated much excitement in clinical therapy. However, the main obstacle of HSCs in clinical application was insufficient number of HSCs which were derived from either bone marrow, peripheral blood or umbilical cord blood. This review briefly discusses the indispensable utility of growth factors and cytokines, stromal cells, extracellular matrix, bionic scaffold and microenvironment aiming to control the hematopoiesis in all directions and provide a better and comprehensive understanding for in vitro expansion of hematopoietic stem cells. PMID:26883144

  14. Biology of Marrow Failure Syndromes: Role of Microenvironment and Niches

    PubMed Central

    Balderman, Sophia R.; Calvi, Laura M.

    2015-01-01

    The marrow microenvironment and its components regulate hematopoietic stem and progenitor cell (HSC) fate. An abnormality in the marrow microenvironment and specific dysfunction of the HSC niche could play a critical role in initiation, disease progression and response to therapy of marrow failure syndromes. Therefore, the identification of changes in the HSC niche in marrow failure syndromes should lead to further knowledge of the signals that disrupt the normal microenvironment. In turn, niche disruption may contribute to disease morbidity resulting in pancytopenia and clonal evolution, and its understanding could point to new therapeutic targets for these conditions. We briefly (a) review evidence for the importance of the marrow microenvironment as a regulator of normal hematopoiesis, (b) summarize the current knowledge regarding the role of dysfunctions in the marrow microenvironment in marrow failure syndromes, and (c) propose a strategy through which niche stimulation can complement current treatment for MDS. PMID:25696837

  15. Distinguishing autocrine and paracrine signals in hematopoietic stem cell culture using a biofunctional microcavity platform

    PubMed Central

    Müller, Eike; Wang, Weijia; Qiao, Wenlian; Bornhäuser, Martin; Zandstra, Peter W.; Werner, Carsten; Pompe, Tilo

    2016-01-01

    Homeostasis of hematopoietic stem cells (HSC) in the mammalian bone marrow stem cell niche is regulated by signals of the local microenvironment. Besides juxtacrine, endocrine and metabolic cues, paracrine and autocrine signals are involved in controlling quiescence, proliferation and differentiation of HSC with strong implications on expansion and differentiation ex vivo as well as in vivo transplantation. Towards this aim, a cell culture analysis on a polymer microcavity carrier platform was combined with a partial least square analysis of a mechanistic model of cell proliferation. We could demonstrate the discrimination of specific autocrine and paracrine signals from soluble factors as stimulating and inhibitory effectors in hematopoietic stem and progenitor cell culture. From that we hypothesize autocrine signals to be predominantly involved in maintaining the quiescent state of HSC in single-cell niches and advocate our analysis platform as an unprecedented option for untangling convoluted signaling mechanisms in complex cell systems being it of juxtacrine, paracrine or autocrine origin. PMID:27535453

  16. Distinguishing autocrine and paracrine signals in hematopoietic stem cell culture using a biofunctional microcavity platform.

    PubMed

    Müller, Eike; Wang, Weijia; Qiao, Wenlian; Bornhäuser, Martin; Zandstra, Peter W; Werner, Carsten; Pompe, Tilo

    2016-01-01

    Homeostasis of hematopoietic stem cells (HSC) in the mammalian bone marrow stem cell niche is regulated by signals of the local microenvironment. Besides juxtacrine, endocrine and metabolic cues, paracrine and autocrine signals are involved in controlling quiescence, proliferation and differentiation of HSC with strong implications on expansion and differentiation ex vivo as well as in vivo transplantation. Towards this aim, a cell culture analysis on a polymer microcavity carrier platform was combined with a partial least square analysis of a mechanistic model of cell proliferation. We could demonstrate the discrimination of specific autocrine and paracrine signals from soluble factors as stimulating and inhibitory effectors in hematopoietic stem and progenitor cell culture. From that we hypothesize autocrine signals to be predominantly involved in maintaining the quiescent state of HSC in single-cell niches and advocate our analysis platform as an unprecedented option for untangling convoluted signaling mechanisms in complex cell systems being it of juxtacrine, paracrine or autocrine origin. PMID:27535453

  17. Tumor microenvironment and nanotherapeutics

    PubMed Central

    Upreti, Meenakshi; Jyoti, Amar; Sethi, Pallavi

    2014-01-01

    Recent studies delineate a predominant role for the tumor microenvironment in tumor growth and progression. Improved knowledge of cancer biology and investigation of the complex functional interrelation between the cellular and noncellular compartments of the tumor microenvironment have provided an ideal platform for the evolution of novel cancer nanotherapies. In addition, multifunctional “smart” nanoparticles carrying imaging agents and delivering multiple drugs targeted preferentially to the tumor/tumor microenvironment will lead to early diagnosis and better treatment for patients with cancer. The emerging knowledge of the tumor microenvironment has enabled rational designing of nanoparticles for combinatorial treatment strategies that include radiotherapy, antiangiogenesis and chemotherapy. This multimodality approach is thus expected to achieve therapeutic efficacy and enhance the quality of life of cancer patients. This review highlights the unique characteristics of the tumor microenvironment that are exploited by nanotechnology to develop novel drug delivery systems aimed to target the tumor/tumor microenvironment. PMID:24634853

  18. Imaging the Tumor Microenvironment

    PubMed Central

    LeBleu, Valerie

    2015-01-01

    The tumor microenvironment is a complex, heterogeneous, and dominant component of solid tumors. Cancer imaging strategies of a subset of characteristics of the tumor microenvironment are under active development and currently used modalities and novel approaches are summarized here. Understanding the dynamic and evolving functions of the tumor microenvironment is critical to accurately inform imaging and clinical care of cancer. Novel insights into distinct roles of the tumor microenvironment in cancer progression urge careful interpretation of imaging data and impel the development of novel modalities. PMID:26049696

  19. Lymphoma Microenvironment and Immunotherapy.

    PubMed

    Xu, Mina L; Fedoriw, Yuri

    2016-03-01

    Understanding of the lymphoma tumor microenvironment is poised to expand in the era of next-generation sequencing studies of the tumor cells themselves. Successful therapies of the future will rely on deeper appreciation of the interactions between elements of the microenvironment. Although the phenotypic, cytogenetic, and molecular characterization of tumor cells in lymphomas has progressed faster than most other solid organ tumors, concrete advancements in understanding the lymphoma microenvironment have been fewer. This article explores the composition of the lymphoma tumor microenvironment; its role in immune surveillance, evasion, and drug resistance; and its potential role in the development of targeted therapies. PMID:26940270

  20. The role of CD44 in fetal and adult hematopoietic stem cell regulation

    PubMed Central

    Cao, Huimin; Heazlewood, Shen Y.; Williams, Brenda; Cardozo, Daniela; Nigro, Julie; Oteiza, Ana; Nilsson, Susan K.

    2016-01-01

    Throughout development, hematopoietic stem cells migrate to specific microenvironments, where their fate is, in part, extrinsically controlled. CD44 standard as a member of the cell adhesion molecule family is extensively expressed within adult bone marrow and has been previously reported to play important roles in adult hematopoietic regulation via CD44 standard-ligand interactions. In this manuscript, CD44 expression and function are further assessed and characterized on both fetal and adult hematopoietic stem cells. Using a CD44−/− mouse model, conserved functional roles of CD44 are revealed throughout development. CD44 is critical in the maintenance of hematopoietic stem and progenitor pools, as well as in hematopoietic stem cell migration. CD44 expression on hematopoietic stem cells as well as other hematopoietic cells within the bone marrow microenvironment is important in the homing and lodgment of adult hematopoietic stem cells isolated from the bone/bone marrow interface. CD44 is also involved in fetal hematopoietic stem cell migration out of the liver, via a process involving stromal cell-derived factor-1α. The absence of CD44 in neonatal bone marrow has no impact on the size of the long-term reconstituting hematopoietic stem cell pool, but results in an enhanced long-term engraftment potential of hematopoietic stem cells. PMID:26546504

  1. Tumor microenvironment indoctrination

    PubMed Central

    2012-01-01

    Nastiness of cancer does not only reside in the corruption of cancer cells by genetic aberrations that drive their sustained proliferative power—the roots of malignancy—but also in its aptitude to reciprocally sculpt its surrounding environment and cellular stromal ecosystem, in such a way that the corrupted tumor microenvironment becomes a full pro-tumorigenic entity. Such a contribution had been appreciated three decades ago already, with the discovery of tumor angiogenesis and extracellular matrix remodeling. Nevertheless, the recent emergence of the tumor microenvironment as the critical determinant in cancer biology is paralleled by the promising therapeutic potential it carries, opening alternate routes to fight cancer. The study of the tumor microenvironment recruited numerous lead-scientists over the years, with distinct perspectives, and some of them have kindly accepted to contribute to the elaboration of this special issue entitled Tumor microenvironment indoctrination: An emerging hallmark of cancer. PMID:22863738

  2. Prostate Cancer and Parasitism of the Bone Hematopoietic Stem Cell Niche

    PubMed Central

    Yu, Chunyan; Shiozawa, Yusuke; Taichman, Russell S.; McCauley, Laurie K.; Pienta, Kenneth J.; Keller, Evan T.

    2013-01-01

    A subpopulation of men that appear cured of prostate cancer (PCa) develop bone metastases many years after prostatectomy. This observation indicates that PCa cells were present outside of the prostate at the time of prostatectomy and remained dormant. Several lines of evidence indicate that there are disseminated tumor cells (DTCs) in the bone marrow at the time of prostatectomy. DTCs parasitize the bone microenvironment, where they derive support and impact the microenvironment itself. These DTCs appear to be a heterogeneous population of PCa cells; however, some of them appear to have some aspects of a cancer stem cell (CSC) phenotype as they can develop into clinically detectable metastases. The concept of CSC is controversial; however, several markers of CSC have been identified for PCa, which may represent cells of either basal or luminal origin. These DTCs have now been shown to compete for the hematopoietic stem cell niche in bone, where they may be placed in a dormant state. Interaction with a variety of host factors, including cytokine and cells, may impact the metastatic development and progression, including the dormant state. For example, myeloid cells have been shown to impact both the premetastatic niche and established tumors. Understanding the concepts of how PCa successfully parasitizes the bone microenvironment is paramount toward identifying therapeutic candidates to prevent or diminish PCa bone metastases. PMID:22856431

  3. An Irradiation-Altered Bone Marrow Microenvironment Impacts Anabolic Actions of PTH

    PubMed Central

    Koh, A. J.; Novince, C. M.; Li, X.; Wang, T.; Taichman, R. S.

    2011-01-01

    PTH stimulates bone formation and increases hematopoietic stem cells through mechanisms as yet uncertain. The purpose of this study was to identify mechanisms by which PTH links actions on cells of hematopoietic origin with osteoblast-mediated bone formation. C57B6 mice (10 d) were nonlethally irradiated and then administered PTH for 5–20 d. Irradiation reduced bone marrow cellularity with retention of cells lining trabeculae. PTH anabolic activity was greater in irradiated vs. nonirradiated mice, which could not be accounted for by altered osteoblasts directly or osteoclasts but instead via an altered bone marrow microenvironment. Irradiation increased fibroblast growth factor 2, TGFβ, and IL-6 mRNA levels in the bone marrow in vivo. Irradiation decreased B220 cell numbers, whereas the percent of Lin−Sca-1+c-kit+ (LSK), CD11b+, CD68+, CD41+, Lin−CD29+Sca-1+ cells, and proliferating CD45−Nestin+ cells was increased. Megakaryocyte numbers were reduced with irradiation and located more closely to trabecular surfaces with irradiation and PTH. Bone marrow TGFβ was increased in irradiated PTH-treated mice, and inhibition of TGFβ blocked the PTH augmentation of bone in irradiated mice. In conclusion, irradiation created a permissive environment for anabolic actions of PTH that was TGFβ dependent but osteoclast independent and suggests that a nonosteoclast source of TGFβ drives mesenchymal stem cell recruitment to support PTH anabolic actions. PMID:22045660

  4. Mutual Interference between Cytomegalovirus and Reconstitution of Protective Immunity after Hematopoietic Cell Transplantation.

    PubMed

    Reddehase, Matthias J

    2016-01-01

    Hematopoietic cell transplantation (HCT) is a therapy option for aggressive forms of hematopoietic malignancies that are resistant to standard antitumoral therapies. Hematoablative treatment preceding HCT, however, opens a "window of opportunity" for latent Cytomegalovirus (CMV) by releasing it from immune control with the consequence of reactivation of productive viral gene expression and recurrence of infectious virus. A "window of opportunity" for the virus represents a "window of risk" for the patient. In the interim between HCT and reconstitution of antiviral immunity, primarily mediated by CD8(+) T cells, initially low amounts of reactivated virus can expand exponentially, disseminate to essentially all organs, and cause multiple organ CMV disease, with interstitial pneumonia (CMV-IP) representing the most severe clinical manifestation. Here, I will review predictions originally made in the mouse model of experimental HCT and murine CMV infection, some of which have already paved the way to translational preclinical research and promising clinical trials of a preemptive cytoimmunotherapy of human CMV disease. Specifically, the mouse model has been pivotal in providing "proof of concept" for preventing CMV disease after HCT by adoptive transfer of preselected, virus epitope-specific effector and memory CD8(+) T cells bridging the critical interim. However, CMV is not a "passive antigen" but is a pathogen that actively interferes with the reconstitution of protective immunity by infecting bone marrow (BM) stromal cells that otherwise form niches for hematopoiesis by providing the structural microenvironment and by producing hematopoietically active cytokines, the hemopoietins. Depending on the precise conditions of HCT, reduced homing of transplanted hematopoietic stem- and progenitor cells to infected BM stroma and impaired colony growth and lineage differentiation can lead to "graft failure." In consequence, uncontrolled virus spread causes morbidity and

  5. Human Olfactory Mucosa Multipotent Mesenchymal Stromal Cells Promote Survival, Proliferation, and Differentiation of Human Hematopoietic Cells

    PubMed Central

    Diaz-Solano, Dylana; Wittig, Olga; Ayala-Grosso, Carlos; Pieruzzini, Rosalinda

    2012-01-01

    Multipotent mesenchymal stromal cells (MSCs) from the human olfactory mucosa (OM) are cells that have been proposed as a niche for neural progenitors. OM-MSCs share phenotypic and functional properties with bone marrow (BM) MSCs, which constitute fundamental components of the hematopoietic niche. In this work, we investigated whether human OM-MSCs may promote the survival, proliferation, and differentiation of human hematopoietic stem cells (HSCs). For this purpose, human bone marrow cells (BMCs) were co-cultured with OM-MSCs in the absence of exogenous cytokines. At different intervals, nonadherent cells (NACs) were harvested from BMC/OM-MSC co-cultures, and examined for the expression of blood cell markers by flow cytometry. OM-MSCs supported the survival (cell viability >90%) and proliferation of BMCs, after 54 days of co-culture. At 20 days of co-culture, flow cytometric and microscopic analyses showed a high percentage (73%) of cells expressing the pan-leukocyte marker CD45, and the presence of cells of myeloid origin, including polymorphonuclear leukocytes, monocytes, basophils, eosinophils, erythroid cells, and megakaryocytes. Likewise, T (CD3), B (CD19), and NK (CD56/CD16) cells were detected in the NAC fraction. Colony-forming unit–granulocyte/macrophage (CFU-GM) progenitors and CD34+ cells were found, at 43 days of co-culture. Reverse transcriptase–polymerase chain reaction (RT-PCR) studies showed that OM-MSCs constitutively express early and late-acting hematopoietic cytokines (i.e., stem cell factor [SCF] and granulocyte- macrophage colony-stimulating factor [GM-CSF]). These results constitute the first evidence that OM-MSCs may provide an in vitro microenvironment for HSCs. The capacity of OM-MSCs to support the survival and differentiation of HSCs may be related with the capacity of OM-MSCs to produce hematopoietic cytokines. PMID:22471939

  6. MicroRNAs are shaping the hematopoietic landscape

    PubMed Central

    Bissels, Ute; Bosio, Andreas; Wagner, Wolfgang

    2012-01-01

    Hematopoiesis is regulated by microRNAs (miRNAs). These small regulatory RNAs are master regulators of developmental processes that modulate expression of several target genes post-transcriptionally. Various miRNAs are up-regulated at specific stages during hematopoietic development and the functional relevance of miRNAs has been proven at many different stages of lineage specification. Knockout of specific miRNAs can produce dramatic phenotypes leading to severe hematopoietic defects. Furthermore, several studies demonstrated that specific miRNAs are differentially expressed in hematopoietic stem cells. However, the emerging picture is extremely complex due to differences between species, cell type dependent variation in miRNA expression and differential expression of diverse target genes that are involved in various regulatory networks. There is also evidence that miRNAs play a role in cellular aging or in the inter-cellular crosstalk between hematopoietic cells and their microenvironment. The field is rapidly evolving due to new profiling tools and deep sequencing technology. The expression profiles of miRNAs are of diagnostic relevance for classification of different diseases. Recent reports on the generation of induced pluripotent stem cells with miRNAs have fuelled the hope that specific miRNAs and culture conditions facilitate directed differentiation or culture expansion of the hematopoietic stem cell pool. This review summarizes our current knowledge about miRNA expression in hematopoietic stem and progenitor cells, and their role in the hematopoietic stem cell niche. PMID:22058204

  7. Consequences of irradiation on bone and marrow phenotypes, and its relation to disruption of hematopoietic precursors

    PubMed Central

    Green, Danielle E.; Rubin, Clinton T.

    2014-01-01

    The rising levels of radiation exposure, specifically for medical treatments and accidental exposures, have added great concern for the long term risks of bone fractures. Both the bone marrow and bone architecture are devastated following radiation exposure. Even sub-lethal doses cause a deficit to the bone marrow microenvironment, including a decline in hematopoietic cells, and this deficit occurs in a dose dependent fashion. Certain cell phenotypes though are more susceptible to radiation damage, with mesenchymal stem cells being more resilient than the hematopoietic stem cells. The decline in total bone marrow hematopoietic cells is accompanied with elevated adipocytes into the marrow cavity, thereby inhibiting hematopoiesis and recovery of the bone marrow microenvironment. Poor bone marrow is also associated with a decline in bone architectural quality. Therefore, the ability to maintain the bone marrow microenvironment would hinder much of the trabecular bone loss caused by radiation exposure, ultimately decreasing some comorbidities in patients exposed to radiation. PMID:24607941

  8. Single-Cell Cytokine Profiling to Investigate Cellular Functional Diversity in Hematopoietic Malignancies.

    PubMed

    Chen, Jonathan J; Kwak, Minsuk; Fan, Rong

    2016-01-01

    Single-cell analysis of cytokine production is increasingly recognized as an important method to understand the inflammatory microenvironment and hematopoietic disease state. Certain cytokines are critical to the regulation of lineage specification, and the aberrant production of these cytokines can contribute to lineage reprogramming. Here, we describe of a platform combining subnanoliter microchambers and a high-density antibody barcode array for the study of single-cell cytokine secretions in hematopoietic cancer cell populations. PMID:27581152

  9. Targeting the tumor microenvironment

    PubMed Central

    Bournazou, Eirini; Bromberg, Jacqueline

    2013-01-01

    Persistent JAK-STAT3 signaling is implicated in many aspects of tumorigenesis. Apart from its tumor-intrinsic effects, STAT3 also exerts tumor-extrinsic effects, supporting tumor survival and metastasis. These involve the regulation of paracrine cytokine signaling, alterations in metastatic sites rendering these permissive for the growth of cancer cells and subversion of host immune responses to create an immunosuppressive environment. Targeting this signaling pathway is considered a novel promising therapeutic approach, especially in the context of tumor immunity. In this article, we will review to what extent JAK-STAT3-targeted therapies affect the tumor microenvironment and whether the observed effects underlie responsiveness to therapy. PMID:24058812

  10. Targeting the tumor microenvironment

    SciTech Connect

    Kenny, P.A.; Lee, G.Y.; Bissell, M.J.

    2006-11-07

    Despite some notable successes cancer remains, for the most part, a seemingly intractable problem. There is, however, a growing appreciation that targeting the tumor epithelium in isolation is not sufficient as there is an intricate mutually sustaining synergy between the tumor epithelial cells and their surrounding stroma. As the details of this dialogue emerge, new therapeutic targets have been proposed. The FDA has already approved drugs targeting microenvironmental components such as VEGF and aromatase and many more agents are in the pipeline. In this article, we describe some of the 'druggable' targets and processes within the tumor microenvironment and review the approaches being taken to disrupt these interactions.

  11. Sympathetic nervous system regulation of the tumour microenvironment

    PubMed Central

    Cole, Steven W.; Nagaraja, Archana S.; Lutgendorf, Susan K.; Green, Paige A.; Sood, Anil K.

    2016-01-01

    The peripheral autonomic nervous system (ANS) is known to regulate gene expression in primary tumours and their surrounding microenvironment. Activation of the sympathetic division of the ANS in particular modulates gene expression programs that promote metastasis of solid tumours by stimulating macrophage infiltration, inflammation, angiogenesis, epithelial-mesenchymal transition, and tumour invasion, and by inhibiting cellular immune responses and programmed cell death. Haematological cancers are modulated by sympathetic nervous system (SNS) regulation of stem cell biology and hematopoietic differentiation programs. In addition to identifying a molecular basis for physiologic stress effects on cancer, these findings have also identified new pharmacologic strategies to inhibit cancer progression in vivo. PMID:26299593

  12. Gelatinous marrow transformation and hematopoietic atrophy in a miniature horse stallion.

    PubMed

    Beeler-Marfisi, J; Gallastegui Menoyo, A; Beck, A; König, J; Hewson, J; Bienzle, D

    2011-03-01

    Gelatinous marrow transformation, or serous atrophy of bone marrow fat, has been noted in livestock, laboratory animals, and wildlife in association with an inadequate plane of nutrition, inanition, or intoxication. This is a report of gelatinous marrow transformation and hematopoietic marrow atrophy in a 5-year-old miniature horse stallion. The horse had oral malformations leading to poor food assimilation and emaciation. A bone marrow biopsy obtained to investigate persistent anemia and leukopenia showed hematopoietic atrophy and replacement of fat with a granular extracellular substance, which stained with alcian blue, consistent with acidic mucopolysaccharide content. Surgical correction of the dental abnormalities resulted in improved food assimilation, weight gain, and resolution of cytopenias. In humans, gelatinous bone marrow transformation and hematopoietic atrophy are commonly associated with malnutrition from anorexia nervosa and other causes. The cause of hematopoietic atrophy is unknown but may relate to a nonsupportive marrow microenvironment and inadequate hematopoietic substrate availability. Similar pathogenic mechanisms were suspected in this horse. PMID:20587692

  13. The effect of environmental chemicals on the tumor microenvironment

    PubMed Central

    Casey, Stephanie C.; Vaccari, Monica; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Barcellos-Hoff, Mary Helen; Brown, Dustin G.; Chapellier, Marion; Christopher, Joseph; Curran, Colleen S.; Forte, Stefano; Hamid, Roslida A.; Heneberg, Petr; Koch, Daniel C.; Krishnakumar, P.K.; Laconi, Ezio; Maguer-Satta, Veronique; Marongiu, Fabio; Memeo, Lorenzo; Mondello, Chiara; Raju, Jayadev; Roman, Jesse; Roy, Rabindra; Ryan, Elizabeth P.; Ryeom, Sandra; Salem, Hosni K.; Scovassi, A.Ivana; Singh, Neetu; Soucek, Laura; Vermeulen, Louis; Whitfield, Jonathan R.; Woodrick, Jordan; Colacci, Anna Maria; Bisson, William H.; Felsher, Dean W.

    2015-01-01

    Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis. PMID:26106136

  14. The effect of environmental chemicals on the tumor microenvironment.

    PubMed

    Casey, Stephanie C; Vaccari, Monica; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Barcellos-Hoff, Mary Helen; Brown, Dustin G; Chapellier, Marion; Christopher, Joseph; Curran, Colleen S; Forte, Stefano; Hamid, Roslida A; Heneberg, Petr; Koch, Daniel C; Krishnakumar, P K; Laconi, Ezio; Maguer-Satta, Veronique; Marongiu, Fabio; Memeo, Lorenzo; Mondello, Chiara; Raju, Jayadev; Roman, Jesse; Roy, Rabindra; Ryan, Elizabeth P; Ryeom, Sandra; Salem, Hosni K; Scovassi, A Ivana; Singh, Neetu; Soucek, Laura; Vermeulen, Louis; Whitfield, Jonathan R; Woodrick, Jordan; Colacci, Annamaria; Bisson, William H; Felsher, Dean W

    2015-06-01

    Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis. PMID:26106136

  15. Segmentation of vascular structures and hematopoietic cells in 3D microscopy images and quantitative analysis

    NASA Astrophysics Data System (ADS)

    Mu, Jian; Yang, Lin; Kamocka, Malgorzata M.; Zollman, Amy L.; Carlesso, Nadia; Chen, Danny Z.

    2015-03-01

    In this paper, we present image processing methods for quantitative study of how the bone marrow microenvironment changes (characterized by altered vascular structure and hematopoietic cell distribution) caused by diseases or various factors. We develop algorithms that automatically segment vascular structures and hematopoietic cells in 3-D microscopy images, perform quantitative analysis of the properties of the segmented vascular structures and cells, and examine how such properties change. In processing images, we apply local thresholding to segment vessels, and add post-processing steps to deal with imaging artifacts. We propose an improved watershed algorithm that relies on both intensity and shape information and can separate multiple overlapping cells better than common watershed methods. We then quantitatively compute various features of the vascular structures and hematopoietic cells, such as the branches and sizes of vessels and the distribution of cells. In analyzing vascular properties, we provide algorithms for pruning fake vessel segments and branches based on vessel skeletons. Our algorithms can segment vascular structures and hematopoietic cells with good quality. We use our methods to quantitatively examine the changes in the bone marrow microenvironment caused by the deletion of Notch pathway. Our quantitative analysis reveals property changes in samples with deleted Notch pathway. Our tool is useful for biologists to quantitatively measure changes in the bone marrow microenvironment, for developing possible therapeutic strategies to help the bone marrow microenvironment recovery.

  16. TNFα and Endothelial Cells Modulate Notch Signaling in the Bone Marrow Microenvironment during Inflammation

    PubMed Central

    Fernandez, Luis; Rodriguez, Sonia; Huang, Hui; Chora, Angelo; Mumaw, Christin; Cruz, Eugenia; Pollok, Karen; Cristina, Filipa; Price, Joanne E.; Ferkowicz, Michael J.; Scadden, David T.; Clauss, Matthias; Cardoso, Angelo A.; Carlesso, Nadia

    2009-01-01

    Objective Homeostasis of the hematopoietic compartment is challenged and maintained during conditions of stress by mechanisms that are poorly defined. To understand how the bone marrow (BM) microenvironment influences hematopoiesis, we explored the role of Notch signaling and bone marrow endothelial cells in providing microenvironmental cues to hematopoietic cells in the presence of inflammatory stimuli. Methods The human BM endothelial cell line BMEC and primary human BM endothelial cells were analyzed for expression of Notch ligands and the ability to expand hematopoietic progenitors in an in vitro co-culture system. In vivo experiments were carried out to identify modulation of Notch signaling in BM endothelial and hematopoietic cells in mice challenged with TNFα or LPS, or in Tie2-tmTNFα transgenic mice characterized by constitutive TNFα activation. Results BM endothelial cells were found to express Jagged ligands and to greatly support progenitor’s colony-forming ability. This effect was markedly decreased by Notch antagonists and augmented by increasing levels of Jagged2. Physiologic upregulation of Jagged2 expression on BMEC was observed upon TNFα activation. Injection of TNFα or LPS upregulated 3 to 4 fold Jagged2 expression on murine BM endothelial cells in vivo and resulted in increased Notch activation on murine hematopoietic stem/progenitor cells. Similarly, constitutive activation of endothelial cells in Tie2-tmTNFα mice was characterized by increased expression of Jagged2 and by augmented Notch activation on hematopoietic stem/progenitor cells. Conclusions Our results provide the first evidence that BM endothelial cells promote expansion of hematopoietic progenitor cells by a Notch-dependent mechanism and that TNFα and LPS can modulate the levels of Notch ligand expression and Notch activation in the bone marrow microenvironment in vivo. PMID:18439488

  17. Are hematopoietic stem cells involved in hepatocarcinogenesis?

    PubMed Central

    Antonino, Matteo; Del Prete, Valentina; Neve, Viviana; Scavo, Maria Principia; Barone, Michele

    2014-01-01

    The liver has three cell lineages able to proliferate after a hepatic injury: the mature hepatocyte, the ductular “bipolar” progenitor cell termed “oval cell” and the putative periductular stem cell. Hepatocytes can only produce other hepatocytes whereas ductular progenitor cells are considerate bipolar since they can give rise to biliary cells or hepatocytes. Periductular stem cells are rare in the liver, have a very long proliferation potential and may be multipotent, being this aspect still under investigation. They originate in the bone marrow since their progeny express genetic markers of donor hematopoietic cells after bone marrow transplantation. Since the liver is the hematopoietic organ of the fetus, it is possible that hematopoietic stem cells may reside in the liver of the adult. This assumption is proved by the finding that oval cells express hematopoietic markers like CD34, CD45, CD 109, Thy-1, c-kit, and others, which are also expressed by bone marrow-derived hematopoietic stem cells (BMSCs). Few and discordant studies have evaluated the role of BMSC in hepatocarcinogenesis so far and further studies in vitro and in vivo are warranted in order to definitively clarify such an issue. PMID:25202697

  18. Role of osteoclasts in regulating hematopoietic stem and progenitor cells

    PubMed Central

    Miyamoto, Takeshi

    2013-01-01

    Bone marrow (BM) cavities are utilized for hematopoiesis and to maintain hematopoietic stem cells (HSCs). HSCs have the ability to self-renew as well as to differentiate into multiple different hematopoietic lineage cells. HSCs produce their daughter cells throughout the lifespan of individuals and thus, maintaining HSCs is crucial for individual life. BM cavities provide a specialized microenvironment termed “niche” to support HSCs. Niches are composed of various types of cells such as osteoblasts, endothelial cells and reticular cells. Osteoclasts are unique cells which resorb bones and are required for BM cavity formation. Loss of osteoclast function or differentiation results in inhibition of BM cavity formation, an osteopetrotic phenotype. Osteoclasts are also reportedly required for hematopoietic stem and progenitor cell (HSPC) mobilization to the periphery from BM cavities. Thus, lack of osteoclasts likely results in inhibition of HSC maintenance and HSPC mobilization. However, we found that osteoclasts are dispensable for hematopoietic stem cell maintenance and mobilization by using three independent osteoclast-less animal models. In this review, I will discuss the roles of osteoclasts in hematopoietic stem cell maintenance and mobilization. PMID:24147255

  19. Origins.

    ERIC Educational Resources Information Center

    Online-Offline, 1999

    1999-01-01

    Provides an annotated list of resources dealing with the theme of origins of life, the universe, and traditions. Includes Web sites, videos, books, audio materials, and magazines with appropriate grade levels and/or subject disciplines indicated; professional resources; and learning activities. (LRW)

  20. Engineering the Human Thymic Microenvironment to Support Thymopoiesis in Vivo

    PubMed Central

    Chung, Brile; Montel-Hagen, Amélie; Ge, Shundi; Blumberg, Garrett; Kim, Kenneth; Klein, Sam; Zhu, Yuhua; Parekh, Chintan; Balamurugan, Arumugam; Yang, Otto O.; Crooks, Gay M.

    2014-01-01

    A system that allows manipulation of the human thymic microenvironment is needed both to elucidate the extrinsic mechanisms that control human thymopoiesis, and to develop potential cell therapies for thymic insufficiency. In this report, we developed an implantable thymic microenvironment composed of two human thymic stroma populations critical for thymopoiesis; thymic epithelial cells (TECs) and thymic mesenchyme (TM). TECs and TM from postnatal human thymi were cultured in specific conditions, allowing cell expansion and manipulation of gene expression, prior to re-aggregation into a functional thymic unit. Human CD34+ hematopoietic stem and progenitor cells (HSPC) differentiated into T cells in the aggregates in vitro and in vivo following inguinal implantation of aggregates in immune deficient mice. Cord blood HSPC previously engrafted into murine bone marrow, migrated to implants and differentiated into human T cells with a broad T cell receptor repertoire. Furthermore, lentiviral-mediated expression of vascular endothelial growth factor in TM enhanced implant size and function, and significantly increased thymocyte production. These results demonstrate an in vivo system for the generation of T cells from human HSPC, and represent the first model to allow manipulation of gene expression and cell composition in the microenvironment of the human thymus. PMID:24801626

  1. Mutual Interference between Cytomegalovirus and Reconstitution of Protective Immunity after Hematopoietic Cell Transplantation

    PubMed Central

    Reddehase, Matthias J.

    2016-01-01

    Hematopoietic cell transplantation (HCT) is a therapy option for aggressive forms of hematopoietic malignancies that are resistant to standard antitumoral therapies. Hematoablative treatment preceding HCT, however, opens a “window of opportunity” for latent Cytomegalovirus (CMV) by releasing it from immune control with the consequence of reactivation of productive viral gene expression and recurrence of infectious virus. A “window of opportunity” for the virus represents a “window of risk” for the patient. In the interim between HCT and reconstitution of antiviral immunity, primarily mediated by CD8+ T cells, initially low amounts of reactivated virus can expand exponentially, disseminate to essentially all organs, and cause multiple organ CMV disease, with interstitial pneumonia (CMV-IP) representing the most severe clinical manifestation. Here, I will review predictions originally made in the mouse model of experimental HCT and murine CMV infection, some of which have already paved the way to translational preclinical research and promising clinical trials of a preemptive cytoimmunotherapy of human CMV disease. Specifically, the mouse model has been pivotal in providing “proof of concept” for preventing CMV disease after HCT by adoptive transfer of preselected, virus epitope-specific effector and memory CD8+ T cells bridging the critical interim. However, CMV is not a “passive antigen” but is a pathogen that actively interferes with the reconstitution of protective immunity by infecting bone marrow (BM) stromal cells that otherwise form niches for hematopoiesis by providing the structural microenvironment and by producing hematopoietically active cytokines, the hemopoietins. Depending on the precise conditions of HCT, reduced homing of transplanted hematopoietic stem- and progenitor cells to infected BM stroma and impaired colony growth and lineage differentiation can lead to “graft failure.” In consequence, uncontrolled virus spread

  2. Hematopoietic stem cells: an overview.

    PubMed

    Mosaad, Youssef Mohamed

    2014-12-01

    Considerable efforts have been made in recent years in understanding the mechanisms that govern hematopoietic stem cell (HSC) origin, development, differentiation, self-renewal, aging, trafficking, plasticity and transdifferentiation. Hematopoiesis occurs in sequential waves in distinct anatomical locations during development and these shifts in location are accompanied by changes in the functional status of the stem cells and reflect the changing needs of the developing organism. HSCs make a choice of either self-renewal or committing to differentiation. The balance between self-renewal and differentiation is considered to be critical to the maintenance of stem cell numbers. It is still under debate if HSC can rejuvenate infinitely or if they do not possess ''true" self-renewal and undergo replicative senescence such as any other somatic cell. Gene therapy applications that target HSCs offer a great potential for the treatment of hematologic and immunologic diseases. However, the clinical success has been limited by many factors. This review is intended to summarize the recent advances made in the human HSC field, and will review the hematopoietic stem cell from definition through development to clinical applications. PMID:25457002

  3. Hematopoietic Stem Cell: Self-renewal versus Differentiation

    PubMed Central

    Seita, Jun; Weissman, Irving L.

    2010-01-01

    The mammalian blood system, containing more than ten distinct mature cell types, stands on one specific cell type, hematopoietic stem cell (HSC). Within the system, only HSC possess the ability of both multi-potency and self-renewal. Multi-potency is the ability to differentiate into all functional blood cells. Self-renewal is the ability to give rise to HSC itself without differentiation. Since mature blood cells are predominantly short lived, HSC continuously provide more differentiated progenitors while properly maintaining the HSC pool size properly throughout life by precisely balancing self-renewal and differentiation. Thus, understanding the mechanisms of self-renewal and differentiation of HSC has been a central issue. In this review, we focus on the hierarchical structure of the hematopoietic system, the current understanding of microenvironment and molecular cues regulating self-renewal and differentiation of adult HSC, and the currently emerging systems approaches to understand HSC biology. PMID:20890962

  4. Ectopic bone formation in severely combat-injured orthopedic patients -- a hematopoietic niche.

    PubMed

    Davis, Thomas A; Lazdun, Yelena; Potter, Benjamin K; Forsberg, Jonathan A

    2013-09-01

    Combat-related heterotopic ossification (HO) has emerged as a common and problematic complication of modern wartime extremity injuries, contributing to substantial patient morbidity and loss of function. We have previously reported that HO-forming patients exhibit a more pronounced systemic and local inflammatory response very early in the wound healing process. Moreover, traumatized muscle-derived mesenchymal progenitor cells from these patients have a skewed differentiation potential toward bone. Here, we demonstrate that HO lesions excised from this patient population contain highly vascularized, mature, cancellous bone containing adipogenic marrow. Histologic analysis showed immature hematopoietic cells located within distinct foci in perivascular regions. The adipogenic marrow often contained low numbers of functional erythroid (BFU-E), myeloid (CFU-GM, CFU-M) and multilineage (CFU-GEMM) colony-forming hematopoietic progenitor cells (HPCs). Conversely, tissue from control muscle and non-HO traumatic wound granulation tissue showed no evidence of hematopoietic progenitor cell activity. In summary, our findings suggest that ectopic bone can provide an appropriate hematopoietic microenvironment for supporting the proliferation and differentiation of HPCs. This reactive and vibrant cell population may help maintain normal hematopoietic function, particularly in those with major extremity amputations who have sustained both massive blood loss, prompting systemic marrow stimulation, as well as loss of available native active marrow space. These findings begin to characterize the functional biology of ectopic bone and elucidate the interactions between HPC and non-hematopoietic cell types within the ectopic intramedullary hematopoietic microenvironmental niche identified. PMID:23727270

  5. Generation of axolotl hematopoietic chimeras

    PubMed Central

    Lopez, David; Scott, Edward W.

    2015-01-01

    Wound repair is an extremely complex process that requires precise coordination between various cell types including immune cells. Unfortunately, in mammals this usually results in scar formation instead of restoration of the original fully functional tissue, otherwise known as regeneration. Various animal models like frogs and salamanders are currently being studied to determine the intracellular and intercellular pathways, controlled by gene expression, that elicit cell proliferation, differentiation, and migration of cells during regenerative healing. Now, the necessary genetic tools to map regenerative pathways are becoming available for the axolotl salamander, thus allowing comparative studies between scarring and regeneration. Here, we describe in detail three methods to produce axolotl hematopoietic cell-tagged chimeras for the study of hematopoiesis and regeneration. PMID:26366424

  6. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    PubMed Central

    Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

    2015-01-01

    Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system. PMID:26136659

  7. An overlooked tumor promoting immunoregulation by non-hematopoietic stromal cells.

    PubMed

    Bose, Anamika; Ghosh, Tithi; Baral, Rathindranath

    2016-08-01

    Multidirectional complex communication between tumor-residing hematopoietic and non-hematopoietic stromal cells (NHSCs) decisively regulates cancer development, progression and therapeutic responses. HSCs predominantly participate in the immune regulations, while, NHSCs, provide parenchymal support or serve as a conduit for other cells or support angiogenesis. However, recent reports suggest NHSCs can additionally participate in ongoing tumor promoting immune reactions within tumor-microenvironment (TME). In this review, based on the state-of-art knowledge and accumulated evidence by us, we discuss the role of quite a few NHSCs in tumor from immunological perspectives. Understanding such consequence of NHSCs will surely pave the way in crafting effective cancer management. PMID:27311851

  8. Histological and In Vivo Microscopic Analysis of the Bone Marrow Microenvironment in a Murine Model of Chronic Myelogenous Leukemia.

    PubMed

    Weissenberger, Eva S; Krause, Daniela S

    2016-01-01

    Imaging of the leukemic bone marrow microenvironment, also called the leukemic bone marrow niche, is an essential method to determine and to evaluate the progression of chronic myelogenous leukemia (CML) and other leukemias in murine models. In this chapter we introduce the murine model of CML primarily used in our laboratory by describing blood and bone marrow analysis as well as the method of histological sectioning and immunohistochemistry in combination with various stainings that can help to understand the complex interaction between leukemic cells, their normal hematopoietic counterparts, and the bone marrow microenvironment. We conclude with describing how to image the bone marrow niche using in vivo microscopy. PMID:27581139

  9. Tumor microenvironment: Sanctuary of the devil.

    PubMed

    Hui, Lanlan; Chen, Ye

    2015-11-01

    Tumor cells constantly interact with the surrounding microenvironment. Increasing evidence indicates that targeting the tumor microenvironment could complement traditional treatment and improve therapeutic outcomes for these malignancies. In this paper, we review new insights into the tumor microenvironment, and summarize selected examples of the cross-talk between tumor cells and their microenvironment, which have enhanced our understanding of pathophysiology of the microenvironment. We believe that this rapidly moving field promises many more to come, and they will guide the rational design of combinational therapies for success in cancer eradication. PMID:26276713

  10. Hematopoietic stem cell transplantation

    PubMed Central

    Hatzimichael, Eleftheria; Tuthill, Mark

    2010-01-01

    More than 25,000 hematopoietic stem cell transplantations (HSCTs) are performed each year for the treatment of lymphoma, leukemia, immune-deficiency illnesses, congenital metabolic defects, hemoglobinopathies, and myelodysplastic and myeloproliferative syndromes. Before transplantation, patients receive intensive myeloablative chemoradiotherapy followed by stem cell “rescue.” Autologous HSCT is performed using the patient’s own hematopoietic stem cells, which are harvested before transplantation and reinfused after myeloablation. Allogeneic HSCT uses human leukocyte antigen (HLA)-matched stem cells derived from a donor. Survival after allogeneic transplantation depends on donor–recipient matching, the graft-versus-host response, and the development of a graft versus leukemia effect. This article reviews the biology of stem cells, clinical efficacy of HSCT, transplantation procedures, and potential complications. PMID:24198516

  11. Human cord cell hematopoiesis in three-dimensional nonwoven fibrous matrices: in vitro simulation of the marrow microenvironment.

    PubMed

    Li, Y; Ma, T; Kniss, D A; Yang, S T; Lasky, L C

    2001-06-01

    Current hematopoietic culture systems mainly utilize two-dimensional devices with limited ability to promote self-renewal of early progenitors. In vivo-like three-dimensional (3-D) culture environments might be conducive to regulating stem cell proliferation and differentiation similar to in vivo hematopoiesis. The few 3-D cultures reported in the literature either produced few progenitors or provided little information about microenvironment. In this study, we constructed a 3-D hematopoietic microenvironment composed of nonwoven matrix and human cord blood (CB) cells to simulate the marrow microenvironment and expand cord progenitors. Nonwoven polyethylene terephthalate (PET) fabric with defined microstructure was used as the 3-D scaffold and the PET surface was modified by hydrolysis to improve cell adhesion. Different cell organizations were formed in a 3-D matrix in a developmental manner, from individual cells and cells bridging between fibers to large cell aggregates. Both stromal and hematopoietic cells were distributed spatially within the scaffold. Compared to two-dimensional (2-D) CD34(+) cell culture, 3-D culture produced 30-100% higher total cells and progenitors without exogenous cytokines. With thrombopoietin and flt-3/flk-2 ligand, it supported two- to three-fold higher total cell number (62.1- vs. 24.6-fold), CD34(+) cell number (6.8- vs. 2.8-fold) and colony-forming unit (CFU) number for 7-9 weeks (n = 6), indicating a hematopoiesis pathway that promoted progenitor production. Culture in 3-D nonwoven matrices enhanced cell-cell and cell-matrix interactions and allowed 3-D distribution of stromal and hematopoietic cells. The formation of cell aggregates and higher progenitor content indicated that the spatial microenvironment in 3-D culture played an important role in promoting hematopoiesis. This 3-D culture system can be used as an in vitro model to study stem cell or progenitor behavior, and to achieve sustained progenitor expansion. PMID

  12. Spleens of myelofibrosis patients contain malignant hematopoietic stem cells

    PubMed Central

    Wang, Xiaoli; Prakash, Sonam; Lu, Min; Tripodi, Joseph; Ye, Fei; Najfeld, Vesna; Li, Yan; Schwartz, Myron; Weinberg, Rona; Roda, Paul; Orazi, Attilio; Hoffman, Ronald

    2012-01-01

    Cancer stem cell behavior is thought to be largely determined by intrinsic properties and by regulatory signals provided by the microenvironment. Myelofibrosis (MF) is characterized by hematopoiesis occurring not only in the marrow but also in extramedullary sites such as the spleen. In order to study the effects of these different microenvironments on primitive malignant hematopoietic cells, we phenotypically and functionally characterized splenic and peripheral blood (PB) MF CD34+ cells from patients with MF. MF spleens contained greater numbers of malignant primitive HPCs than PB. Transplantation of PB MF CD34+ cells into immunodeficient (NOD/SCID/IL2Rγnull) mice resulted in a limited degree of donor cell chimerism and a differentiation program skewed toward myeloid lineages. By contrast, transplanted splenic MF CD34+ cells achieved a higher level of chimerism and generated both myeloid and lymphoid cells that contained molecular or cytogenetic abnormalities indicating their malignant nature. Only splenic MF CD34+ cells were able to sustain hematopoiesis for prolonged periods (9 months) and were able to engraft secondary recipients. These data document the existence of MF stem cells (MF-SCs) that reside in the spleens of MF patients and demonstrate that these MF-SCs retain a differentiation program identical to that of normal hematopoietic stem cells. PMID:23023702

  13. TopBP1 Governs Hematopoietic Stem/Progenitor Cells Survival in Zebrafish Definitive Hematopoiesis

    PubMed Central

    Gao, Lei; Li, Dantong; Ma, Ke; Zhang, Wenjuan; Xu, Tao; Fu, Cong; Jing, Changbin; Jia, Xiaoe; Wu, Shuang; Sun, Xin; Dong, Mei; Deng, Min; Chen, Yi; Zhu, Wenge; Peng, Jinrong; Wan, Fengyi; Zhou, Yi; Zon, Leonard I.; Pan, Weijun

    2015-01-01

    In vertebrate definitive hematopoiesis, nascent hematopoietic stem/progenitor cells (HSPCs) migrate to and reside in proliferative hematopoietic microenvironment for transitory expansion. In this process, well-established DNA damage response pathways are vital to resolve the replication stress, which is deleterious for genome stability and cell survival. However, the detailed mechanism on the response and repair of the replication stress-induced DNA damage during hematopoietic progenitor expansion remains elusive. Here we report that a novel zebrafish mutantcas003 with nonsense mutation in topbp1 gene encoding topoisomerase II β binding protein 1 (TopBP1) exhibits severe definitive hematopoiesis failure. Homozygous topbp1cas003 mutants manifest reduced number of HSPCs during definitive hematopoietic cell expansion, without affecting the formation and migration of HSPCs. Moreover, HSPCs in the caudal hematopoietic tissue (an equivalent of the fetal liver in mammals) in topbp1cas003 mutant embryos are more sensitive to hydroxyurea (HU) treatment. Mechanistically, subcellular mislocalization of TopBP1cas003 protein results in ATR/Chk1 activation failure and DNA damage accumulation in HSPCs, and eventually induces the p53-dependent apoptosis of HSPCs. Collectively, this study demonstrates a novel and vital role of TopBP1 in the maintenance of HSPCs genome integrity and survival during hematopoietic progenitor expansion. PMID:26131719

  14. Epigenetic Control of Apolipoprotein E Expression Mediates Gender-Specific Hematopoietic Regulation.

    PubMed

    Vasanthakumar, Aparna; Zullow, Hayley; Lepore, Janet B; Thomas, Kenya; Young, Natalie; Anastasi, John; Reardon, Catherine A; Godley, Lucy A

    2015-12-01

    Epigenetic alterations play a central role in the control of normal and malignant blood cell development. We demonstrate here that expression of a truncated DNA methyltransferase 3B isoform DNMT3B7, which has been shown to alter cellular epigenetic patterns, decreases the overall number of hematopoietic stem and progenitor cells (HSPCs), and markedly diminishes blood cell reconstitution within the female hormonal microenvironment. Gene expression profiling of HSPCs isolated from DNMT3B7 transgenic embryos identified Apolipoprotein E (Apoe) as overexpressed. The CpG island controlling Apoe expression had lower levels of modified cytosines in DNMT3B7 transgenic HSPCs, corresponding with the observed increase in gene expression. Furthermore, we observed that spleens and bone marrows of female mice transplanted with DNMT3B7 transgenic HSPCs express very high levels of Apoe. Finally, the introduction of Apoe-overexpressing HSPCs into male recipients decreased bone marrow engraftment, recapitulating our original observations in female recipients. Our work reveals a dynamic interplay between the intrinsic epigenetic changes in HSPCs and extrinsic endocrine factors acting on these cells to regulate the efficiency of HSPC engraftment and reconstitution. We have identified a novel mechanism by which gender-specific hormones modulate HSPC function, which could serve as a target for augmenting hematopoiesis in cases with limited HSC functionality. PMID:26417967

  15. Dissecting the multiple myeloma-bone microenvironment reveals new therapeutic opportunities.

    PubMed

    Shay, G; Hazlehurst, L; Lynch, C C

    2016-01-01

    Multiple myeloma is a plasma cell skeletal malignancy. While therapeutic agents such as bortezomib and lenalidomide have significantly improved overall survival, the disease is currently incurable with the emergence of drug resistance limiting the efficacy of chemotherapeutic strategies. Failure to cure the disease is in part due to the underlying genetic heterogeneity of the cancer. Myeloma progression is critically dependent on the surrounding microenvironment. Defining the interactions between myeloma cells and the more genetically stable hematopoietic and mesenchymal components of the bone microenvironment is critical for the development of new therapeutic targets. In this review, we discuss recent advances in our understanding of how microenvironmental elements contribute to myeloma progression and, therapeutically, how those elements can or are currently being targeted in a bid to eradicate the disease. PMID:26423531

  16. Targeting of the bone marrow microenvironment improves outcome in a murine model of myelodysplastic syndrome

    PubMed Central

    Balderman, Sophia R.; Li, Allison J.; Hoffman, Corey M.; Frisch, Benjamin J.; Goodman, Alexandra N.; LaMere, Mark W.; Georger, Mary A.; Evans, Andrew G.; Liesveld, Jane L.; Becker, Michael W.

    2016-01-01

    In vitro evidence suggests that the bone marrow microenvironment (BMME) is altered in myelodysplastic syndromes (MDSs). Here, we study the BMME in MDS in vivo using a transgenic murine model of MDS with hematopoietic expression of the translocation product NUP98-HOXD13 (NHD13). This model exhibits a prolonged period of cytopenias prior to transformation to leukemia and is therefore ideal to interrogate the role of the BMME in MDS. In this model, hematopoietic stem and progenitor cells (HSPCs) were decreased in NHD13 mice by flow cytometric analysis. The reduction in the total phenotypic HSPC pool in NHD13 mice was confirmed functionally with transplantation assays. Marrow microenvironmental cellular components of the NHD13 BMME were found to be abnormal, including increases in endothelial cells and in dysfunctional mesenchymal and osteoblastic populations, whereas megakaryocytes were decreased. Both CC chemokine ligand 3 and vascular endothelial growth factor, previously shown to be increased in human MDS, were increased in NHD13 mice. To assess whether the BMME contributes to disease progression in NHD13 mice, we performed transplantation of NHD13 marrow into NHD13 mice or their wild-type (WT) littermates. WT recipients as compared with NHD13 recipients of NHD13 marrow had a lower rate of the combined outcome of progression to leukemia and death. Moreover, hematopoietic function was superior in a WT BMME as compared with an NHD13 BMME. Our data therefore demonstrate a contributory role of the BMME to disease progression in MDS and support a therapeutic strategy whereby manipulation of the MDS microenvironment may improve hematopoietic function and overall survival. PMID:26637787

  17. Chemopreventive agents targeting tumor microenvironment.

    PubMed

    Sharma, Sharada H; Thulasingam, Senthilkumar; Nagarajan, Sangeetha

    2016-01-15

    Recent studies have shown that tumor development and progression depend not only on the perturbed genes that govern cell proliferation, but is also highly determined by the non-tumor cells of the stromal compartment surrounding the tumor called tumor microenvironment (TME). These findings highlight the importance of targeting the microenvironment in combination with therapies aimed at tumor cells as a valuable approach. The innate and adaptive immune cells in the TME interact among themselves and also with the endothelial cells, pericytes and mast cells of the stromal compartment through various autocrine and paracrine manner to regulate abnormal cell proliferation. Direct cytotoxic killing of cancer cells and/or reversion of the immunosuppressive TME are to be considered as better strategies for chemoprevention and chemotherapy. With a growing emphasis on a "hallmark targeting" strategy for cancer therapy, the TME now appears as a promising target for cancer prevention using natural products. Clarification on the nontumor stromal cells, the mediators involved, interactions with immune response cells, and immune-evasive mechanisms are needed in order to manipulate the characteristics of the TME by natural pharmacological agents to design effective therapies. This review will provide a glimpse on the roles played by various non-tumor cells in tumor progression and their intervention by pharmacological agents. PMID:26679106

  18. LDEF microenvironments, observed and predicted

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.

    1992-01-01

    Complex protrusions and surface indentations on spacecraft equipment alter exposure environments by casting shadows, producing reflections and scattering incident atomic oxygen flux and UV radiation. A computer model is being developed to predict these effects. The model accounts for any arbitrary shape, size, orientation, or curvature of exposed objects. LDEF offers a unique opportunity to compare model prediction with observations. For this purpose, a study is underway on twelve of LDEF's copper grounding straps. These straps were exposed at various angles from the ram vector during the LDEF flight. Microenvironment variables include shadowing and reflections from clamps and fasteners, and varying exposure caused by bending of the straps. Strap measurements include optical properties, surface film composition by ESCA, and film thickness measurements by optical interference techniques. The features of the microenvironment model and the analytical methods used to examine the straps are discussed. Data are presented showing predicted microenvironmental variations. These variations are compared with observed point to point differences in surface properties of the straps.

  19. Endothelin-1 in the tumor microenvironment correlates with melanoma invasion.

    PubMed

    Chiriboga, Luis; Meehan, Shane; Osman, Iman; Glick, Michael; de la Cruz, Gelo; Howell, Brittny S; Friedman-Jiménez, George; Schneider, Robert J; Jamal, Sumayah

    2016-06-01

    Endothelin-1 (ET-1) is a vasoactive peptide that also plays a role in the tanning response of the skin. Animal and cell culture studies have also implicated ET-1 in melanoma progression, but no association studies have been performed to link ET-1 expression and melanoma in humans. Here, we present the first in-vivo study of ET-1 expression in pigmented lesions in humans: an ET-1 immunohistochemical screen of melanocytic nevi, melanoma in situ lesions, invasive melanomas, metastatic melanomas, and blue nevi was performed. Twenty-six percent of melanocytic nevi and 44% of melanoma in situ lesions demonstrate ET-1 expression in the perilesional microenvironment, whereas expression in nevus or melanoma cells was rare to absent. In striking contrast, 100% of moderately to highly pigmented invasive melanomas contained numerous ET-1-positive cells in the tumor microenvironment, with 79% containing ET-1-positive melanoma cells, confirmed by co-staining with melanoma tumor marker HMB45. Hypopigmented invasive melanomas had reduced ET-1 expression, suggesting a correlation between ET-1 expression and pigmented melanomas. ET-1-positive perilesional cells were CD68-positive, indicating macrophage origin. Sixty-two percent of highly pigmented metastatic melanomas demonstrated ET-1 expression in melanoma cells, in contrast to 28.2% of hypopigmented specimens. Eighty-nine percent of benign nevi, known as blue nevi, which have a dermal localization, were associated with numerous ET-1-positive macrophages in the perilesional microenvironment, but no ET-1 expression was detected in the melanocytes. We conclude that ET-1 expression in the microenvironment increases with advancing stages of melanocyte transformation, implicating a critical role for ET-1 in melanoma progression, and the importance of the tumor microenvironment in the melanoma phenotype. PMID:26825037

  20. The Hematopoietic Niche in Myeloproliferative Neoplasms

    PubMed Central

    Schmitt-Graeff, Annette H.; Nitschke, Roland; Zeiser, Robert

    2015-01-01

    Specialized microanatomical areas of the bone marrow provide the signals that are mandatory for the maintenance and regulation of hematopoietic stem cells (HSCs) and progenitor cells. A complex microenvironment adjacent to the marrow vasculature (vascular niche) and close to the endosteum (endosteal niche) harbors multiple cell types including mesenchymal stromal cells and their derivatives such as CAR cells expressing high levels of chemokines C-X-C motif ligand 12 and early osteoblastic lineage cells, endothelial cells, and megakaryocytes. The characterization of the cellular and molecular networks operating in the HSC niche has opened new perspectives for the understanding of the bidirectional cross-talk between HSCs and stromal cell populations in normal and malignant conditions. A structural and functional remodeling of the niche may contribute to the development of myeloproliferative neoplasms (MPN). Malignant HSCs may alter the function and survival of MSCs that do not belong to the neoplastic clone. For example, a regression of nestin+ MSCs by apoptosis has been attributed to neuroglial damage in MPN. Nonneoplastic MSCs in turn can promote aggressiveness and drug resistance of malignant cells. In the future, strategies to counteract the pathological interaction between the niche and neoplastic HSCs may offer additional treatment strategies for MPN patients. PMID:26696752

  1. Commensal bacteria modulate the tumor microenvironment.

    PubMed

    Poutahidis, Theofilos; Erdman, Susan E

    2016-09-28

    It has been recently shown that gut microbes modulate whole host immune and hormonal factors impacting the fate of distant preneoplastic lesions toward malignancy or regression. This raises the possibility that the tumor microenvironment interacts with broader systemic microbial-immune networks. These accumulated findings suggest novel therapeutic opportunities for holobiont engineering in emerging tumor microenvironments. PMID:26739062

  2. Metabolic exchanges within tumor microenvironment.

    PubMed

    Chiarugi, Paola; Cirri, Paolo

    2016-09-28

    Tumor progression toward malignancy often requires a metabolic rewiring of cancer cells to meet changes in metabolic demand to forefront nutrient and oxygen withdrawal, together with strong anabolic requests to match high proliferation rate. Tumor microenvironment highly contributes to metabolic rewiring of cancer cells, fostering complete nutrient exploitation, favoring OXPHOS of lipids and glutamine at the expense of glycolysis and enhancing exchanges via extracellular microvesicles or exosomes of proteins, lipids and small RNAs among tumor and stromal cells. Noteworthy, the same molecular drivers of metabolic reprogramming within tumor and stroma are also able to elicit motility, survival and self-renewal on cancer cells, thereby sustaining successful escaping strategies to circumvent the hostile hypoxic, acidic and inflammatory environment. This review highlights the emerging role of nutrients and vesicle-mediated exchanges among tumor and stromal cells, defining their molecular pathways and offering new perspectives to develop treatments targeting this complex metabolic rewiring. PMID:26546872

  3. Endothelial cells mitigate DNA damage and promote the regeneration of hematopoietic stem cells after radiation injury

    PubMed Central

    Zachman, Derek K.; Leon, Ronald P.; Das, Prerna; Goldman, Devorah C.; Hamlin, Kimberly L.; Guha, Chandan; Fleming, William H.

    2014-01-01

    Endothelial cells (ECs) are an essential component of the hematopoietic microenvironment, which maintains and regulates hematopoietic stem cells (HSCs). Although ECs can support the regeneration of otherwise lethally-irradiated HSCs, the mechanisms are not well understood. To further understand this phenomenon, we studied HSC regeneration from irradiated bone marrow using co-culture with human aortic endothelial cells (HAECs). Co-culture with HAECs induced a 24-fold expansion of long-term HSCs (CD150+, lineagelo, Sca-1+, c-Kit+; CD150+LSK cells) in vitro. These cells gave rise to functional hematopoietic stem and progenitor cells (HSPCs) with colony-forming activity, multilineage reconstitution and serial transplantation potential. Furthermore, HAECs significantly reduced DNA damage in irradiated LSK cells within 24 hours. Remarkably, we were able to delay the exposure of irradiated bone marrow to the regenerative, HAEC-derived signals for up to 48 hours and still rescue functional HSCs. G-CSF is the gold standard for promoting hematopoietic regeneration in vivo. However, when compared to HAECs, in vitro G-CSF treatment promoted lineage differentiation and regenerated 5-fold fewer CD150+LSK cells. Together, our results show that HAECs are powerful, direct mitigators of HSC injury and DNA damage. Identification of the HAEC-derived factors that rescue HSCs may lead to improved therapies for hematopoietic regeneration after radiation injury. PMID:23939266

  4. Acidic extracellular microenvironment and cancer

    PubMed Central

    2013-01-01

    Acidic extracellular pH is a major feature of tumor tissue, extracellular acidification being primarily considered to be due to lactate secretion from anaerobic glycolysis. Clinicopathological evidence shows that transporters and pumps contribute to H+ secretion, such as the Na+/H+ exchanger, the H+-lactate co-transporter, monocarboxylate transporters, and the proton pump (H+-ATPase); these may also be associated with tumor metastasis. An acidic extracellular pH not only activates secreted lysosomal enzymes that have an optimal pH in the acidic range, but induces the expression of certain genes of pro-metastatic factors through an intracellular signaling cascade that is different from hypoxia. In addition to lactate, CO2 from the pentose phosphate pathway is an alternative source of acidity, showing that hypoxia and extracellular acidity are, while being independent from each other, deeply associated with the cellular microenvironment. In this article, the importance of an acidic extracellular pH as a microenvironmental factor participating in tumor progression is reviewed. PMID:24004445

  5. Differential regulation of myeloid leukemias by the bone marrow microenvironment.

    PubMed

    Krause, Daniela S; Fulzele, Keertik; Catic, André; Sun, Chia Chi; Dombkowski, David; Hurley, Michael P; Lezeau, Sanon; Attar, Eyal; Wu, Joy Y; Lin, Herbert Y; Divieti-Pajevic, Paola; Hasserjian, Robert P; Schipani, Ernestina; Van Etten, Richard A; Scadden, David T

    2013-11-01

    Like their normal hematopoietic stem cell counterparts, leukemia stem cells (LSCs) in chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML) are presumed to reside in specific niches in the bone marrow microenvironment (BMM) and may be the cause of relapse following chemotherapy. Targeting the niche is a new strategy to eliminate persistent and drug-resistant LSCs. CD44 (refs. 3,4) and interleukin-6 (ref. 5) have been implicated previously in the LSC niche. Transforming growth factor-β1 (TGF-β1) is released during bone remodeling and plays a part in maintenance of CML LSCs, but a role for TGF-β1 from the BMM has not been defined. Here, we show that alteration of the BMM by osteoblastic cell-specific activation of the parathyroid hormone (PTH) receptor attenuates BCR-ABL1 oncogene-induced CML-like myeloproliferative neoplasia (MPN) but enhances MLL-AF9 oncogene-induced AML in mouse transplantation models, possibly through opposing effects of increased TGF-β1 on the respective LSCs. PTH treatment caused a 15-fold decrease in LSCs in wild-type mice with CML-like MPN and reduced engraftment of immune-deficient mice with primary human CML cells. These results demonstrate that LSC niches in CML and AML are distinct and suggest that modulation of the BMM by PTH may be a feasible strategy to reduce LSCs, a prerequisite for the cure of CML. PMID:24162813

  6. Hematopoietic ontogeny and its relevance for pediatric leukemias.

    PubMed

    Udroiu, Ion; Sgura, Antonella

    2016-03-01

    Fetal and infant hematopoiesis display characteristics different from the adult one: our suggestion is that these features may help to explain the peculiar incidence rates of acute leukemias. Hematopoietic stem cells (HSCs) are fast-cycling (those in adults instead are largely quiescent) and studies in mice demonstrated that their relative contribution to myelo- and lymphopoiesis varies during development. We hypothesize that during development some of the "hits" needed for the onset of leukemia are usually occurring (being part of the normal development), so leukemogenesis needs less mutations than in adults to take place and therefore it's more probable. The switch between the relative incidence of acute myeloid and lymphoid leukemias may be related to the changes of the percentage of lymphoid-deficient and lymphoid-proficient sub-set of HSCs during development. Further investigations may clarify this hypothesis, elucidating also the roles of the different microenvironments in determining the myeloid/lymphoid predisposition of the HSCs. PMID:26880643

  7. [Physiological regulation of hematopoietic stem cell and its molecular basis].

    PubMed

    Dong, Fang; Hao, Sha; Cheng, Hui; Cheng, Tao

    2016-08-25

    As a classical type of tissue stem cells, hematopoietic stem cell (HSC) is the earliest discovered and has been widely applied in the clinic as a great successful example for stem cell therapy. Thus, HSC research represents a leading field in stem cell biology and regenerative medicine. Self-renewal, differentiation, quiescence, apoptosis and trafficking constitute major characteristics of functional HSCs. These characteristics also signify different dynamic states of HSC through physiological interactions with the microenvironment cues in vivo. This review covers our current knowledge on the physiological regulation of HSC and its underlying molecular mechanisms. It is our hope that this review will not only help our colleagues to understand how HSC is physiologically regulated but also serve as a good reference for the studies on stem cell and regenerative medicine in general. PMID:27546503

  8. Genetic and Epigenetic Mechanisms That Maintain Hematopoietic Stem Cell Function

    PubMed Central

    Kosan, Christian; Godmann, Maren

    2016-01-01

    All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC) have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem cell niche provides the microenvironment to keep HSC in a quiescent state. Furthermore, several transcription factors and epigenetic modifiers are involved in this process. These create modifications that regulate the cell fate in a more or less reversible and dynamic way and contribute to HSC homeostasis. In addition, HSC respond in a unique way to DNA damage. These mechanisms also contribute to the regulation of HSC function and are essential to ensure viability after DNA damage. How HSC maintain their quiescent stage during the entire life is still matter of ongoing research. Here we will focus on the molecular mechanisms that regulate HSC function. PMID:26798358

  9. CD34+ hematopoietic precursors are present in human decidua and differentiate into natural killer cells upon interaction with stromal cells.

    PubMed

    Vacca, Paola; Vitale, Chiara; Montaldo, Elisa; Conte, Romana; Cantoni, Claudia; Fulcheri, Ezio; Darretta, Valeria; Moretta, Lorenzo; Mingari, Maria Cristina

    2011-02-01

    Natural killer (NK) cells are the main lymphoid population in the maternal decidua during the first trimester of pregnancy. Decidual NK (dNK) cells display a unique functional profile and play a key role in promoting tissue remodeling, neoangiogenesis, and immune modulation. However, little information exists on their origin and development. Here we discovered CD34(+) hematopoietic precursors in human decidua (dCD34(+)). We show that dCD34(+) cells differ from cord blood- or peripheral blood-derived CD34(+) precursors. The expression of IL-15/IL-2 receptor common β-chain (CD122), IL-7 receptor α-chain (CD127), and mRNA for E4BP4 and ID2 transcription factors suggested that dCD34(+) cells are committed to the NK cell lineage. Moreover, they could undergo in vitro differentiation into functional (i.e., IL-8- and IL-22-producing) CD56(bright)CD16(-)KIR(+/-) NK cells in the presence of growth factors or even upon coculture with decidual stromal cells. Their NK cell commitment was further supported by the failure to undergo myeloid differentiation in the presence of GM-CSF. Our findings strongly suggest that decidual NK cells may directly derive from CD34(+) cell precursors present in the decidua upon specific cellular interactions with components of the decidual microenvironment. PMID:21248224

  10. Ophthalmic Manifestations of Hematopoietic Malignancy.

    PubMed

    Yoshida-Hata, Natsuyo; Katai, Naomichi; Oshitari, Toshiyuki

    2016-01-01

    Purpose. To report the ocular findings in patients with hematopoietic malignancy with optic nerve involvement and abducens nerve palsy. Methods. The medical records of all cases of hematopoietic cancer with ophthalmic involvements seen in the Department of Ophthalmology of the National Center for Global Health and Medicine between 2009 and 2014 were reviewed. Results. Eight patients with hematopoietic cancer with optic nerve invasion or abducens nerve palsy were studied. The primary diseases were 3 cases of multiple myeloma, 1 case of acute lymphocytic leukemia, 1 case of follicular lymphoma, and 3 cases of AIDS-related lymphoma. Six cases had optic nerve invasion, 2 cases had abducens nerve palsy, and 1 case had optic nerve invasion of both eyes. The median visual acuity of eyes with optic nerve invasion was 0.885 logarithm of the minimum angle of resolution (logMAR) units. The final visual acuity of eyes with optic nerve invasion was 1.25 logMAR units, and that of those with sixth-nerve palsy was -0.1 logMAR units. Six cases died during the five-year follow-up period. An ophthalmic involvement in patients with hematopoietic cancer, especially AIDS-related lymphoma, was associated with poor prognosis. Conclusion. Because ophthalmic involvement in patients with hematopoietic malignancy has a poor prognosis, an early diagnosis of the cancers by the ophthalmologic findings by ophthalmologists could improve the prognosis. PMID:27375913

  11. Ophthalmic Manifestations of Hematopoietic Malignancy

    PubMed Central

    2016-01-01

    Purpose. To report the ocular findings in patients with hematopoietic malignancy with optic nerve involvement and abducens nerve palsy. Methods. The medical records of all cases of hematopoietic cancer with ophthalmic involvements seen in the Department of Ophthalmology of the National Center for Global Health and Medicine between 2009 and 2014 were reviewed. Results. Eight patients with hematopoietic cancer with optic nerve invasion or abducens nerve palsy were studied. The primary diseases were 3 cases of multiple myeloma, 1 case of acute lymphocytic leukemia, 1 case of follicular lymphoma, and 3 cases of AIDS-related lymphoma. Six cases had optic nerve invasion, 2 cases had abducens nerve palsy, and 1 case had optic nerve invasion of both eyes. The median visual acuity of eyes with optic nerve invasion was 0.885 logarithm of the minimum angle of resolution (logMAR) units. The final visual acuity of eyes with optic nerve invasion was 1.25 logMAR units, and that of those with sixth-nerve palsy was −0.1 logMAR units. Six cases died during the five-year follow-up period. An ophthalmic involvement in patients with hematopoietic cancer, especially AIDS-related lymphoma, was associated with poor prognosis. Conclusion. Because ophthalmic involvement in patients with hematopoietic malignancy has a poor prognosis, an early diagnosis of the cancers by the ophthalmologic findings by ophthalmologists could improve the prognosis. PMID:27375913

  12. Catalog of gene expression in adult neural stem cells and their in vivo microenvironment

    SciTech Connect

    Williams, Cecilia; Wirta, Valtteri; Meletis, Konstantinos; Wikstroem, Lilian; Carlsson, Leif; Frisen, Jonas; Lundeberg, Joakim . E-mail: joakim.lundeberg@biotech.kth.se

    2006-06-10

    Stem cells generally reside in a stem cell microenvironment, where cues for self-renewal and differentiation are present. However, the genetic program underlying stem cell proliferation and multipotency is poorly understood. Transcriptome analysis of stem cells and their in vivo microenvironment is one way of uncovering the unique stemness properties and provides a framework for the elucidation of stem cell function. Here, we characterize the gene expression profile of the in vivo neural stem cell microenvironment in the lateral ventricle wall of adult mouse brain and of in vitro proliferating neural stem cells. We have also analyzed an Lhx2-expressing hematopoietic-stem-cell-like cell line in order to define the transcriptome of a well-characterized and pure cell population with stem cell characteristics. We report the generation, assembly and annotation of 50,792 high-quality 5'-end expressed sequence tag sequences. We further describe a shared expression of 1065 transcripts by all three stem cell libraries and a large overlap with previously published gene expression signatures for neural stem/progenitor cells and other multipotent stem cells. The sequences and cDNA clones obtained within this framework provide a comprehensive resource for the analysis of genes in adult stem cells that can accelerate future stem cell research.

  13. T-cell exhaustion in the tumor microenvironment

    PubMed Central

    Jiang, Y; Li, Y; Zhu, B

    2015-01-01

    T-cell exhaustion was originally identified during chronic infection in mice, and was subsequently observed in humans with cancer. The exhausted T cells in the tumor microenvironment show overexpressed inhibitory receptors, decreased effector cytokine production and cytolytic activity, leading to the failure of cancer elimination. Restoring exhausted T cells represents an inspiring strategy for cancer treatment, which has yielded promising results and become a significant breakthrough in the cancer immunotherapy. In this review, we overview the updated understanding on the exhausted T cells in cancer and their potential regulatory mechanisms and discuss current therapeutic interventions targeting exhausted T cells in clinical trials. PMID:26086965

  14. SHIPi Enhances Autologous and Allogeneic Hematopoietic Stem Cell Transplantation

    PubMed Central

    Fernandes, Sandra; Brooks, Robert; Gumbleton, Matthew; Park, Mi-Young; Russo, Christopher M.; Howard, Kyle T.; Chisholm, John D.; Kerr, William G.

    2015-01-01

    Hematopoietic stem cell transplantation (HSCT) is a highly effective procedure enabling long-term survival for patients with hematologic malignancy or heritable defects. Although there has been a dramatic increase in the success rate of HSCT over the last two decades, HSCT can result in serious, sometimes untreatable disease due to toxic conditioning regimens and Graft-versus-Host-Disease. Studies utilizing germline knockout mice have discovered several candidate genes that could be targeted pharmacologically to create a more favorable environment for transplant success. SHIP1 deficiency permits improved engraftment of hematopoietic stem-progenitor cells (HS-PCs) and produces an immunosuppressive microenvironment ideal for incoming allogeneic grafts. The recent development of small molecule SHIP1 inhibitors has opened a different therapeutic approach by creating transient SHIP1-deficiency. Here we show that SHIP1 inhibition (SHIPi) mobilizes functional HS-PC, accelerates hematologic recovery, and enhances donor HS-PC engraftment in both allogeneic and autologous transplant settings. We also observed the expansion of key cell populations known to suppress host-reactive cells formed during engraftment. Therefore, SHIPi represents a non-toxic, new therapeutic that has significant potential to improve the success and safety of therapies that utilize autologous and allogeneic HSCT. PMID:26052545

  15. Regulation of Hematopoietic Stem Cell Activity by Inflammation

    PubMed Central

    Schuettpelz, Laura G.; Link, Daniel C.

    2013-01-01

    Hematopoietic stem cells (HSCs) are quiescent cells with self-renewal capacity and the ability to generate all mature blood cells. HSCs normally reside in specialized niches in the bone marrow that help maintain their quiescence and long-term repopulating activity. There is emerging evidence that certain cytokines induced during inflammation have significant effects on HSCs in the bone marrow. Type I and II interferons, tumor necrosis factor, and lipopolysaccharide (LPS) directly stimulate HSC proliferation and differentiation, thereby increasing the short-term output of mature effector leukocytes. However, chronic inflammatory cytokine signaling can lead to HSC exhaustion and may contribute the development of hematopoietic malignancies. Pro-inflammatory cytokines such as G-CSF can also indirectly affect HSCs by altering the bone marrow microenvironment, disrupting the stem cell niche, and leading to HSC mobilization into the blood. Herein, we review our current understanding of the effects of inflammatory mediators on HSCs, and we discuss the potential clinical implications of these findings with respect to bone marrow failure and leukemogenesis. PMID:23882270

  16. Engineering the hematopoietic stem cell niche: Frontiers in biomaterial science

    PubMed Central

    Choi, Ji Sun; Mahadik, Bhushan P.; Harley, Brendan A. C.

    2016-01-01

    Hematopoietic stem cells (HSCs) play a crucial role in the generation of the body’s blood and immune cells. This process takes place primarily in the bone marrow in specialized ‘niche’ microenvironments, which provide signals responsible for maintaining a balance between HSC quiescence, self-renewal, and lineage specification required for life-long hematopoiesis. While our understanding of these signaling mechanisms continues to improve, our ability to engineer them in vitro for the expansion of clinically relevant HSC populations is still lacking. In this review, we focus on development of biomaterials-based culture platforms for in vitro study of interactions between HSCs and their local microenvironment. The tools and techniques used for both examining HSC-niche interactions as well as applying these findings towards controlled HSC expansion or directed differentiation in 2D and 3D platforms are discussed. These novel techniques hold the potential to push the existing boundaries of HSC cultures towards high-throughput, real-time, and single-cell level biomimetic approaches that enable a more nuanced understanding of HSC regulation and function. Their application in conjunction with innovative biomaterial platforms can pave the way for engineering artificial bone marrow niches for clinical applications as well as elucidating the pathology of blood-related cancers and disorders. PMID:26356030

  17. Late Adherent Human Bone Marrow Stromal Cells Form Bone and Restore the Hematopoietic Microenvironment In Vivo

    PubMed Central

    Vianna, Verônica Fernandes; Bonfim, Danielle Cabral; Cavalcanti, Amanda dos Santos; Fernandes, Marco Cury; Kahn, Suzana Assad; Casado, Priscila Ladeira; Lima, Inayá Correa; Murray, Samuel S.; Murray, Elsa J. Brochmann; Duarte, Maria Eugenia Leite

    2013-01-01

    Bone marrow stromal cells (BMSCs) are a valuable resource for skeletal regenerative medicine because of their osteogenic potential. In spite of the very general term “stem cell,” this population of cells is far from homogeneous, and different BMSCs clones have greatly different phenotypic properties and, therefore, potentially different therapeutic potential. Adherence to a culture flask surface is a primary defining characteristic of BMSCs. We hypothesized that based on the adherence time we could obtain an enriched population of cells with a greater therapeutic potential. We characterized two populations of bone marrow-derived cells, those that adhered by three days (R-cells) and those that did not adhere by three days but did by six days (L-cells). Clones derived from L-cells could be induced into adipogenic, chondrogenic, and osteogenic differentiation in vitro. L-cells appeared to have greater proliferative capacity, as manifested by larger colony diameter and clones with higher CD146 expression. Only clones from L-cells developed bone marrow stroma in vivo. We conclude that the use of late adherence of BMSCs is one parameter that can be used to enrich for cells that will constitute a superior final product for cell therapy in orthopedics. PMID:23710460

  18. Two Hemocyte Lineages Exist in Silkworm Larval Hematopoietic Organ

    PubMed Central

    Nakahara, Yuichi; Kanamori, Yasushi; Kiuchi, Makoto; Kamimura, Manabu

    2010-01-01

    Background Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster. Methodology/Principal Findings To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO) into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes, oenocytoids, and spherulocytes. Five days after implantation of enzymatically-dispersed HPO cells from a GFP-expressing transgenic line into the hemocoel of normal larvae, differentiation into plasmatocytes, granulocytes and oenocytoids, but not spherulocytes, was observed. When the HPO cells were cultured in vitro, plasmatocytes appeared rapidly, and oenocytoids possessing prophenol oxidase activity appeared several days later. HPO cells were also able to differentiate into a small number of granulocytes, but not into spherulocytes. When functionally mature plasmatocytes were cultured in vitro, oenocytoids were observed 10 days later. These results suggest that the hemocyte precursors in HPO first differentiate into plasmatocytes, which further change into oenocytoids. Conclusions/Significance From these results, we propose that B. mori hemocytes can be divided into two major lineages, a granulocyte lineage and a plasmatocyte-oenocytoid lineage. The origins of the spherulocytes could not be determined in this study. We construct a model for the hematopoietic lineages at the larval stage of B. mori. PMID:20676370

  19. The hematopoietic system in the context of regenerative medicine.

    PubMed

    Porada, Christopher D; Atala, Anthony J; Almeida-Porada, Graça

    2016-04-15

    Hematopoietic stem cells (HSC) represent the prototype stem cell within the body. Since their discovery, HSC have been the focus of intensive research, and have proven invaluable clinically to restore hematopoiesis following inadvertent radiation exposure and following radio/chemotherapy to eliminate hematologic tumors. While they were originally discovered in the bone marrow, HSC can also be isolated from umbilical cord blood and can be "mobilized" peripheral blood, making them readily available in relatively large quantities. While their ability to repopulate the entire hematopoietic system would already guarantee HSC a valuable place in regenerative medicine, the finding that hematopoietic chimerism can induce immunological tolerance to solid organs and correct autoimmune diseases has dramatically broadened their clinical utility. The demonstration that these cells, through a variety of mechanisms, can also promote repair/regeneration of non-hematopoietic tissues as diverse as liver, heart, and brain has further increased their clinical value. The goal of this review is to provide the reader with a brief glimpse into the remarkable potential HSC possess, and to highlight their tremendous value as therapeutics in regenerative medicine. PMID:26319943

  20. Hematopoietic stem cell compartment: Acute and late effects of radiation therapy an chemotherapy

    SciTech Connect

    Mauch, P.; Constine, L.; Greenberger, J.

    1995-03-30

    The bone marrow is an important dose-limiting cell renewal tissue for chemotherapy, wide-field irradiation, and autologous bone marrow transplantion. Over the past 5-10 years a great deal has been discovered about the hematopoietic stem cell compartment. Although the toxicity associated with prolonged myelosuppression continue to limit the wider use of chemotherapy and irradiation, ways are being discovered to circumvent this toxicity such as with the increasing use of cytokines. This review describes what is known of how chemotherapy and irradiation damage stem cells and the microenvironment, how cytokines protect hematopoietic cells from radiation damage and speed marrow recovery after chemotherapy or marrow transplantation, and how various types of blood marrow cells contribute to engraftment and long-term hematopoiesis after high doses of cytotoxic agents and/or total body irradiation. 167 refs., 7 figs., 6 tabs.

  1. Endothelium and NOTCH specify and amplify aorta-gonad-mesonephros-derived hematopoietic stem cells.

    PubMed

    Hadland, Brandon K; Varnum-Finney, Barbara; Poulos, Michael G; Moon, Randall T; Butler, Jason M; Rafii, Shahin; Bernstein, Irwin D

    2015-05-01

    Hematopoietic stem cells (HSCs) first emerge during embryonic development within vessels such as the dorsal aorta of the aorta-gonad-mesonephros (AGM) region, suggesting that signals from the vascular microenvironment are critical for HSC development. Here, we demonstrated that AGM-derived endothelial cells (ECs) engineered to constitutively express AKT (AGM AKT-ECs) can provide an in vitro niche that recapitulates embryonic HSC specification and amplification. Specifically, nonengrafting embryonic precursors, including the VE-cadherin-expressing population that lacks hematopoietic surface markers, cocultured with AGM AKT-ECs specified into long-term, adult-engrafting HSCs, establishing that a vascular niche is sufficient to induce the endothelial-to-HSC transition in vitro. Subsequent to hematopoietic induction, coculture with AGM AKT-ECs also substantially increased the numbers of HSCs derived from VE-cadherin⁺CD45⁺ AGM hematopoietic cells, consistent with a role in supporting further HSC maturation and self-renewal. We also identified conditions that included NOTCH activation with an immobilized NOTCH ligand that were sufficient to amplify AGM-derived HSCs following their specification in the absence of AGM AKT-ECs. Together, these studies begin to define the critical niche components and resident signals required for HSC induction and self-renewal ex vivo, and thus provide insight for development of defined in vitro systems targeted toward HSC generation for therapeutic applications. PMID:25866967

  2. Automated Identification and Localization of Hematopoietic Stem Cells in 3D Intravital Microscopy Data

    PubMed Central

    Khorshed, Reema A.; Hawkins, Edwin D.; Duarte, Delfim; Scott, Mark K.; Akinduro, Olufolake A.; Rashidi, Narges M.; Spitaler, Martin; Lo Celso, Cristina

    2015-01-01

    Summary Measuring three-dimensional (3D) localization of hematopoietic stem cells (HSCs) within the bone marrow microenvironment using intravital microscopy is a rapidly expanding research theme. This approach holds the key to understanding the detail of HSC-niche interactions, which are critical for appropriate stem cell function. Due to the complex tissue architecture of the bone marrow and to the progressive introduction of scattering and signal loss at increasing imaging depths, there is no ready-made software to handle efficient segmentation and unbiased analysis of the data. To address this, we developed an automated image analysis tool that simplifies and standardizes the biological interpretation of 3D HSC microenvironment images. The algorithm identifies HSCs and measures their localization relative to surrounding osteoblast cells and bone collagen. We demonstrate here the effectiveness, consistency, and accuracy of the proposed approach compared to current manual analysis and its wider applicability to analyze other 3D bone marrow components. PMID:26120058

  3. Spatial Heterogeneity in the Tumor Microenvironment.

    PubMed

    Yuan, Yinyin

    2016-01-01

    Recent developments in studies of tumor heterogeneity have provoked new thoughts on cancer management. There is a desperate need to understand influence of the tumor microenvironment on cancer development and evolution. Applying principles and quantitative methods from ecology can suggest novel solutions to fulfil this need. We discuss spatial heterogeneity as a fundamental biological feature of the microenvironment, which has been largely ignored. Histological samples can provide spatial context of diverse cell types coexisting within the microenvironment. Advanced computer-vision techniques have been developed for spatial mapping of cells in histological samples. This has enabled the applications of experimental and analytical tools from ecology to cancer research, generating system-level knowledge of microenvironmental spatial heterogeneity. We focus on studies of immune infiltrate and tumor resource distribution, and highlight statistical approaches for addressing the emerging challenges based on these new approaches. PMID:27481837

  4. Bone Marrow GvHD after Allogeneic Hematopoietic Stem Cell Transplantation

    PubMed Central

    Szyska, Martin; Na, Il-Kang

    2016-01-01

    The bone marrow is the origin of all hematopoietic lineages and an important homing site for memory cells of the adaptive immune system. It has recently emerged as a graft-versus-host disease (GvHD) target organ after allogeneic stem cell transplantation (alloHSCT), marked by depletion of both hematopoietic progenitors and niche-forming cells. Serious effects on the restoration of hematopoietic function and immunological memory are common, especially in patients after myeloablative conditioning therapy. Cytopenia and durable immunodeficiency caused by the depletion of hematopoietic progenitors and destruction of bone marrow niches negatively influence the outcome of alloHSCT. The complex balance between immunosuppressive and cell-depleting treatments, GvHD and immune reconstitution, as well as the desirable graft-versus-tumor (GvT) effect remains a great challenge for clinicians. PMID:27066008

  5. Bone Marrow GvHD after Allogeneic Hematopoietic Stem Cell Transplantation.

    PubMed

    Szyska, Martin; Na, Il-Kang

    2016-01-01

    The bone marrow is the origin of all hematopoietic lineages and an important homing site for memory cells of the adaptive immune system. It has recently emerged as a graft-versus-host disease (GvHD) target organ after allogeneic stem cell transplantation (alloHSCT), marked by depletion of both hematopoietic progenitors and niche-forming cells. Serious effects on the restoration of hematopoietic function and immunological memory are common, especially in patients after myeloablative conditioning therapy. Cytopenia and durable immunodeficiency caused by the depletion of hematopoietic progenitors and destruction of bone marrow niches negatively influence the outcome of alloHSCT. The complex balance between immunosuppressive and cell-depleting treatments, GvHD and immune reconstitution, as well as the desirable graft-versus-tumor (GvT) effect remains a great challenge for clinicians. PMID:27066008

  6. The microenvironment reprograms circuits in tumor cells

    PubMed Central

    Cai, Qingchun; Xu, Yan

    2015-01-01

    In the course of multistep oncogenesis, initially normal cells acquire several new functions that render them malignant. We have recently demonstrated that the peritoneal microenvironment promotes resistance to anoikis in ovarian cancer cells by reprogramming SRC/AKT/ERK signaling and metabolism. These findings have prognostic and therapeutic implications. PMID:27308400

  7. Mucins in pancreatic cancer and its microenvironment

    PubMed Central

    Kaur, Sukhwinder; Kumar, Sushil; Momi, Navneet; Sasson, Aaron R.; Batra, Surinder K.

    2014-01-01

    Pancreatic cancer remains a lethal malignancy with poor prognosis owing to therapeutic resistance, frequent recurrence and the absence of treatment strategies that specifically target the tumour and its supporting stroma. Deregulated cell-surface proteins drive neoplastic transformations and are envisioned to mediate crosstalk between the tumour and its microenvironment. Emerging studies have elaborated on the role of mucins in diverse biological functions, including enhanced tumorigenicity, invasiveness, metastasis and drug resistance through their characteristic O-linked and N-linked oligosaccharides (glycans), extended structures and unique domains. Multiple mucin domains differentially interact and regulate different components of the tumour microenvironment. This Review discusses: the expression pattern of various mucins in the pancreas under healthy, inflammatory, and cancerous conditions; the context-dependent attributes of mucins that differ under healthy and pathological conditions; the contribution of the tumour microenvironment in pancreatic cancer development and/or progression; diagnostic and/or prognostic efficacy of mucins; and mucin-based therapeutic strategies. Overall, this information should help to delineate the intricacies of pancreatic cancer by exploring the family of mucins, which, through various mechanisms in both tumour cells and the microenvironment, worsen disease outcome. PMID:23856888

  8. Nonmyeloablative allogeneic hematopoietic cell transplantation

    PubMed Central

    Storb, Rainer; Sandmaier, Brenda M.

    2016-01-01

    Most hematological malignancies occur in older patients. Until recently these patients and those with comorbidities were not candidates for treatment with allogeneic hematopoietic transplantation because they were unable to tolerate the heretofore used high-dose conditioning regimens. The finding that many of the cures achieved with allogeneic hematopoietic transplantation were due to graft-versus-tumor effects led to the development of less toxic and well-tolerated reduced intensity and nonmyeloablative regimens. These regimens enabled allogeneic engraftment, thereby setting the stage for graft-versus-tumor effects. This review summarizes the encouraging early results seen with the new regimens and discusses the two hurdles that need to be overcome for achieving even greater success, disease relapse and graft-versus-host disease. PMID:27132278

  9. Making a Hematopoietic Stem Cell

    PubMed Central

    Daniel, Michael G.; Pereira, Carlos-Filipe; Lemischka, Ihor R.; Moore, Kateri A.

    2016-01-01

    Previous attempts to either generate or expand hematopoietic stem cells (HSCs) in vitro have involved either ex vivo expansion of pre-existing patient or donor HSCs or de novo generation from pluripotent stem cells (PSCs), comprising both embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). iPSCs alleviated ESC ethical issues but attempts to generate functional mature hematopoietic stem and progenitor cells (HSPCs) have been largely unsuccessful. New efforts focus on directly reprogramming somatic cells into definitive HSCs and HSPCs. To meet clinical needs and to advance drug discovery and stem cell therapy, alternative approaches are necessary. In this review, we synthesize the strategies used and the key findings made in recent years by those trying to make an HSC. PMID:26526106

  10. DNA methylation in hematopoietic development and disease.

    PubMed

    Gore, Aniket V; Weinstein, Brant M

    2016-09-01

    DNA methylation is an important epigenetic modification that can have profound and widespread effects on gene expression and on cellular fate and function. Recent work has indicated that DNA methylation plays a critical role in hematopoietic development and hematopoietic disease. DNA methyltransferases and Ten-eleven translocation enzymes are required to add and remove methyl "marks" from DNA, respectively, and both sets of genes have been found necessary for proper formation and maintenance of hematopoietic stem cells and for differentiation of downstream hematopoietic lineages during development. DNA methylation and demethylation enzymes have also been implicated in hematopoietic disorders such as acute myeloid leukemia and myelodysplastic syndrome. Here, we review some of the recent literature regarding the role of DNA methylation in hematopoietic health and disease. PMID:27178734

  11. bantam miRNA is important for Drosophila blood cell homeostasis and a regulator of proliferation in the hematopoietic progenitor niche

    SciTech Connect

    Lam, Victoria; Tokusumi, Tsuyoshi; Tokusumi, Yumiko; Schulz, Robert A.

    2014-10-24

    Highlights: • bantam miRNA is endogenously expressed in the hematopoietic progenitor niche. • bantam is necessary and sufficient to induce cellular proliferation in the PSC. • bantam is upstream of the Insulin Receptor signaling pathway. • A model for positive regulation of hematopoietic niche growth is proposed. - Abstract: The Drosophila hematopoietic system is utilized in this study to gain novel insights into the process of growth control of the hematopoietic progenitor niche in blood development. The niche microenvironment is an essential component controlling the balance between progenitor populations and differentiated, mature blood cells and has been shown to lead to hematopoietic malignancies in humans when misregulated. MicroRNAs are one class of regulators associated with blood malignancies; however, there remains a relative paucity of information about the role of miRNAs in the niche. Here we demonstrate that bantam miRNA is endogenously active in the Drosophila hematopoietic progenitor niche, the posterior signaling center (PSC), and functions in the primary hematopoietic organ, the lymph gland, as a positive regulator of growth. Loss of bantam leads to a significant reduction in the PSC and overall lymph gland size, as well as a loss of the progenitor population and correlative premature differentiation of mature hemocytes. Interestingly, in addition to being essential for proper lymph gland development, we have determined bantam to be a novel upstream component of the insulin signaling cascade in the PSC and have unveiled dMyc as one factor central to bantam activity. These important findings identify bantam as a new hematopoietic regulator, place it in an evolutionarily conserved signaling pathway, present one way in which it is regulated, and provide a mechanism through which it facilitates cellular proliferation in the hematopoietic niche.

  12. Cathepsin X is secreted by human osteoblasts, digests CXCL-12 and impairs adhesion of hematopoietic stem and progenitor cells to osteoblasts

    PubMed Central

    Staudt, Nicole D.; Aicher, Wilhelm K.; Kalbacher, Hubert; Stevanovic, Stefan; Carmona, Adriana K.; Bogyo, Matthew; Klein, Gerd

    2010-01-01

    Background Hematopoietic stem cells are retained within discrete bone marrow niches through the effects of cell adhesion molecules and chemokine gradients. However, a small proportion of hematopoietic stem cells can also be found trafficking in the peripheral blood. During induced stem cell mobilization a proteolytic microenvironment is generated, but whether proteases are also involved in physiological trafficking of hematopoietic stem cells is not known. In the present study we examined the expression, secretion and function of the cysteine protease cathepsin X by cells of the human bone marrow. Design and Methods Human osteoblasts, bone marrow stromal cells and hematopoietic stem and progenitor cells were analyzed for the secretion of cathepsin X by western blotting, active site labeling, immunofluorescence staining and activity assays. A possible involvement of cathepsin X in cell adhesion and CXCL-12-mediated cell migration was studied in functional assays. Matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) analysis revealed the digestion mechanism of CXCL-12 by cathepsin X. Results Osteoblasts and stromal cells secrete cathepsin X, whereas hematopoietic stem and progenitor cells do not. Using a cathepsin X-selective substrate, we detected the catalytic activity of cathepsin X in cell culture supernatants of osteoblasts. Activated cathepsin X is able to reduce cellular adhesive interactions between CD34+ hematopoietic stem and progenitor cells and adherent osteoblasts. The chemokine CXCL-12, a highly potent chemoattractant for hematopoietic stem cells secreted by osteoblasts, is readily digested by cathepsin X. Conclusions The exo-peptidase cathepsin X has been identified as a new member of the group of CXCL-12-degrading enzymes secreted by non-hematopoietic bone marrow cells. Functional data indicate that cathepsin X can influence hematopoietic stem and progenitor cell trafficking in the bone marrow. PMID:20494937

  13. Murine Hematopoietic Stem cells and Progenitors Express Adrenergic Receptors

    PubMed Central

    Muthu, Kuzhali; Iyer, Sivaraman; He, L-K.; Szilagyi, Andrea; Gamelli, Richard L; Shankar, Ravi; Jones, Stephen B

    2007-01-01

    Association between the nervous and immune system is well documented. Immune cells originate within the bone marrow that is innervated. Thermal injury induces adrenergic stimulation, augments monocytopoiesis and alters the β-adrenergic receptor (AR) profile of bone marrow monocyte committed progenitors. This provides an impetus to study AR expression in hematopoietic progenitors along myeloid lineage. Using FACS analysis and confocal microscopy, we report the expression of α1-, α2- and β2- AR in enriched populations of ER-MP20+ and ER-MP12+ myeloid progenitors, CD117+ and CD34+ multi-potential progenitors and more importantly pluripotent stem cells suggesting a plausible role for catecholamine in hematopoietic development. PMID:17428548

  14. Nanocomposite Membranes Enhance Bone Regeneration Through Restoring Physiological Electric Microenvironment.

    PubMed

    Zhang, Xuehui; Zhang, Chenguang; Lin, Yuanhua; Hu, Penghao; Shen, Yang; Wang, Ke; Meng, Song; Chai, Yuan; Dai, Xiaohan; Liu, Xing; Liu, Yun; Mo, Xiaoju; Cao, Cen; Li, Shue; Deng, Xuliang; Chen, Lili

    2016-08-23

    Physiological electric potential is well-known for its indispensable role in maintaining bone volume and quality. Although implanted biomaterials simulating structural, morphological, mechanical, and chemical properties of natural tissue or organ has been introduced in the field of bone regeneration, the concept of restoring physiological electric microenvironment remains ignored in biomaterials design. In this work, a flexible nanocomposite membrane mimicking the endogenous electric potential is fabricated to explore its bone defect repair efficiency. BaTiO3 nanoparticles (BTO NPs) were first coated with polydopamine. Then the composite membranes are fabricated with homogeneous distribution of Dopa@BTO NPs in poly(vinylidene fluoridetrifluoroethylene) (P(VDF-TrFE)) matrix. The surface potential of the nanocomposite membranes could be tuned up to -76.8 mV by optimizing the composition ratio and corona poling treatment, which conform to the level of endogenous biopotential. Remarkably, the surface potential of polarized nanocomposite membranes exhibited a dramatic stability with more than half of original surface potential remained up to 12 weeks in the condition of bone defect. In vitro, the membranes encouraged bone marrow mesenchymal stem cells (BM-MSCs) activity and osteogenic differentiation. In vivo, the membranes sustainably maintained the electric microenvironment giving rise to rapid bone regeneration and complete mature bone-structure formation. Our findings evidence that physiological electric potential repair should be paid sufficient attention in biomaterials design, and this concept might provide an innovative and well-suited strategy for bone regenerative therapies. PMID:27389708

  15. Donor Dependent Variations in Hematopoietic Differentiation among Embryonic and Induced Pluripotent Stem Cell Lines

    PubMed Central

    Féraud, Olivier; Valogne, Yannick; Melkus, Michael W.; Zhang, Yanyan; Oudrhiri, Noufissa; Haddad, Rima; Daury, Aurélie; Rocher, Corinne; Larbi, Aniya; Duquesnoy, Philippe; Divers, Dominique; Gobbo, Emilie; Brunet de la Grange, Philippe; Louache, Fawzia; Bennaceur-Griscelli, Annelise; Mitjavila-Garcia, Maria Teresa

    2016-01-01

    Hematopoiesis generated from human embryonic stem cells (ES) and induced pluripotent stem cells (iPS) are unprecedented resources for cell therapy. We compared hematopoietic differentiation potentials from ES and iPS cell lines originated from various donors and derived them using integrative and non-integrative vectors. Significant differences in differentiation toward hematopoietic lineage were observed among ES and iPS. The ability of engraftment of iPS or ES-derived cells in NOG mice varied among the lines with low levels of chimerism. iPS generated from ES cell-derived mesenchymal stem cells (MSC) reproduce a similar hematopoietic outcome compared to their parental ES cell line. We were not able to identify any specific hematopoietic transcription factors that allow to distinguish between good versus poor hematopoiesis in undifferentiated ES or iPS cell lines. There is a relatively unpredictable variation in hematopoietic differentiation between ES and iPS cell lines that could not be predicted based on phenotype or gene expression of the undifferentiated cells. These results demonstrate the influence of genetic background in variation of hematopoietic potential rather than the reprogramming process. PMID:26938212

  16. ESAM is a novel human hematopoietic stem cell marker associated with a subset of human leukemias.

    PubMed

    Ishibashi, Tomohiko; Yokota, Takafumi; Tanaka, Hirokazu; Ichii, Michiko; Sudo, Takao; Satoh, Yusuke; Doi, Yukiko; Ueda, Tomoaki; Tanimura, Akira; Hamanaka, Yuri; Ezoe, Sachiko; Shibayama, Hirohiko; Oritani, Kenji; Kanakura, Yuzuru

    2016-04-01

    Reliable markers are essential to increase our understanding of the biological features of human hematopoietic stem cells and to facilitate the application of hematopoietic stem cells in the field of transplantation and regenerative medicine. We previously identified endothelial cell-selective adhesion molecule (ESAM) as a novel functional marker of hematopoietic stem cells in mice. Here, we found that ESAM can also be used to purify human hematopoietic stem cells from all the currently available sources (adult bone marrow, mobilized peripheral blood, and cord blood). Multipotent colony-forming units and long-term hematopoietic-reconstituting cells in immunodeficient mice were found exclusively in the ESAM(High) fraction of CD34(+)CD38(-) cells. The CD34(+)CD38(-) fraction of cord blood and collagenase-treated bone marrow contained cells exhibiting extremely high expression of ESAM; these cells are likely to be related to the endothelial lineage. Leukemia cell lines of erythroid and megakaryocyte origin, but not those of myeloid or lymphoid descent, were ESAM positive. However, high ESAM expression was observed in some primary acute myeloid leukemia cells. Furthermore, KG-1a myeloid leukemia cells switched from ESAM negative to ESAM positive with repeated leukemia reconstitution in vivo. Thus, ESAM is a useful marker for studying both human hematopoietic stem cells and leukemia cells. PMID:26774386

  17. Hematopoietic Progenitors from Early Murine Fetal Liver Possess Hepatic Differentiation Potential

    PubMed Central

    Khurana, Satish; Mukhopadhyay, Asok

    2008-01-01

    Bipotential hepatoblasts differentiate into hepatocytes and cholangiocytes during liver development. It is believed that hepatoblasts originate from endodermal tissue. Here, we provide evidence for the presence of hepatic progenitor cells in the hematopoietic compartment at an early stage of liver development. Flow cytometric analysis showed that at early stages of liver development, approximately 13% of CD45+ cells express Δ-like protein-1, a marker of hepatoblasts. Furthermore, reverse transcriptase-PCR data suggest that many hepatic genes are expressed in these cells. Cell culture experiments confirmed the hepatic differentiation potential of these cells with the loss of the CD45 marker. We observed that both hematopoietic activity in Δ-like protein-1+ cells and hepatic activity in CD45+ cells were high at embryonic day 10.5 and declined thereafter. Clonal analysis revealed that the hematopoietic fraction of fetal liver cells at embryonic day 10.5 gave rise to both hepatic and hematopoietic colonies. The above results suggest a common source of these two functionally distinct cell lineages. In utero transplantation experiments confirmed these results, as green fluorescent protein-expressing CD45+ cells at the same stage of development yielded functional hepatocytes and hematopoietic reconstitution. Since these cells were unable to differentiate into cytokeratin-19-expressing cholangiocytes, we distinguished them from hepatoblasts. This preliminary study provides hope to correct many liver diseases during prenatal development via transplantation of fetal liver hematopoietic cells. PMID:18988804

  18. Adult hematopoietic stem cells lacking Hif-1α self-renew normally

    PubMed Central

    Vukovic, Milica; Sepulveda, Catarina; Subramani, Chithra; Guitart, Amélie V.; Mohr, Jasmine; Allen, Lewis; Panagopoulou, Theano I.; Paris, Jasmin; Lawson, Hannah; Villacreces, Arnaud; Armesilla-Diaz, Alejandro; Gezer, Deniz; Holyoake, Tessa L.; Ratcliffe, Peter J.

    2016-01-01

    The hematopoietic stem cell (HSC) pool is maintained under hypoxic conditions within the bone marrow microenvironment. Cellular responses to hypoxia are largely mediated by the hypoxia-inducible factors, Hif-1 and Hif-2. The oxygen-regulated α subunits of Hif-1 and Hif-2 (namely, Hif-1α and Hif-2α) form dimers with their stably expressed β subunits and control the transcription of downstream hypoxia-responsive genes to facilitate adaptation to low oxygen tension. An initial study concluded that Hif-1α is essential for HSC maintenance, whereby Hif-1α–deficient HSCs lost their ability to self-renew in serial transplantation assays. In another study, we demonstrated that Hif-2α is dispensable for cell-autonomous HSC maintenance, both under steady-state conditions and following transplantation. Given these unexpected findings, we set out to revisit the role of Hif-1α in cell-autonomous HSC functions. Here we demonstrate that inducible acute deletion of Hif-1α has no impact on HSC survival. Notably, unstressed HSCs lacking Hif-1α efficiently self-renew and sustain long-term multilineage hematopoiesis upon serial transplantation. Finally, Hif-1α–deficient HSCs recover normally after hematopoietic injury induced by serial administration of 5-fluorouracil. We therefore conclude that despite the hypoxic nature of the bone marrow microenvironment, Hif-1α is dispensable for cell-autonomous HSC maintenance. PMID:27060169

  19. Adult hematopoietic stem cells lacking Hif-1α self-renew normally.

    PubMed

    Vukovic, Milica; Sepulveda, Catarina; Subramani, Chithra; Guitart, Amélie V; Mohr, Jasmine; Allen, Lewis; Panagopoulou, Theano I; Paris, Jasmin; Lawson, Hannah; Villacreces, Arnaud; Armesilla-Diaz, Alejandro; Gezer, Deniz; Holyoake, Tessa L; Ratcliffe, Peter J; Kranc, Kamil R

    2016-06-01

    The hematopoietic stem cell (HSC) pool is maintained under hypoxic conditions within the bone marrow microenvironment. Cellular responses to hypoxia are largely mediated by the hypoxia-inducible factors, Hif-1 and Hif-2. The oxygen-regulated α subunits of Hif-1 and Hif-2 (namely, Hif-1α and Hif-2α) form dimers with their stably expressed β subunits and control the transcription of downstream hypoxia-responsive genes to facilitate adaptation to low oxygen tension. An initial study concluded that Hif-1α is essential for HSC maintenance, whereby Hif-1α-deficient HSCs lost their ability to self-renew in serial transplantation assays. In another study, we demonstrated that Hif-2α is dispensable for cell-autonomous HSC maintenance, both under steady-state conditions and following transplantation. Given these unexpected findings, we set out to revisit the role of Hif-1α in cell-autonomous HSC functions. Here we demonstrate that inducible acute deletion of Hif-1α has no impact on HSC survival. Notably, unstressed HSCs lacking Hif-1α efficiently self-renew and sustain long-term multilineage hematopoiesis upon serial transplantation. Finally, Hif-1α-deficient HSCs recover normally after hematopoietic injury induced by serial administration of 5-fluorouracil. We therefore conclude that despite the hypoxic nature of the bone marrow microenvironment, Hif-1α is dispensable for cell-autonomous HSC maintenance. PMID:27060169

  20. Medulloblastoma—Biology and Microenvironment: A Review

    PubMed Central

    Byrd, Tiara; Grossman, Robert G.; Ahmed, Nabil

    2014-01-01

    Medulloblastoma (MB) is a cancer of the cerebellum and the most common primary pediatric malignancy of the central nervous system. Classified as a primitive neural ectoderm tumor; it is thought to arise from granule cell precursors in the cerebellum. The standard of care consists of surgery, chemotherapy and age-dependent radiation therapy. Despite aggressive multimodality therapy; approximately 30% of MB patients remain incurable. Moreover, for long-term survivors, the treatment related sequelae are often debilitating. Side effects include cerebellar mutism, sterility, neurocognitive deficits, and a substantial risk of developing secondary cancers. In a quest for more effective and targeted therapies, scientists have begun to investigate the biological events that not only initiate but also sustain the malignant phenotype in MB. Of particular interest is, the role of the tumor microenvironment in tumor pathogenesis. This review seeks to highlight several key processes observed in cancer biology, particularly the involvement of the tumor microenvironment, with relevant examples from MB. PMID:22742590

  1. Monitoring immune responses in the tumor microenvironment.

    PubMed

    Wargo, Jennifer A; Reddy, Sangeetha M; Reuben, Alexandre; Sharma, Padmanee

    2016-08-01

    Immune monitoring in the tumor microenvironment allows for important insights into immune mechanisms of response and resistance to various cancer treatments; however clinical challenges exist using current strategies. Significant questions remain regarding monitoring of archival versus fresh tissue, assessment of static versus dynamic markers, evaluation of limited tissue samples, and the translation of insights gained from immunologically 'hot' tumors such as melanoma to other 'cold' tumor microenvironments prevalent in other cancer types. Current and emerging immune monitoring strategies will be examined herein, and genomic-based assays complementing these techniques will also be discussed. Finally, host genomic and external environmental factors influencing anti-tumor immune responses will be considered, including the role of the gut microbiome. Though optimal immune monitoring techniques are in evolution, great promise exists in recent advances that will help guide patient selection as far as type, sequence, and combination of therapeutic regimens to enhance anti-tumor immunity and clinical responses. PMID:27240055

  2. Engineering the CNS stem cell microenvironment

    PubMed Central

    Williams, Cicely A; Lavik, Erin B

    2010-01-01

    The loss of neural tissue underlies the symptomatology of several neurological insults of disparate etiology, including trauma, cerebrovascular insult and neurodegenerative disease. Restoration of damaged neural tissue through the use of exogenous or endogenous neural stem or progenitor cells is an enticing therapeutic option provided one can control their proliferation, migration and differentiation. Initial attempts at CNS tissue engineering relied on the intrinsic cellular properties of progenitor cells; however, it is now appreciated that the microenvironment surrounding the cells plays an indispensible role in regulating stem cell behavior. This article focuses on attempts to engineer the neural stem cell microenvironment by utilizing the major cellular components of the niche (endothelial cells, astrocytes and ependymal cells) and the extracellular matrix in which they are embedded. PMID:19903005

  3. Neuropharmacologic Approaches to Restore the Brain's Microenvironment.

    PubMed

    Li, Weizhe; Tong, Hsin-I; Gorantla, Santhi; Poluektova, Larisa Y; Gendelman, Howard E; Lu, Yuanan

    2016-09-01

    Maintaining the central nervous system microenvironment after injury, infection, inflammatory and degenerative diseases is contingent upon adequate control of glial homeostatic functions. Disease is caused by microbial, environmental and endogenous factors that compromise ongoing nervous system functions. The final result is neuronal injury, dropout and nerve connection loss, and these underlie the pathobiology of Alzheimer's and Parkinson's disease, amyotrophic lateral sclerosis, stroke, and bacterial, parasitic and viral infections. However, what promotes disease are homeostatic changes in the brain's microenvironment affected by innate glial immune pro-inflammatory and adaptive immune responses. These events disturb the brain's metabolic activities and communication abilities. How the process affects the brain's regulatory functions that can be harnessed for therapeutic gain is the subject at hand. Specific examples are provided that serve to modulate inflammation and improve disease outcomes specifically for HIV-associated neurocognitive disorders. PMID:27352074

  4. Dynamic Reciprocity in the Wound Microenvironment

    PubMed Central

    Schultz, Gregory S.; Davidson, Jeffrey M.; Kirsner, Robert S.; Bornstein, Paul; Herman, Ira M.

    2011-01-01

    Here, we define dynamic reciprocity (DR) as an ongoing, bidirectional interaction amongst cells and their surrounding microenvironment. In the review, we posit that DR is especially meaningful during wound healing as the DR-driven biochemical, biophysical and cellular responses to injury play pivotal roles in regulating tissue regenerative responses. Such cell-extracellular matrix interactions not only guide and regulate cellular morphology, but cellular differentiation, migration, proliferation, and survival during tissue development, including e.g. embryogenesis, angiogenesis, as well as during pathologic processes including cancer diabetes, hypertension and chronic wound healing. Herein, we examine DR within the wound microenvironment while considering specific examples across acute and chronic wound healing. This review also considers how a number of hypotheses that attempt to explain chronic wound pathophysiology, which may be understood within the DR framework. The implications of applying the principles of dynamic reciprocity to optimize wound care practice and future development of innovative wound healing therapeutics are also briefly considered. PMID:21362080

  5. Interaction of tumor cells with the microenvironment

    PubMed Central

    2011-01-01

    Recent advances in tumor biology have revealed that a detailed analysis of the complex interactions of tumor cells with their adjacent microenvironment (tumor stroma) is mandatory in order to understand the various mechanisms involved in tumor growth and the development of metastasis. The mutual interactions between tumor cells and cellular and non-cellular components (extracellular matrix = ECM) of the tumor microenvironment will eventually lead to a loss of tissue homeostasis and promote tumor development and progression. Thus, interactions of genetically altered tumor cells and the ECM on the one hand and reactive non-neoplastic cells on the other hand essentially control most aspects of tumorigenesis such as epithelial-mesenchymal-transition (EMT), migration, invasion (i.e. migration through connective tissue), metastasis formation, neovascularisation, apoptosis and chemotherapeutic drug resistance. In this mini-review we will focus on these issues that were recently raised by two review articles in CCS. PMID:21914164

  6. Defined three-dimensional microenvironments boost induction of pluripotency.

    PubMed

    Caiazzo, Massimiliano; Okawa, Yuya; Ranga, Adrian; Piersigilli, Alessandra; Tabata, Yoji; Lutolf, Matthias P

    2016-03-01

    Since the discovery of induced pluripotent stem cells (iPSCs), numerous approaches have been explored to improve the original protocol, which is based on a two-dimensional (2D) cell-culture system. Surprisingly, nothing is known about the effect of a more biologically faithful 3D environment on somatic-cell reprogramming. Here, we report a systematic analysis of how reprogramming of somatic cells occurs within engineered 3D extracellular matrices. By modulating microenvironmental stiffness, degradability and biochemical composition, we have identified a previously unknown role for biophysical effectors in the promotion of iPSC generation. We find that the physical cell confinement imposed by the 3D microenvironment boosts reprogramming through an accelerated mesenchymal-to-epithelial transition and increased epigenetic remodelling. We conclude that 3D microenvironmental signals act synergistically with reprogramming transcription factors to increase somatic plasticity. PMID:26752655

  7. Defined three-dimensional microenvironments boost induction of pluripotency

    NASA Astrophysics Data System (ADS)

    Caiazzo, Massimiliano; Okawa, Yuya; Ranga, Adrian; Piersigilli, Alessandra; Tabata, Yoji; Lutolf, Matthias P.

    2016-03-01

    Since the discovery of induced pluripotent stem cells (iPSCs), numerous approaches have been explored to improve the original protocol, which is based on a two-dimensional (2D) cell-culture system. Surprisingly, nothing is known about the effect of a more biologically faithful 3D environment on somatic-cell reprogramming. Here, we report a systematic analysis of how reprogramming of somatic cells occurs within engineered 3D extracellular matrices. By modulating microenvironmental stiffness, degradability and biochemical composition, we have identified a previously unknown role for biophysical effectors in the promotion of iPSC generation. We find that the physical cell confinement imposed by the 3D microenvironment boosts reprogramming through an accelerated mesenchymal-to-epithelial transition and increased epigenetic remodelling. We conclude that 3D microenvironmental signals act synergistically with reprogramming transcription factors to increase somatic plasticity.

  8. Metastasis Suppressors and the Tumor Microenvironment

    PubMed Central

    Cook, Leah M.; Hurst, Douglas R.; Welch, Danny R.

    2011-01-01

    The most lethal and debilitating attribute of cancer cells is their ability to metastasize. Throughout the process of metastasis, tumor cells interact with other tumor cells, host cells and a variety of molecules. Tumor cells are also faced with a number of insults, such as hemodynamic sheer pressure and immune selection. This brief review explores how metastasis suppressor proteins regulate interactions between tumor cells and the microenvironments in which tumor cells find themselves. PMID:21168504

  9. Analyzing the Tumor Microenvironment by Flow Cytometry.

    PubMed

    Young, Yoon Kow; Bolt, Alicia M; Ahn, Ryuhjin; Mann, Koren K

    2016-01-01

    Flow cytometry is an essential tool for studying the tumor microenvironment. It allows us to quickly quantify and identify multiple cell types in a heterogeneous sample. A brief overview of flow cytometry instrumentation and the appropriate considerations and steps in building a good flow cytometry staining panel are discussed. In addition, a lymphoid tissue and solid tumor leukocyte infiltrate flow cytometry staining protocol and an example of flow cytometry data analysis are presented. PMID:27581017

  10. Combined procedure of vascularized bone marrow transplantation and mesenchymal stem cells graft - an effective solution for rapid hematopoietic reconstitution and prevention of graft-versus-host disease.

    PubMed

    Coliţă, Andrei; Coliţă, Anca; Zamfirescu, Dragos; Lupu, Anca Roxana

    2012-09-01

    Hematopoietic stem cell transplantation (HSCT) is a a standard therapeutic option for several diseases. The success of the procedure depends on quality and quantity of transplanted cells and on stromal capacity to create an optimal microenvironment, that supports survival and development of the hematopoietic elements. Conditions associated with stromal dysfunction lead to slower/insufficient engraftment and/or immune reconstitution. A possible solution to this problem is to realize a combined graft of hematopoietic stem cells along with the medular stroma in the form of vascularized bone marrow transplant (VBMT). Another major drawback of HSCT is the risk of graft versus host disease (GVHD). Recently, mesenchymal stromal cells (MSC) have demonstrated the capacity to down-regulate alloreactive T-cell and to enhance the engraftment. Cotransplantation of MSC could be a therapeutic option for a better engraftment and GVHD prevention. PMID:22677297

  11. Effects of laser immunotherapy on tumor microenvironment

    NASA Astrophysics Data System (ADS)

    Acquaviva, Joseph T.; Wood, Ethan W.; Hasanjee, Aamr; Chen, Wei R.; Vaughan, Melville B.

    2014-02-01

    The microenvironments of tumors are involved in a complex and reciprocal dialog with surrounding cancer cells. Any novel treatment must consider the impact of the therapy on the microenvironment. Recently, clinical trials with laser immunotherapy (LIT) have proven to effectively treat patients with late-stage, metastatic breast cancer and melanoma. LIT is the synergistic combination of phototherapy (laser irradiation) and immunological stimulation. One prominent cell type found in the tumor stroma is the fibroblast. Fibroblast cells can secrete different growth factors and extracellular matrix modifying molecules. Furthermore, fibroblast cells found in the tumor stroma often express alpha smooth muscle actin. These particular fibroblasts are coined cancer-associated fibroblast cells (CAFs). CAFs are known to facilitate the malignant progression of tumors. A collagen lattice assay with human fibroblast cells is used to elucidate the effects LIT has on the microenvironment of tumors. Changes in the contraction of the lattice, the differentiation of the fibroblast cells, as well as the proliferation of the fibroblast cells will be determined.

  12. Probing the tumor microenvironment: collection and induction

    NASA Astrophysics Data System (ADS)

    Williams, James K.; Padgen, Michael R.; Wang, Yarong; Entenberg, David; Gertler, Frank; Condeelis, John S.; Castracane, James

    2012-03-01

    The Nano Intravital Device, or NANIVID, is under development as an optically transparent, implantable tool to study the tumor microenvironment. Two etched glass substrates are sealed using a thin polymer membrane to create a reservoir with a single outlet. This reservoir is loaded with a hydrogel blend that contains growth factors or other chemicals to be delivered to the tumor microenvironment. When the device is implanted in the tumor, the hydrogel will swell and release these entrapped molecules, forming a gradient. Validation of the device has been performed in vitro using epidermal growth factor (EGF) and MenaINV, a highly invasive, rat mammary adenocarcinoma cell line. In both 2-D and 3-D environments, cells migrated toward the gradient of EGF released from the device. The chorioallantoic membrane (CAM) of White Leghorn chicken eggs is being utilized to grow xenograft tumors that will be used for ex vivo cell collection. Device optimization is being performed for in vivo use as a tool to collect the invasive cell population. Preliminary cell collection experiments in vivo were performed using a mouse model of breast cancer. As a second application, the device is being explored as a delivery vehicle for chemicals that induce controlled changes in the tumor microenvironment. H2O2 was loaded in the device and generated intracellular reactive oxygen species (ROS) in cells near the device outlet. In the future, other induction targets will be explored, including hypoglycemia and the manipulation of extracellular matrix stiffness.

  13. Targeting the tumour microenvironment in ovarian cancer.

    PubMed

    Hansen, Jean M; Coleman, Robert L; Sood, Anil K

    2016-03-01

    The study of cancer initiation, growth, and metastasis has traditionally been focused on cancer cells, and the view that they proliferate due to uncontrolled growth signalling owing to genetic derangements. However, uncontrolled growth in tumours cannot be explained solely by aberrations in cancer cells themselves. To fully understand the biological behaviour of tumours, it is essential to understand the microenvironment in which cancer cells exist, and how they manipulate the surrounding stroma to promote the malignant phenotype. Ovarian cancer is the leading cause of death from gynaecologic cancer worldwide. The majority of patients will have objective responses to standard tumour debulking surgery and platinum-taxane doublet chemotherapy, but most will experience disease recurrence and chemotherapy resistance. As such, a great deal of effort has been put forth to develop therapies that target the tumour microenvironment in ovarian cancer. Herein, we review the key components of the tumour microenvironment as they pertain to this disease, outline targeting opportunities and supporting evidence thus far, and discuss resistance to therapy. PMID:26849037

  14. Temperature and humidity within the clothing microenvironment.

    PubMed

    Sullivan, P J; Mekjavić, I B

    1992-03-01

    The present study investigates clothing microenvironment conditions that may develop during prolonged exposure of workers to a hot environment. Five subjects were exposed to a linear increase in ambient temperature from 20-40 degrees C over a 90-min period, and then remained at 40 degrees C for an additional 90 min. During the exposures, subjects were clad in four types of helicopter personnel suits (Gore-Tex, Cotton Ventile, Nomex/Insulite, and Nomex/Neoprene), incorporating both dry-suit and wet-suit designs. Continuous assessment was made of skin temperature, rectal temperature, and of microenvironment temperature, relative humidity, and vapor pressure (T mu, RH mu, and VP mu) 8 mm from the surface of the skin. Results indicate that although microenvironment temperatures were similar among suits and slightly lower than that of the environment, the RH mu and VP mu were much greater than those of the ambient air. The Nomex/Insulite and Nomex/Neoprene suits showed the highest VP mu, of which only the Nomex/Insulite resulted in significantly greater increases in rectal temperature, likely due to complete covering of the body with the impermeable insulite component. The present study demonstrates the need to discern between the ambient conditions and the conditions encountered next to the skin when protective clothing is worn. PMID:1567319

  15. Experiments on gene transferring to primary hematopoietic cells by liposome.

    PubMed

    Hu, L; Zhang, B

    2000-01-01

    Liposomes have showed many advantages in mediating exogenous gene into many cell types in vitro and in vivo. But few data are available concerning gene transfer into hematopoietic cells. In this report, we described two-marker genes (Neo R and Lac Z) co-transferred into hematopoietic cells of human and mouse by using liposome in vitro. The efficiency of gene transfer was tested by X-gal staining and observation of colony formation. The X-gal blue staining rate of transduced cells was about (13.33 +/- 2.68)% in human and about (16.28 +/- 2.95)% in mouse without G418 selection. After G418 selection, the blue cell rate was (46.06 +/- 3.47)% in human and (43.45 +/- 4.1)% in mouse, which were markedly higher than those before selection, suggesting that high-efficiency gene transfer and expression could be attained in primary hematopoietic cells using this easy and harmless transduction protocol. At the same time, this protocol provided experimental data for clinicians to investigate the biology of marrow reconstitution and trace the origin of relapse after autologous bone marrow transplantation for the patients with leukemia. PMID:12840913

  16. Myocardial infarction activates CCR2+ hematopoietic stem and progenitor cells

    PubMed Central

    Dutta, Partha; Sager, Hendrik B.; Stengel, Kristy R.; Naxerova, Kamila; Courties, Gabriel; Saez, Borja; Silberstein, Lev; Heidt, Timo; Sebas, Matthew; Sun, Yuan; Wojtkiewicz, Gregory; Feruglio, Paolo Fumene; King, Kevin; Baker, Joshua N.; van der Laan, Anja M.; Borodovsky, Anna; Fitzgerald, Kevin; Hulsmans, Maarten; Hoyer, Friedrich; Iwamoto, Yoshiko; Vinegoni, Claudio; Brown, Dennis; Di Carli, Marcelo; Libby, Peter; Hiebert, Scott; Scadden, David; Swirski, Filip K.; Weissleder, Ralph; Nahrendorf, Matthias

    2015-01-01

    SUMMARY Following myocardial infarction (MI), myeloid cells derived from the hematopoietic system drive a sharp increase in systemic leukocyte levels that correlate closely with mortality. The origin of these myeloid cells, and the response of hematopoietic stem and progenitor cells (HSPCs) to MI, however, is unclear. Here, we identify a CCR2+CD150+CD48− LSK hematopoietic subset as the most upstream contributor to emergency myelopoiesis after ischemic organ injury. CCR2+ HSPC have fourfold higher proliferation rates than CCR2−CD150+CD48− LSK cells, display a myeloid differentiation bias, and dominate the migratory HSPC population. We further demonstrate the myeloid translocation gene 16 (Mtg16) regulates CCR2+ HSPC emergence. Mtg16−/− mice have decreased levels of systemic monocytes and infarct-associated macrophages and display compromised tissue healing and post-MI heart failure. Together, these data provide insights into regulation of emergency hematopoiesis after ischemic injury, and identify potential therapeutic targets to modulate leukocyte output after MI. PMID:25957903

  17. Plasticity of hematopoietic stem cells.

    PubMed

    Ogawa, Makio; LaRue, Amanda C; Mehrotra, Meenal

    2015-01-01

    Almost two decades ago, a number of cell culture and preclinical transplantation studies suggested the striking concept of the tissue-reconstituting ability of hematopoietic stem cells (HSCs). While this heralded an exciting time of radically new therapies for disorders of many organs and tissues, the concept was soon mired by controversy and remained dormant. This chapter provides a brief review of evidence for HSC plasticity including our findings based on single HSC transplantation in mouse. These studies strongly support the concept that HSCs are pluripotent and may be the source for the majority, if not all, of the cell types in our body. PMID:26590762

  18. (Lymph)angiogenic influences on hematopoietic cells in acute myeloid leukemia

    PubMed Central

    Lee, Ji Yoon; Kim, Hee-Je

    2014-01-01

    The purpose of this review is to provide an overview of the effect of (lymph)angiogenic cytokines on hematopoietic cells involved in acute myeloid leukemia (AML). Like angiogenesis, lymphangiogenesis occurs in pathophysiological conditions but not in healthy adults. AML is closely associated with the vasculature system, and the interplay between lymphangiogenic cytokines maintains leukemic blast survival in the bone marrow (BM). Once AML is induced, proangiogenic cytokines function as angiogenic or lymphangiogenic factors and affect hematopoietic cells, including BM-derived immune cells. Simultaneously, the representative cytokines, VEGFs and their receptors are expressed on AML blasts in vascular and osteoblast niches in both the BM and the peripheral circulation. After exposure to (lymph)angiogenic cytokines in leukemogenesis and infiltration, immune cell phenotypes and functions are affected. These dynamic behaviors in the BM reflect the clinical features of AML. In this review, we note the importance of lymphangiogenic factors and their receptors in hematopoietic cells in AML. Understanding the functional characterization of (lymph)angiogenic factors in the BM niche in AML will also be helpful in interrupting the engraftment of leukemic stem cells and for enhancing immune cell function by modulating the tumor microenvironment. PMID:25412683

  19. Lamins regulate cell trafficking and lineage maturation of adult human hematopoietic cells

    PubMed Central

    Shin, Jae-Won; Spinler, Kyle R.; Swift, Joe; Chasis, Joel A.; Mohandas, Narla; Discher, Dennis E.

    2013-01-01

    Hematopoietic stem and progenitor cells, as well as nucleated erythroblasts and megakaryocytes, reside preferentially in adult marrow microenvironments whereas other blood cells readily cross the endothelial barrier into the circulation. Because the nucleus is the largest organelle in blood cells, we hypothesized that (i) cell sorting across microporous barriers is regulated by nuclear deformability as controlled by lamin-A and -B, and (ii) lamin levels directly modulate hematopoietic programs. Mass spectrometry-calibrated intracellular flow cytometry indeed reveals a lamin expression map that partitions human blood lineages between marrow and circulating compartments (P = 0.00006). B-type lamins are highly variable and predominate only in CD34+ cells, but migration through micropores and nuclear flexibility in micropipette aspiration both appear limited by lamin-A:B stoichiometry across hematopoietic lineages. Differentiation is also modulated by overexpression or knockdown of lamins as well as retinoic acid addition, which regulates lamin-A transcription. In particular, erythroid differentiation is promoted by high lamin-A and low lamin-B1 expression whereas megakaryocytes of high ploidy are inhibited by lamin suppression. Lamins thus contribute to both trafficking and differentiation. PMID:24191023

  20. Hematopoietic Age at Onset of Triple-Negative Breast Cancer Dictates Disease Aggressiveness and Progression.

    PubMed

    Marsh, Timothy; Wong, Irene; Sceneay, Jaclyn; Barakat, Amey; Qin, Yuanbo; Sjödin, Andreas; Alspach, Elise; Nilsson, Björn; Stewart, Sheila A; McAllister, Sandra S

    2016-05-15

    Triple-negative breast cancer (TNBC) is considered an early onset subtype of breast cancer that carries with it a poorer prognosis in young rather than older women for reasons that remain poorly understood. Hematopoiesis in the bone marrow becomes altered with age and may therefore affect the composition of tumor-infiltrating hematopoietic cells and subsequent tumor progression. In this study, we investigated how age- and tumor-dependent changes to bone marrow-derived hematopoietic cells impact TNBC progression. Using multiple mouse models of TNBC tumorigenesis and metastasis, we found that a specific population of bone marrow cells (BMC) upregulated CSF-1R and secreted the growth factor granulin to support stromal activation and robust tumor growth in young mice. However, the same cell population in old mice expressed low levels of CSF1R and granulin and failed to promote tumor outgrowth, suggesting that age influences the tumorigenic capacity of BMCs in response to tumor-associated signals. Importantly, BMCs from young mice were sufficient to activate a tumor-supportive microenvironment and induce tumor progression in old mice. These results indicate that hematopoietic age is an important determinant of TNBC aggressiveness and provide rationale for investigating age-stratified therapies designed to prevent the protumorigenic effects of activated BMCs. Cancer Res; 76(10); 2932-43. ©2016 AACR. PMID:27197230

  1. Embryonic hematopoiesis in vertebrate somites gives rise to definitive hematopoietic stem cells.

    PubMed

    Qiu, Juhui; Fan, Xiaoying; Wang, Yixia; Jin, Hongbin; Song, Yixiao; Han, Yang; Huang, Shenghong; Meng, Yaping; Tang, Fuchou; Meng, Anming

    2016-08-01

    Hematopoietic stem cells (HSCs) replenish all types of blood cells. It is debating whether HSCs in adults solely originate from the aorta-gonad-mesonephros (AGM) region, more specifically, the dorsal aorta, during embryogenesis. Here, we report that somite hematopoiesis, a previously unwitnessed hematopoiesis, can generate definitive HSCs (dHSCs) in zebrafish. By transgenic lineage tracing, we found that a subset of cells within the forming somites emigrate ventromedially and mix with lateral plate mesoderm-derived primitive hematopoietic cells before the blood circulation starts. These somite-derived hematopoietic precursors and stem cells (sHPSCs) subsequently enter the circulation and colonize the kidney of larvae and adults. RNA-seq analysis reveals that sHPSCs express hematopoietic genes with sustained expression of many muscle/skeletal genes. Embryonic sHPSCs transplanted into wild-type embryos expand during growth and survive for life time with differentiation into various hematopoietic lineages, indicating self-renewal and multipotency features. Therefore, the embryonic origin of dHSCs in adults is not restricted to the AGM. PMID:27252540

  2. Replication stress caused by low MCM expression limits fetal erythropoiesis and hematopoietic stem cell functionality

    PubMed Central

    Alvarez, Silvia; Díaz, Marcos; Flach, Johanna; Rodriguez-Acebes, Sara; López-Contreras, Andrés J.; Martínez, Dolores; Cañamero, Marta; Fernández-Capetillo, Oscar; Isern, Joan; Passegué, Emmanuelle; Méndez, Juan

    2015-01-01

    Replicative stress during embryonic development influences ageing and predisposition to disease in adults. A protective mechanism against replicative stress is provided by the licensing of thousands of origins in G1 that are not necessarily activated in the subsequent S-phase. These ‘dormant' origins provide a backup in the presence of stalled forks and may confer flexibility to the replication program in specific cell types during differentiation, a role that has remained unexplored. Here we show, using a mouse strain with hypomorphic expression of the origin licensing factor mini-chromosome maintenance (MCM)3 that limiting origin licensing in vivo affects the functionality of hematopoietic stem cells and the differentiation of rapidly-dividing erythrocyte precursors. Mcm3-deficient erythroblasts display aberrant DNA replication patterns and fail to complete maturation, causing lethal anemia. Our results indicate that hematopoietic progenitors are particularly sensitive to replication stress, and full origin licensing ensures their correct differentiation and functionality. PMID:26456157

  3. A humanized bone marrow ossicle xenotransplantation model enables improved engraftment of healthy and leukemic human hematopoietic cells.

    PubMed

    Reinisch, Andreas; Thomas, Daniel; Corces, M Ryan; Zhang, Xiaohua; Gratzinger, Dita; Hong, Wan-Jen; Schallmoser, Katharina; Strunk, Dirk; Majeti, Ravindra

    2016-07-01

    Xenotransplantation models represent powerful tools for the investigation of healthy and malignant human hematopoiesis. However, current models do not fully mimic the components of the human bone marrow (BM) microenvironment, and they enable only limited engraftment of samples from some human malignancies. Here we show that a xenotransplantation model bearing subcutaneous humanized ossicles with an accessible BM microenvironment, formed by in situ differentiation of human BM-derived mesenchymal stromal cells, enables the robust engraftment of healthy human hematopoietic stem and progenitor cells, as well as primary acute myeloid leukemia (AML) samples, at levels much greater than those in unmanipulated mice. Direct intraossicle transplantation accelerated engraftment and resulted in the detection of substantially higher leukemia-initiating cell (LIC) frequencies. We also observed robust engraftment of acute promyelocytic leukemia (APL) and myelofibrosis (MF) samples, and identified LICs in these malignancies. This humanized ossicle xenotransplantation approach provides a system for modeling a wide variety of human hematological diseases. PMID:27213817

  4. L-arginine is a radioprotector for hematopoietic progenitor cells.

    PubMed

    Pearce, Linda L; Zheng, Xichen; Martinez-Bosch, Sandra; Kerr, Patrick P; Khlangwiset, Pornsri; Epperly, Michael W; Fink, Mitchell P; Greenberger, Joel S; Peterson, Jim

    2012-06-01

    L-arginine is shown to protect hematopoietic progenitor (32D cl 3) cells from death due to exposure to γ radiation ((137)Cs). Some of the other intermediates in the urea cycle, namely ornithine and citrulline, plus urea itself, were not found to have any significant impact on cell survival after irradiation. Intriguingly, supplementation of irradiated cells with L-arginine results in decreased production of peroxynitrite, suggesting that suppression of superoxide generation by nitric oxide synthase in one or more microenvironments is an important factor in the observed radioprotection. The absence of any radioprotective effect of L-arginine in cells at 3% oxygen also confirms the involvement of one or more oxygen-derived species. Knockdown experiments with nitric oxide synthase (NOS) siRNAs in cells and NOS knockout animals confirm that the observed radioprotection is associated with nNOS (NOS-1). L-arginine also ameliorates the transient inhibition of the electron-transport chain complex I that occurs within 30 min of completing the dose (10 Gy) and that appears to be a functional marker for postirradiation mitochondrial oxidant production. PMID:22175298

  5. Endoplasmic reticulum stress regulation in hematopoietic stem cells.

    PubMed

    Miharada, Kenichi

    2016-08-01

    Adult hematopoietic stem cells (HSCs) reside in bone marrow and are maintained in a dormant state within a special microenvironment, their so-called "niche". Detaching from the niche induces cell cycle progression, resulting in a reduction of the reconstitution capacity of HSCs. In contrast, fetal liver HSCs actively divide without losing their stem cell potentials. Thus, it has been unclear what types of cellular responses and metabolic changes occur in growing HSCs. We previously discovered that HSCs express relatively low levels of endoplasmic reticulum (ER) chaperone proteins governing protein folding, making HSCs vulnerable to an elevation of stress signals caused by accumulation of un-/misfolded proteins (ER stress) upon in vitro culture. Interestingly, fetal liver HSCs do not show ER stress elevation despite unchanged levels of chaperone proteins. Our latest studies utilizing multiple mouse models revealed that in the fetal liver bile acids as chemical chaperones play a key role supporting the protein folding which results in the suppression of ER stress induction. These findings highlight the importance of ER stress regulations in hematopoiesis. PMID:27599423

  6. l-Arginine is a Radioprotector for Hematopoietic Progenitor Cells

    PubMed Central

    Pearce, Linda L.; Zheng, Xichen; Martinez-Bosch, Sandra; Kerr, Patrick P.; Khlangwiset, Pornsri; Epperly, Michael W.; Fink, Mitchell P.; Greenberger, Joel S.; Peterson, Jim

    2012-01-01

    l-Arginine is shown to protect hematopoietic progenitor (32D cl 3) cells from death due to exposure to γ radiation (137Cs). Some of the other intermediates in the urea cycle, namely ornithine and citrulline, plus urea itself, were not found to have any significant impact on cell survival after irradiation. Intriguingly, supplementation of irradiated cells with l-arginine results in decreased production of peroxynitrite, suggesting that suppression of superoxide generation by nitric oxide synthase in one or more microenvironments is an important factor in the observed radioprotection. The absence of any radioprotective effect of l-arginine in cells at 3% oxygen also confirms the involvement of one or more oxygen-derived species. Knockdown experiments with nitric oxide synthase (NOS) siRNAs in cells and NOS knockout animals confirm that the observed radioprotection is associated with nNOS (NOS-1). l-Arginine also ameliorates the transient inhibition of the electron-transport chain complex I that occurs within 30 min of completing the dose (10 Gy) and that appears to be a functional marker for postirradiation mitochondrial oxidant production. PMID:22175298

  7. Modeling of Sulfide Microenvironments on Mars

    NASA Technical Reports Server (NTRS)

    Schwenzer, S. P.; Bridges, J. C.; McAdam, A.; Steer, E. D.; Conrad, P. G.; Kelley, S. P.; Wiens, R. C.; Mangold, N.; Grotzinger, J.; Eigenbrode, J. L.; Franz, H. B.; Sutter, B.

    2016-01-01

    Yellowknife Bay (YKB; sol 124-198) is the second site that the Mars Science Laboratory Rover Curiosity investigated in detail on its mission in Gale Crater. YKB represents lake bed sediments from an overall neutral pH, low salinity environment, with a mineralogical composition which includes Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral phyllosilicates. We investigate whether sulfide alteration could be associated with ancient habitable microenvironments in the Gale mudstones. Some textural evidence for such alteration may be pre-sent in the nodules present in the mudstone.

  8. Cancer Microenvironment and Inflammation: Role of Hyaluronan

    PubMed Central

    Nikitovic, Dragana; Tzardi, Maria; Berdiaki, Aikaterini; Tsatsakis, Aristidis; Tzanakakis, George N.

    2015-01-01

    The role of inflammation in the development of cancer was described as early as the nineteenth century. Abundant evidence supports the preposition that various cancers are triggered by infection and chronic inflammatory disease whereas, evading immune destruction has been proposed as one of the new “hallmarks of cancer.” Changes of the tumor microenvironment have been closely correlated to cancer-mediated inflammation. Hyaluronan (HA), an important extracellular matrices component, has become recognized as an active participant in inflammatory, angiogenic, fibrotic, and cancer promoting processes. This review discusses how HA and specific HA-binding proteins participate in and regulate cancer-related inflammatory processes. PMID:25926834

  9. Matrix Metalloproteinases: Regulators of the Tumor Microenvironment

    PubMed Central

    Kessenbrock, Kai; Plaks, Vicki; Werb, Zena

    2010-01-01

    Extracellular proteolysis mediates tissue homeostasis. In cancer, altered proteolysis leads to unregulated tumor growth, tissue remodeling, inflammation, tissue invasion, and metastasis. The matrix metalloproteinases (MMPs) represent the most prominent family of proteinases associated with tumorigenesis. Recent technological developments have markedly advanced our understanding of MMPs as modulators of the tumor microenvironment. In addition to their role in extracellular matrix turnover and cancer cell migration, MMPs regulate signaling pathways that control cell growth, inflammation, or angiogenesis and may even work in a nonproteolytic manner. These aspects of MMP function are reorienting our approaches to cancer therapy. PMID:20371345

  10. Metabolic reprogramming of the tumour microenvironment.

    PubMed

    Xing, Yazhi; Zhao, Shimin; Zhou, Binhua P; Mi, Jun

    2015-10-01

    Tumour cells, stromal cells and the stroma comprise the tumour microenvironment. The metabolism of both tumour cells and several types of tumour stromal cells, such as cancer-associated fibroblasts and tumour-associated macrophages, is reprogrammed. Current studies have found that stromal cells promote tumour progression and metastasis, through not only the paracrine secretion of cytokines or chemokines, but also intermediate metabolites. Here, we summarize the latest insights into the mechanism of metabolic reprogramming in cancer cells, cancer-associated fibroblasts and tumour-associated macrophages, and their potential roles in tumour progression and metastasis. PMID:26255648

  11. Parasitic Infections in Hematopoietic Stem Cell Transplantation

    PubMed Central

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  12. Parasitic Infections in Hematopoietic Stem Cell Transplantation.

    PubMed

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  13. Hematopoietic Stem Cells, Their Niche, and the Concept of Co-Culture Systems: A Critical Review.

    PubMed

    Vaidya, Anuradha; Kale, Vaijayanti

    2015-01-01

    Hematopoietic stem cells (HSCs) have the ability to self-renew and give rise to all lineages of blood cells. HSCs reside in niches that are local tissue microenvironments that maintain and regulate them. Although much progress has been made in elucidating the location and cellular components of the HSC niche, however it still remains incompletely defined. Transplantation using HSCs has been applied for the treatment of several diseases but with limited success. Furthermore, although human HSC transplantation has been widely used to rescue the patients after cytoablative therapies, quantitative in vivo human assays for hematopoietic cells have been considered to be neither ethical nor practical. Since HSCs persist in small quantities in the body, understanding the mechanism that govern their fate is essential for the advancement of HSC expansion and transplantation in the future. Since bone marrow is the primary site of HSC maintenance and hematopoiesis, defining the niche components that work in concert to regulate hematopoiesis is crucial to improve regeneration following injury or following HSC transplantation and to also understand how disordered niche function could contribute to disease. In recent years, there has been a growing realization of the limitations in identifying the primitive HSCs by its phenotype alone and therefore the concept of co-culture systems (functional in vitro assays) has become increasingly important to demonstrate the presence of primitive hematopoietic cells by estimating their biological functions. This system has provided a basis for the development of powerful assay procedures for expanding, quantitating and distinguishing cells at discrete stages of early hematopoietic cell differentiation. PMID:26665935

  14. Radioimmunotherapy for hematopoietic cell transplantation.

    PubMed

    Jurcic, Joseph G

    2013-04-01

    Radioimmunotherapy (RIT) represents an attractive strategy to deliver radiation selectively to tumor and other target organs while minimizing toxicity to normal tissues. RIT with β-particle-emitting isotopes targeting CD33, CD45 and CD66 can potentially allow intensification of conditioning before hematopoietic cell transplantation (HCT) in leukemia. Similarly, RIT directed against CD20 has shown promise in the setting of autologous and allogeneic HCT for B-cell lymphomas. α-particle immunotherapy with isotopes such as bismuth-213, actinium-225 and astatinine-211 offers the possibility of more selective and efficient killing of target cells while sparing the surrounding normal cells. Pretargeting strategies may further improve target:normal organ dose ratios. While RIT has demonstrated significant antitumor activity, ultimately, randomized studies will be required to determine if conditioning regimens that include this therapeutic modality can improve patient outcomes after HCT. PMID:23557421

  15. The influence of the microenvironment on the malignant phenotype

    NASA Technical Reports Server (NTRS)

    Park, C. C.; Bissell, M. J.; Barcellos-Hoff, M. H.

    2000-01-01

    Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. As tissue becomes cancerous, there are reciprocal interactions between neoplastic cells, adjacent normal cells such as stroma and endothelium, and their microenvironments. The current dominant paradigm wherein multiple genetic lesions provide both the impetus for, and the Achilles heel of, cancer might be inadequate to understand cancer as a disease process. In the following brief review, we will use selected examples to illustrate the influence of the microenvironment in the evolution of the malignant phenotype. We will also discuss recent studies that suggest novel therapeutic interventions might be derived from focusing on microenvironment and tumor cells interactions.

  16. Endothelial-to-hematopoietic transition: Notch-ing vessels into blood.

    PubMed

    Kanz, Dirk; Konantz, Martina; Alghisi, Elisa; North, Trista E; Lengerke, Claudia

    2016-04-01

    During development, hematopoietic stem cells (HSCs) are formed in a temporally and spatially restricted manner, arising from specialized endothelial cells (ECs) in the ventral wall of the dorsal aorta within the evolutionary conserved aorta-gonad-mesonephros region. Our understanding of the processes regulating the birth of HSCs from ECs has been recently advanced by comprehensive molecular analyses of developing murine hematopoietic cell populations complemented by studies in the zebrafish model, with the latter offering unique advantages for genetic studies and direct in vivo visualization of HSC emergence. Here, we provide a concise review of the current knowledge and recent advances regarding the cellular origin and molecular regulation of HSC development, with particular focus on the process of endothelial-to-hematopoietic transition and its primary regulator, the Notch signaling pathway. PMID:27015586

  17. Engineering Strategies to Mimic the Glioblastoma Microenvironment

    PubMed Central

    Rape, Andrew; Ananthanarayanan, Badriprasad; Kumar, Sanjay

    2014-01-01

    Glioblastoma multiforme (GBM) is the most common and deadly brain tumor, with a mean survival time of only 21 months. Despite the dramatic improvements in our understanding of GBM fueled by recent revolutions in molecular and systems biology, treatment advances for GBM have progressed inadequately slowly, which is due in part to the wide cellular and molecular heterogeneity both across tumors and within a single tumor. Thus, there is increasing clinical interest in targeting cell-extrinsic factors as way of slowing or halting the progression of GBM. These cell-extrinsic factors, collectively termed the microenvironment, include the extracellular matrix, blood vessels, stromal cells that surround tumor cells, and all associated soluble and scaffold-bound signals. In this review, we will first describe the regulation of GBM tumors by these microenvironmental factors. Next, we will discuss the various in vitro approaches that have been exploited to recapitulate and model the GBM tumor microenvironment in vitro. We conclude by identifying future challenges and opportunities in this field, including the development of microenvironmental platforms amenable to high-throughput discovery and screening. We anticipate that these ongoing efforts will prove to be valuable both as enabling tools for accelerating our understanding of microenvironmental regulation in GBM and as foundations for next-generation molecular screening platforms that may serve as a conceptual bridge between traditional reductionist systems and animal or clinical studies. PMID:25174308

  18. Tumor microenvironment and metabolism in prostate cancer.

    PubMed

    Chiarugi, Paola; Paoli, Paolo; Cirri, Paolo

    2014-04-01

    Prostate cancer is no longer viewed mostly as a disease of abnormally proliferating epithelial cells, but rather as a disease affecting the complex interactions between the cells of the prostate epithelial compartment and the surrounding stromal compartment in which they live. Indeed, the microenvironment in which tumor cells evolve towards an aggressive phenotype is highly heterogeneous, as it is composed of different cell populations such as endothelial cells, fibroblasts, macrophages, and lymphocytes, either resident or trans-differentiated by bone marrow-derived mesenchymal stem cells recruited at the tumor site. Cancer-associated fibroblasts, the most abundant population within this microenvironment, exert a mandatory role in prostate cancer progression as they metabolically sustain cancer cell survival and growth, recruit inflammatory and immune cells, and promote cancer cells stemness and epithelial mesenchymal transition, thereby favoring metastatic dissemination of aggressive cancers. The interruption of this two-compartment crosstalk, together with the idea that stromal cells are mostly vulnerable, being drug-sensitive, could lead to the development of anticancer therapies that target tumor stromal elements. PMID:24787298

  19. Exploiting the tumor microenvironment for theranostic imaging

    PubMed Central

    Stasinopoulos, Ioannis; Penet, Marie-France; Chen, Zhihang; Kakkad, Samata; Glunde, Kristine; Bhujwalla, Zaver M.

    2011-01-01

    The integration of chemistry and molecular biology with imaging is providing some of the most exciting opportunities in the treatment of cancer. The field of theranostic imaging, where diagnosis is combined with therapy, is particularly suitable for a disease as complex as cancer, especially now that genomic and proteomic profiling can provide an extensive `fingerprint' of each tumor. Using this information, theranostic agents can be shaped for personalized treatment to target specific compartments, such as the tumor microenvironment (TME), whilst minimizing damage to normal tissue. These theranostic agents can also be used to target multiple pathways or networks by incorporating multiple small interfering RNAs (siRNAs) within a single agent. A decade ago genetic alterations were the primary focus in cancer research. Now it is apparent that the tumor physiological microenvironment, interactions between cancer cells and stromal cells, such as endothelial cells, fibroblasts and macrophages, the extracellular matrix (ECM), and a host of secreted factors and cytokines, influence progression to metastatic disease, aggressiveness and the response of the disease to treatment. In this review, we outline some of the characteristics of the TME, describe the theranostic agents currently available to target the TME and discuss the unique opportunities the TME provides for the design of novel theranostic agents for cancer therapy. PMID:21793072

  20. Leukemia cell microvesicles promote survival in umbilical cord blood hematopoietic stem cells

    PubMed Central

    Razmkhah, Farnaz; Soleimani, Masoud; Mehrabani, Davood; Karimi, Mohammad Hossein; Kafi-abad, Sedigheh Amini

    2015-01-01

    Microvesicles can transfer their contents, proteins and RNA, to target cells and thereby transform them. This may induce apoptosis or survival depending on cell origin and the target cell. In this study, we investigate the effect of leukemic cell microvesicles on umbilical cord blood hematopoietic stem cells to seek evidence of apoptosis or cell survival. Microvesicles were isolated from both healthy donor bone marrow samples and Jurkat cells by ultra-centrifugation and were added to hematopoietic stem cells sorted from umbilical cord blood samples by magnetic associated cell sorting (MACS) technique. After 7 days, cell count, cell viability, flow cytometry analysis for hematopoietic stem cell markers and qPCR for P53 gene expression were performed. The results showed higher cell number, higher cell viability rate and lower P53 gene expression in leukemia group in comparison with normal and control groups. Also, CD34 expression as the most important hematopoietic stem cell marker, did not change during the treatment and lineage differentiation was not observed. In conclusion, this study showed anti-apoptotic effect of leukemia cell derived microvesicles on umbilical cord blood hematopoietic stem cells. PMID:26862318

  1. The contribution of the Tie2+ lineage to primitive and definitive hematopoietic cells.

    PubMed

    Tang, Yuefeng; Harrington, Anne; Yang, Xuehui; Friesel, Robert E; Liaw, Lucy

    2010-09-01

    The regulatory elements of the Tie2/Tek promoter are commonly used in mouse models to direct transgene expression to endothelial cells. Tunica intima endothelial kinase 2 (Tie2) is also expressed in hematopoietic cells, although this has not been fully characterized. We determine the lineages of adult hematopoietic cells derived from Tie2-expressing populations using Tie2-Cre;Rosa26R-EYFP mice. In Tie2-Cre;Rosa26R-EYFP mice, analysis of bone marrow cells showed Cre-mediated recombination in 85% of the population. In adult bone marrow and spleen, we analyzed subclasses of early hematopoietic progenitors, T cells, monocytes, granulocytes, and B cells. We found that ∼ 84% of each lineage was EYFP(+), and nearly all cells that come from Tie2-expressing lineages are CD45(+), confirming widespread contribution to definitive hematopoietic cells. In addition, more than 82% of blood cells within the embryonic yolk sac were of Tie2(+) origin. Our findings of high levels of Tie2-Cre recombination in the hematopoietic lineage have implications for the use of the Tie2-Cre mouse as a lineage-restricted driver strain. PMID:20645309

  2. The Biology of Allogeneic Hematopoietic Cell Resistance

    PubMed Central

    Shizuru, Judith A.; Bhattacharya, Deepta; Cavazzana-Calvo, Marina

    2016-01-01

    At the most basic level, success of an allogeneic hematopoietic cell transplantation (HCT) procedure relies upon the engraftment of recipients with donor hematopoietic stem cells (HSCs) that will generate blood formation for the life of that individual. The formula to achieve durable HSC engraftment involves multiple factors including the recipient conditioning regimen, the nature of the genetic disparity between donor and recipient, and the content of the hematopoietic graft. Animal and clinical studies have shown that the biology of host resistance is complex, involving both immune and nonimmune elements. In this article, we review the factors that contribute to host resistance, describe emerging concepts on the basic biology of resistance, and discuss hematopoietic resistance as it relates specifically to patients with severe combined immunodeficiencies (SCID)— disorders that bring unique insights into the dynamics of cell replacement by allogeneic HSCs and progenitor cells. PMID:19913629

  3. TGFβ restores hematopoietic homeostasis after myelosuppressive chemotherapy

    PubMed Central

    Brenet, Fabienne; Kermani, Pouneh; Spektor, Roman; Rafii, Shahin

    2013-01-01

    Myelosuppression is a life-threatening complication of antineoplastic therapy, but treatment is restricted to a few cytokines with unilineage hematopoietic activity. Although hematopoietic stem cells (HSCs) are predominantly quiescent during homeostasis, they are rapidly recruited into cell cycle by stresses, including myelosuppressive chemotherapy. Factors that induce HSCs to proliferate during stress have been characterized, but it is not known how HSC quiescence is then reestablished. In this study, we show that TGFβ signaling is transiently activated in hematopoietic stem and progenitor cells (HSPCs) during hematopoietic regeneration. Blockade of TGFβ signaling after chemotherapy accelerates hematopoietic reconstitution and delays the return of cycling HSCs to quiescence. In contrast, TGFβ blockade during homeostasis fails to induce cycling of HSPCs. We identified the cyclin-dependent kinase inhibitor Cdkn1c (p57) as a key downstream mediator of TGFβ during regeneration because the recovery of chimeric mice, incapable of expressing p57 in HSPCs, phenocopies blockade of TGFβ signaling after chemotherapy. This study demonstrates that context-dependent activation of TGFβ signaling is central to an unrecognized counterregulatory mechanism that promotes homeostasis once hematopoiesis has sufficiently recovered from myelosuppressive chemotherapy. These results open the door to new, potentially superior, approaches to promote multilineage hematopoietic recovery by blocking the TGFβ signaling that dampens regeneration. PMID:23440043

  4. SNP Array in Hematopoietic Neoplasms: A Review

    PubMed Central

    Song, Jinming; Shao, Haipeng

    2015-01-01

    Cytogenetic analysis is essential for the diagnosis and prognosis of hematopoietic neoplasms in current clinical practice. Many hematopoietic malignancies are characterized by structural chromosomal abnormalities such as specific translocations, inversions, deletions and/or numerical abnormalities that can be identified by karyotype analysis or fluorescence in situ hybridization (FISH) studies. Single nucleotide polymorphism (SNP) arrays offer high-resolution identification of copy number variants (CNVs) and acquired copy-neutral loss of heterozygosity (LOH)/uniparental disomy (UPD) that are usually not identifiable by conventional cytogenetic analysis and FISH studies. As a result, SNP arrays have been increasingly applied to hematopoietic neoplasms to search for clinically-significant genetic abnormalities. A large numbers of CNVs and UPDs have been identified in a variety of hematopoietic neoplasms. CNVs detected by SNP array in some hematopoietic neoplasms are of prognostic significance. A few specific genes in the affected regions have been implicated in the pathogenesis and may be the targets for specific therapeutic agents in the future. In this review, we summarize the current findings of application of SNP arrays in a variety of hematopoietic malignancies with an emphasis on the clinically significant genetic variants. PMID:27600067

  5. Radiation and the Microenvironment - Tumorigenesis andTherapy

    SciTech Connect

    Barcellos-Hoff, Mary Helen; Park, Catherine; Wright, Eric G.

    2005-10-01

    Radiation rapidly and persistently alters the soluble and insoluble components of the tissue microenvironment. This affects the cell phenotype, tissue composition and the physical interactions and signaling between cells. These alterations in the microenvironment can contribute to carcinogenesis and alter the tissue response to anticancer therapy. Examples of these responses and their implications are discussed with a view to therapeutic intervention.

  6. Of Microenvironments and Mammary Stem Cells

    SciTech Connect

    LaBarge, Mark A; Petersen, Ole W; Bissell, Mina J

    2007-06-01

    In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.

  7. Morphological plasticity of astroglia: Understanding synaptic microenvironment

    PubMed Central

    2015-01-01

    Memory formation in the brain is thought to rely on the remodeling of synaptic connections which eventually results in neural network rewiring. This remodeling is likely to involve ultrathin astroglial protrusions which often occur in the immediate vicinity of excitatory synapses. The phenomenology, cellular mechanisms, and causal relationships of such astroglial restructuring remain, however, poorly understood. This is in large part because monitoring and probing of the underpinning molecular machinery on the scale of nanoscopic astroglial compartments remains a challenge. Here we briefly summarize the current knowledge regarding the cellular organisation of astroglia in the synaptic microenvironment and discuss molecular mechanisms potentially involved in use‐dependent astroglial morphogenesis. We also discuss recent observations concerning morphological astroglial plasticity, the respective monitoring methods, and some of the newly emerging techniques that might help with conceptual advances in the area. GLIA 2015;63:2133–2151 PMID:25782611

  8. Targeting Pancreatic Ductal Adenocarcinoma Acidic Microenvironment

    NASA Astrophysics Data System (ADS)

    Cruz-Monserrate, Zobeida; Roland, Christina L.; Deng, Defeng; Arumugam, Thiruvengadam; Moshnikova, Anna; Andreev, Oleg A.; Reshetnyak, Yana K.; Logsdon, Craig D.

    2014-03-01

    Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA, accounting for ~40,000 deaths annually. The dismal prognosis for PDAC is largely due to its late diagnosis. Currently, the most sensitive diagnosis of PDAC requires invasive procedures, such as endoscopic ultrasonography, which has inherent risks and accuracy that is highly operator dependent. Here we took advantage of a general characteristic of solid tumors, the acidic microenvironment that is generated as a by-product of metabolism, to develop a novel approach of using pH (Low) Insertion Peptides (pHLIPs) for imaging of PDAC. We show that fluorescently labeled pHLIPs can localize and specifically detect PDAC in human xenografts as well as PDAC and PanIN lesions in genetically engineered mouse models. This novel approach may improve detection, differential diagnosis and staging of PDAC.

  9. Sensitivity of Dendritic Cells to Microenvironment Signals

    PubMed Central

    Motta, Juliana Maria; Rumjanek, Vivian Mary

    2016-01-01

    Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies. PMID:27088097

  10. The Tumor Microenvironment in Colorectal Carcinogenesis

    PubMed Central

    Peddareddigari, Vijay G.; Wang, Dingzhi

    2010-01-01

    Colorectal cancer is the second leading cause of cancer-related mortality in the United States. Therapeutic developments in the past decade have extended life expectancy in patients with metastatic disease. However, metastatic colorectal cancers remain incurable. Numerous agents that were demonstrated to have significant antitumor activity in experimental models translated into disappointing results in extending patient survival. This has resulted in more attention being focused on the contribution of tumor microenvironment to the progression of a number of solid tumors including colorectal cancer. A more complete understanding of interactions between tumor epithelial cells and their stromal elements will enhance therapeutic options and improve clinical outcome. Here we will review the role of various stromal components in colorectal carcinogenesis and discuss the potential of targeting these components for the development of future therapeutic agents. PMID:21209781

  11. Manipulating the Microvasculature and Its Microenvironment

    PubMed Central

    Krishnan, Laxminarayanan; Chang, Carlos C.; Nunes, Sara S; Williams, Stuart K.; Weiss, Jeffrey A.; Hoying, James B.

    2014-01-01

    The microvasculature is a dynamic cellular system necessary for tissue health and function. Therapeutic strategies that target the microvasculature are expanding and evolving, including those promoting angiogenesis and microvascular expansion. When considering how to manipulate angiogenesis, either as part of a tissue construction approach or a therapy to improve tissue blood flow, it is important to know the microenvironmental factors that regulate and direct neovessel sprouting and growth. Much is known concerning both diffusible and matrix-bound angiogenic factors, which stimulate and guide angiogenic activity. How the other aspects of the extravascular microenvironment, including tissue biomechanics and structure, influence new vessel formation is less well known. Recent research, however, is providing new insights into these mechanisms and demonstrating that the extent and character of angiogenesis (and the resulting new microcirculation) is significantly affected. These observations and the resulting implications with respect to tissue construction and microvascular therapy are addressed. PMID:24580565

  12. Extracellular vesicles in lung microenvironment and pathogenesis.

    PubMed

    Fujita, Yu; Kosaka, Nobuyoshi; Araya, Jun; Kuwano, Kazuyoshi; Ochiya, Takahiro

    2015-09-01

    Increasing attention is being paid to the role of extracellular vesicles (EVs) in various lung diseases. EVs are released by a variety of cells, including respiratory cells and immune cells, and they encapsulate various molecules, such as proteins and microRNAs, as modulators of intercellular communication. Cancer cell-derived EVs play crucial roles in promoting tumor progression and modifying their microenvironment. By contrast, noncancerous cell-derived EVs demonstrate protective functions against injury, such as tissue recovery and repair, to maintain physiological homeostasis. Airway cells in contact with harmful substances may alter their EV composition and modify the balanced reciprocal interactions with surrounding mesenchymal cells. We summarize the novel findings of EV function in various lung diseases, primarily chronic obstructive pulmonary disease (COPD) and lung cancer. PMID:26231094

  13. Targeting SDF-1 in multiple myeloma tumor microenvironment.

    PubMed

    Bouyssou, Juliette M C; Ghobrial, Irene M; Roccaro, Aldo M

    2016-09-28

    Multiple myeloma (MM) is a type of B-cell malignancy that remains incurable to date. The bone marrow (BM) microenvironment plays a crucial role in MM progression. The chemokine SDF-1 (CXCL12) is an important actor of the BM microenvironment that has the ability to regulate numerous processes related to its malignant transformation during MM development. The activity of SDF-1 is mainly mediated by its specific receptor CXCR4, which is expressed at the surface of MM cells and various other BM cell types. Current treatments available for MM patients mainly target tumor cells but have limited effects on the BM microenvironment. In this context, SDF-1 and CXCR4 represent ideal targets for the normalization of the MM-supportive BM microenvironment. The present review focuses on the activity of SDF-1 in the MM BM microenvironment and the current efforts carried out to target the SDF-1/CXCR4 axis for treatment of MM. PMID:26655999

  14. Role of the tumor microenvironment in pancreatic adenocarcinoma.

    PubMed

    Sun, Xian-Jun; Jiang, Ting-Hui; Zhang, Xiao-Ping; Mao, Ai-Wu

    2016-01-01

    Pancreatic cancer is a devastating disease with proclivity for early metastasis, which accounts for its poor prognosis. The clinical problem of pancreatic cancer is its resistance to conventional therapies, such as chemotherapy or radiation. Based upon these challenges, the focus of research on pancreatic cancer has shifted gradually towards the tumor microenvironment. The cancer microenvironment consists of various components, including fibroblasts, endothelial cells, immune cells, and endocrine cells, that interact with each other, and with the cancer cells in a complex fashion. Evidence is accumulating that the cancer microenvironment plays an active role in disease progression, and efforts are being made to target this interplay between cancer cells and host cells, to improve the prognosis of the disease. In the present review, we describe the cellular microenvironment of pancreatic ductal adenocarcinoma (PDA), the major type of pancreatic cancer. Our hope is that a better understanding of the cellular microenvironment of PDA will eventually lead to better treatments for this disease. PMID:26709759

  15. Functional Interference in the Bone Marrow Microenvironment by Disseminated Breast Cancer Cells.

    PubMed

    Dhawan, Abhishek; von Bonin, Malte; Bray, Laura J; Freudenberg, Uwe; Pishali Bejestani, Elham; Werner, Carsten; Hofbauer, Lorenz C; Wobus, Manja; Bornhäuser, Martin

    2016-08-01

    Skeletal metastasis of breast cancer is associated with a poor prognosis and significant morbidity. Investigations in other solid tumors have revealed an impairment in hematopoietic function upon bone marrow invasion. However, the interaction between disseminated breast cancer cells and the bone marrow microenvironment which harbors them has not been addressed comprehensively. Employing advanced co-culture assays, proteomic studies, organotypic models as well as in vivo xenotransplant models, we define the consequences of this interaction on the stromal compartment of bone marrow, affected molecular pathways and subsequent effects on the hematopoietic stem and progenitor cells (HSPCs). The results showed a basic fibroblast growth factor (bFGF)-mediated, synergistic increase in proliferation of breast cancer cells and mesenchymal stromal cells (MSCs) in co-culture. The stromal induction was associated with elevated phosphoinositide-3 kinase (PI3K) signaling in the stroma, which coupled with elevated bFGF levels resulted in increased migration of breast cancer cells towards the MSCs. The perturbed cytokine profile in the stroma led to reduction in the osteogenic differentiation of MSCs via downregulation of platelet-derived growth factor-BB (PDGF-BB). Long term co-cultures of breast cancer cells, HSPCs, MSCs and in vivo studies in NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl) /SzJ (NSG) mice showed a reduced support for HSPCs in the altered niche. The resultant non- conducive phenotype of the niche for HSPC support emphasizes the importance of the affected molecular pathways in the stroma as clinical targets. These findings can be a platform for further development of therapeutic strategies aiming at the blockade of bone marrow support to disseminated breast cancer cells. Stem Cells 2016;34:2224-2235. PMID:27090603

  16. Identification of kinase inhibitor targets in the lung cancer microenvironment by chemical and phosphoproteomics

    PubMed Central

    Gridling, Manuela; Ficarro, Scott B.; Breitwieser, Florian P.; Song, Lanxi; Parapatics, Katja; Colinge, Jacques; Haura, Eric B.; Marto, Jarrod A.; Superti-Furga, Giulio; Bennett, Keiryn L.; Rix, Uwe

    2014-01-01

    A growing number of gene mutations, which are recognized as cancer drivers, can be successfully targeted with drugs. The redundant and dynamic nature of oncogenic signaling networks and complex interactions between cancer cells and the microenvironment, however, can cause drug resistance. Whereas these challenges can be addressed by developing drug combinations or polypharmacology drugs, this benefits greatly from a detailed understanding of the proteome-wide target profiles. Using mass spectrometry-based chemical proteomics, we report the comprehensive characterization of the drug-protein interaction networks for the multikinase inhibitors dasatinib and sunitinib in primary lung cancer tissue specimens derived from patients. We observed in excess of 100 protein kinase targets plus various protein complexes involving, for instance, AMPK, TBK1 (sunitinib) and ILK (dasatinib). Importantly, comparison with lung cancer cell lines and mouse xenografts thereof showed that most targets were shared between cell lines and tissues. Several targets, however, were only present in tumor tissues. In xenografts, most of these proteins were of mouse origin suggesting that they originate from the tumor microenvironment. Furthermore, intersection with subsequent global phosphoproteomic analysis identified several activated signaling pathways. These included MAPK, immune and integrin signaling, which were affected by these drugs in both cancer cells and the microenvironment. Thus, the combination of chemical and phosphoproteomics can generate a systems view of proteins, complexes and signaling pathways that are simultaneously engaged by multi-targeted drugs in cancer cells and the tumor microenvironment. This may allow for the design of novel anticancer therapies that concurrently target multiple tumor compartments. PMID:25189542

  17. A three-dimensional culture system for the growth of hematopoietic cells.

    PubMed

    Naughton, B A; Jacob, L; Naughton, G K

    1990-01-01

    A physiological three-dimensional culture system was developed for the growth of human bone marrow. Bone marrow stromal cells were established on a nylon filtration screen template, suspended in liquid medium and grown to 70% confluence, and inoculated with hematopoietic cells. An intricate microenvironment is established to support hematopoiesis, which proceeds in a three-dimensional orientation. Analysis of the adherent zone of these cultures with flow cytometry and progenitor cell assays reveals multilineage hematologic expression and active proliferation of immature cells for the 12 week experimental period. Similar results were obtained with rat bone marrow cultures using this methodology. The suspended nylon mesh system is novel in that it supports the growth of several hematologic lineages concurrently. This system may lend itself to the growth of purged or untreated bone marrow for transplantation. PMID:2308994

  18. The Role of Chemoattractant Receptors in Shaping the Tumor Microenvironment

    PubMed Central

    Xiang, Yi; Yoshimura, Teizo; Chen, Keqiang; Gong, Wanghua; Huang, Jian; Zhou, Ye; Yao, Xiaohong; Bian, Xiuwu; Wang, Ji Ming

    2014-01-01

    Chemoattractant receptors are a family of seven transmembrane G protein coupled receptors (GPCRs) initially found to mediate the chemotaxis and activation of immune cells. During the past decades, the functions of these GPCRs have been discovered to not only regulate leukocyte trafficking and promote immune responses, but also play important roles in homeostasis, development, angiogenesis, and tumor progression. Accumulating evidence indicates that chemoattractant GPCRs and their ligands promote the progression of malignant tumors based on their capacity to orchestrate the infiltration of the tumor microenvironment by immune cells, endothelial cells, fibroblasts, and mesenchymal cells. This facilitates the interaction of tumor cells with host cells, tumor cells with tumor cells, and host cells with host cells to provide a basis for the expansion of established tumors and development of distant metastasis. In addition, many malignant tumors of the nonhematopoietic origin express multiple chemoattractant GPCRs that increase the invasiveness and metastasis of tumor cells. Therefore, GPCRs and their ligands constitute targets for the development of novel antitumor therapeutics. PMID:25110692

  19. Regulation of prostate cancer progression by the tumor microenvironment.

    PubMed

    Shiao, Stephen L; Chu, Gina Chia-Yi; Chung, Leland W K

    2016-09-28

    Prostate cancer remains the most frequently diagnosed cancer in men in North America, and despite recent advances in treatment patients with metastatic disease continue to have poor five-year survival rates. Recent studies in prostate cancer have revealed the critical role of the tumor microenvironment in the initiation and progression to advanced disease. Experimental data have uncovered a reciprocal relationship between the cells in the microenvironment and malignant tumor cells in which early changes in normal tissue microenvironment can promote tumorigenesis and in turn tumor cells can promote further pro-tumor changes in the microenvironment. In the tumor microenvironment, the presence of persistent immune infiltrates contributes to the recruitment and reprogramming of other non-immune stromal cells including cancer-associated fibroblasts and a unique recently identified population of metastasis-initiating cells (MICs). These MICs, which can also be found as part of the circulating tumor cell (CTC) population in PC patients, promote cancer cell transformation, enhance metastatic potential and confer therapeutic resistance. MICs act can on other cells within the tumor microenvironment in part by secreting exosomes that reprogram adjacent stromal cells to create a more favorable tumor microenvironment to support continued cancer growth and progression. We review here the current data on the intricate relationship between inflammation, reactive stroma, tumor cells and disease progression in prostate cancer. PMID:26828013

  20. Engineering humanized mice for improved hematopoietic reconstitution

    PubMed Central

    Drake, Adam C; Chen, Qingfeng; Chen, Jianzhu

    2012-01-01

    Humanized mice are immunodeficient animals engrafted with human hematopoietic stem cells that give rise to various lineages of human blood cells throughout the life of the mouse. This article reviews recent advances in the generation of humanized mice, focusing on practical considerations. We discuss features of different immunodeficient recipient mouse strains, sources of human hematopoietic stem cells, advances in expansion and genetic modification of hematopoietic stem cells, and techniques to modulate the cytokine environment of recipient mice, in order to enhance reconstitution of specific human blood lineage cells. We highlight the opportunities created by new technologies and discuss practical considerations on how to make best use of the widening array of basic models for specific research applications. PMID:22425741

  1. Long noncoding RNAs in hematopoietic malignancies.

    PubMed

    Rodríguez-Malavé, Norma I; Rao, Dinesh S

    2016-05-01

    Recent years have witnessed the discovery of several classes of noncoding RNAs (ncRNAs), which are indispensable for the regulation of cellular processes. Many of these RNAs are regulatory in nature with functions in gene expression regulation such as piwi-interacting RNAs, small interfering RNAs and micro RNAs. Long noncoding RNAs (lncRNAs) comprise the most recently characterized class. LncRNAs are involved in transcriptional regulation, chromatin remodeling, imprinting, splicing, and translation, among other critical functions in the cell. Recent studies have elucidated the importance of lncRNAs in hematopoietic development. Dysregulation of lncRNA expression is a feature of various diseases and cancers, and is also seen in hematopoietic malignancies. This article focuses on lncRNAs that have been implicated in the pathogenesis of hematopoietic malignancies. PMID:26612601

  2. Sphingolipid signaling and hematopoietic malignancies: to the rheostat and beyond.

    PubMed

    Loh, Kenneth C; Baldwin, Dianna; Saba, Julie D

    2011-11-01

    Sphingosine-1-phosphate (S1P) is a bioactive lipid with diverse functions including the promotion of cell survival, proliferation and migration, as well as the regulation of angiogenesis, inflammation, immunity, vascular permeability and nuclear mechanisms that control gene transcription. S1P is derived from metabolism of ceramide, which itself has diverse and generally growth-inhibitory effects through its impact on downstream targets involved in regulation of apoptosis, senescence and cell cycle progression. Regulation of ceramide, S1P and the biochemical steps that modulate the balance and interconversion of these two lipids are major determinants of cell fate, a concept referred to as the "sphingolipid rheostat." There is abundant evidence that the sphingolipid rheostat plays a role in the origination, progression and drug resistance patterns of hematopoietic malignancies. The pathway has also been exploited to circumvent the problem of chemotherapy resistance in leukemia and lymphoma. Given the broad effects of sphingolipids, targeting multiple steps in the metabolic pathway may provide possible therapeutic avenues. However, new observations have revealed that sphingolipid signaling effects are more complex than previously recognized, requiring a revision of the sphingolipid rheostat model. Here, we summarize recent insights regarding the sphingolipid metabolic pathway and its role in hematopoietic malignancies. PMID:21707493

  3. Microenvironment-induced PTEN loss by exosomal microRNA primes brain metastasis outgrowth

    PubMed Central

    Yao, Jun; Lowery, Frank J.; Zhang, Qingling; Huang, Wen-Chien; Li, Ping; Li, Min; Wang, Xiao; Zhang, Chenyu; Wang, Hai; Ellis, Kenneth; Cheerathodi, Mujeeburahiman; McCarty, Joseph H.; Palmieri, Diane; Saunus, Jodi; Lakhani, Sunil; Huang, Suyun; Sahin, Aysegul A.; Aldape, Kenneth D.; Steeg, Patricia S.; Yu, Dihua

    2016-01-01

    Summary Development of life-threatening cancer metastases at distant organs requires disseminated tumor cells’ adaptation to and co-evolution with the drastically different microenvironments of metastatic sites1. Cancer cells of common origin manifest distinct gene expression patterns after metastasizing to different organs2. Clearly, the dynamic interplay between metastatic tumor cells and extrinsic signals at individual metastatic organ sites critically impacts the subsequent metastatic outgrowth3,4. Yet, it is unclear when and how disseminated tumor cells acquire the essential traits from the microenvironment of metastatic organs that prime their subsequent outgrowth. Here we show that primary tumor cells with normal expression of PTEN, an important tumor suppressor, lose PTEN expression after dissemination to the brain, but not to other organs. PTEN level in PTEN-loss brain metastatic tumor cells is restored after leaving brain microenvironment. This brain microenvironment-dependent, reversible PTEN mRNA and protein down-regulation is epigenetically regulated by microRNAs (miRNAs) from astrocytes. Mechanistically, astrocyte-derived exosomes mediate an intercellular transfer of PTEN-targeting miRNAs to metastatic tumor cells, while astrocyte-specific depletion of PTEN-targeting miRNAs or blockade of astrocyte exosome secretion rescues the PTEN loss and suppresses brain metastasis in vivo. Furthermore, this adaptive PTEN loss in brain metastatic tumor cells leads to an increased secretion of cytokine chemokine (C-C motif) ligand 2 (CCL2), which recruits Iba1+ myeloid cells that reciprocally enhance outgrowth of brain metastatic tumor cells via enhanced proliferation and reduced apoptosis. Our findings demonstrate a remarkable plasticity of PTEN expression in metastatic tumor cells in response to different organ microenvironments, underpinning an essential role of co-evolution between the metastatic cells and their microenvironment during the adaptive metastatic

  4. Biomaterials and Emerging Anticancer Therapeutics: Engineering the Microenvironment

    PubMed Central

    Gu, Luo; Mooney, David J

    2016-01-01

    The microenvironment is increasingly recognized to play key roles in cancer, and biomaterials provide a means to engineer microenvironments both in vitro and in vivo to study and manipulate cancer. In vitro cancer models using 3D matrices recapitulate key elements of the tumor microenvironment and have revealed new aspects of cancer biology. Cancer vaccines based on some of the same biomaterials have, in parallel, allowed for the engineering of durable prophylactic and therapeutic anticancer activity in preclinical studies, and some of these vaccines have moved to clinical trials. The impact of biomaterials engineering on cancer treatment is expected to further increase in importance in the years to come. PMID:26694936

  5. The importance of the tissue microenvironment in hairy cell leukemia.

    PubMed

    Sivina, Mariela; Burger, Jan A

    2015-12-01

    Hairy cell leukemia (HCL) cells engage in complex cellular and molecular interactions with accessory cells, matrix proteins, and various cytokines in the bone marrow and spleen, collectively referred to as the tissue microenvironment. Chemokine receptors and adhesion molecules are critical players for homing and retention within these microenvironments. Engagement of B cell antigen receptors and CD40 on HCL cells promote survival and proliferation. In this chapter, we summarize the current knowledge about the cellular and molecular interactions between HCL cells and their supportive tissue microenvironment, and provide insight into new therapeutic approaches targeting B cell receptor signaling in HCL. PMID:26614899

  6. Modeling the Spatiotemporal Evolution of the Melanoma Tumor Microenvironment

    NASA Astrophysics Data System (ADS)

    Signoriello, Alexandra; Bosenberg, Marcus; Shattuck, Mark; O'Hern, Corey

    The tumor microenvironment, which includes tumor cells, tumor-associated macrophages (TAM), cancer-associated fibroblasts, and endothelial cells, drives the formation and progression of melanoma tumors. Using quantitative analysis of in vivo confocal images of melanoma tumors in three spatial dimensions, we examine the physical properties of the melanoma tumor microenvironment, including the numbers of different cells types, cell size, and morphology. We also compute the nearest neighbor statistics and measure intermediate range spatial correlations between different cell types. We also calculate the step size distribution, mean-square displacement, and non-Gaussian parameter from the spatial trajectories of different cell types in the tumor microenvironment.

  7. BMP and Hedgehog Regulate Distinct AGM Hematopoietic Stem Cells Ex Vivo.

    PubMed

    Crisan, Mihaela; Solaimani Kartalaei, Parham; Neagu, Alex; Karkanpouna, Sofia; Yamada-Inagawa, Tomoko; Purini, Caterina; Vink, Chris S; van der Linden, Reinier; van Ijcken, Wilfred; Chuva de Sousa Lopes, Susana M; Monteiro, Rui; Mummery, Christine; Dzierzak, Elaine

    2016-03-01

    Hematopoietic stem cells (HSC), the self-renewing cells of the adult blood differentiation hierarchy, are generated during embryonic stages. The first HSCs are produced in the aorta-gonad-mesonephros (AGM) region of the embryo through endothelial to a hematopoietic transition. BMP4 and Hedgehog affect their production and expansion, but it is unknown whether they act to affect the same HSCs. In this study using the BRE GFP reporter mouse strain that identifies BMP/Smad-activated cells, we find that the AGM harbors two types of adult-repopulating HSCs upon explant culture: One type is BMP-activated and the other is a non-BMP-activated HSC type that is indirectly controlled by Hedgehog signaling through the VEGF pathway. Transcriptomic analyses demonstrate that the two HSC types express distinct but overlapping genetic programs. These results revealing the bifurcation in HSC types at early embryonic stages in the AGM explant model suggest that their development is dependent upon the signaling molecules in the microenvironment. PMID:26923823

  8. BMP and Hedgehog Regulate Distinct AGM Hematopoietic Stem Cells Ex Vivo

    PubMed Central

    Crisan, Mihaela; Solaimani Kartalaei, Parham; Neagu, Alex; Karkanpouna, Sofia; Yamada-Inagawa, Tomoko; Purini, Caterina; Vink, Chris S.; van der Linden, Reinier; van Ijcken, Wilfred; Chuva de Sousa Lopes, Susana M.; Monteiro, Rui; Mummery, Christine; Dzierzak, Elaine

    2016-01-01

    Summary Hematopoietic stem cells (HSC), the self-renewing cells of the adult blood differentiation hierarchy, are generated during embryonic stages. The first HSCs are produced in the aorta-gonad-mesonephros (AGM) region of the embryo through endothelial to a hematopoietic transition. BMP4 and Hedgehog affect their production and expansion, but it is unknown whether they act to affect the same HSCs. In this study using the BRE GFP reporter mouse strain that identifies BMP/Smad-activated cells, we find that the AGM harbors two types of adult-repopulating HSCs upon explant culture: One type is BMP-activated and the other is a non-BMP-activated HSC type that is indirectly controlled by Hedgehog signaling through the VEGF pathway. Transcriptomic analyses demonstrate that the two HSC types express distinct but overlapping genetic programs. These results revealing the bifurcation in HSC types at early embryonic stages in the AGM explant model suggest that their development is dependent upon the signaling molecules in the microenvironment. PMID:26923823

  9. In vivo imaging of transplanted hematopoietic stem and progenitor cells in mouse calvarium bone marrow

    PubMed Central

    Lo Celso, Cristina; Lin, Charles P; Scadden, David T

    2011-01-01

    In vivo imaging of transplanted hematopoietic stem and progenitor cells (HSPCs) was developed to investigate the relationship between HSPCs and components of their microenvironment in the bone marrow. In particular, it allows a direct observation of the behavior of hematopoietic cells during the first few days after transplantation, when the critical events in homing and early engraftment are occurring. By directly imaging these events in living animals, this method permits a detailed assessment of functions previously evaluated by crude assessments of cell counts (homing) or after prolonged periods (engraftment). This protocol offers a new means of investigating the role of cell-intrinsic and cell-extrinsic molecular regulators of hematopoiesis during the early stages of transplantation, and it is the first to allow the study of cell-cell interactions within the bone marrow in three dimensions and in real time. In this paper, we describe how to isolate, label and inject HSPCs, as well as how to perform calvarium intravital microscopy and analyze the resulting images. A typical experiment can be performed and analyzed in ~1 week. PMID:21212779

  10. Spatiotemporal dynamics of the biological interface between cancer and the microenvironment: a fractal anomalous diffusion model with microenvironment plasticity

    PubMed Central

    2012-01-01

    Background The invasion-metastasis cascade of cancer involves a process of parallel progression. A biological interface (module) in which cells is linked with ECM (extracellular matrix) by CAMs (cell adhesion molecules) has been proposed as a tool for tracing cancer spatiotemporal dynamics. Methods A mathematical model was established to simulate cancer cell migration. Human uterine leiomyoma specimens, in vitro cell migration assay, quantitative real-time PCR, western blotting, dynamic viscosity, and an in vivo C57BL6 mouse model were used to verify the predictive findings of our model. Results The return to origin probability (RTOP) and its related CAM expression ratio in tumors, so-called "tumor self-seeding", gradually decreased with increased tumor size, and approached the 3D Pólya random walk constant (0.340537) in a periodic structure. The biphasic pattern of cancer cell migration revealed that cancer cells initially grew together and subsequently began spreading. A higher viscosity of fillers applied to the cancer surface was associated with a significantly greater inhibitory effect on cancer migration, in accordance with the Stokes-Einstein equation. Conclusion The positional probability and cell-CAM-ECM interface (module) in the fractal framework helped us decipher cancer spatiotemporal dynamics; in addition we modeled the methods of cancer control by manipulating the microenvironment plasticity or inhibiting the CAM expression to the Pólya random walk, Pólya constant. PMID:22889191

  11. All-Trans Retinoic Acid Activity in Acute Myeloid Leukemia: Role of Cytochrome P450 Enzyme Expression by the Microenvironment

    PubMed Central

    Su, Meng; Alonso, Salvador; Jones, Jace W.; Yu, Jianshi; Kane, Maureen A.; Jones, Richard J.; Ghiaur, Gabriel

    2015-01-01

    Differentiation therapy with all-trans retinoic acid (atRA) has markedly improved outcome in acute promyelocytic leukemia (APL) but has had little clinical impact in other AML sub-types. Cell intrinsic mechanisms of resistance have been previously reported, yet the majority of AML blasts are sensitive to atRA in vitro. Even in APL, single agent atRA induces remission without cure. The microenvironment expression of cytochrome P450 (CYP)26, a retinoid-metabolizing enzyme was shown to determine normal hematopoietic stem cell fate. Accordingly, we hypothesized that the bone marrow (BM) microenvironment is responsible for difference between in vitro sensitivity and in vivo resistance of AML to atRA-induced differentiation. We observed that the pro-differentiation effects of atRA on APL and non-APL AML cells as well as on leukemia stem cells from clinical specimens were blocked by BM stroma. In addition, BM stroma produced a precipitous drop in atRA levels. Inhibition of CYP26 rescued atRA levels and AML cell sensitivity in the presence of stroma. Our data suggest that stromal CYP26 activity creates retinoid low sanctuaries in the BM that protect AML cells from systemic atRA therapy. Inhibition of CYP26 provides new opportunities to expand the clinical activity of atRA in both APL and non-APL AML. PMID:26047326

  12. All-Trans Retinoic Acid Activity in Acute Myeloid Leukemia: Role of Cytochrome P450 Enzyme Expression by the Microenvironment.

    PubMed

    Su, Meng; Alonso, Salvador; Jones, Jace W; Yu, Jianshi; Kane, Maureen A; Jones, Richard J; Ghiaur, Gabriel

    2015-01-01

    Differentiation therapy with all-trans retinoic acid (atRA) has markedly improved outcome in acute promyelocytic leukemia (APL) but has had little clinical impact in other AML sub-types. Cell intrinsic mechanisms of resistance have been previously reported, yet the majority of AML blasts are sensitive to atRA in vitro. Even in APL, single agent atRA induces remission without cure. The microenvironment expression of cytochrome P450 (CYP)26, a retinoid-metabolizing enzyme was shown to determine normal hematopoietic stem cell fate. Accordingly, we hypothesized that the bone marrow (BM) microenvironment is responsible for difference between in vitro sensitivity and in vivo resistance of AML to atRA-induced differentiation. We observed that the pro-differentiation effects of atRA on APL and non-APL AML cells as well as on leukemia stem cells from clinical specimens were blocked by BM stroma. In addition, BM stroma produced a precipitous drop in atRA levels. Inhibition of CYP26 rescued atRA levels and AML cell sensitivity in the presence of stroma. Our data suggest that stromal CYP26 activity creates retinoid low sanctuaries in the BM that protect AML cells from systemic atRA therapy. Inhibition of CYP26 provides new opportunities to expand the clinical activity of atRA in both APL and non-APL AML. PMID:26047326

  13. Epigenetic and in vivo comparison of diverse MSC sources reveals an endochondral signature for human hematopoietic niche formation

    PubMed Central

    Etchart, Nathalie; Thomas, Daniel; Hofmann, Nicole A.; Fruehwirth, Margareta; Sinha, Subarna; Chan, Charles K.; Senarath-Yapa, Kshemendra; Seo, Eun-Young; Wearda, Taylor; Hartwig, Udo F.; Beham-Schmid, Christine; Trajanoski, Slave; Lin, Qiong; Wagner, Wolfgang; Dullin, Christian; Alves, Frauke; Andreeff, Michael; Weissman, Irving L.; Longaker, Michael T.; Schallmoser, Katharina; Majeti, Ravindra; Strunk, Dirk

    2015-01-01

    In the last decade there has been a rapid expansion in clinical trials using mesenchymal stromal cells (MSCs) from a variety of tissues. However, despite similarities in morphology, immunophenotype, and differentiation behavior in vitro, MSCs sourced from distinct tissues do not necessarily have equivalent biological properties. We performed a genome-wide methylation, transcription, and in vivo evaluation of MSCs from human bone marrow (BM), white adipose tissue, umbilical cord, and skin cultured in humanized media. Surprisingly, only BM-derived MSCs spontaneously formed a BM cavity through a vascularized cartilage intermediate in vivo that was progressively replaced by hematopoietic tissue and bone. Only BM-derived MSCs exhibited a chondrogenic transcriptional program with hypomethylation and increased expression of RUNX3, RUNX2, BGLAP, MMP13, and ITGA10 consistent with a latent and primed skeletal developmental potential. The humanized MSC–derived microenvironment permitted homing and maintenance of long-term murine SLAM+ hematopoietic stem cells (HSCs), as well as human CD34+/CD38−/CD90+/CD45RA+ HSCs after cord blood transplantation. These studies underscore the profound differences in developmental potential between MSC sources independent of donor age, with implications for their clinical use. We also demonstrate a tractable human niche model for studying homing and engraftment of human hematopoietic cells in normal and neoplastic states. PMID:25406351

  14. Microcavity arrays as an in vitro model system of the bone marrow niche for hematopoietic stem cells.

    PubMed

    Wuchter, Patrick; Saffrich, Rainer; Giselbrecht, Stefan; Nies, Cordula; Lorig, Hanna; Kolb, Stephanie; Ho, Anthony D; Gottwald, Eric

    2016-06-01

    In previous studies human mesenchymal stromal cells (MSCs) maintained the "stemness" of human hematopoietic progenitor cells (HPCs) through direct cell-cell contact in two-dimensional co-culture systems. We establish a three-dimensional (3D) co-culture system based on a custom-made chip, the 3(D)-KITChip, as an in vitro model system of the human hematopoietic stem cell niche. This array of up to 625 microcavities, with 300 μm size in each orientation, was inserted into a microfluidic bioreactor. The microcavities of the 3(D)-KITChip were inoculated with human bone marrow MSCs together with umbilical cord blood HPCs. MSCs used the microcavities as a scaffold to build a complex 3D mesh. HPCs were distributed three-dimensionally inside this MSC network and formed ß-catenin- and N-cadherin-based intercellular junctions to the surrounding MSCs. Using RT(2)-PCR and western blots, we demonstrate that a proportion of HPCs maintained the expression of CD34 throughout a culture period of 14 days. In colony-forming unit assays, the hematopoietic stem cell plasticity remained similar after 14 days of bioreactor co-culture, whereas monolayer co-cultures showed increasing signs of HPC differentiation and loss of stemness. These data support the notion that the 3D microenvironment created within the microcavity array preserves vital stem cell functions of HPCs more efficiently than conventional co-culture systems. PMID:26829941

  15. In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

    PubMed Central

    Scott, Mark K.; Akinduro, Olufolake; Lo Celso, Cristina

    2014-01-01

    Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2]. We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells. Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space. PMID:25225854

  16. Targeting the Metabolic Microenvironment of Tumors

    PubMed Central

    Bailey, Kate M.; Wojtkowiak, Jonathan W.; Hashim, Arig Ibrahim; Gillies, Robert J.

    2013-01-01

    The observation of aerobic glycolysis by tumor cells in 1924 by Otto Warburg, and subsequent innovation of imaging glucose uptake by tumors in patients with PET-CT has incited a renewed interest in the altered metabolism of tumors. As tumors grow in situ, a fraction of it is further away from their blood supply, leading to decreased oxygen concentrations (hypoxia), which induces the hypoxia response pathways of HIF1α, mTOR and UPR. In normal tissues, these responses mitigate hypoxic stress and induce neo-angiogenesis. In tumors, these pathways are dysregulated and lead to decreased perfusion and exacerbation of hypoxia as a result of immature and chaotic blood vessels. Hypoxia selects for a glycolytic phenotype and resultant acidification of the tumor microenvironment, facilitated by upregulation of proton transporters. Acidification selects for enhanced metastatic potential and reduced drug efficacy through ion trapping. In this review, we provide a comprehensive summary of pre-clinical and clinical drugs under development for targeting aerobic glycolysis, acidosis, hypoxia and hypoxia-response pathways. Hypoxia and acidosis can be manipulated, providing further therapeutic benefit for cancers that feature these common phenotypes. PMID:22959024

  17. [The immunosuppressive microenvironment of malignant gliomas].

    PubMed

    Borisov, K E; Sakaeva, D D

    2015-01-01

    The dogma of the central nervous system (CNS) as an immune-privileged site has been substantially revised in recent years. CNS is an immunocompetent organ and actively interacts with the immune system. Microglia plays a leading role in a CNS immune response. However, in malignant gliomas, there is M2-polarization of microglia acquiring immunosuppressive and tumor-supportive properties. It occurs under the influence of tumor cytokines, such as transforming growth factor-β, interleukin-10, and prostaglandin E2. M2-polarized microglia exhibits reduced phagocytic activity, changes in the expression of many cellular determinants, or inverse of their functions, STAT3 activation, and production of immunosuppressive cytokines that suppress the function of cytotoxic CD8+ T cells or CD4+ T-helper cells type I. Myeloid-derived suppressor cells and regulatory T-lymphocytes, which have been recruited from peripheral blood into tumor tissue, also have immunosuppressive properties. The development of new treatment options for malignant gliomas must consider the role of the microenvironment in maintaining tumor vitality and progression. PMID:26841651

  18. Therapeutic Lymphoid Organogenesis in the Tumor Microenvironment

    PubMed Central

    Weinstein, Aliyah M.; Storkus, Walter J.

    2016-01-01

    The inflammatory status of the tumor microenvironment (TME) has been heavily investigated in recent years. Chemokine and cytokine signaling pathways such as CCR7, CXCR5, lymphotoxin, and IL-36, which are involved in the generation of secondary lymphoid organs and effector immune responses, are now recognized as having value both as prognostic factors and as immunomodulatory therapeutics in the context of cancer. Furthermore, when produced in the TME, these mediators have been shown to promote the recruitment of immune cells, including T cells, B cells, dendritic cells (DC), and other specialized immune cell subsets such as follicular dendritic cells (FDC) and T follicular helper (Tfh) cells, in association with the formation of “tertiary” lymphoid structures (TLS) within or adjacent to sites of disease. Although TLS are composed of a heterogeneous collection of immune cell types, whose composition differs based on cancer subtype, the qualitative presence of TLS has been shown to represent a biomarker of good prognosis for cancer patients. A comprehensive understanding of the role each of these pathways plays within the TME may support the rational design of future immunotherapies to selectively promote/bolster TLS formation and function, leading to improved clinical outcomes across the vast range of solid cancer types. PMID:26216634

  19. [Colonic microenvironment in familial helicobacter infection].

    PubMed

    Shcherbakov, P L; Vorob'ev, A A; Nesvizhskiĭ, Iu V; Mitrokhin, S D; Kudriavtseva, L V; Minaev, V I; Filin, V A; Petrova, N N; Zaĭtseva, S V

    1998-01-01

    To elucidate the significance of the familial microenvironment in the genesis of Helicobacter infection, a clinical and instrumental investigation was made of 13 families selected by the probands who had digestive diseases associated with H. pylori: gastroduodenitis and duodenal ulcer disease. The occurrence of Helicobacter infection and gastritis in the family members was ascertained to be largely determined by their concurrent residence in the limited area, i.e. by the way of life. The contribution of the "family" factor in antral gastritis, fundal gastritis, and H. pylori infection was 60.0, 40.0, and about 90.0%, respectively. The patients with gastroenterological abnormalities associated with H. pylori were found to show changes in the species-specific and quantitative composition of the colonic microbiocenosis, which were symptomatic and revealed by bacteriological studies in 47.5% of cases and severe in 32.5%. When antihelicobacter therapy is planned, a through treatment of all family members and, if possible, pets should be made. Colonic microbiocenosis should be monitored while treating Helicobacter infection. PMID:9662996

  20. Roles of Tumor Microenvironment in Hepatocelluar Carcinoma

    PubMed Central

    Seo, Haeng R.

    2015-01-01

    Hepatocellular carcinoma (HCC) is one of the most malignant human cancers, with a high mortality rate worldwide despite its early diagnosis in patients and improvement in therapeutic technology. Most cases of liver cancer show a strong resistance to anticancer therapy. Moreover, liver cancer patients generally have poor tolerance to chemotherapy due to liver dysfunction. In these situations, liver-targeting drugs with fewer side effects and a high efficacy are urgently needed during drug discovery for liver cancer. Researchers have aimed to derive target genes and drug candidates for HCC; however, the development of targeted drugs has not yet improved the outcome significantly. Recently, the role of the tumor microenvironment (TME) in HCC has been probed to combat this deadly disease. A deeper knowledge of the crosstalk between tumor cells and their TME is needed to fully understand tumor development, progression and chemo-resistance in HCC because this cancer develops from chronically damaged tissue that contains large amounts of inflammation and fibrosis. In this review, we summarize how distinct stromal cells of TME are involved in tumorigenesis and chemo-resistance in HCC and the significant challenge to recapitulate tumor complexity and heterogeneity enhancement.

  1. Tumor microenvironment and cancer therapy resistance.

    PubMed

    Sun, Yu

    2016-09-28

    Innate resistance to various therapeutic interventions is a hallmark of cancer. In recent years, however, acquired resistance has emerged as a daunting challenge to anticancer treatments including chemotherapy, radiation and targeted therapy, which abolishes the efficacy of otherwise successful regimens. Cancer cells gain resistance through a variety of mechanisms in both primary and metastatic sites, involving cell intrinsic and extrinsic factors, but the latter often remains overlooked. Mounting evidence suggests critical roles played by the tumor microenvironment (TME) in multiple aspects of cancer progression particularly therapeutic resistance. The TME decreases drug penetration, confers proliferative and antiapoptotic advantages to surviving cells, facilitates resistance without causing genetic mutations and epigenetic changes, collectively modifying disease modality and distorting clinical indices. Recent studies have set the baseline for future investigation on the intricate relationship between cancer resistance and the TME in pathological backgrounds. This review provides an updated outline of research advances in TME biology and highlights the prospect of targeting the TME as an essential strategy to overcome cancer resistance and improve therapeutic outcomes through precise intervention. In the long run, continued inputs into translational medicine remain highly desired to achieve durable responses in the current era of personalized clinical oncology. PMID:26272180

  2. In utero hematopoietic cell transplantation for hemoglobinopathies

    PubMed Central

    Derderian, S. Christopher; Jeanty, Cerine; Walters, Mark C.; Vichinsky, Elliott; MacKenzie, Tippi C.

    2014-01-01

    In utero hematopoietic cell transplantation (IUHCTx) is a promising strategy to circumvent the challenges of postnatal hematopoietic stem cell (HSC) transplantation. The goal of IUHCTx is to introduce donor cells into a naïve host prior to immune maturation, thereby inducing donor–specific tolerance. Thus, this technique has the potential of avoiding host myeloablative conditioning with cytotoxic agents. Over the past two decades, several attempts at IUHCTx have been made to cure numerous underlying congenital anomalies with limited success. In this review, we will briefly review the history of IUHCTx and give a perspective on alpha thalassemia major, one target disease for its clinical application. PMID:25628564

  3. Tissue-resident macrophage enhancer landscapes are shaped by the local microenvironment.

    PubMed

    Lavin, Yonit; Winter, Deborah; Blecher-Gonen, Ronnie; David, Eyal; Keren-Shaul, Hadas; Merad, Miriam; Jung, Steffen; Amit, Ido

    2014-12-01

    Macrophages are critical for innate immune defense and also control organ homeostasis in a tissue-specific manner. They provide a fitting model to study the impact of ontogeny and microenvironment on chromatin state and whether chromatin modifications contribute to macrophage identity. Here, we profile the dynamics of four histone modifications across seven tissue-resident macrophage populations. We identify 12,743 macrophage-specific enhancers and establish that tissue-resident macrophages have distinct enhancer landscapes beyond what can be explained by developmental origin. Combining our enhancer catalog with gene expression profiles and open chromatin regions, we show that a combination of tissue- and lineage-specific transcription factors form the regulatory networks controlling chromatin specification in tissue-resident macrophages. The environment is capable of shaping the chromatin landscape of transplanted bone marrow precursors, and even differentiated macrophages can be reprogrammed when transferred into a new microenvironment. These results provide a comprehensive view of macrophage regulatory landscape and highlight the importance of the microenvironment, along with pioneer factors in orchestrating identity and plasticity. PMID:25480296

  4. TGFβ Signaling in the Pancreatic Tumor Microenvironment Promotes Fibrosis and Immune Evasion to Facilitate Tumorigenesis.

    PubMed

    Principe, Daniel R; DeCant, Brian; Mascariñas, Emman; Wayne, Elizabeth A; Diaz, Andrew M; Akagi, Naomi; Hwang, Rosa; Pasche, Boris; Dawson, David W; Fang, Deyu; Bentrem, David J; Munshi, Hidayatullah G; Jung, Barbara; Grippo, Paul J

    2016-05-01

    In early pancreatic carcinogenesis, TGFβ acts as a tumor suppressor due to its growth-inhibitory effects in epithelial cells. However, in advanced disease, TGFβ appears to promote tumor progression. Therefore, to better understand the contributions of TGFβ signaling to pancreatic carcinogenesis, we generated mouse models of pancreatic cancer with either epithelial or systemic TGFBR deficiency. We found that epithelial suppression of TGFβ signals facilitated pancreatic tumorigenesis, whereas global loss of TGFβ signaling protected against tumor development via inhibition of tumor-associated fibrosis, stromal TGFβ1 production, and the resultant restoration of antitumor immune function. Similarly, TGFBR-deficient T cells resisted TGFβ-induced inactivation ex vivo, and adoptive transfer of TGFBR-deficient CD8(+) T cells led to enhanced infiltration and granzyme B-mediated destruction of developing tumors. These findings paralleled our observations in human patients, where TGFβ expression correlated with increased fibrosis and associated negatively with expression of granzyme B. Collectively, our findings suggest that, despite opposing the proliferation of some epithelial cells, TGFβ may promote pancreatic cancer development by affecting stromal and hematopoietic cell function. Therefore, the use of TGFBR inhibition to target components of the tumor microenvironment warrants consideration as a potential therapy for pancreatic cancer, particularly in patients who have already lost tumor-suppressive TGFβ signals in the epithelium. Cancer Res; 76(9); 2525-39. ©2016 AACR. PMID:26980767

  5. The tumor microenvironment shapes hallmarks of mature B-cell malignancies.

    PubMed

    Shain, K H; Dalton, W S; Tao, J

    2015-09-01

    B-cell tumorigenesis results from a host of known and unknown genetic anomalies, including non-random translocations of genes that normally function as determinants of cell proliferation or cell survival to regions juxtaposed to active immunoglobulin heavy chain enhancer elements, chromosomal aneuploidy, somatic mutations that further affect oncogenic signaling and loss of heterozygosity of tumor-suppressor genes. However, it is critical to recognize that even in the setting of a genetic disease, the B-cell/plasma cell tumor microenvironment (TME) contributes significantly to malignant transformation and pathogenesis. Over a decade ago, we proposed the concept of cell adhesion-mediated drug resistance to delineate a form of TME-mediated drug resistance that protects hematopoietic tumor cells from the initial effect of diverse therapies. In the interim, it has been increasingly appreciated that TME also contributes to tumor initiation and progression through sustained growth/proliferation, self-renewal capacity, immune evasion, migration and invasion as well as resistance to cell death in a host of B-cell malignancies, including mantle cell lymphoma, diffuse large B-cell lymphoma, Waldenstroms macroglobulinemia, chronic lymphocytic leukemia and multiple myeloma. Within this review, we propose that TME and the tumor co-evolve as a consequence of bidirectional signaling networks. As such, TME represents an important target and should be considered integral to tumor progression and drug response. PMID:25639873

  6. TLR-mediated albuminuria needs TNFα-mediated cooperativity between TLRs present in hematopoietic tissues and CD80 present on non-hematopoietic tissues in mice

    PubMed Central

    Jain, Nidhi; Khullar, Bhavya; Oswal, Neelam; Banoth, Balaji; Joshi, Prashant; Ravindran, Balachandran; Panda, Subrat; Basak, Soumen; George, Anna; Rath, Satyajit; Sopory, Shailaja

    2016-01-01

    ABSTRACT Transient albuminuria induced by pathogen-associated molecular patterns (PAMPs) in mice through engagement of Toll-like receptors (TLRs) is widely studied as a partial model for some forms of human nephrotic syndrome (NS). In addition to TLRs, CD80 has been shown to be essential for PAMP-mediated albuminuria. However, the mechanistic relationships between TLRs, CD80 and albuminuria remain unclear. Here, we show that albuminuria and CD80-uria induced in mice by many TLR ligands are dependent on the expression of TLRs and their downstream signalling intermediate MyD88 exclusively in hematopoietic cells and, conversely, on CD80 expression exclusively in non-hematopoietic cells. TNFα is crucial for TLR-mediated albuminuria and CD80-uria, and induces CD80 expression in cultured renal podocytes. IL-10 from hematopoietic cells ameliorates TNFα production, albuminuria and CD80-uria but does not prevent TNFα-mediated induction of podocyte CD80 expression. Chitohexaose, a small molecule originally of parasite origin, mediates TLR4-dependent anti-inflammatory responses, and blocks TLR-mediated albuminuria and CD80-uria through IL-10. Thus, TNFα is a prominent mediator of renal CD80 induction and resultant albuminuria in this model, and small molecules modulating TLR-mediated inflammatory activation might have contributory or adjunct therapeutic potential in some contexts of NS development. PMID:27125280

  7. The arterial microenvironment: the where and why of atherosclerosis.

    PubMed

    Yurdagul, Arif; Finney, Alexandra C; Woolard, Matthew D; Orr, A Wayne

    2016-05-15

    The formation of atherosclerotic plaques in the large and medium sized arteries is classically driven by systemic factors, such as elevated cholesterol and blood pressure. However, work over the past several decades has established that atherosclerotic plaque development involves a complex coordination of both systemic and local cues that ultimately determine where plaques form and how plaques progress. Although current therapeutics for atherosclerotic cardiovascular disease primarily target the systemic risk factors, a large array of studies suggest that the local microenvironment, including arterial mechanics, matrix remodelling and lipid deposition, plays a vital role in regulating the local susceptibility to plaque development through the regulation of vascular cell function. Additionally, these microenvironmental stimuli are capable of tuning other aspects of the microenvironment through collective adaptation. In this review, we will discuss the components of the arterial microenvironment, how these components cross-talk to shape the local microenvironment, and the effect of microenvironmental stimuli on vascular cell function during atherosclerotic plaque formation. PMID:27208212

  8. Hydrogels in Healthcare: From Static to Dynamic Material Microenvironments

    PubMed Central

    Kirschner, Chelsea M.; Anseth, Kristi S.

    2013-01-01

    Advances in hydrogel design have revolutionized the way biomaterials are applied to address biomedical needs. Hydrogels were introduced in medicine over 50 years ago and have evolved from static, bioinert materials to dynamic, bioactive microenvironments, which can be used to direct specific biological responses such as cellular ingrowth in wound healing or on-demand delivery of therapeutics. Two general classes of mechanisms, those defined by the user and those dictated by the endogenous cells and tissues, can control dynamic hydrogel microenvironments. These highly tunable materials have provided bioengineers and biological scientists with new ways to not only treat patients in the clinic but to study the fundamental cellular responses to engineered microenvironments as well. Here, we provide a brief history of hydrogels in medicine and follow with a discussion of the synthesis and implementation of dynamic hydrogel microenvironments for healthcare-related applications. PMID:23929381

  9. Remodeling Components of the Tumor Microenvironment to Enhance Cancer Therapy

    PubMed Central

    Gkretsi, Vasiliki; Stylianou, Andreas; Papageorgis, Panagiotis; Polydorou, Christiana; Stylianopoulos, Triantafyllos

    2015-01-01

    Solid tumor pathophysiology is characterized by an abnormal microenvironment that guides tumor progression and poses barriers to the efficacy of cancer therapies. Most common among tumor types are abnormalities in the structure of the tumor vasculature and stroma. Remodeling the tumor microenvironment with the aim to normalize any aberrant properties has the potential to improve therapy. In this review, we discuss structural abnormalities of the tumor microenvironment and summarize the therapeutic strategies that have been developed to normalize tumors as well as their potential to enhance therapy. Finally, we present different in vitro models that have been developed to analyze and better understand the effects of the tumor microenvironment on cancer cell behavior. PMID:26528429

  10. Shaping of the tumor microenvironment: Stromal cells and vessels.

    PubMed

    Blonska, Marzenna; Agarwal, Nitin K; Vega, Francisco

    2015-10-01

    Lymphomas develop and progress in a specialized tissue microenvironment such as bone marrow as well as secondary lymphoid organs such as lymph node and spleen. The lymphoma microenvironment is characterized by a heterogeneous population of stromal cells, including fibroblastic reticular cells, nurse-like cells, mesenchymal stem cells, follicular dendritic cells, and inflammatory cells such as macrophages, T- and B-cells. These cell populations interact with the lymphoma cells to promote lymphoma growth, survival and drug resistance through multiple mechanisms. Angiogenesis is also recognized as an important factor associated with lymphoma progression. In recent years, we have learned that the interaction between the malignant and non-malignant cells is bidirectional and resembles, at least in part, the pattern seen between non-neoplastic lymphoid cells and the normal microenvironment of lymphoid organs. A summary of the current knowledge of lymphoma microenvironment focusing on the cellular components will be reviewed here. PMID:25794825

  11. The Mammary Gland Microenvironment Directs Progenitor Cell Fate In Vivo

    PubMed Central

    Bussard, Karen M.; Smith, Gilbert H.

    2011-01-01

    The mammary gland is a unique organ that continually undergoes postnatal developmental changes. In mice, the mammary gland is formed via signals from terminal end buds, which direct ductal growth and elongation. Intriguingly, it is likely that the entire cellular repertoire of the mammary gland is formed from a single antecedent cell. Furthermore, in order to produce progeny of varied lineages (e.g., luminal and myoepithelial cells), signals from the local tissue microenvironment influence mammary stem/progenitor cell fate. Data have shown that cells from the mammary gland microenvironment reprogram adult somatic cells from other organs (testes, nerve) into cells that produce milk and express mammary epithelial cell proteins. Similar results were found for human tumorigenic epithelial carcinoma cells. Presently, it is unclear how the deterministic power of the mammary gland microenvironment controls epithelial cell fate. Regardless, signals generated by the microenvironment have a profound influence on progenitor cell differentiation in vivo. PMID:21647291

  12. Biomechanical force in blood development: extrinsic physical cues drive pro-hematopoietic signaling

    PubMed Central

    Lee, Hyun Jung; Li, Nan; Evans, Siobahn M.; Diaz, Miguel F.; Wenzel, Pamela L.

    2013-01-01

    The hematopoietic system is dynamic during development and in adulthood, undergoing countless spatial and temporal transitions during the course of one’s life. Microenvironmental cues in the many unique hematopoietic niches differ, characterized by distinct soluble molecules, membrane-bound factors, and biophysical features that meet the changing needs of the blood system. Research from the last decade has revealed the importance of substrate elasticity and biomechanical force in determination of stem cell fate. Our understanding of the role of these factors in hematopoiesis is still relatively poor; however, the developmental origin of blood cells from the endothelium promts a model for comparison. Many endothelial mechanical sensors and second messenger systems may also determine hematopoietic stem cell fate, self renewal, and homing behaviors. Further, the intimate contact of hematopoietic cells with mechanosensitive cell types, including osteoblasts, endothelial cells, mesenchymal stem cells, and pericytes, places them in close proximity to paracrine signaling downstream of mechanical signals. The objective of this review is to present an overview of the sensors and intracellular signaling pathways activated by mechanical cues and highlight the role of mechanotransductive pathways in hematopoiesis. PMID:23850217

  13. Low oxygen tension favored expansion and hematopoietic reconstitution of CD34(+) CD38(-) cells expanded from human cord blood-derived CD34(+) Cells.

    PubMed

    Wang, Ziyan; Du, Zheng; Cai, Haibo; Ye, Zhaoyang; Fan, Jinli; Tan, Wen-Song

    2016-07-01

    Oxygen tension is an important factor that regulates hematopoietic stem cells (HSCs) in both in vivo hematopoietic microenvironment and ex vivo culture system. Although the effect of oxygen tension on ex vivo expansion of HSCs was extensively studied, there were no clear descriptions on physiological function and gene expression analysis of HSCs under different oxygen tensions. In this study, the effects of oxygen tension on ex vivo expansion characteristics of human umbilical cord blood (UCB)-derived CD34(+) cells are evaluated. Moreover, the physiological function of expanded CD34(+) cells was assessed by secondary expansion ability ex vivo and hematopoietic reconstitution ability in vivo. Also, genetic profiling was applied to analyze the expression of genes related to cell function. It was found that low oxygen tension favored expansion of CD34(+) CD38(-) cells. Additionally, CD34(+) cells expanded under low oxygen tension showed better secondary expansion ability and reconstitution ability than those under atmospheric oxygen concentration. Finally, the genetic profiling of CD34(+) CD38(-) cells cultured under low oxygen tension was more akin to freshly isolated cells. These results collectively demonstrate that low oxygen tension was able to better maintain both self-renewal and hematopoietic reconstitution potential and may lay an experimental basis for clinical transplantation of HSCs. PMID:26997358

  14. Supportive Care of Hematopoietic Cell Transplant Patients

    PubMed Central

    Jim, Heather S. L.; Syrjala, Karen L.; Rizzo, Doug

    2012-01-01

    Hematopoietic cell transplant survivors face a number of challenges including low energy and stamina, “chemo-brain” and emotional distress, and late effects that can compromise functioning or lead to early mortality. This session will review the most recent interventions and recommendations to avoid or mitigate these complications. PMID:22226095

  15. Hematopoiesis and hematopoietic organs in arthropods.

    PubMed

    Grigorian, Melina; Hartenstein, Volker

    2013-03-01

    Hemocytes (blood cells) are motile cells that move throughout the extracellular space and that exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and the body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self-renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review, we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  16. Hematopoiesis and Hematopoietic Organs in Arthropods

    PubMed Central

    Grigorian, Melina; Hartenstein, Volker

    2013-01-01

    Hemocytes (blood cells) are motile cells moving throughout the extracellular space and exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  17. Epigenetic Regulation of Hematopoietic Stem Cells

    PubMed Central

    Sharma, Shilpa; Gurudutta, Gangenahalli

    2016-01-01

    Hematopoietic stem cells are endowed with a distinct potential to bolster self-renewal and to generate progeny that differentiate into mature cells of myeloid and lymphoid lineages. Both hematopoietic stem cells and mature cells have the same genome, but their gene expression is controlled by an additional layer of epigenetics such as DNA methylation and post-translational histone modifications, enabling each cell-type to acquire various forms and functions. Until recently, several studies have largely focussed on the transcription factors andniche factors for the understanding of the molecular mechanisms by which hematopoietic cells replicate and differentiate. Several lines of emerging evidence suggest that epigenetic modifications eventually result in a defined chromatin structure and an “individual” gene expression pattern, which play an essential role in the regulation of hematopoietic stem cell self-renewal and differentiation. Distinct epigenetic marks decide which sets of genes may be expressed and which genes are kept silent. Epigenetic mechanisms are interdependent and ensure lifelong production of blood and bone marrow, thereby contributing to stem cell homeostasis. The epigenetic analysis of hematopoiesis raises the exciting possibility that chromatin structure is dynamic enough for regulated expression of genes. Though controlled chromatin accessibility plays an essential role in maintaining blood homeostasis; mutations in chromatin impacts on the regulation of genes critical to the development of leukemia. In this review, we explored the contribution of epigenetic machinery which has implications for the ramification of molecular details of hematopoietic self-renewal for normal development and underlying events that potentially co-operate to induce leukemia. PMID:27426084

  18. Exosome mediated communication within the tumor microenvironment.

    PubMed

    Milane, Lara; Singh, Amit; Mattheolabakis, George; Suresh, Megha; Amiji, Mansoor M

    2015-12-10

    It is clear that exosomes (endosome derived vesicles) serve important roles in cellular communication both locally and distally and that the exosomal process is abnormal in cancer. Cancer cells are not malicious cells; they are cells that represent 'survival of the fittest' at its finest. All of the mutations, abnormalities, and phenomenal adaptations to a hostile microenvironment, such as hypoxia and nutrient depletion, represent the astute ability of cancer cells to adapt to their environment and to intracellular changes to achieve a single goal - survival. The aberrant exosomal process in cancer represents yet another adaptation that promotes survival of cancer. Cancer cells can secrete more exosomes than healthy cells, but more importantly, the content of cancer cells is distinct. An illustrative distinction is that exosomes derived from cancer cells contain more microRNA than healthy cells and unlike exosomes released from healthy cells, this microRNA can be associated with the RNA-induced silencing complex (RISC) which is required for processing mature and biologically active microRNA. Cancer derived exosomes have the ability to transfer metastatic potential to a recipient cell and cancer exosomes function in the physical process of invasion. In this review we conceptualize the aberrant exosomal process (formation, content selection, loading, trafficking, and release) in cancer as being partially attributed to cancer specific differences in the endocytotic process of receptor recycling/degradation and plasma membrane remodeling and the function of the endosome as a signaling entity. We discuss this concept and, to advance comprehension of exosomal function in cancer as mediators of communication, we detail and discuss exosome biology, formation, and communication in health and cancer; exosomal content in cancer; exosomal biomarkers in cancer; exosome mediated communication in cancer metastasis, drug resistance, and interfacing with the immune system; and

  19. Analysis of the Contribution of Nonresident Progenitor Cells and Hematopoietic Cells to Reparative Dentinogenesis Using Parabiosis Model in Mice

    PubMed Central

    Frozoni, Marcos; Zaia, Alexandre Augusto; Line, Sergio Roberto Peres; Mina, Mina

    2013-01-01

    Introduction The aim of this study was to analyze the contribution of nonresident progenitor/stem cells and hematopoietic cells to reparative dentinogenesis. Methods Parabiosis was established between C57BL/6-TgN(ACTbEGFP)10sb/J transgenic mice (GFP+) and C57BL/6 wild-type mice (GFP−) to ensure blood cross-circulation between animals. Reparative dentinogenesis was stimulated by pulp exposures and capping on the first maxillary molar in the GFP− mice. Histologic sections of injured molars from GFP− mice were analyzed by epifluorescence microscopy to examine the contributions of GFP+ cells (nonresident progenitor cells and hematopoietic cells originating from GFP+ mice) to reparative dentinogenesis. Results GFP+ cells were detected in close association with reparative dentin formed at the site of pulp exposure in the maxillary first molars of the GFP− mice. Conclusions The present study suggests the participation of the nonresident progenitor cells and hematopoietic cells in reparative dentinogenesis. PMID:22892738

  20. Second hematopoietic stem cell transplantation for the treatment of graft failure, graft rejection or relapse after allogeneic transplantation.

    PubMed

    Wolff, S N

    2002-04-01

    Failure to engraft after hematopoietic stem cell transplantation (graft dysfunction) or to sustain engraftment (graft rejection) is a formidable complication due to many possible factors. These include inadequate stem cell numbers, infections, graft-versus-host disease and immunological mediated processes. Fortunately, this complication is uncommon and can be overcome by additional hematopoietic stem cell infusions. Multiple treatment alternatives have been explored including hematopoietic growth factors, additional infusions of stem cells alone, with augmented immunosuppression or with additional cytotoxic therapy. Various sources of the additional stem cells are feasible including the original donor, using another donor, using stem cells collected from the marrow or after cytokine mobilization from the peripheral blood. This report will overview this complication and review the various studies that have attempted to define both cause and therapy. However, a lack of well-designed prospective studies has made definitive recommendations difficult although basic principles have been established. PMID:11979301

  1. Vascular precursors: origin, regulation and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this miniseries, we discuss the phenotype, origin, and specialized microenvironment (niche) of distinct populations of stem and progenitor cells that exhibit vascular potential. Their usefulness and effectiveness for clinical therapies are also described. We have learned a great deal about post...

  2. Multimodal imaging of lung cancer and its microenvironment (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hariri, Lida P.; Niederst, Matthew J.; Mulvey, Hillary; Adams, David C.; Hu, Haichuan; Chico Calero, Isabel; Szabari, Margit V.; Vakoc, Benjamin J.; Hasan, Tayyaba; Bouma, Brett E.; Engelman, Jeffrey A.; Suter, Melissa J.

    2016-03-01

    Despite significant advances in targeted therapies for lung cancer, nearly all patients develop drug resistance within 6-12 months and prognosis remains poor. Developing drug resistance is a progressive process that involves tumor cells and their microenvironment. We hypothesize that microenvironment factors alter tumor growth and response to targeted therapy. We conducted in vitro studies in human EGFR-mutant lung carcinoma cells, and demonstrated that factors secreted from lung fibroblasts results in increased tumor cell survival during targeted therapy with EGFR inhibitor, gefitinib. We also demonstrated that increased environment stiffness results in increased tumor survival during gefitinib therapy. In order to test our hypothesis in vivo, we developed a multimodal optical imaging protocol for preclinical intravital imaging in mouse models to assess tumor and its microenvironment over time. We have successfully conducted multimodal imaging of dorsal skinfold chamber (DSC) window mice implanted with GFP-labeled human EGFR mutant lung carcinoma cells and visualized changes in tumor development and microenvironment facets over time. Multimodal imaging included structural OCT to assess tumor viability and necrosis, polarization-sensitive OCT to measure tissue birefringence for collagen/fibroblast detection, and Doppler OCT to assess tumor vasculature. Confocal imaging was also performed for high-resolution visualization of EGFR-mutant lung cancer cells labeled with GFP, and was coregistered with OCT. Our results demonstrated that stromal support and vascular growth are essential to tumor progression. Multimodal imaging is a useful tool to assess tumor and its microenvironment over time.

  3. Microenvironment and autophagy cross-talk: Implications in cancer therapy.

    PubMed

    Gomes, Luciana R; Vessoni, Alexandre T; Menck, Carlos F M

    2016-05-01

    There are many ongoing clinical trials to validate tumour microenvironment or autophagic pathway components as targets for anticancer therapies. Different components of the tumour microenvironment play important roles in tumour cell responses, directly affecting malignant transformation, drug resistance and metastasis. Autophagy is also related to chemotherapy responses by inducing tumour cell death or survival. Thus, the autophagy pathway may act as oncosuppressor, in addition to protecting cells from chemotherapy. The cross-talk between the microenvironment and autophagy is very complex and poorly understood. In a recent study using a three-dimensional (3D) cell culture model, the well-documented chemotherapy-mediated activation of autophagy was impaired in breast cancer cells, suggesting a context-dependent outcome for autophagy modulators, under the control of the p53 protein. A deeper understanding of this microenvironment/autophagy interplay may provide important clues for identifying differences in the tumour cell signalling network from in vitro basic research studies to the actual clinical context. In this work, we summarize the role of the microenvironment and autophagy in physiological and tumourigenic conditions, their interactions, and the challenges related to the use of drugs that target these pathways in cancer treatment protocols, emphasizing the potential use of 3D cell culture models in preclinical studies. PMID:27037157

  4. The First Tianjin, China Forum on Tumor Microenvironment

    PubMed Central

    Keller, Evan T.; Li, Lu-Yuan

    2010-01-01

    Although it is well recognized that the tumor microenvironment plays a key role in regulating tumor progression the mechanisms through which this occurs need to be defined. Current international research activities towards defining the role of the tumor microenvironment in cancer progression were the subject of the 1st Tianjin Forum on Tumor Microenvironment held at Nankai University in Tianjin, China, July 2 to 4, 2010. The importance of variety of processes, such as inflammation and angiogenesis, in the role of tumor progression were described for multiple tumor types including breast, prostate, and hepatic cancers as well as the process of bone metastasis. Identification of novel signaling pathways that impact both angiogenesis and bone remodeling were presented. Several themes emerged from this meeting including that (1) tumor cells modify the microenvironment to enhance their own survival and progression; (2) targeting host factors, in addition to targeting tumor cells, will have important therapeutic effects; and (3) host cells distribution within the tumor has both prognostic and therapeutic significance. Several priorities for future research were defined including use of a systems biology approach to define the role of host factors in tumor progression; defining the importance of targeting both arms of the bone remodeling process for therapy of bone metastasis and determining how different cell subsets contribute to microenvironment-mediated regulation of tumor progression. PMID:21224351

  5. Improving drug delivery to solid tumors: priming the tumor microenvironment.

    PubMed

    Khawar, Iftikhar Ali; Kim, Jung Ho; Kuh, Hyo-Jeong

    2015-03-10

    Malignant transformation and growth of the tumor mass tend to induce changes in the surrounding microenvironment. Abnormality of the tumor microenvironment provides a driving force leading not only to tumor progression, including invasion and metastasis, but also to acquisition of drug resistance, including pharmacokinetic (drug delivery-related) and pharmacodynamic (sensitivity-related) resistance. Drug delivery systems exploiting the enhanced permeability and retention (EPR) effect and active targeting moieties were expected to be able to cope with delivery-related drug resistance. However, recent evidence supports a considerable barrier role of tumors via various mechanisms, which results in imperfect or inefficient EPR and/or targeting effect. The components of the tumor microenvironment such as abnormal tumor vascular system, deregulated composition of the extracellular matrix, and interstitial hypertension (elevated interstitial fluid pressure) collectively or cooperatively hinder the drug distribution, which is prerequisite to the efficacy of nanoparticles and small-molecule drugs used in cancer medicine. Hence, the abnormal tumor microenvironment has recently been suggested to be a promising target for the improvement of drug delivery to improve therapeutic efficacy. Strategies to modulate the abnormal tumor microenvironment, referred to here as "solid tumor priming" (vascular normalization and/or solid stress alleviation leading to improvement in blood perfusion and convective molecular movement), have shown promising results in the enhancement of drug delivery and anticancer efficacy. These strategies may provide a novel avenue for the development of new chemotherapeutics and combination chemotherapeutic regimens as well as reassessment of previously ineffective agents. PMID:25526702

  6. Metastasis genetics, epigenetics, and the tumor microenvironment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    KISS1 is a member of a family of genes known as metastasis suppressors, defined by their ability to block metastasis without blocking primary tumor development and growth. KISS1 re-expression in multiple metastatic cell lines of diverse cellular origin suppresses metastasis; yet, still allows comple...

  7. Retinoic Acid Receptor γ Regulates B and T Lymphopoiesis via Nestin-Expressing Cells in the Bone Marrow and Thymic Microenvironments.

    PubMed

    Joseph, Chacko; Nota, Celeste; Fletcher, Jessica L; Maluenda, Ana C; Green, Alanna C; Purton, Louise E

    2016-03-01

    Vitamin A has essential but largely unexplained roles in regulating lymphopoiesis. We have previously shown that retinoic acid receptor (RAR) γ-deficient mice have hematopoietic defects, some phenotypes of which were microenvironment induced. Bone marrow (BM) microenvironment cells identified by either their expression of nestin (Nes) or osterix (Osx) have previously been shown to have roles in regulating lymphopoiesis. We therefore conditionally deleted Rarγ in Nes- or Osx-expressing microenvironment cells. Osx cell-specific deletion of Rarγ had no impact on hematopoiesis. In contrast, deletion of Rarγ in Nes-expressing cells resulted in reductions in peripheral blood B cells and CD4(+) T cells, accompanied by reductions of immature PreB cells in BM. The mice lacking Rarγ in Nes-expressing cells also had smaller thymi, with reductions in double-negative 4 T cell precursors, accompanied by reduced numbers of both TCRβ(low) immature single-positive CD8(+) cells and double-positive T cells. In the thymus, Nes expression was restricted to thymic stromal cells that expressed cerebellar degeneration-related Ag 1 and lacked expression of epithelial cell adhesion molecule. These cells expressed platelet-derived growth factor α and high transcript levels of Rars, Cxcl12, and stem cell factor (Scf). Short-term treatment of mice with all-trans retinoic acid resulted in increased PreB lymphopoiesis in BM and an increase in thymic double-negative 4 T cells, inverse to that observed upon Nes cell-specific deletion of Rarγ. Collectively, these studies show that RARγ is a regulator of B and T lymphopoiesis via Nes-expressing cells in the BM and thymic microenvironments, respectively. PMID:26843326

  8. Galectin-3 in bone tumor microenvironment: a beacon for individual skeletal metastasis management.

    PubMed

    Nakajima, Kosei; Kho, Dong Hyo; Yanagawa, Takashi; Zimel, Melissa; Heath, Elisabeth; Hogan, Victor; Raz, Avraham

    2016-06-01

    The skeleton is frequently a secondary growth site of disseminated cancers, often leading to painful and devastating clinical outcomes. Metastatic cancer distorts bone marrow homeostasis through tumor-derived factors, which shapes different bone tumor microenvironments depending on the tumor cells' origin. Here, we propose a novel insight on tumor-secreted Galectin-3 (Gal-3) that controls the induction of an inflammatory cascade, differentiation of osteoblasts, osteoclasts, and bone marrow cells, resulting in bone destruction and therapeutic failure. In the approaching era of personalized medicine, the current treatment modalities targeting bone metastatic environments are provided to the patient with limited consideration of the cancer cells' origin. Our new outlook suggests delivering individual tumor microenvironment treatments based on the expression level/activity/functionality of tumor-derived factors, rather than utilizing a commonly shared therapeutic umbrella. The notion of "Gal-3-associated bone remodeling" could be the first step toward a specific personalized therapy for each cancer type generating a different bone niche in patients afflicted with non-curable bone metastasis. PMID:27067726

  9. Immunoselection techniques in hematopoietic stem cell transplantation.

    PubMed

    Li Pira, Giuseppina; Biagini, Simone; Cicchetti, Elisabetta; Merli, Pietro; Brescia, Letizia Pomponia; Milano, Giuseppe Maria; Montanari, Mauro

    2016-06-01

    Hematopoietic Stem Cells Transplantation (HSCT) is an effective treatment for hematological and non-hematological diseases. The main challenge in autologous HSCT is purging of malignant cells to prevent relapse. In allogeneic HSCT graft-versus-host disease (GvHD) and opportunistic infections are frequent complications. Two types of graft manipulation have been introduced: the first one in the autologous context aimed at separating malignant cells from hematopoietic stem cells (HSC), and the second one in allogeneic HSCT aimed at reducing the incidence of GvHD and at accelerating immune reconstitution. Here we describe the manipulations used for cell purging in autologous HSCT or for T Cell Depletion (TCD) and T cell selection in allogeneic HSCT. More complex manipulations, requiring a Good Manufacturing Practice (GMP) facility, are briefly mentioned. PMID:27209628

  10. Proinflammatory signaling regulates hematopoietic stem cell emergence.

    PubMed

    Espín-Palazón, Raquel; Stachura, David L; Campbell, Clyde A; García-Moreno, Diana; Del Cid, Natasha; Kim, Albert D; Candel, Sergio; Meseguer, José; Mulero, Victoriano; Traver, David

    2014-11-20

    Hematopoietic stem cells (HSCs) underlie the production of blood and immune cells for the lifetime of an organism. In vertebrate embryos, HSCs arise from the unique transdifferentiation of hemogenic endothelium comprising the floor of the dorsal aorta during a brief developmental window. To date, this process has not been replicated in vitro from pluripotent precursors, partly because the full complement of required signaling inputs remains to be determined. Here, we show that TNFR2 via TNF? activates the Notch and NF-?B signaling pathways to establish HSC fate, indicating a requirement for inflammatory signaling in HSC generation. We determine that primitive neutrophils are the major source of TNF?, assigning a role for transient innate immune cells in establishing the HSC program. These results demonstrate that proinflammatory signaling, in the absence of infection, is utilized by the developing embryo to generate the lineal precursors of the adult hematopoietic system. PMID:25416946

  11. Proinflammatory signaling regulates hematopoietic stem cell emergence

    PubMed Central

    Espín-Palazón, Raquel; Stachura, David L.; Campbell, Clyde A.; García-Moreno, Diana; Cid, Natasha Del; Kim, Albert D.; Candel, Sergio; Meseguer, José; Mulero, Victoriano; Traver, David

    2014-01-01

    Summary Hematopoietic stem cells (HSCs) underlie the production of blood and immune cells for the lifetime of an organism. In vertebrate embryos, HSCs arise from the unique transdifferentiation of hemogenic endothelium comprising the floor of the dorsal aorta during a brief developmental window. To date, this process has not been replicated in vitro from pluripotent precursors, partly because the full complement of required signaling inputs remains to be determined. Here, we show that TNFR2 via TNFα activates the Notch and NF-κB signaling pathways to establish HSC fate, indicating a requirement for inflammatory signaling in HSC generation. We determine that primitive neutrophils are the major source of TNFα, assigning a role for transient innate immune cells in establishing the HSC program. These results demonstrate that proinflammatory signaling, in the absence of infection, is utilized by the developing embryo to generate the lineal precursors of the adult hematopoietic system. PMID:25416946

  12. Hematopoietic stem cell engineering at a crossroads

    PubMed Central

    Rivière, Isabelle; Dunbar, Cynthia E.

    2012-01-01

    The genetic engineering of hematopoietic stem cells is the basis for potentially treating a large array of hereditary and acquired diseases, and stands as the paradigm for stem cell engineering in general. Recent clinical reports support the formidable promise of this approach but also highlight the limitations of the technologies used to date, which have on occasion resulted in clonal expansion, myelodysplasia, or leukemogenesis. New research directions, predicated on improved vector designs, targeted gene delivery or the therapeutic use of pluripotent stem cells, herald the advent of safer and more effective hematopoietic stem cell therapies that may transform medical practice. In this review, we place these recent advances in perspective, emphasizing the solutions emerging from a wave of new technologies and highlighting the challenges that lie ahead. PMID:22096239

  13. Exogenous endothelial cells as accelerators of hematopoietic reconstitution

    PubMed Central

    2012-01-01

    Despite the successes of recombinant hematopoietic-stimulatory factors at accelerating bone marrow reconstitution and shortening the neutropenic period post-transplantation, significant challenges remain such as cost, inability to reconstitute thrombocytic lineages, and lack of efficacy in conditions such as aplastic anemia. A possible means of accelerating hematopoietic reconstitution would be administration of cells capable of secreting hematopoietic growth factors. Advantages of this approach would include: a) ability to regulate secretion of cytokines based on biological need; b) long term, localized production of growth factors, alleviating need for systemic administration of factors that possess unintended adverse effects; and c) potential to actively repair the hematopoietic stem cell niche. Here we overview the field of hematopoietic growth factors, discuss previous experiences with mesenchymal stem cells (MSC) in accelerating hematopoiesis, and conclude by putting forth the rationale of utilizing exogenous endothelial cells as a novel cellular therapy for acceleration of hematopoietic recovery. PMID:23171397

  14. Hypoxic tumor microenvironment: Opportunities to develop targeted therapies.

    PubMed

    Patel, Akhil; Sant, Shilpa

    2016-01-01

    In recent years, there has been great progress in the understanding of tumor biology and its surrounding microenvironment. Solid tumors create regions with low oxygen levels, generally termed as hypoxic regions. These hypoxic areas offer a tremendous opportunity to develop targeted therapies. Hypoxia is not a random by-product of the cellular milieu due to uncontrolled tumor growth; rather it is a constantly evolving participant in overall tumor growth and fate. This article reviews current trends and recent advances in drug therapies and delivery systems targeting hypoxia in the tumor microenvironment. In the first part, we give an account of important physicochemical changes and signaling pathways activated in the hypoxic microenvironment. This is then followed by various treatment strategies including hypoxia-sensitive signaling pathways and approaches to develop hypoxia-targeted drug delivery systems. PMID:27143654

  15. The Tumor Microenvironment: A Pitch for Multiple Players

    PubMed Central

    Schiavoni, Giovanna; Gabriele, Lucia; Mattei, Fabrizio

    2013-01-01

    The cancer microenvironment may be conceptually regarded as a pitch where the main players are resident and non-resident cellular components, each covering a defined role and interconnected by a complex network of soluble mediators. The crosstalk between these cells and the tumor cells within this environment crucially determines the fate of tumor progression. Immune cells that infiltrate the tumor bed are transported there by blood circulation and exert a variety of effects, either counteracting or favoring tumor outgrowth. Here, we review and discuss the multiple populations composing the tumor bed, with special focus on immune cells subsets that positively or negatively dictate neoplastic progression. In this scenario, the contribution of cancer stem cells within the tumor microenvironment will also be discussed. Finally, we illustrate recent advances on new integrated approaches to investigate the tumor microenvironment in vitro. PMID:23616948

  16. Chronic variable stress activates hematopoietic stem cells

    PubMed Central

    Courties, Gabriel; Dutta, Partha; Iwamoto, Yoshiko; Zaltsman, Alex; von zur Muhlen, Constantin; Bode, Christoph; Fricchione, Gregory L.; Denninger, John; Lin, Charles P.; Vinegoni, Claudio; Libby, Peter; Swirski, Filip K.; Weissleder, Ralph; Nahrendorf, Matthias

    2014-01-01

    Exposure to psychosocial stress is a risk factor for many diseases, including atherosclerosis1,2. While incompletely understood, interaction between the psyche and the immune system provides one potential mechanism linking stress and disease inception and progression. Known crosstalk between the brain and immune system includes the hypothalamic–pituitary–adrenal axis, which centrally drives glucocorticoid production in the adrenal cortex, and the sympathetic–adrenal–medullary axis, which controls stress–induced catecholamine release in support of the fight–or–flight reflex3,4. It remains unknown however if chronic stress changes hematopoietic stem cell activity. Here we show that stress increases proliferation of these most primitive progenitors, giving rise to higher levels of disease–promoting inflammatory leukocytes. We found that chronic stress induced monocytosis and neutrophilia in humans. While investigating the source of leukocytosis in mice, we discovered that stress activates upstream hematopoietic stem cells. Sympathetic nerve fibers release surplus noradrenaline, which uses the β3 adrenergic receptor to signal bone marrow niche cells to decrease CXCL12 levels. Consequently, elevated hematopoietic stem cell proliferation increases output of neutrophils and inflammatory monocytes. When atherosclerosis–prone ApoE−/− mice encounter chronic stress, accelerated hematopoiesis promotes plaque features associated with vulnerable lesions that cause myocardial infarction and stroke in humans. PMID:24952646

  17. Genotoxic sensitivity of the developing hematopoietic system.

    PubMed

    Udroiu, Ion; Sgura, Antonella

    2016-01-01

    Genotoxic sensitivity seems to vary during ontogenetic development. Animal studies have shown that the spontaneous mutation rate is higher during pregnancy and infancy than in adulthood. Human and animal studies have found higher levels of DNA damage and mutations induced by mutagens in fetuses/newborns than in adults. This greater susceptibility could be due to reduced DNA repair capacity. In fact, several studies indicated that some DNA repair pathways seem to be deficient during ontogenesis. This has been demonstrated also in murine hematopoietic stem cells. Genotoxicity in the hematopoietic system has been widely studied for several reasons: it is easy to assess, deals with populations cycling also in the adults and may be relevant for leukemogenesis. Reviewing the literature concerning the application of the micronucleus test (a validated assay to assess genotoxicity) in fetus/newborns and adults, we found that the former show almost always higher values than the latter, both in animals treated with genotoxic substances and in those untreated. Therefore, we draw the conclusion that the genotoxic sensitivity of the hematopoietic system is more pronounced during fetal life and decreases during ontogenic development. PMID:27036061

  18. Modification of the tumor microenvironment to enhance immunity.

    PubMed

    Liao, Yu-Pei; Schaue, Dorthe; McBride, William H

    2007-01-01

    The growth and spread of cancer depends as much on the host response to tumor as on the biological characteristics of the tumor itself. This interaction is at its most intimate and dynamic within the tumor microenvironment. It is here that the battle is fought that leads to mutual evolution of tumor and host cell phenotypes. Contributing to this evolutionary process are physiological changes distinctive for the tumor microenvironment, such as hypoxia, low nutrient levels, low extracellular pH, and high interstitial fluid pressure. These largely result from the chaotic intratumoral vasculature but are impacted by the nature of the tumor and the inflammatory and wound healing responses that are generated. Numerous infiltrating immune cells, including macrophages, lymphocytes, natural killer cells and dendritic cells infiltrate the tumor, contributing to high levels of growth factors, hormones, and cytokines. We suggest that the integrated interplay between host and tumor factors results in distinct phenotypes that determine the response to therapy as well as tumor behavior. Targeting the tumor microenvironment to awaken or reawaken immune cells, or to redirect it from a pro-tumor to an anti-tumor state, will require understanding of this phenotype. Current conventional therapies target tumors not tumor cells and clearly affect the host infiltrate and the physiological characteristics of the tumor microenvironment. This may an advantage that has yet to be effectively exploited due to lack of knowledge of existing phenotypes resulting from the tumor-host interactions. The same lack of knowledge impacts outcomes of clinical immunotherapy (IT) trials that have so far not broken through the ceiling of 10% success rate that seems to exist even in melanoma. It seems obvious that more could be achieved by combining therapies that tackle malignancies from multiple angles, with the tumor microenvironment conditioned to support a powerful effector arm generated by IT. The

  19. The Tumour Microenvironment after Radiotherapy: Mechanisms of Resistance and Recurrence

    PubMed Central

    Barker, Holly E.; Paget, James T. E.; Khan, Aadil A.; Harrington, Kevin J.

    2016-01-01

    Radiotherapy plays a central part in curing cancer. For decades, most research on improving treatment outcomes has focussed on modulating radiation-induced biological effects on cancer cells. Recently, we have better understood that components within the tumour microenvironment have pivotal roles in determining treatment outcomes. In this Review, we describe vascular, stromal and immunological changes induced in the tumour microenvironment by irradiation and discuss how they may promote radioresistance and tumour recurrence. Subsequently, we highlight how this knowledge is guiding the development of new treatment paradigms in which biologically targeted agents will be combined with radiotherapy. PMID:26105538

  20. Leukemia Stem Cells and Microenvironment: Biology and Therapeutic Targeting

    PubMed Central

    Konopleva, Marina Y.; Jordan, Craig T.

    2011-01-01

    Acute myelogenous leukemia is propagated by a subpopulation of leukemia stem cells (LSCs). In this article, we review both the intrinsic and extrinsic components that are known to influence the survival of human LSCs. The intrinsic factors encompass regulators of cell cycle and prosurvival pathways (such as nuclear factor kappa B [NF-κB], AKT), pathways regulating oxidative stress, and specific molecular components promoting self-renewal. The extrinsic components are generated by the bone marrow microenvironment and include chemokine receptors (CXCR4), adhesion molecules (VLA-4 and CD44), and hypoxia-related proteins. New strategies that exploit potentially unique properties of the LSCs and their microenvironment are discussed. PMID:21220598

  1. The tumour microenvironment after radiotherapy: mechanisms of resistance and recurrence.

    PubMed

    Barker, Holly E; Paget, James T E; Khan, Aadil A; Harrington, Kevin J

    2015-07-01

    Radiotherapy plays a central part in curing cancer. For decades, most research on improving treatment outcomes has focused on modulating radiation-induced biological effects on cancer cells. Recently, we have better understood that components within the tumour microenvironment have pivotal roles in determining treatment outcomes. In this Review, we describe vascular, stromal and immunological changes that are induced in the tumour microenvironment by irradiation and discuss how these changes may promote radioresistance and tumour recurrence. We also highlight how this knowledge is guiding the development of new treatment paradigms in which biologically targeted agents will be combined with radiotherapy. PMID:26105538

  2. The Bone Microenvironment: a Fertile Soil for Tumor Growth.

    PubMed

    Buenrostro, Denise; Mulcrone, Patrick L; Owens, Philip; Sterling, Julie A

    2016-08-01

    Bone metastatic disease remains a significant and frequent problem for cancer patients that can lead to increased morbidity and mortality. Unfortunately, despite decades of research, bone metastases remain incurable. Current studies have demonstrated that many properties and cell types within the bone and bone marrow microenvironment contribute to tumor-induced bone disease. Furthermore, they have pointed to the importance of understanding how tumor cells interact with their microenvironment in order to help improve both the development of new therapeutics and the prediction of response to therapy. PMID:27255469

  3. Intravital Microscopy for Imaging the Tumor Microenvironment in Live Mice.

    PubMed

    Naumenko, Victor; Jenne, Craig; Mahoney, Douglas J

    2016-01-01

    The development of intravital microscopy has provided unprecedented capacity to study the tumor microenvironment in live mice. The dynamic behavior of cancer, stromal, vascular, and immune cells can be monitored in real time, in situ, in both primary tumors and metastatic lesions, allowing treatment responses to be observed at single cell resolution and therapies tracked in vivo. These features provide a unique opportunity to elucidate the cellular mechanisms underlying the biology and treatment of cancer. We describe here a method for imaging the microenvironment of subcutaneous tumors grown in mice using intravital microscopy. PMID:27581025

  4. The LMO2 oncogene regulates DNA replication in hematopoietic cells

    PubMed Central

    Sincennes, Marie-Claude; Humbert, Magali; Grondin, Benoît; Lisi, Véronique; Veiga, Diogo F. T.; Haman, André; Cazaux, Christophe; Mashtalir, Nazar; Affar, EL Bachir; Verreault, Alain; Hoang, Trang

    2016-01-01

    Oncogenic transcription factors are commonly activated in acute leukemias and subvert normal gene expression networks to reprogram hematopoietic progenitors into preleukemic stem cells, as exemplified by LIM-only 2 (LMO2) in T-cell acute lymphoblastic leukemia (T-ALL). Whether or not these oncoproteins interfere with other DNA-dependent processes is largely unexplored. Here, we show that LMO2 is recruited to DNA replication origins by interaction with three essential replication enzymes: DNA polymerase delta (POLD1), DNA primase (PRIM1), and minichromosome 6 (MCM6). Furthermore, tethering LMO2 to synthetic DNA sequences is sufficient to transform these sequences into origins of replication. We next addressed the importance of LMO2 in erythroid and thymocyte development, two lineages in which cell cycle and differentiation are tightly coordinated. Lowering LMO2 levels in erythroid progenitors delays G1-S progression and arrests erythropoietin-dependent cell growth while favoring terminal differentiation. Conversely, ectopic expression in thymocytes induces DNA replication and drives these cells into cell cycle, causing differentiation blockade. Our results define a novel role for LMO2 in directly promoting DNA synthesis and G1-S progression. PMID:26764384

  5. Microenvironments and microscale productivity of cyanobacterial desert crusts

    USGS Publications Warehouse

    Garcia-Pichel, F.; Belnap, Jayne

    1996-01-01

    We used microsensors to characterize physicochemical microenvironments and photosynthesis occurring immediately after water saturation in two desert soil crusts from southeastern Utah, which were formed by the cyanobacteria Microcoleus vaginatus Gomont, Nostoc spp., and Scytonema sp. The light fields within the crusts presented steep vertical gradients in magnitude and spectral composition. Near-surface light-trapping zones were formed due to the scattering nature of the sand particles, but strong light attenuation resulted in euphotic zones only ca. 1 mm deep, which were progressively enriched in longer wavelengths with depth. Rates of gross photosynthesis (3.4a??9.4 mmol O2A?ma??2A?ha??1) and dark respiration (0.81a??3.1 mmol Oa??2A?ma??2A?ha??1) occurring within 1 to several mm from the surface were high enough to drive the formation of marked oxygen microenvironments that ranged from oxygen supersaturation to anoxia. The photosynthetic activity also resulted in localized pH values in excess of 10, 2a??3 units above the soil pH. Differences in metabolic parameters and community structure between two types of crusts were consistent with a successional pattern, which could be partially explained on the basis of the microenvironments. We discuss the significance of high metabolic rates and the formation of microenvironments for the ecology of desert crusts, as well as the advantages and limitations of microsensor-based methods for crust investigation.

  6. Tumor microenvironment derived exosomes pleiotropically modulate cancer cell metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cancer-associated fibroblasts (CAFs) are a major cellular component of tumor microenvironment in most solid cancers. Altered cellular metabolism is a hallmark of cancer, and much of the published literature has focused on neoplastic cell-autonomous processes for these adaptations. We demonstrate tha...

  7. Screening the Cellular Microenvironment: A Role for Microfluidics

    PubMed Central

    Warrick, Jay W.; Murphy, William L.; Beebe, David J.

    2010-01-01

    The cellular microenvironment is an increasingly discussed topic in cell biology as it has been implicated in the progression of cancer and the maintenance of stem cells. The microenvironment of a cell is an organized combination of extracellular matrix (ECM), cells, and interstitial fluid that influence cellular phenotype through physical, mechanical, and biochemical mechanisms. Screening can be used to map combinations of cells and microenvironments to phenotypic outcomes in a way that can help develop more predictive in vitro models and to better understand phenotypic mechanisms from a systems biology perspective. This paper examines microenvironmental screening in terms of outcomes and benefits, key elements of the screening process, challenges for implementation, and a possible role for microfluidics as the screening platform. To assess microfluidics for use in microenvironmental screening, examples and categories of micro-scale and microfluidic technology are highlighted. Microfluidic technology shows promise for simultaneous control of multiple parameters of the microenvironment and can provide a base for scaling advanced cell-based experiments into automated high-throughput formats. PMID:20190880

  8. Tumor-Associated Macrophages and Neutrophils in Tumor Microenvironment

    PubMed Central

    Kim, Jaehong; Bae, Jong-Sup

    2016-01-01

    Distinct tumor microenvironment forms in each progression step of cancer and has diverse capacities to induce both adverse and beneficial consequences for tumorigenesis. It is now known that immune cells can be activated to favor tumor growth and progression, most probably influenced by the tumor microenvironment. Tumor-associated macrophages and tumor-associated neutrophils can exert protumoral functions, enhancing tumor cell invasion and metastasis, angiogenesis, and extracellular matrix remodeling, while inhibiting the antitumoral immune surveillance. Considering that neutrophils in inflammatory environments recruit macrophages and that recruited macrophages affect neutrophil functions, there may be various degrees of interaction between tumor-associated macrophages and tumor-associated neutrophils. Platelets also play an important role in the recruitment and regulation of monocytic and granulocytic cells in the tumor tissues, suggesting that platelet function may be essential for generation of tumor-associated macrophages and tumor-associated neutrophils. In this review, we will explore the biology of tumor-associated macrophages and tumor-associated neutrophils and their possible interactions in the tumor microenvironment. Special attention will be given to the recruitment and activation of these tumor-associated cells and to the roles they play in maintenance of the tumor microenvironment and progression of tumors. PMID:26966341

  9. Exosomic microRNAs in the Tumor Microenvironment

    PubMed Central

    Neviani, Paolo; Fabbri, Muller

    2015-01-01

    Dissecting the crosstalk between tumor cells and tumor microenvironment is quickly becoming the new frontier in cancer research. It is now widely accepted that cancer cells can exert a profound influence over their surroundings, by changing the microenvironment from a normal to a tumor-supportive state that allows for sustained tumor growth, invasion, and drug resistance. Extracellular vesicles, especially exosomes, are recognized as a new category of intercellular communicator, and they are emerging as of primary importance in controlling the interplay between the tumor and its environment. Exosomes derived from cancer cells or from cells of the tumor microenvironment allow for the horizontal transfer of information by virtue of their cargo, made of functional proteins and nucleic acids that are specifically sorted and loaded in exosomes during their biogenesis. In this review, we will discuss the current knowledge regarding the role invested by microRNAs, a family of short non-coding RNAs frequently deregulated in malignancies and present in exosomes, in shaping the microenvironment in a cancer-dependent manner. PMID:26258125

  10. Parallel Aspects of the Microenvironment in Cancer and Autoimmune Disease.

    PubMed

    Rahat, Michal A; Shakya, Jivan

    2016-01-01

    Cancer and autoimmune diseases are fundamentally different pathological conditions. In cancer, the immune response is suppressed and unable to eradicate the transformed self-cells, while in autoimmune diseases it is hyperactivated against a self-antigen, leading to tissue injury. Yet, mechanistically, similarities in the triggering of the immune responses can be observed. In this review, we highlight some parallel aspects of the microenvironment in cancer and autoimmune diseases, especially hypoxia, and the role of macrophages, neutrophils, and their interaction. Macrophages, owing to their plastic mode of activation, can generate a pro- or antitumoral microenvironment. Similarly, in autoimmune diseases, macrophages tip the Th1/Th2 balance via various effector cytokines. The contribution of neutrophils, an additional plastic innate immune cell population, to the microenvironment and disease progression is recently gaining more prominence in both cancer and autoimmune diseases, as they can secrete cytokines, chemokines, and reactive oxygen species (ROS), as well as acquire an enhanced ability to produce neutrophil extracellular traps (NETs) that are now considered important initiators of autoimmune diseases. Understanding the contribution of macrophages and neutrophils to the cancerous or autoimmune microenvironment, as well as the role their interaction and cooperation play, may help identify new targets and improve therapeutic strategies. PMID:26997761

  11. Operation of the computer model for microenvironment atomic oxygen exposure

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.; Gillis, J. R.; Gruenbaum, P. E.

    1995-01-01

    A computer model for microenvironment atomic oxygen exposure has been developed to extend atomic oxygen modeling capability to include shadowing and reflections. The model uses average exposure conditions established by the direct exposure model and extends the application of these conditions to treat surfaces of arbitrary shape and orientation.

  12. Ex vivo Live Imaging of Lung Metastasis and Their Microenvironment.

    PubMed

    van den Bijgaart, Renske J E; Kong, Niwen; Maynard, Carrie; Plaks, Vicki

    2016-01-01

    Metastasis is a major cause for cancer-related morbidity and mortality. Metastasis is a multistep process and due to its complexity, the exact cellular and molecular processes that govern metastatic dissemination and growth are still elusive. Live imaging allows visualization of the dynamic and spatial interactions of cells and their microenvironment. Solid tumors commonly metastasize to the lungs. However, the anatomical location of the lungs poses a challenge to intravital imaging. This protocol provides a relatively simple and quick method for ex vivo live imaging of the dynamic interactions between tumor cells and their surrounding stroma within lung metastasis. Using this method, the motility of cancer cells as well as interactions between cancer cells and stromal cells in their microenvironment can be visualized in real time for several hours. By using transgenic fluorescent reporter mice, a fluorescent cell line, injectable fluorescently labeled molecules and/or antibodies, multiple components of the lung microenvironment can be visualized, such as blood vessels and immune cells. To image the different cell types, a spinning disk confocal microscope that allows long-term continuous imaging with rapid, four-color image acquisition has been used. Time-lapse movies compiled from images collected over multiple positions and focal planes show interactions between live metastatic and immune cells for at least 4 hr. This technique can be further used to test chemotherapy or targeted therapy. Moreover, this method could be adapted for the study of other lung-related pathologies that may affect the lung microenvironment. PMID:26862704

  13. Parallel Aspects of the Microenvironment in Cancer and Autoimmune Disease

    PubMed Central

    Rahat, Michal A.

    2016-01-01

    Cancer and autoimmune diseases are fundamentally different pathological conditions. In cancer, the immune response is suppressed and unable to eradicate the transformed self-cells, while in autoimmune diseases it is hyperactivated against a self-antigen, leading to tissue injury. Yet, mechanistically, similarities in the triggering of the immune responses can be observed. In this review, we highlight some parallel aspects of the microenvironment in cancer and autoimmune diseases, especially hypoxia, and the role of macrophages, neutrophils, and their interaction. Macrophages, owing to their plastic mode of activation, can generate a pro- or antitumoral microenvironment. Similarly, in autoimmune diseases, macrophages tip the Th1/Th2 balance via various effector cytokines. The contribution of neutrophils, an additional plastic innate immune cell population, to the microenvironment and disease progression is recently gaining more prominence in both cancer and autoimmune diseases, as they can secrete cytokines, chemokines, and reactive oxygen species (ROS), as well as acquire an enhanced ability to produce neutrophil extracellular traps (NETs) that are now considered important initiators of autoimmune diseases. Understanding the contribution of macrophages and neutrophils to the cancerous or autoimmune microenvironment, as well as the role their interaction and cooperation play, may help identify new targets and improve therapeutic strategies. PMID:26997761

  14. Synthetic Extracellular Microenvironment for Modulating Stem Cell Behaviors

    PubMed Central

    Chandra, Prafulla; Lee, Sang Jin

    2015-01-01

    The innate ability of stem cells to self-renew and differentiate into multiple cell types makes them a promising source for tissue engineering and regenerative medicine applications. Their capacity for self-renewal and differentiation is largely influenced by the combination of physical, chemical, and biological signals found in the stem cell niche, both temporally and spatially. Embryonic and adult stem cells are potentially useful for cell-based approaches; however, regulating stem cell behavior remains a major challenge in their clinical use. Most of the current approaches for controlling stem cell fate do not fully address all of the complex signaling pathways that drive stem cell behaviors in their natural microenvironments. To overcome this limitation, a new generation of biomaterials is being developed for use as three-dimensional synthetic microenvironments that can mimic the regulatory characteristics of natural extracellular matrix (ECM) proteins and ECM-bound growth factors. These synthetic microenvironments are currently being investigated as a substrate with surface immobilization and controlled release of bioactive molecules to direct the stem cell fate in vitro, as a tissue template to guide and improve the neo-tissue formation both in vitro and in vivo, and as a delivery vehicle for cell therapy in vivo. The continued advancement of such an intelligent biomaterial system as the synthetic extracellular microenvironment holds the promise of improved therapies for numerous debilitating medical conditions for which no satisfactory cure exists today. PMID:26106260

  15. MicroRNA Targeting to Modulate Tumor Microenvironment

    PubMed Central

    Kuninty, Praneeth R.; Schnittert, Jonas; Storm, Gert; Prakash, Jai

    2016-01-01

    Communication between stromal cells and tumor cells initiates tumor growth, angiogenesis, invasion, and metastasis. Stromal cells include cancer-associated fibroblasts, tumor-associated macrophages, pericytes, endothelial cells, and infiltrating immune cells. MicroRNAs (miRNAs) in the tumor microenvironment have emerged as key players involved in the development of cancer and its progression. miRNAs are small endogenous non-protein-coding RNAs that negatively regulate the expression of multiple target genes at post-transcriptional level and thereby control many cellular processes. In this review, we provide a comprehensive overview of miRNAs dysregulated in different stromal cells and their impact on the regulation of intercellular crosstalk in the tumor microenvironment. We also discuss the therapeutic significance potential of miRNAs to modulate the tumor microenvironment. Since miRNA delivery is quite challenging and the biggest hurdle for clinical translation of miRNA therapeutics, we review various non-viral miRNA delivery systems that can potentially be used for targeting miRNA to stromal cells within the tumor microenvironment. PMID:26835418

  16. MEASUREMENT AND DECOMPOSITION OF TOTAL EXPOSURE USING THE TOTAL-ISOLATED-BY-MICROENVIRONMENT-EXPOSURE (TIME) MONITOR

    EPA Science Inventory

    This paper describes a new, highly compact and lightweight monitor that directly measures personal exposure resolved into four microenvironments. he device is the "Total-Isolated-by-Microenvironment-Exposure (TIME)" monitor. he monitor can identify electronically a subject's micr...

  17. Hematopoietic Stem and Progenitor Cell Migration After Hypofractionated Radiation Therapy in a Murine Model

    SciTech Connect

    Kane, Jonathan; Krueger, Sarah A.; Dilworth, Joshua T.; Torma, John T.; Wilson, George D.; Marples, Brian; Madlambayan, Gerard J.

    2013-12-01

    Purpose: To characterize the recruitment of bone marrow (BM)-derived hematopoietic stem and progenitor cells (HSPCs) within tumor microenvironment after radiation therapy (RT) in a murine, heterotopic tumor model. Methods and Materials: Lewis lung carcinoma tumors were established in C57BL/6 mice and irradiated with 30 Gy given as 2 fractions over 2 days. Tumors were imaged with positron emission tomography/computed tomography (PET/CT) and measured daily with digital calipers. The HSPC and myelomonocytic cell content was assessed via immunofluorescent staining and flow cytometry. Functionality of tumor-associated HSPCs was verified in vitro using colony-forming cell assays and in vivo by rescuing lethally irradiated C57BL/6 recipients. Results: Irradiation significantly reduced tumor volumes and tumor regrowth rates compared with nonirradiated controls. The number of CD133{sup +} HSPCs present in irradiated tumors was higher than in nonirradiated tumors during all stages of regrowth. CD11b{sup +} counts were similar. PET/CT imaging and growth rate analysis based on standardized uptake value indicated that HSPC recruitment directly correlated to the extent of regrowth and intratumor cell activity after irradiation. The BM-derived tumor-associated HSPCs successfully formed hematopoietic colonies and engrafted irradiated mice. Finally, targeted treatment with a small animal radiation research platform demonstrated localized HSPC recruitment to defined tumor subsites exposed to radiation. Conclusions: Hypofractionated irradiation resulted in a pronounced and targeted recruitment of BM-derived HSPCs, possibly as a mechanism to promote tumor regrowth. These data indicate for the first time that radiation therapy regulates HSPC content within regrowing tumors.

  18. Angiogenin Defines Heterogeneity at the Core of the Hematopoietic Niche.

    PubMed

    Di Scala, Marianna; Hidalgo, Andrés

    2016-09-01

    Successful hematopoietic regeneration demands preservation of stemness while enabling expansion and differentiation into blood lineages. Now, Silberstein et al. (2016) and Goncalves et al. (2016) identify a ribonuclease secreted by proximal niche cells that simultaneously drives quiescence of HSCs and proliferation of myeloid progenitors and dramatically enhances hematopoietic recovery after HSC transplantation. PMID:27588743

  19. Hematopoietic Stem Cells Transplantation Can Normalize Thyroid Function in a Cystinosis Mouse Model.

    PubMed

    Gaide Chevronnay, H P; Janssens, V; Van Der Smissen, P; Rocca, C J; Liao, X H; Refetoff, S; Pierreux, C E; Cherqui, S; Courtoy, P J

    2016-04-01

    Hypothyroidism is the most frequent and earliest endocrine complication in cystinosis, a multisystemic lysosomal storage disease caused by defective transmembrane cystine transporter, cystinosin (CTNS gene). We recently demonstrated in Ctns(-/-) mice that altered thyroglobulin biosynthesis associated with endoplasmic reticulum stress, combined with defective lysosomal processing, caused hypothyroidism. In Ctns(-/-) kidney, hematopoietic stem cell (HSC) transplantation provides long-term functional and structural protection. Tissue repair involves transfer of cystinosin-bearing lysosomes from HSCs differentiated as F4/80 macrophages into deficient kidney tubular cells, via tunneling nanotubes that cross basement laminae. Here we evaluated the benefit of HSC transplantation for cystinotic thyroid and investigated the underlying mechanisms. HSC engraftment in Ctns(-/-) thyroid drastically decreased cystine accumulation, normalized the TSH level, and corrected the structure of a large fraction of thyrocytes. In the thyroid microenvironment, HSCs differentiated into a distinct, mixed macrophage/dendritic cell lineage expressing CD45 and major histocompatibility complex II but low CD11b and F4/80. Grafted HSCs closely apposed to follicles and produced tunneling nanotube-like extensions that crossed follicular basement laminae. HSCs themselves further squeezed into follicles, allowing extensive contact with thyrocytes, but did not transdifferentiate into Nkx2.1-expressing cells. Our observations revealed significant differences of basement lamina porosity between the thyroid and kidney and/or intrinsic macrophage invasive properties once in the thyroid microenvironment. The contrast between extensive thyrocyte protection and low HSC abundance at steady state suggests multiple sequential encounters and/or remanent impact. This is the first report demonstrating the potential of HSC transplantation to correct thyroid disease and supports a major multisystemic benefit of stem

  20. Glioma Stem Cells and Their Microenvironments: Providers of Challenging Therapeutic Targets

    PubMed Central

    Codrici, Elena; Enciu, Ana-Maria; Popescu, Ionela-Daniela; Mihai, Simona; Tanase, Cristiana

    2016-01-01

    Malignant gliomas are aggressive brain tumors with limited therapeutic options, possibly because of highly tumorigenic subpopulations of glioma stem cells. These cells require specific microenvironments to maintain their “stemness,” described as perivascular and hypoxic niches. Each of those niches induces particular signatures in glioma stem cells (e.g., activation of Notch signaling, secretion of VEGF, bFGF, SDF1 for the vascular niche, activation of HIF2α, and metabolic reprogramming for hypoxic niche). Recently, accumulated knowledge on tumor-associated macrophages, possibly delineating a third niche, has underlined the role of immune cells in glioma progression, via specific chemoattractant factors and cytokines, such as macrophage-colony stimulation factor (M-CSF). The local or myeloid origin of this new component of glioma stem cells niche is yet to be determined. Such niches are being increasingly recognized as key regulators involved in multiple stages of disease progression, therapy resistance, immune-escaping, and distant metastasis, thereby substantially impacting the future development of frontline interventions in clinical oncology. This review focuses on the microenvironment impact on the glioma stem cell biology, emphasizing GSCs cross talk with hypoxic, perivascular, and immune niches and their potential use as targeted therapy. PMID:26977157

  1. IL-12 Delivered Intratumorally by Multilamellar Liposomes Reactivates Memory T Cells in Human Tumor Microenvironments

    PubMed Central

    Simpson-Abelson, Michelle R.; Purohit, Vivek S.; Pang, Wing Man; Iyer, Vandana; Odunsi, Kunle; Demmy, Todd L; Yokota, Sandra J.; Loyall, Jenni L.; Kelleher, Raymond J.; Balu-Iyer, Sathy; Bankert, Richard B.

    2009-01-01

    Using a novel loading technique, IL-12 is reported here to be efficiently encapsulated within large multilamellar liposomes. The preclinical efficacy of the cytokine loaded liposomes to deliver IL-12 into human tumors and to reactive tumor-associated T cells in situ is tested using a human tumor xenograft model. IL-12 is released in vivo from these liposomes in a biologically active form when injected into tumor xenografts that are established by the subcutaneous implantation of non-disrupted pieces of human lung, breast or ovarian tumors into immunodeficient mice. The histological architecture of the original tumor tissue, including tumor-associated leukocytes, tumor cells and stromal cells is preserved anatomically and the cells remain functionally responsive to cytokines in these xenografts. The local and sustained release of IL-12 into the tumor microenvironment reactivates tumor-associated quiescent effector memory T cells to proliferate, produce and release IFN-γ resulting in the killing of tumor cells in situ. Very little IL-12 is detected in the serum of mice for up to 5 days after an intratumoral injection of the IL-12 liposomes. We conclude that IL-12 loaded large multilamellar liposomes provide a safe method for the local and sustained delivery of IL-12 to tumors and a therapeutically effective way of reactivating existing tumor-associated T cells in human solid tumor microenvironments. The potential of this local in situ T cell re-stimulation to induce a systemic anti-tumor immunity is discussed. PMID:19395317

  2. Tumor-associated stromal cells as key contributors to the tumor microenvironment.

    PubMed

    Bussard, Karen M; Mutkus, Lysette; Stumpf, Kristina; Gomez-Manzano, Candelaria; Marini, Frank C

    2016-01-01

    The tumor microenvironment is a heterogeneous population of cells consisting of the tumor bulk plus supporting cells. It is becoming increasingly evident that these supporting cells are recruited by cancer cells from nearby endogenous host stroma and promote events such as tumor angiogenesis, proliferation, invasion, and metastasis, as well as mediate mechanisms of therapeutic resistance. In addition, recruited stromal cells range in type and include vascular endothelial cells, pericytes, adipocytes, fibroblasts, and bone-marrow mesenchymal stromal cells. During normal wound healing and inflammatory processes, local stromal cells change their phenotype to become that of reactive stroma. Under certain conditions, however, tumor cells can co-opt these reactive stromal cells and further transition them into tumor-associated stromal cells (TASCs). These TASCs express higher levels of proteins, including alpha-smooth muscle actin, fibroblast activating protein, and matrix metalloproteinases, compared with their normal, non-reactive counterparts. TASCs are also known to secrete many pro-tumorigenic factors, including IL-6, IL-8, stromal-derived factor-1 alpha, vascular endothelial growth factor, tenascin-C, and matrix metalloproteinases, among others, which recruit additional tumor and pro-tumorigenic cells to the developing microenvironment. Here, we review the current literature pertaining to the origins of recruited host stroma, contributions toward tumor progression, tumor-associated stromal cells, and mechanisms of crosstalk between endogenous host stroma and tumor cells. PMID:27515302

  3. Phenotypic and functional heterogeneity of cancer-associated fibroblast within the tumor microenvironment.

    PubMed

    Ishii, Genichiro; Ochiai, Atsushi; Neri, Shinya

    2016-04-01

    Cancer microenvironment is created not only by malignant epithelial cells, but also by several kinds of stromal cells. Since Paget proposed the "seed and soil" hypothesis, the biological importance of the cancer microenvironment has come to be widely accepted. The main compartment of host stromal cells are fibroblasts (Cancer-Associated Fibroblasts; CAFs), which are the main source of the collagen-producing cells. CAFs directly communicate with the cancer cells and other types of stromal cells to acquire a specific biological phenotype. CAFs play important roles in several aspects of the tumor progression process and the chemotherapeutic process. However, CAFs have heterogeneous origins, phenotypes, and functions under these conditions. A crucial challenge is to understand how much of this heterogeneity serves different biological responses to cancer cells. In this review, we highlight the issue of how diverse and heterogeneous functions given by CAFs can exert potent influences on tumor progression and therapeutic response. Furthermore, we also discuss the current advances in the development of novel therapeutic strategies against CAFs. PMID:26278673

  4. Registered report: Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis.

    PubMed

    Fiering, Steven; Ang, Lay-Hong; Lacoste, Judith; Smith, Tim D; Griner, Erin

    2015-01-01

    The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replicating selected results from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012 were selected on the basis of citations and Altimetric scores (Errington et al., 2014). This Registered report describes the proposed replication plan of key experiments from 'Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis' by Goetz and colleagues, published in Cell in 2011 (Goetz et al., 2011). The key experiments being replicated are those reported in Figures 7C (a-d), Supplemental Figure S2A, and Supplemental Figure S7C (a-c) (Goetz et al., 2011). In these experiments, which are a subset of all the experiments reported in the original publication, Goetz and colleagues show in a subcutaneous xenograft model that stromal caveolin-1 remodels the intratumoral microenvironment, which is correlated with increased metastasis formation. The Reproducibility Project: Cancer Biology is a collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife. PMID:26179155

  5. Recapitulation of complex transport and action of drugs at the tumor microenvironment using tumor-microenvironment-on-chip.

    PubMed

    Han, Bumsoo; Qu, Chunjing; Park, Kinam; Konieczny, Stephen F; Korc, Murray

    2016-09-28

    Targeted delivery aims to selectively distribute drugs to targeted tumor tissues but not to healthy tissues. This can address many clinical challenges by maximizing the efficacy but minimizing the toxicity of anti-cancer drugs. However, a complex tumor microenvironment poses various barriers hindering the transport of drugs and drug delivery systems. New tumor models that allow for the systematic study of these complex environments are highly desired to provide reliable test beds to develop drug delivery systems for targeted delivery. Recently, research efforts have yielded new in vitro tumor models, the so called tumor-microenvironment-on-chip, that recapitulate certain characteristics of the tumor microenvironment. These new models show benefits over other conventional tumor models, and have the potential to accelerate drug discovery and enable precision medicine. However, further research is warranted to overcome their limitations and to properly interpret the data obtained from these models. In this article, key features of the in vivo tumor microenvironment that are relevant to drug transport processes for targeted delivery were discussed, and the current status and challenges for developing in vitro transport model systems were reviewed. PMID:26688098

  6. Neuromuscular complications of hematopoietic stem cell transplantation.

    PubMed

    Ruzhansky, Katherine M; Brannagan, Thomas H

    2015-10-01

    Neuromuscular diseases such as polymyositis, dermatomyositis, peripheral neuropathy, and disorders of neuromuscular transmission are reported to be complications of hematopoietic stem cell transplantation (HSCT). Although cases have been reported with allogeneic HSCT in the setting of chronic graft versus host disease, they are also known to occur without evidence thereof and even occur in the setting of autologous HSCT. The 2005 National Institutes of Health Consensus Criteria classify polymyositis and dermatomyositis as "distinctive" features, and neuropathy and MG as "other" features. These neuromuscular complications present very similarly to the idiopathic autoimmune disorders and respond to similar treatment modalities. PMID:26044357

  7. Reactive Oxygen Species Limit the Ability of Bone Marrow Stromal Cells to Support Hematopoietic Reconstitution in Aging Mice

    PubMed Central

    Khatri, Rahul; Krishnan, Shyam; Roy, Sushmita; Chattopadhyay, Saborni; Kumar, Vikash

    2016-01-01

    Aging of organ and abnormal tissue regeneration are recurrent problems in physiological and pathophysiological conditions. This is most crucial in case of high-turnover tissues, like bone marrow (BM). Using reciprocal transplantation experiments in mouse, we have shown that self-renewal potential of hematopoietic stem and progenitor cells (HSPCs) and BM cellularity are markedly influenced with the age of the recipient mice rather than donor mice. Moreover, accumulation of excessive reactive oxygen species (ROS) in BM stromal cells compared to HSPC compartment, in time-dependent manner, suggests that oxidative stress is involved in suppression of BM cellularity by affecting microenvironment in aged mice. Treatment of these mice with a polyphenolic antioxidant curcumin is found to partially quench ROS, thereby rescues stromal cells from oxidative stress-dependent cellular injury. This rejuvenation of stromal cells significantly improves hematopoietic reconstitution in 18-month-old mice compared to age control mice. In conclusion, this study implicates the role of ROS in perturbation of stromal cell function upon aging, which in turn affects BM's reconstitution ability in aged mice. Thus, a rejuvenation therapy using curcumin, before HSPC transplantation, is found to be an efficient strategy for successful marrow reconstitution in older mice. PMID:27140293

  8. Mesenchymal stem/progenitor cells promote the reconstitution of exogenous hematopoietic stem cells in Fancg−/− mice in vivo

    PubMed Central

    Li, Yan; Chen, Shi; Yuan, Jin; Yang, Yanzhu; Li, Jingling; Ma, Jin; Wu, Xiaohua; Freund, Marcel; Pollok, Karen; Hanenberg, Helmut; Goebel, W. Scott

    2009-01-01

    Fanconi anemia (FA) is a heterogeneous genetic disorder characterized by bone marrow failure and complex congenital anomalies. Although mutations in FA genes result in a characteristic phenotype in the hematopoietic stem/progenitor cells (HSPCs), little is known about the consequences of a nonfunctional FA pathway in other stem/progenitor cell compartments. Given the intense functional interactions between HSPCs and the mesenchymalmicroenvironment, we investigated the FA pathway on the cellular functions of murine mesenchymal stem/progenitor cells (MSPCs) and their interactions with HSPCs in vitro and in vivo. Here, we show that loss of the murine homologue of FANCG (Fancg) results in a defect in MSPC proliferation and in their ability to support the adhesion and engraftment of murine syngeneic HSPCs in vitro or in vivo. Transplantation of wild-type (WT) but not Fancg−/− MSPCs into the tibiae of Fancg−/− recipient mice enhances the HSPC engraftment kinetics, the BM cellularity, and the number of progenitors per tibia of WT HSPCs injected into lethally irradiated Fancg−/− recipients. Collectively, these data show that FA proteins are required in the BM microenvironment to maintain normal hematopoiesis and provide genetic and quantitative evidence that adoptive transfer of WT MSPCs enhances hematopoietic stem cell engraftment. PMID:19129541

  9. Transcriptome comparison of distinct osteolineage subsets in the hematopoietic stem cell niche using a triple fluorescent transgenic mouse model

    PubMed Central

    Yu, Vionnie W.C.; Lymperi, Stefania; Ferraro, Francesca; Scadden, David T.

    2015-01-01

    The bone marrow niche is recognized as a central player in maintaining and regulating the behavior of hematopoietic stem and progenitor cells. Specific gain-of and loss-of function experiments perturbing a range of osteolineage cells or their secreted proteins had been shown to affect stem cell maintenance (Calvi et al, 2003 [1]; Stier et al., 2005 [2]; Zhang et al., 2003 [3]; Nilsson et al., 2005 [4]; Greenbaum et al., 2013 [5]) and engraftment (Adam et al., 2006, 2009 [6], [7]). We used specific in vivo cell deletion approaches to dissect the niche cell-parenchymal cell dependency in a complex bone marrow microenvironment. Endogenous deletion of osteocalcin-expressing (Ocn+) cells led to a loss of T immune cells (Yu et al., 2015 [8]. Ocn+ cells express the Notch ligand DLL4 to communicate with T-competent progenitors, and thereby ensuring T precursor production and expression of chemotactic molecules on their cell surface for subsequent thymic seeding. In contrast, depletion of osterix-expressing (Osx+) osteoprogenitors led to reduced B immune cells. These distinct hematopoietic phenotypes suggest specific pairing of mesenchymal niche cells and parenchymal hematopoietic cells in the bone marrow to create unique functional units to support hematopoiesis. Here, we present the global gene expression profiles of these osteolineage subtypes utilizing a triple fluorescent transgenic mouse model (OsxCre+;Rosa-mCh+;Ocn:Topaz+) that labels Osx+ cells red, Ocn+ cells green, and Osx+ Ocn+ cells yellow. This system allows isolation of distinct osteolineage subsets within the same animal by flow cytometry. Array data that have been described in our study [8] are also publically available from NCBI Gene Expression Omnibus (GEO) with the accession number GSE66042. Differences in gene expression may correlate with functional difference in supporting hematopoiesis. PMID:26484277

  10. Transcriptome comparison of distinct osteolineage subsets in the hematopoietic stem cell niche using a triple fluorescent transgenic mouse model.

    PubMed

    Yu, Vionnie W C; Lymperi, Stefania; Ferraro, Francesca; Scadden, David T

    2015-09-01

    The bone marrow niche is recognized as a central player in maintaining and regulating the behavior of hematopoietic stem and progenitor cells. Specific gain-of and loss-of function experiments perturbing a range of osteolineage cells or their secreted proteins had been shown to affect stem cell maintenance (Calvi et al, 2003 [1]; Stier et al., 2005 [2]; Zhang et al., 2003 [3]; Nilsson et al., 2005 [4]; Greenbaum et al., 2013 [5]) and engraftment (Adam et al., 2006, 2009 [6,7]). We used specific in vivo cell deletion approaches to dissect the niche cell-parenchymal cell dependency in a complex bone marrow microenvironment. Endogenous deletion of osteocalcin-expressing (Ocn(+)) cells led to a loss of T immune cells (Yu et al., 2015 [8]. Ocn(+) cells express the Notch ligand DLL4 to communicate with T-competent progenitors, and thereby ensuring T precursor production and expression of chemotactic molecules on their cell surface for subsequent thymic seeding. In contrast, depletion of osterix-expressing (Osx(+)) osteoprogenitors led to reduced B immune cells. These distinct hematopoietic phenotypes suggest specific pairing of mesenchymal niche cells and parenchymal hematopoietic cells in the bone marrow to create unique functional units to support hematopoiesis. Here, we present the global gene expression profiles of these osteolineage subtypes utilizing a triple fluorescent transgenic mouse model (OsxCre(+);Rosa-mCh(+);Ocn:Topaz(+)) that labels Osx(+) cells red, Ocn(+) cells green, and Osx(+) Ocn(+) cells yellow. This system allows isolation of distinct osteolineage subsets within the same animal by flow cytometry. Array data that have been described in our study [8] are also publically available from NCBI Gene Expression Omnibus (GEO) with the accession number GSE66042. Differences in gene expression may correlate with functional difference in supporting hematopoiesis. PMID:26484277

  11. Differential Regulation of CXCL5 by FGF2 in Osteoblastic and Endothelial Niche Cells Supports Hematopoietic Stem Cell Migration

    PubMed Central

    Yoon, Kyung-Ae; Cho, Hye-Sim; Shin, Hong-In

    2012-01-01

    Stem cell maintenance requires a specific microenvironment. Hematopoietic stem cells (HSCs) are mainly maintained by the endosteal osteoblast (OB) niche, which provides a quiescent HSC microenvironment, and the vascular niche, which regulates the proliferation, differentiation, and mobilization of HSCs. The systemic administration of FGF2 failed to induce normal hematopoiesis in bone marrow (BM) by reducing SDF-1, an important factor for hematopoiesis. Interestingly, SDF-1 levels were decreased in the OBs, but increased in vascular endothelial C166 cells when FGF2 was administered. We hypothesized that FGF2 induces changes in HSC migration from BM; therefore, we investigated FGF2-induced factors of HSC migration by a microarray chip. We searched the genes that were decreased in primary OBs, but increased in C166 cells upon FGF2 treatment. We confirmed selected genes that function in the extracellular region and identified the CXCR2-related chemokine candidate LIX/Cxcl5. A chemotaxis assay showed that CXCL5 induced the migration of HSCs (CD34−/lowLSK). Our data suggest that the differential regulation of the chemokine CXCL5 between OBs and endothelial cells upon FGF2 treatment is involved in HSC mobilization from the OB niche or BM to peripheral blood. PMID:22827607

  12. Fancb deficiency impairs hematopoietic stem cell function

    PubMed Central

    Du, Wei; Amarachintha, Surya; Erden, Ozlem; Wilson, Andrew; Meetei, Amom Ruhikanta; Andreassen, Paul R.; Namekawa, Satoshi H.; Pang, Qishen

    2015-01-01

    Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, variable congenital malformations and a predisposition to malignancies. FANCB (also known as FAAP95), is the only X-linked FA gene discovered thus far. In the present study, we investigated hematopoiesis in adult Fancb deficient (Fancb−/y) mice and found that Fancb−/y mice have decreased hematopoietic stem cell (HSC) quiescence accompanied by reduced progenitor activity in vitro and reduced repopulating capacity in vivo. Like other FA mouse models previously reported, the hematopoietic system of Fancb−/y mice is hypersensitive to DNA cross-linking agent mitomycin C (MMC), which induces bone marrow failure in Fancb−/y mice. Furthermore, Fancb−/y BM exhibits slower recovery kinetics and less tolerance to myelotoxic stress induced by 5-fluorouracil than wild-type littermates. RNA-seq analysis reveals altered expression of genes involved in HSC function and cell cycle regulation in Fancb−/y HSC and progenitor cells. Thus, this Fancb−/y mouse model provides a novel approach for studying the critical role of the FA pathway not only in germ cell development but also in the maintenance of HSC function. PMID:26658157

  13. Functions of TET Proteins in Hematopoietic Transformation

    PubMed Central

    Han, Jae-A; An, Jungeun; Ko, Myunggon

    2015-01-01

    DNA methylation is a well-characterized epigenetic modification that plays central roles in mammalian development, genomic imprinting, X-chromosome inactivation and silencing of retrotransposon elements. Aberrant DNA methylation pattern is a characteristic feature of cancers and associated with abnormal expression of oncogenes, tumor suppressor genes or repair genes. Ten-eleven-translocation (TET) proteins are recently characterized dioxygenases that catalyze progressive oxidation of 5-methylcytosine to produce 5-hydroxymethylcytosine and further oxidized derivatives. These oxidized methylcytosines not only potentiate DNA demethylation but also behave as independent epigenetic modifications per se. The expression or activity of TET proteins and DNA hydroxymethylation are highly dysregulated in a wide range of cancers including hematologic and non-hematologic malignancies, and accumulating evidence points TET proteins as a novel tumor suppressor in cancers. Here we review DNA demethylation-dependent and -independent functions of TET proteins. We also describe diverse TET loss-of-function mutations that are recurrently found in myeloid and lymphoid malignancies and their potential roles in hematopoietic transformation. We discuss consequences of the deficiency of individual Tet genes and potential compensation between different Tet members in mice. Possible mechanisms underlying facilitated oncogenic transformation of TET-deficient hematopoietic cells are also described. Lastly, we address non-mutational mechanisms that lead to suppression or inactivation of TET proteins in cancers. Strategies to restore normal 5mC oxidation status in cancers by targeting TET proteins may provide new avenues to expedite the development of promising anti-cancer agents. PMID:26552488

  14. Epigenetic regulation of hematopoietic stem cell aging

    SciTech Connect

    Beerman, Isabel

    2014-12-10

    Aging is invariably associated with alterations of the hematopoietic stem cell (HSC) compartment, including loss of functional capacity, altered clonal composition, and changes in lineage contribution. Although accumulation of DNA damage occurs during HSC aging, it is unlikely such consistent aging phenotypes could be solely attributed to changes in DNA integrity. Another mechanism by which heritable traits could contribute to the changes in the functional potential of aged HSCs is through alterations in the epigenetic landscape of adult stem cells. Indeed, recent studies on hematopoietic stem cells have suggested that altered epigenetic profiles are associated with HSC aging and play a key role in modulating the functional potential of HSCs at different stages during ontogeny. Even small changes of the epigenetic landscape can lead to robustly altered expression patterns, either directly by loss of regulatory control or through indirect, additive effects, ultimately leading to transcriptional changes of the stem cells. Potential drivers of such changes in the epigenetic landscape of aged HSCs include proliferative history, DNA damage, and deregulation of key epigenetic enzymes and complexes. This review will focus largely on the two most characterized epigenetic marks – DNA methylation and histone modifications – but will also discuss the potential role of non-coding RNAs in regulating HSC function during aging.

  15. The biology of hematopoietic stem cells.

    PubMed

    Szilvassy, Stephen J

    2003-01-01

    Rarely has so much interest from the lay public, government, biotechnology industry, and special interest groups been focused on the biology and clinical applications of a single type of human cell as is today on stem cells, the founder cells that sustain many, if not all, tissues and organs in the body. Granting organizations have increasingly targeted stem cells as high priority for funding, and it appears clear that the evolving field of tissue engineering and regenerative medicine will require as its underpinning a thorough understanding of the molecular regulation of stem cell proliferation, differentiation, self-renewal, and aging. Despite evidence suggesting that embryonic stem (ES) cells might represent a more potent regenerative reservoir than stem cells collected from adult tissues, ethical considerations have redirected attention upon primitive cells residing in the bone marrow, blood, brain, liver, muscle, and skin, from where they can be harvested with relative sociological impunity. Among these, it is arguably the stem and progenitor cells of the mammalian hematopoietic system that we know most about today, and their intense study in rodents and humans over the past 50 years has culminated in the identification of phenotypic and molecular genetic markers of lineage commitment and the development of functional assays that facilitate their quantitation and prospective isolation. This review focuses exclusively on the biology of hematopoietic stem cells (HSCs) and their immediate progeny. Nevertheless, many of the concepts established from their study can be considered fundamental tenets of an evolving stem cell paradigm applicable to many regenerating cellular systems. PMID:14734085

  16. CXCR4 inhibitor AMD3100 disrupts the interaction of multiple myeloma cells with the bone marrow microenvironment and enhances their sensitivity to therapy

    PubMed Central

    Azab, Abdel Kareem; Runnels, Judith M.; Pitsillides, Costas; Moreau, Anne-Sophie; Azab, Feda; Leleu, Xavier; Jia, Xiaoying; Wright, Renee; Ospina, Beatriz; Carlson, Alicia L.; Alt, Clemens; Burwick, Nicholas; Roccaro, Aldo M.; Ngo, Hai T.; Farag, Mena; Melhem, Molly R.; Sacco, Antonio; Munshi, Nikhil C.; Hideshima, Teru; Rollins, Barrett J.; Anderson, Kenneth C.; Kung, Andrew L.

    2009-01-01

    The interaction of multiple myeloma (MM) cells with their microenvironment in the bone marrow (BM) provides a protective environment and resistance to therapeutic agents. We hypothesized that disruption of the interaction of MM cells with their BM milieu would lead to their sensitization to therapeutic agents such as bortezomib, melphalan, doxorubicin, and dexamethasone. We report that the CXCR4 inhibitor AMD3100 induces disruption of the interaction of MM cells with the BM reflected by mobilization of MM cells into the circulation in vivo, with kinetics that differed from that of hematopoietic stem cells. AMD3100 enhanced sensitivity of MM cell to multiple therapeutic agents in vitro by disrupting adhesion of MM cells to bone marrow stromal cells (BMSCs). Moreover, AMD3100 increased mobilization of MM cells to the circulation in vivo, increased the ratio of apoptotic circulating MM cells, and enhanced the tumor reduction induced by bortezomib. Mechanistically, AMD3100 significantly inhibited Akt phosphorylation and enhanced poly(ADP-ribose) polymerase (PARP) cleavage as a result of bortezomib, in the presence of BMSCs in coculture. These experiments provide a proof of concept for the use of agents that disrupt interaction with the microenvironment for enhancement of efficacy of cytotoxic agents in cancer therapy. PMID:19139079

  17. Bioengineering paradigms for cell migration in confined microenvironments.

    PubMed

    Stroka, Kimberly M; Gu, Zhizhan; Sun, Sean X; Konstantopoulos, Konstantinos

    2014-10-01

    Cell migration is a fundamental process underlying diverse (patho)physiological phenomena. The classical understanding of the molecular mechanisms of cell migration has been based on in vitro studies on two-dimensional substrates. More recently, mounting evidence from intravital studies has shown that during metastasis, tumor cells must navigate complex microenvironments in vivo, including narrow, pre-existing microtracks created by anatomical structures. It is becoming apparent that unraveling the mechanisms of confined cell migration in this context requires a multi-disciplinary approach through integration of in vivo and in vitro studies, along with sophisticated bioengineering techniques and mathematical modeling. Here, we highlight such an approach that has led to discovery of a new model for cell migration in confined microenvironments (i.e., the Osmotic Engine Model). PMID:24973724

  18. Tumor microenvironment: The culprit for ovarian cancer metastasis?

    PubMed

    Luo, Zhongyue; Wang, Qiu; Lau, Wayne Bond; Lau, Bonnie; Xu, Lian; Zhao, Linjie; Yang, Huiliang; Feng, Min; Xuan, Yu; Yang, Yanfei; Lei, Lingzi; Wang, Chenlu; Yi, Tao; Zhao, Xia; Wei, Yuquan; Zhou, Shengtao

    2016-07-28

    Despite chemotherapy and surgical debulking options, ovarian cancer recurs and disseminates frequently, with poor prognosis. However, the molecular mechanisms underlying ovarian cancer metastasis still remain unelucidated. The tumor microenvironment, consisting of stromal cells (including fibroblasts, macrophages, regulatory T cells, myeloid-derived suppressor cells, endothelial cells, pericytes and platelets), the extracellular matrix component (EMC) (including inflammatory cytokines, chemokines, matrix metalloproteinases, integrins, and other secreted molecules) and exosomes (small extracellular vesicles loaded with molecules), establishes an autocrine-paracrine communication circuit that reinforces invasion and cancer cell metastasis via reciprocal signaling. Recent evidences have unraveled the significant contribution of tumor microenvironment to ovarian cancer metastasis. In this review, we provide a comprehensive landscape of the reciprocity between tumor stroma and ovarian cancer cells upon metastasis, aiming to offer novel clues on the development of novel diagnostic biomarkers and therapeutic targets for ovarian cancer in future clinical practice. PMID:27131957

  19. Molecular imaging of tumor microenvironment: challenges and perspectives.

    PubMed

    Del Vecchio, S; Zannetti, A; Iommelli, F; Lettieri, A; Brunetti, A; Salvatore, M

    2010-06-01

    Tumor microenvironment consists of a number of components including host resident stromal cells, infiltrating immune cells and extracellular matrix. The architecture surrounding tumor cells is not static but is subjected to a continuous remodeling in response to the dynamic interplay between tumor and stromal cells and to the production of extracellular proteases. In addition all these microenvironmental components along with cancer cells are exposed to abnormal physiologic conditions such as hypoxia and acidic extracellular pH that may induce both adaptive and constitutive changes in cancer and stromal cells. In this review, we will primarily focus on the possibility to visualize in vivo tumor microenvironment components and conditions as well as interactions with cancer cells. The major goal is to highlight the difficulties and the opportunities of this approach and how each imaging technology helps to overcome specific challenge. PMID:20639812

  20. Molecular Connections between Cancer Cell Metabolism and the Tumor Microenvironment

    PubMed Central

    Justus, Calvin R.; Sanderlin, Edward J.; Yang, Li V.

    2015-01-01

    Cancer cells preferentially utilize glycolysis, instead of oxidative phosphorylation, for metabolism even in the presence of oxygen. This phenomenon of aerobic glycolysis, referred to as the “Warburg effect”, commonly exists in a variety of tumors. Recent studies further demonstrate that both genetic factors such as oncogenes and tumor suppressors and microenvironmental factors such as spatial hypoxia and acidosis can regulate the glycolytic metabolism of cancer cells. Reciprocally, altered cancer cell metabolism can modulate the tumor microenvironment which plays important roles in cancer cell somatic evolution, metastasis, and therapeutic response. In this article, we review the progression of current understandings on the molecular interaction between cancer cell metabolism and the tumor microenvironment. In addition, we discuss the implications of these interactions in cancer therapy and chemoprevention. PMID:25988385

  1. Metabolomics Analyses of Cancer Cells in Controlled Microenvironments.

    PubMed

    Gravel, Simon-Pierre; Avizonis, Daina; St-Pierre, Julie

    2016-01-01

    The tumor microenvironment is a complex and heterogeneous milieu in which cancer cells undergo metabolic reprogramming to fuel their growth. Cancer cell lines grown in vitro using traditional culture methods represent key experimental models to gain a mechanistic understanding of tumor biology. This protocol describes the use of gas chromatography-mass spectrometry (GC-MS) to assess metabolic changes in cancer cells grown under varied levels of oxygen and nutrients that may better mimic the tumor microenvironment. Intracellular metabolite changes, metabolite uptake and release, as well as stable isotope ((13)C) tracer analyses are done in a single experimental setup to provide an integrated understanding of metabolic adaptation. Overall, this chapter describes some essential tools and methods to perform comprehensive metabolomics analyses. PMID:27581029

  2. Impact of the physical microenvironment on tumor progression and metastasis.

    PubMed

    Spill, Fabian; Reynolds, Daniel S; Kamm, Roger D; Zaman, Muhammad H

    2016-08-01

    The tumor microenvironment is increasingly understood to contribute to cancer development and progression by affecting the complex interplay of genetic and epigenetic changes within the cells themselves. Moreover, recent research has highlighted that, besides biochemical cues from the microenvironment, physical cues can also greatly alter cellular behavior such as proliferation, cancer stem cell properties, and metastatic potential. Whereas initial assays have focused on basic ECM physical properties, such as stiffness, novel in vitro systems are becoming increasingly sophisticated in differentiating between distinct physical cues-ECM pore size, fiber alignment, and molecular composition-and elucidating the different roles these properties play in driving tumor progression and metastasis. Combined with advances in our understanding of the mechanisms responsible for how cells sense these properties, a new appreciation for the role of mechanics in cancer is emerging. PMID:26938687

  3. Challenges in Immunotherapy Presented by the Glioblastoma Multiforme Microenvironment

    PubMed Central

    Jackson, Christopher; Ruzevick, Jacob; Phallen, Jillian; Belcaid, Zineb; Lim, Michael

    2011-01-01

    Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite intensive treatment, the prognosis for patients with GBM remains grim with a median survival of only 14.6 months. Immunotherapy has emerged as a promising approach for treating many cancers and affords the advantages of cellular-level specificity and the potential to generate durable immune surveillance. The complexity of the tumor microenvironment poses a significant challenge to the development of immunotherapy for GBM, as multiple signaling pathways, cytokines, and cell types are intricately coordinated to generate an immunosuppressive milieu. The development of new immunotherapy approaches frequently uncovers new mechanisms of tumor-mediated immunosuppression. In this review, we discuss many of the current approaches to immunotherapy and focus on the challenges presented by the tumor microenvironment. PMID:22190972

  4. Assembly of complex cell microenvironments using geometrically docked hydrogel shapes

    PubMed Central

    Eng, George; Lee, Benjamin W.; Parsa, Hesam; Chin, Curtis D.; Schneider, Jesse; Linkov, Gary; Sia, Samuel K.; Vunjak-Novakovic, Gordana

    2013-01-01

    Cellular communities in living tissues act in concert to establish intricate microenvironments, with complexity difficult to recapitulate in vitro. We report a method for docking numerous cellularized hydrogel shapes (100–1,000 µm in size) into hydrogel templates to construct 3D cellular microenvironments. Each shape can be uniquely designed to contain customizable concentrations of cells and molecular species, and can be placed into any spatial configuration, providing extensive compositional and geometric tunability of shape-coded patterns using a highly biocompatible hydrogel material. Using precisely arranged hydrogel shapes, we investigated migratory patterns of human mesenchymal stem cells and endothelial cells. We then developed a finite element gradient model predicting chemotactic directions of cell migration in micropatterned cocultures that were validated by tracking ∼2,500 individual cell trajectories. This simple yet robust hydrogel platform provides a comprehensive approach to the assembly of 3D cell environments. PMID:23487790

  5. Microenvironment-Driven Resistance to BRAF Inhibition Comes of Age.

    PubMed

    Menon, Dinoop Ravindran; Schaider, Helmut

    2015-12-01

    Increasingly comprehensive observations indicate that the tumor microenvironment contributes to drug resistance toward small molecule inhibitors. Fedorenko et al. describe a role for fibroblasts in creating a favorable niche for melanoma cell survival if treated with the BRAF inhibitor vemurafenib. TGF-β released by vemurafenib-treated melanoma cells stimulated fibroblasts for increased α-smooth muscle actin, neuregulin (NRG), and fibronectin expression. Off-target effects of vemurafenib led to paradoxical secretion of hepatocyte growth factor (HGF) by fibroblasts. Combined inhibition of BRAF/MET/HER kinases was insufficient to reverse the protective effect of the fibroblasts, whereas reversal was achieved by combined BRAF/PI3K inhibition. A thorough understanding of the complex spatiotemporal interactions in tumor microenvironments holds promise for improved targeting using combination therapies in patients with melanoma. PMID:26569587

  6. Bioengineering Paradigms for Cell Migration in Confined Microenvironments

    PubMed Central

    Stroka, Kimberly M.; Gu, Zhizhan; Sun, Sean X.; Konstantopoulos, Konstantinos

    2014-01-01

    Cell migration is a fundamental process underlying diverse (patho)physiological phenomena. The classical understanding of the molecular mechanisms of cell migration has been based on in vitro studies on two-dimensional substrates. More recently, mounting evidence from intravital studies has shown that during metastasis, tumor cells must navigate complex microenvironments in vivo, including narrow, pre-existing microtracks created by anatomical structures. It is becoming apparent that unraveling the mechanisms of confined cell migration in this context requires a multi-disciplinary approach through integration of in vivo and in vitro studies, along with sophisticated bioengineering techniques and mathematical modeling. Here, we highlight such an approach that has led to discovery of a new model for cell migration in confined microenvironments (i.e., the Osmotic Engine Model). PMID:24973724

  7. A supramolecular microenvironment strategy for transition metal catalysis.

    PubMed

    Kaphan, David M; Levin, Mark D; Bergman, Robert G; Raymond, Kenneth N; Toste, F Dean

    2015-12-01

    A self-assembled supramolecular complex is reported to catalyze alkyl-alkyl reductive elimination from high-valent transition metal complexes [such as gold(III) and platinum(IV)], the central bond-forming elementary step in many catalytic processes. The catalytic microenvironment of the supramolecular assembly acts as a functional enzyme mimic, applying the concepts of enzymatic catalysis to a reactivity manifold not represented in biology. Kinetic experiments delineate a Michaelis-Menten-type mechanism, with measured rate accelerations (k(cat)/k(uncat)) up to 1.9 × 10(7) (here k(cat) and k(uncat) are the Michaelis-Menten enzymatic rate constant and observed uncatalyzed rate constant, respectively). This modality has further been incorporated into a dual catalytic cross-coupling reaction, which requires both the supramolecular microenvironment catalyst and the transition metal catalyst operating in concert to achieve efficient turnover. PMID:26785485

  8. Tumor microenvironment-specific nanoparticles activatable by stepwise transformation.

    PubMed

    Ko, Hyewon; Son, Soyoung; Jeon, Jueun; Thambi, Thavasyappan; Kwon, Seunglee; Chae, Yee Soo; Kang, Young Mo; Park, Jae Hyung

    2016-07-28

    In an attempt to develop the tumor-targeted nanocarrier which can surmount major challenges for in vivo application, we prepared tumor microenvironment-specific nanoparticles which can be sequentially activated at the extracellular and intracellular levels of tumor tissue by stepwise transformation. This polymeric nanoparticle has been prepared using an amphiphilic polyethyleneimine derivative with the pH-responsive charge-convertible moiety and the reduction-responsive crosslink. Once reaching the tumor tissue in vivo after systemic administration, the surface charge of this nanoparticle can be converted from negative to positive by recognizing the mildly acidic extracellular matrix of tumor, allowing for the enhanced cellular uptake. After the cellular uptake, the nanoparticle can selectively release the drug at the intracellular level since it has the chemically crosslinked core by the disulfide bond which is cleaved in intracellular reductive environment. The tumor microenvironment-specific nanoparticle shows the high tumor targetability and dramatically improves the antitumor efficacy of the drug. PMID:27164544

  9. Modulation of the Tumor Microenvironment for Cancer Treatment: A Biomaterials Approach

    PubMed Central

    Adjei, Isaac M.; Blanka, Sharma

    2015-01-01

    Tumors are complex tissues that consist of stromal cells, such as fibroblasts, immune cells and mesenchymal stem cells, as well as non-cellular components, in addition to neoplastic cells. Increasingly, there is evidence to suggest that these non-neoplastic cell components support cancer initiation, progression and metastasis and that their ablation or reprogramming can inhibit tumor growth. Our understanding of the activities of different parts of the tumor stroma in advancing cancer has been improved by the use of scaffold and matrix-based 3D systems originally developed for regenerative medicine. Additionally, drug delivery systems made from synthetic and natural biomaterials deliver drugs to kill stromal cells or reprogram the microenvironment for tumor inhibition. In this article, we review the impact of 3D tumor models in increasing our understanding of tumorigenesis. We also discuss how different drug delivery systems aid in the reprogramming of tumor stroma for cancer treatment. PMID:25695337

  10. Novel methods for accurate identification, isolation, and genomic analysis of symptomatic microenvironments in atherosclerotic arteries.

    PubMed

    Slevin, Mark; Baldellou, Maribel; Hill, Elspeth; Alexander, Yvonne; McDowell, Garry; Murgatroyd, Christopher; Carroll, Michael; Degens, Hans; Krupinski, Jerzy; Rovira, Norma; Chowdhury, Mohammad; Serracino-Inglott, Ferdinand; Badimon, Lina

    2014-01-01

    A challenge facing surgeons is identification and selection of patients for carotid endarterectomy or coronary artery bypass/surgical intervention. While some patients with atherosclerosis develop unstable plaques liable to undergo thrombosis, others form more stable plaques and are asymptomatic. Identification of the cellular signaling mechanisms associated with production of the inflammatory, hemorrhagic lesions of mature heterogenic plaques will help significantly in our understanding of the differences in microenvironment associated with development of regions susceptible to rupture and thrombosis and may help to predict the risk of plaque rupture and guide surgical intervention to patients who will most benefit. Here, we demonstrate detailed and novel methodologies for successful and, more importantly, accurate and reproducible extraction, sampling, and analysis of micro-regions in stable and unstable coronary/carotid arteries. This information can be applied to samples from other origins and so should be useful for scientists working with micro-isolation techniques in all fields of biomedical science. PMID:24510873

  11. The Adipose Tissue Microenvironment Regulates Depot-Specific Adipogenesis in Obesity.

    PubMed

    Jeffery, Elise; Wing, Allison; Holtrup, Brandon; Sebo, Zachary; Kaplan, Jennifer L; Saavedra-Peña, Rocio; Church, Christopher D; Colman, Laura; Berry, Ryan; Rodeheffer, Matthew S

    2016-07-12

    The sexually dimorphic distribution of adipose tissue influences the development of obesity-associated pathologies. The accumulation of visceral white adipose tissue (VWAT) that occurs in males is detrimental to metabolic health, while accumulation of subcutaneous adipose tissue (SWAT) seen in females may be protective. Here, we show that adipocyte hyperplasia contributes directly to the differential fat distribution between the sexes. In male mice, high-fat diet (HFD) induces adipogenesis specifically in VWAT, while in females HFD induces adipogenesis in both VWAT and SWAT in a sex hormone-dependent manner. We also show that the activation of adipocyte precursors (APs), which drives adipocyte hyperplasia in obesity, is regulated by the adipose depot microenvironment and not by cell-intrinsic mechanisms. These findings indicate that APs are plastic cells, which respond to both local and systemic signals that influence their differentiation potential independent of depot origin. Therefore, depot-specific AP niches coordinate adipose tissue growth and distribution. PMID:27320063

  12. Omental sclerosing extramedullary hematopoietic tumors in Janus kinase-2 negative myelofibrosis: caveat at frozen section.

    PubMed

    Shinde, Sweety V; Shenoy, Asha S; Balsarkar, Dharmesh J; Shah, Vinaya B

    2014-01-01

    Sclerosing extramedullary hematopoietic tumors (SEMHTs) are associated with chronic myeloproliferative neoplasms. These extremely rare mass lesions were first described in kidney and peritoneum. On histopathology, they are characterized by sclerosis, entrapped fat, atypical megakaryocytes with myeloid and erythroid elements. Only approximately ten cases have been subsequently reported in orbit, lacrimal system, liver, omentum, and skin. The authors present a case of SEMHTs as incidentally detected omental nodules, while the patient was undergoing splenectomy for Janus kinase-2 negative myelofibrosis. The authors postulate their origin in omentum-associated lymphoid tissue; and highlight the diagnostic dilemma presented by SEMHTs at frozen section. PMID:25118752

  13. Pleiotrophin mediates hematopoietic regeneration via activation of RAS.

    PubMed

    Himburg, Heather A; Yan, Xiao; Doan, Phuong L; Quarmyne, Mamle; Micewicz, Eva; McBride, William; Chao, Nelson J; Slamon, Dennis J; Chute, John P

    2014-11-01

    Hematopoietic stem cells (HSCs) are highly susceptible to ionizing radiation-mediated death via induction of ROS, DNA double-strand breaks, and apoptotic pathways. The development of therapeutics capable of mitigating ionizing radiation-induced hematopoietic toxicity could benefit both victims of acute radiation sickness and patients undergoing hematopoietic cell transplantation. Unfortunately, therapies capable of accelerating hematopoietic reconstitution following lethal radiation exposure have remained elusive. Here, we found that systemic administration of pleiotrophin (PTN), a protein that is secreted by BM-derived endothelial cells, substantially increased the survival of mice following radiation exposure and after myeloablative BM transplantation. In both models, PTN increased survival by accelerating the recovery of BM hematopoietic stem and progenitor cells in vivo. PTN treatment promoted HSC regeneration via activation of the RAS pathway in mice that expressed protein tyrosine phosphatase receptor-zeta (PTPRZ), whereas PTN treatment did not induce RAS signaling in PTPRZ-deficient mice, suggesting that PTN-mediated activation of RAS was dependent upon signaling through PTPRZ. PTN strongly inhibited HSC cycling following irradiation, whereas RAS inhibition abrogated PTN-mediated induction of HSC quiescence, blocked PTN-mediated recovery of hematopoietic stem and progenitor cells, and abolished PTN-mediated survival of irradiated mice. These studies demonstrate the therapeutic potential of PTN to improve survival after myeloablation and suggest that PTN-mediated hematopoietic regeneration occurs in a RAS-dependent manner. PMID:25250571

  14. An Mll-dependent Hox program drives hematopoietic progenitor expansion.

    PubMed

    Ernst, Patricia; Mabon, Meghann; Davidson, Alan J; Zon, Leonard I; Korsmeyer, Stanley J

    2004-11-23

    Chromosomal translocations disrupting the Mixed lineage leukemia (Mll) gene result in leukemia, with aberrant expression of some native Mll target genes (reviewed in). The Mll gene encodes a Trithorax-group chromatin regulator that is essential for the development of hematopoietic stem cells (HSCs) during embryogenesis. Like Trithorax, MLL positively regulates clustered homeodomain or Hox genes, yet the role of Hox genes collectively in the development of the mammalian hematopoietic system has been difficult to ascertain because of redundancy among Hox paralogs. Here, we show that in the absence of MLL, early hematopoietic progenitors develop despite reduced expression of HoxA, HoxB, and HoxC genes. However, these progenitors exhibit a marked reduction in their ability to generate hematopoietic colonies, a subsequent process requiring cell division and differentiation. Reactivation of a subset of Hox genes or, remarkably, reexpression of a single Hox gene in Mll-deficient progenitors rescued hematopoietic-colony frequency and growth. In contrast, expression of other MLL target genes such as Pitx2 or expression of anti-apoptotic BCL-2 failed to rescue hematopoietic-colony frequency. Furthermore, our results highlight a shared function of Hox proteins at this point in the development of the hematopoietic system. PMID:15556871

  15. Thymic and peripheral microenvironments differentially mediate development and maturation of iNKT cells by IL-15 transpresentation.

    PubMed

    Castillo, Eliseo F; Acero, Luis F; Stonier, Spencer W; Zhou, Dapeng; Schluns, Kimberly S

    2010-10-01

    Invariant NKT (iNKT) cells are an innate type of T cells, which respond rapidly on activation. iNKT cells acquire these innate-like abilities during development; however, the signals driving development and functional maturation remain only partially understood. Because interleukin-15 (IL-15) is crucial for iNKT development and is delivered by transpresentation, we set out to identify the cell types providing IL-15 to developing iNKT cells and determine their role at the various states of development and maturation. We report here that transpresentation of IL-15 by parenchymal cells was crucial for generating normal number of iNKTs in the thymus, whereas both hematopoietic and parenchymal cells regulated iNKT cell numbers in the periphery, particularly in the liver. Specifically, dendritic cells contributed to peripheral iNKT cell numbers by up-regulating Bcl-2 expression and promoting extrathymic iNKT cell ex-pansion and their homeostatic proliferation. Whether IL-15 affects functional maturation of iNKT cells was also examined. In IL-15Rα(-/-) mice, CD44(High)NK1.1(+) iNKT cells displayed decreased T-bet expression and in response to α-galactosylceramide, had deficient interferon-γ expression. Such defects could be reversed by exogenous IL-15 signals. Overall, these studies identify stage-specific functions of IL-15, which are determined by the tissue microenvironment and elucidate the importance of IL-15 in functional maturation. PMID:20581314

  16. Thymic and peripheral microenvironments differentially mediate development and maturation of iNKT cells by IL-15 transpresentation

    PubMed Central

    Castillo, Eliseo F.; Acero, Luis F.; Stonier, Spencer W.; Zhou, Dapeng

    2010-01-01

    Invariant NKT (iNKT) cells are an innate type of T cells, which respond rapidly on activation. iNKT cells acquire these innate-like abilities during development; however, the signals driving development and functional maturation remain only partially understood. Because interleukin-15 (IL-15) is crucial for iNKT development and is delivered by transpresentation, we set out to identify the cell types providing IL-15 to developing iNKT cells and determine their role at the various states of development and maturation. We report here that transpresentation of IL-15 by parenchymal cells was crucial for generating normal number of iNKTs in the thymus, whereas both hematopoietic and parenchymal cells regulated iNKT cell numbers in the periphery, particularly in the liver. Specifically, dendritic cells contributed to peripheral iNKT cell numbers by up-regulating Bcl-2 expression and promoting extrathymic iNKT cell ex-pansion and their homeostatic proliferation. Whether IL-15 affects functional maturation of iNKT cells was also examined. In IL-15Rα−/− mice, CD44HighNK1.1+ iNKT cells displayed decreased T-bet expression and in response to α-galactosylceramide, had deficient interferon-γ expression. Such defects could be reversed by exogenous IL-15 signals. Overall, these studies identify stage-specific functions of IL-15, which are determined by the tissue microenvironment and elucidate the importance of IL-15 in functional maturation. PMID:20581314

  17. Acidic microenvironment and bone pain in cancer-colonized bone

    PubMed Central

    Yoneda, Toshiyuki; Hiasa, Masahiro; Nagata, Yuki; Okui, Tatsuo; White, Fletcher A

    2015-01-01

    Solid cancers and hematologic cancers frequently colonize bone and induce skeletal-related complications. Bone pain is one of the most common complications associated with cancer colonization in bone and a major cause of increased morbidity and diminished quality of life, leading to poor survival in cancer patients. Although the mechanisms responsible for cancer-associated bone pain (CABP) are poorly understood, it is likely that complex interactions among cancer cells, bone cells and peripheral nerve cells contribute to the pathophysiology of CABP. Clinical observations that specific inhibitors of osteoclasts reduce CABP indicate a critical role of osteoclasts. Osteoclasts are proton-secreting cells and acidify extracellular bone microenvironment. Cancer cell-colonized bone also releases proton/lactate to avoid intracellular acidification resulting from increased aerobic glycolysis known as the Warburg effect. Thus, extracellular microenvironment of cancer-colonized bone is acidic. Acidosis is algogenic for nociceptive sensory neurons. The bone is densely innervated by the sensory neurons that express acid-sensing nociceptors. Collectively, CABP is evoked by the activation of these nociceptors on the sensory neurons innervating bone by the acidic extracellular microenvironment created by bone-resorbing osteoclasts and bone-colonizing cancer cells. As current treatments do not satisfactorily control CABP and can elicit serious side effects, new therapeutic interventions are needed to manage CABP. Understanding of the cellular and molecular mechanism by which the acidic extracellular microenvironment is created in cancer-colonized bone and by which the expression and function of the acid-sensing nociceptors on the sensory neurons are regulated would facilitate to develop novel therapeutic approaches for the management of CABP. PMID:25987988

  18. Hematopoietic stem cell transplantation for auto immune rheumatic diseases.

    PubMed

    Ramaswamy, Subramanian; Jain, Sandeep; Ravindran, Vinod

    2016-03-24

    Stem cells have their origins in the embryo and during the process of organogenesis, these differentiate into specialized cells which mature to form tissues. In addition, stem cell are characterized by an ability to indefinitely self renew. Stem cells are broadly classified into embryonic stem cells and adult stem cells. Adult stem cells can be genetically reprogrammed to form pluripotent stem cells and exist in an embroyonic like state. In the early phase of embryogenesis, human embryonic stem cells only exist transiently. Adult stem cells are omnipresent in the body and function to regenerate during the process of apoptosis or tissue repair. Hematopoietic stem cells (HSC) are adult stem cells that form blood and immune cells. Autoimmune responses are sustained due to the perennial persistence of tissue self autoantigens and/or auto reactive lymphocytes. Immune reset is a process leading to generation of fresh self-tolerant lymphocytes after chemotherapy induced elimination of self or autoreactive lymphocytes. This forms the basis for autologous HSC transplantation (HSCT). In the beginning HSCT had been limited to refractory autoimmune rheumatic diseases (AIRD) due to concern about transplant related mortality and morbidity. However HSCT for AIRD has come a long way with better understanding of patient selection, conditioning regime and supportive care. In this narrative review we have examined the available literature regarding the HSCT use in AIRD. PMID:27011918

  19. Hematopoietic stem cells give rise to osteo-chondrogenic cells

    PubMed Central

    Mehrotra, Meenal; Williams, Christopher R.; Ogawa, Makio; LaRue, Amanda C.

    2012-01-01

    Repair of bone fracture requires recruitment and proliferation of stem cells with the capacity to differentiate to functional osteoblasts. Given the close association of bone and bone marrow (BM), it has been suggested that BM may serve as a source of these progenitors. To test the ability of hematopoietic stem cells (HSCs) to give rise to osteo-chondrogenic cells, we used a single HSC transplantation paradigm in uninjured bone and in conjunction with a tibial fracture model. Mice were lethally irradiated and transplanted with a clonal population of cells derived from a single enhanced green fluorescent protein positive (eGFP+) HSC. Analysis of paraffin sections from these animals showed the presence of eGFP+ osteocytes and hypertrophic chondrocytes. To determine the contribution of HSC-derived cells to fracture repair, non-stabilized tibial fracture was created. Paraffin sections were examined at seven days, two weeks and two months after fracture and eGFP+ hypertrophic chondrocytes, osteoblasts and osteocytes were identified at the callus site. These cells stained positive for Runx-2 or osteocalcin and also stained for eGFP demonstrating their origin from the HSC. Together, these findings strongly support the concept that HSCs generate bone cells and suggest therapeutic potentials of HSCs in fracture repair. PMID:22954476

  20. Hematopoietic stem cell transplantation for auto immune rheumatic diseases

    PubMed Central

    Ramaswamy, Subramanian; Jain, Sandeep; Ravindran, Vinod

    2016-01-01

    Stem cells have their origins in the embryo and during the process of organogenesis, these differentiate into specialized cells which mature to form tissues. In addition, stem cell are characterized by an ability to indefinitely self renew. Stem cells are broadly classified into embryonic stem cells and adult stem cells. Adult stem cells can be genetically reprogrammed to form pluripotent stem cells and exist in an embroyonic like state. In the early phase of embryogenesis, human embryonic stem cells only exist transiently. Adult stem cells are omnipresent in the body and function to regenerate during the process of apoptosis or tissue repair. Hematopoietic stem cells (HSC) are adult stem cells that form blood and immune cells. Autoimmune responses are sustained due to the perennial persistence of tissue self autoantigens and/or auto reactive lymphocytes. Immune reset is a process leading to generation of fresh self-tolerant lymphocytes after chemotherapy induced elimination of self or autoreactive lymphocytes. This forms the basis for autologous HSC transplantation (HSCT). In the beginning HSCT had been limited to refractory autoimmune rheumatic diseases (AIRD) due to concern about transplant related mortality and morbidity. However HSCT for AIRD has come a long way with better understanding of patient selection, conditioning regime and supportive care. In this narrative review we have examined the available literature regarding the HSCT use in AIRD. PMID:27011918

  1. Composite alginate gels for tunable cellular microenvironment mechanics

    NASA Astrophysics Data System (ADS)

    Khavari, Adele; Nydén, Magnus; Weitz, David A.; Ehrlicher, Allen J.

    2016-08-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation.

  2. Obesity, metabolism and the microenvironment: Links to cancer

    PubMed Central

    Sundaram, Sneha; Johnson, Amy R.; Makowski, Liza

    2013-01-01

    Historically, cancer research has focused on identifying mutations or amplification of genes within the tumor, which informed the development of targeted therapies against affected pathways. This work often considers tumor cells in isolation; however, it is becoming increasingly apparent that the microenvironment surrounding tumor cells strongly influences tumor onset and progression. This is the so-called “seed and soil” hypothesis wherein the seed (cancer cell) is fed and molded by the metabolites, growth factors, modifications of the extracellular matrix or angiogenic factors provided by the soil (or stroma). Currently, 65% of the US population is obese or overweight; similarly staggering figures are reported in US children and globally. Obesity mediates and can exacerbate, both normal and tumor microenvironment dysfunction. Many obesity-associated endocrine, metabolic and inflammatory mediators are suspected to play a role in oncogenesis by modifying systemic nutrient metabolism and the nutrient substrates available locally in the stroma. It is vitally important to understand the biological processes linking obesity and cancer to develop better intervention strategies aimed at curbing the carcinogenic events associated with obesity. In this review, obesity-driven changes in both the normal and tumor microenvironment, alterations in metabolism, and release of signaling molecules such as endocrine, growth, and inflammatory mediators will be highlighted. In addition, we will discuss the effects of the timing of obesity onset or particular “windows of susceptibility,” with a focus on breast cancer etiology. PMID:24227994

  3. Impact of tumor microenvironment on oncolytic viral therapy

    PubMed Central

    Wojton, Jeffrey; Kaur, Balveen

    2010-01-01

    Interactions between tumor cells and their microenvironment have been shown to play a very significant role in the initiation, progression, and invasiveness of cancer. These tumor-stromal interactions are capable of altering the delivery and effectiveness of therapeutics into the tumor and are also known to influence future resistance and re-growth after treatment. Here we review recent advances in the understanding of the tumor microenvironment and its response to oncolytic viral therapy. The multifaceted environmental response to viral therapy can influence viral infection, replication, and propagation within the tumor. Recent studies have unveiled the complicated temporal changes in the tumor vasculature post OV treatment, and their impact on tumor biology. Similarly, the secreted extracellular matrix in solid tumors can affect both infection and spread of the therapeutic virus. Together, these complex changes in the tumor microenvironment also modulate the activation of the innate antiviral host immune response, leading to quick and efficient viral clearance. In order to combat these detrimental responses, viruses have been combined with pharmacological adjuvants and “armed” with therapeutic genes in order to suppress the pernicious environmental conditions following therapy. In this review we will discuss the impact of the tumor environment on viral therapy and examine some of the recent literature investigating methods of modulating this environment to enhance oncolysis. PMID:20399700

  4. Cellular microenvironment modulates the galvanotaxis of brain tumor initiating cells

    PubMed Central

    Huang, Yu-Ja; Hoffmann, Gwendolyn; Wheeler, Benjamin; Schiapparelli, Paula; Quinones-Hinojosa, Alfredo; Searson, Peter

    2016-01-01

    Galvanotaxis is a complex process that represents the collective outcome of various contributing mechanisms, including asymmetric ion influxes, preferential activation of voltage-gated channels, and electrophoretic redistribution of membrane components. While a large number of studies have focused on various up- and downstream signaling pathways, little is known about how the surrounding microenvironment may interact and contribute to the directional response. Using a customized galvanotaxis chip capable of carrying out experiments in both two- and three-dimensional microenvironments, we show that cell-extracellular matrix (ECM) interactions modulate the galvanotaxis of brain tumor initiating cells (BTICs). Five different BTICs across three different glioblastoma subtypes were examined and shown to all migrate toward the anode in the presence of a direct-current electric field (dcEF) when cultured on a poly-L-ornithine/laminin coated surface, while the fetal-derived neural progenitor cells (fNPCs) migrated toward the cathode. Interestingly, when embedded in a 3D ECM composed of hyaluronic acid and collagen, BTICs exhibited opposite directional response and migrated toward the cathode. Pharmacological inhibition against a panel of key molecules involved in galvanotaxis further revealed the mechanistic differences between 2- and 3D galvanotaxis in BTICs. Both myosin II and phosphoinositide 3-kinase (PI3K) were found to hold strikingly different roles in different microenvironments. PMID:26898606

  5. Follicular Lymphoma: The Role of the Tumor Microenvironment in Prognosis.

    PubMed

    Sugimoto, Takumi; Watanabe, Takashi

    2016-01-01

    The microenvironment of follicular lymphoma (FL) is composed of tumor-infiltrating CD8(+) T cells, follicular regulatory T cells, lymphoma-associated macrophages and mast cells, follicular helper T cells, follicular dendritic cells, and follicular reticular cells, all of which have been reported to have relevance in the prognosis of FL patients. In addition, some of these cells play a role in the histologic transformation of FL. Macrophages contribute to a poor prognosis in FL patients treated in the pre-rituximab era, but are associated with good prognosis in those treated in the rituximab era. T-cell immunoglobulin and mucin domain protein (TIM) 3 are markers of T-cell exhaustion, and T cells co-expressing programed death 1 (PD1) in peripheral blood and lymph nodes secrete interleukin (IL)-12 in the serum. Serum CXCL9, IL-2 receptor, and IL-1 receptor agonist are associated with shorter survival of FL patients. Agents for manipulation of the microenvironment surrounding FL cells include the immunomodulatory drug lenalidomide, immune check-point inhibitors, and cyclophosphamide prior to rituximab. To battle FL and to improve the outcomes of FL patients, understanding the relationship between neoplastic cells and the various microenvironmental cellular components is crucial for developing therapeutics against the microenvironment. PMID:27334853

  6. Proteoglycans in cancer biology, tumour microenvironment and angiogenesis

    PubMed Central

    Iozzo, Renato V; Sanderson, Ralph D

    2011-01-01

    Proteoglycans, key molecular effectors of cell surface and pericellular microenvironments, perform multiple functions in cancer and angiogenesis by virtue of their polyhedric nature and their ability to interact with both ligands and receptors that regulate neoplastic growth and neovascularization. Some proteoglycans such as perlecan, have pro- and anti-angiogenic activities, whereas other proteoglycans, such as syndecans and glypicans, can also directly affect cancer growth by modulating key signalling pathways. The bioactivity of these proteoglycans is further modulated by several classes of enzymes within the tumour microenvironment: (i) sheddases that cleave transmembrane or cell-associated syndecans and glypicans, (ii) various proteinases that cleave the protein core of pericellular proteoglycans and (iii) heparanases and endosulfatases which modify the structure and bioactivity of various heparan sulphate proteoglycans and their bound growth factors. In contrast, some of the small leucine-rich proteoglycans, such as decorin and lumican, act as tumour repressors by physically antagonizing receptor tyrosine kinases including the epidermal growth factor and the Met receptors or integrin receptors thereby evoking anti-survival and pro-apoptotic pathways. In this review we will critically assess the expanding repertoire of molecular interactions attributed to various proteoglycans and will discuss novel proteoglycan functions modulating cancer progression, invasion and metastasis and how these factors regulate the tumour microenvironment. PMID:21155971

  7. Composite alginate gels for tunable cellular microenvironment mechanics.

    PubMed

    Khavari, Adele; Nydén, Magnus; Weitz, David A; Ehrlicher, Allen J

    2016-01-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4-12 kPa) as compared to healthy tissue (E = 0.4-2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation. PMID:27484403

  8. Chemical and physical microenvironments at the Viking landing sites

    NASA Technical Reports Server (NTRS)

    Clark, B. C.

    1979-01-01

    Physical and chemical considerations permit the division of the near-surface regolith on Mars into at least six zones of distinct microenvironments. The zones are euphotic, duricrust/peds, tempofrost, permafrost, endolithic, and interfacial/transitional. Microenvironments vary significantly in temperature extremes, mean temperature, salt content, relative pressure of water vapor, UV and visible light irradiance, and exposure to ionizing radiation events (100 Mrad) and oxidative molecular species. From what is known of the chemistry of the atmosphere and regolith fines (soil), limits upon the aqueous chemistry of soil pastes may be estimated. Heat of wetting could reach 45 cal/g dry soil; initial pH is indeterminate between 1 and 10; ionic strength and salinity are predicted to be extremely high; freezing point depression is inadequate to provide quantities of liquid water except in special cases. The prospects for biotic survival are grim by terrestrial standards, but the extremes of biological resiliency are inaccessible to evaluation. Second-generation in situ experiments which will better define Martian microenvironments are clearly possible. Antarctic dry valleys are approximations to Martian conditions, but deviate significantly by at least half-a-dozen criteria.

  9. Combination cancer immunotherapies tailored to the tumour microenvironment.

    PubMed

    Smyth, Mark J; Ngiow, Shin Foong; Ribas, Antoni; Teng, Michele W L

    2016-03-01

    Evidence suggests that cancer immunotherapy will be a major part of the combination treatment plan for many patients with many cancer types in the near future. There are many types of immune processes involving different antitumour and tumour-promoting leucocytes, and tumour cells use many strategies to evade the immune response. The tumour microenvironment can help determine which immune suppressive pathways become activated to restrain antitumour immunity. This includes immune checkpoint receptors on effector T-cells and myeloid cells, and release of inhibitory cytokines and metabolites. Therapeutic approaches that target these pathways, particularly immune-checkpoint receptors, can induce durable antitumour responses in patients with advanced-stage cancers, including melanoma. Nevertheless, many patients do not have a good response to monotherapy approaches and alternative strategies are required to achieve optimal therapeutic benefit. These strategies include eliminating the bulk of tumour cells to provoke tumour-antigen release and antigen-presenting cell (APC) function, using adjuvants to enhance APC function, and using agents that enhance effector-cell activity. In this Review, we discuss the stratification of the tumour microenvironment according to tumour-infiltrating lymphocytes and PD-L1 expression in the tumour, and how this stratification enables the design of optimal combination cancer therapies tailored to target different tumour microenvironments. PMID:26598942

  10. Composite alginate gels for tunable cellular microenvironment mechanics

    PubMed Central

    Khavari, Adele; Nydén, Magnus; Weitz, David A.; Ehrlicher, Allen J.

    2016-01-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation. PMID:27484403

  11. The effects of CA IX catalysis products within tumor microenvironment.

    PubMed

    Santi, Alice; Caselli, Anna; Paoli, Paolo; Corti, Denise; Camici, Guido; Pieraccini, Giuseppe; Taddei, Maria Letizia; Serni, Sergio; Chiarugi, Paola; Cirri, Paolo

    2013-01-01

    Solid tumors are composed of both cancer cells and various types of accessory cells, mainly fibroblasts, that collectively compose the so called tumor-microenvironment. Cancer-associated fibroblasts have been described to actively participate in cancer progression by establishing a cytokine-mediated as well as metabolic crosstalk with cancer cells. In the present paper we show that activated human fibroblasts are able to boost tumor cells proliferation and that this effect is greatly dependent on stromal carbonic anhydrase IX (CA IX) activity. In fact fibroblasts show a strong upregulation of CA IX expression upon activation by cancer cells, while CA IX products, protons and bicarbonate, exert differential effects on cancer cells proliferation. While acidification of extracellular pH, a typical condition of rapidly growing solid tumors, is detrimental for tumor cells proliferation, bicarbonate, through its organication, supplies cancer cells with intermediates useful to sustain their high proliferation rate. Here we propose a new kind of fibroblasts/tumor cells crosstalk within tumor microenvironment, mediated by stromal CA IX products, aimed to favor cancer cells growth, opening new perspectives on CA IX role in tumor microenvironment. PMID:24168032

  12. Hypercholesterolemia Tunes Hematopoietic Stem/Progenitor Cells for Inflammation and Atherosclerosis

    PubMed Central

    Ma, Xiaojuan; Feng, Yingmei

    2016-01-01

    As the pathological basis of cardiovascular disease (CVD), atherosclerosis is featured as a chronic inflammation. Hypercholesterolemia is an independent risk factor for CVD. Accumulated studies have shown that hypercholesterolemia is associated with myeloid cell expansion, which stimulates innate and adaptive immune responses, strengthens inflammation, and accelerates atherosclerosis progression. Hematopoietic stem/progenitor cells (HSPC) in bone marrow (BM) expresses a panel of lipoprotein receptors to control cholesterol homeostasis. Deficiency of these receptors abrogates cellular cholesterol efflux, resulting in HSPC proliferation and differentiation in hypercholesterolemic mice. Reduction of the cholesterol level in the lipid rafts by infusion of reconstituted high-density lipoprotein (HDL) or its major apolipoprotein, apoA-I, reverses hypercholesterolemia-induced HSPC expansion. Apart from impaired cholesterol metabolism, inhibition of reactive oxygen species production suppresses HSPC activation and leukocytosis. These data indicate that the mechanisms underlying the effects of hypercholesterolemia on HSPC proliferation and differentiation could be multifaceted. Furthermore, dyslipidemia also regulates HSPC-neighboring cells, resulting in HSPC mobilization. In the article, we review how hypercholesterolemia evokes HSPC activation and mobilization directly or via its modification of BM microenvironment. We hope this review will bring light to finding key molecules to control HSPC expansion, inflammation, and atherosclerosis for the treatment of CVD. PMID:27447612

  13. The impact of regulatory T cells on T-cell immunity following hematopoietic cell transplantation

    PubMed Central

    Nguyen, Vu H.; Shashidhar, Sumana; Chang, Daisy S.; Ho, Lena; Kambham, Neeraja; Bachmann, Michael; Brown, Janice M.

    2008-01-01

    Regulatory T cells (Tregs) prevent graft-versus-host disease (GvHD) by inhibiting the proliferation and function of conventional T cells (Tcons). However, the impact of Tregs on T-cell development and immunity following hematopoietic cell transplantation (HCT) is unknown. Using a murine GvHD model induced by Tcons, we demonstrate that adoptive transfer of Tregs leads to (1) abrogration of GvHD, (2) preservation of thymic and peripheral lymph node architecture, and (3) an accelerated donor lymphoid reconstitution of a diverse TCR-Vβ repertoire. The resultant enhanced lymphoid reconstitution in Treg recipients protects them from lethal cytomegalovirus (MCMV) infection. By contrast, mice that receive Tcons alone have disrupted lymphoid organs from GvHD and remain lymphopenic with a restricted TCR-Vβ repertoire and rapid death on MCMV challenge. Lymphocytes from previously infected Treg recipients generate secondary response specific to MCMV, indicating long-term protective immunity with transferred Tregs. Thymectomy significantly reduces survival after MCMV challenge in Treg recipients compared with euthymic controls. Our results indicate that Tregs enhance immune reconstitution by preventing GvHD-induced damage of the thymic and secondary lymphoid microenvironment. These findings provide new insights into the role of Tregs in affording protection to lymphoid stromal elements important for T-cell immunity. PMID:17916743

  14. Megakaryopoiesis and platelet production: insight into hematopoietic stem cell proliferation and differentiation

    PubMed Central

    Guo, Tianyu; Wang, Xuejun; Qu, Yigong; Yin, Yu; Jing, Tao

    2015-01-01

    Hematopoietic stem cells (HSCs) undergo successive lineage commitment steps to generate megakaryocytes (MKs) in a process referred to as megakaryopoiesis. MKs undergo a unique differentiation process involving endomitosis to eventually produce platelets. Many transcription factors participate in the regulation of this complex progress. Chemokines and other factors in the microenvironment where megakaryopoiesis and platelet production occur play vital roles in the regulation of HSC lineage commitment and MK maturation; among these factors, thrombopoietin (TPO) is the most important. Endomitosis is a vital process of MK maturation, and granules that are formed in MKs are important for platelet function. Proplatelets are firstly generated from mature MKs and then become platelets. The proplatelet production process was verified by novel studies that revealed that the mechanism is partially regulated by the invaginated membrane system (IMS), microtubules and Rho GTPases. The extracellular matrices (ECMs) and shear stress also affect and regulate the process while the mature MKs migrate from the marrow to the sub-endothelium region near the venous sinusoids leading to the release of platelets into the circulation. This review describes the entire process of megakaryopoiesis in detail, illustrates both the transcriptional and microenvironmental regulation of MKs and provides insight into platelet biogenesis. PMID:27358871

  15. Membrane-bound human SCF/KL promotes in vivo human hematopoietic engraftment and myeloid differentiation

    PubMed Central

    Takagi, Shinsuke; Saito, Yoriko; Hijikata, Atsushi; Tanaka, Satoshi; Watanabe, Takashi; Hasegawa, Takanori; Mochizuki, Shinobu; Kunisawa, Jun; Kiyono, Hiroshi; Koseki, Haruhiko; Ohara, Osamu; Saito, Takashi; Taniguchi, Shuichi; Shultz, Leonard D.

    2012-01-01

    In recent years, advances in the humanized mouse system have led to significantly increased levels of human hematopoietic stem cell (HSC) engraftment. The remaining limitations in human HSC engraftment and function include lymphoid-skewed differentiation and inefficient myeloid development in the recipients. Limited human HSC function may partially be attributed to the inability of the host mouse microenvironment to provide sufficient support to human hematopoiesis. To address this problem, we created membrane-bound human stem cell factor (SCF)/KIT ligand (KL)–expressing NOD/SCID/IL2rgKO (hSCF Tg NSG) mice. hSCF Tg NSG recipients of human HSCs showed higher levels of both human CD45+ cell engraftment and human CD45+CD33+ myeloid development compared with NSG recipients. Expression of hSCF/hKL accelerated the differentiation of the human granulocyte lineage cells in the recipient bone marrow. Human mast cells were identified in bone marrow, spleen, and gastrointestinal tissues of the hSCF Tg NSG recipients. This novel in vivo humanized mouse model demonstrates the essential role of membrane-bound hSCF in human myeloid development. Moreover, the hSCF Tg NSG humanized recipients may facilitate investigation of in vivo differentiation, migration, function, and pathology of human mast cells. PMID:22279057

  16. Maintenance of mouse hematopoietic stem cells ex vivo by reprogramming cellular metabolism.

    PubMed

    Liu, Xia; Zheng, Hong; Yu, Wen-Mei; Cooper, Todd M; Bunting, Kevin D; Qu, Cheng-Kui

    2015-03-01

    The difficulty in maintaining the reconstituting capabilities of hematopoietic stem cells (HSCs) in culture outside of the bone marrow microenvironment has severely limited their utilization for clinical therapy. This hurdle is largely due to the differentiation of long-term stem cells. Emerging evidence suggests that energy metabolism plays an important role in coordinating HSC self-renewal and differentiation. Here, we show that treatment with alexidine dihydrochloride, an antibiotic and a selective inhibitor of the mitochondrial phosphatase Ptpmt1, which is crucial for the differentiation of HSCs, reprogrammed cellular metabolism from mitochondrial aerobic metabolism to glycolysis, resulting in a remarkable preservation of long-term HSCs ex vivo in part through hyperactivation of adenosine 5'-monophosphate-activated protein kinase (AMPK). In addition, inhibition of mitochondrial metabolism and activation of AMPK by metformin, a diabetes drug, also decreased differentiation and helped maintain stem cells in culture. Thus, manipulating metabolic pathways represents an effective new strategy for ex vivo maintenance of HSCs. PMID:25593337

  17. FOXN1 recombinant protein enhances T-cell regeneration after hematopoietic stem cell transplantation in mice.

    PubMed

    Song, Yinhong; Su, Min; Zhu, Jing; Di, Wen; Liu, Yalan; Hu, Rong; Rood, Debra; Lai, Laijun

    2016-06-01

    A prolonged period of T-cell recovery is the major challenge in hematopoietic stem cell transplantation (HSCT). Thymic epithelial cells (TECs) are the major component of the thymic microenvironment for T-cell generation. However, TECs undergo degeneration over time. FOXN1 plays a critical role in TEC development and is required to maintain adult TECs for thymopoiesis. To investigate the potential application of FOXN1, we have cloned and expressed recombinant FOXN1 protein (rFOXN1) that was fused with cell-penetrating peptides. We show here that the rFOXN1 protein can translocate from the cell surface into the cytoplasm and nucleus. Administration of rFOXN1 into both congenic and allogeneic HSCT recipient mice increased the number of TECs, resulting in enhanced thymopoiesis that led to an increased number of functional T cells in the periphery. The increased number of TECs is due to the enhanced survival and proliferation of TECs. Our results suggest that rFOXN1 has the potential to be used in enhancing T-cell regeneration in patients following HSCT. PMID:27125859

  18. Hematopoietic cell kinase (HCK) as a therapeutic target in immune and cancer cells

    PubMed Central

    Poh, Ashleigh R.; O'Donoghue, Robert J.J.; Ernst, Matthias

    2015-01-01

    The hematopoietic cell kinase (HCK) is a member of the SRC family of cytoplasmic tyrosine kinases (SFKs), and is expressed in cells of the myeloid and B-lymphocyte cell lineages. Excessive HCK activation is associated with several types of leukemia and enhances cell proliferation and survival by physical association with oncogenic fusion proteins, and with functional interactions with receptor tyrosine kinases. Elevated HCK activity is also observed in many solid malignancies, including breast and colon cancer, and correlates with decreased patient survival rates. HCK enhances the secretion of growth factors and pro-inflammatory cytokines from myeloid cells, and promotes macrophage polarization towards a wound healing and tumor-promoting alternatively activated phenotype. Within tumor associated macrophages, HCK stimulates the formation of podosomes that facilitate extracellular matrix degradation, which enhance immune and epithelial cell invasion. By virtue of functional cooperation between HCK and bona fide oncogenic tyrosine kinases, excessive HCK activation can also reduce drug efficacy and contribute to chemo-resistance, while genetic ablation of HCK results in minimal physiological consequences in healthy mice. Given its known crystal structure, HCK therefore provides an attractive therapeutic target to both, directly inhibit the growth of cancer cells, and indirectly curb the source of tumor-promoting changes in the tumor microenvironment. PMID:26087188

  19. Non-hematopoietic expression of IDO is integrally required for inflammatory tumor promotion

    PubMed Central

    Muller, Alexander J.; DuHadaway, James B.; Chang, Mee Young; Ramalingam, Arivudinambi; Sutanto-Ward, Erika; Boulden, Janette; Soler, Alejandro P.; Mandik-Nayak, Laura; Gilmour, Susan K.

    2010-01-01

    Indoleamine 2,3-dioxygenase (IDO) is generally considered to be immunosuppressive but recent findings suggest this characterization oversimplifies its role in disease pathogenesis. Recently, we showed that IDO is essential for tumor outgrowth in the classical two-stage model of inflammatory skin carcinogenesis. Here, we report that IDO loss did not exacerbate classical inflammatory responses. Rather, IDO induction could be elicited by environmental signals and tumor promoters as an integral component of the inflammatory tissue microenvironment even in the absence of cancer. IDO loss had limited impact on tumor outgrowth in carcinogenesis models that lacked an explicit inflammatory tumor promoter. In the context of inflammatory carcinogenesis where IDO was critical to tumor development, the most important source of IDO was radiation-resistant non-hematopoietic cells, consistent with evidence that loss of the IDO regulatory tumor suppressor gene Bin1 in transformed skin cells facilitates IDO-mediated immune escape by a cell autonomous mechanism. Taken together, our results identify IDO as an integral component of ‘cancer-associated’ inflammation that tilts the immune system toward tumor support. More generally, they promote the concept that mediators of immune escape and cancer-associated inflammation may be genetically synonymous. PMID:20640572

  20. DIABETES IMPAIRS HEMATOPOIETIC STEM CELL MOBILIZATION THROUGH ALTERATION OF NICHE FUNCTION

    PubMed Central

    Ferraro, Francesca; Lymperi, Stefania; Méndez-Ferrer, Simón; Saez, Borja; Spencer, Joel A; Yeap, Beow Y; Masselli, Elena; Graiani, Gallia; Prezioso, Lucia; Rizzini, Elisa Lodi; Mangoni, Marcellina; Rizzoli, Vittorio; Sykes, Stephen M; Lin, Charles P.; Frenette, Paul S.; Quaini, Federico; Scadden, David T.

    2013-01-01

    Autologous hematopoietic stem/progenitor cells (HSPC) transplantation success depends upon adequate cell collection after G-CSF-administration that a substantial fraction of patients fails to achieve. Retrospective analysis of patient records demonstrated that diabetes correlated with lower CD34+ cell mobilization. Using mouse models, we found impaired HSPC egress from the bone marrow in either streptozotocin-induced or db/db diabetic animals. HSPC aberrantly localized within the marrow microenvironment of diabetic animals in association with abnormalities in sympathetic neuron number and function. Markedly increased sympathetic neuron density was accompanied by abnormal response to β-adrenergic stimulation and a failure to generate the G-CSF-induced CXCL12 gradient in nestin-expressing mesenchymal cells associated with HSPC mobilization. Alternative mobilization by direct pharmacologic inhibition of CXCL12-CXCR4 interaction rescued the defect. These data reveal diabetes-induced changes in bone marrow physiology and microanatomy and point to a pathophysiologically based approach to overcome HSPC mobilization defects in diabetic patients. PMID:21998408

  1. Hypercholesterolemia Tunes Hematopoietic Stem/Progenitor Cells for Inflammation and Atherosclerosis.

    PubMed

    Ma, Xiaojuan; Feng, Yingmei

    2016-01-01

    As the pathological basis of cardiovascular disease (CVD), atherosclerosis is featured as a chronic inflammation. Hypercholesterolemia is an independent risk factor for CVD. Accumulated studies have shown that hypercholesterolemia is associated with myeloid cell expansion, which stimulates innate and adaptive immune responses, strengthens inflammation, and accelerates atherosclerosis progression. Hematopoietic stem/progenitor cells (HSPC) in bone marrow (BM) expresses a panel of lipoprotein receptors to control cholesterol homeostasis. Deficiency of these receptors abrogates cellular cholesterol efflux, resulting in HSPC proliferation and differentiation in hypercholesterolemic mice. Reduction of the cholesterol level in the lipid rafts by infusion of reconstituted high-density lipoprotein (HDL) or its major apolipoprotein, apoA-I, reverses hypercholesterolemia-induced HSPC expansion. Apart from impaired cholesterol metabolism, inhibition of reactive oxygen species production suppresses HSPC activation and leukocytosis. These data indicate that the mechanisms underlying the effects of hypercholesterolemia on HSPC proliferation and differentiation could be multifaceted. Furthermore, dyslipidemia also regulates HSPC-neighboring cells, resulting in HSPC mobilization. In the article, we review how hypercholesterolemia evokes HSPC activation and mobilization directly or via its modification of BM microenvironment. We hope this review will bring light to finding key molecules to control HSPC expansion, inflammation, and atherosclerosis for the treatment of CVD. PMID:27447612

  2. Hematopoietic transcription factor mutations and inherited platelet dysfunction

    PubMed Central

    Songdej, Natthapol

    2015-01-01

    The molecular and genetic mechanisms in most patients with inherited platelet dysfunction are unknown. There is increasing evidence that mutations in hematopoietic transcription factors are major players in the pathogenesis of defective megakaryopoiesis and platelet dysfunction in patients with inherited platelet disorders. These hematopoietic transcription factors include RUNX1, FLI1, GATA-1, and GFI1B. Mutations involving these transcription factors affect diverse aspects of platelet production and function at the genetic and molecular levels, culminating in clinical manifestations of thrombocytopenia and platelet dysfunction. This review focuses on these hematopoietic transcription factors in the pathobiology of inherited platelet dysfunction. PMID:26097739

  3. Allogeneic hematopoietic stem cell transplantation in Tunisia.

    PubMed

    Ben Othman, T; Torjemane, L; Abdelkefi, A; Lakhal, A; Ladeb, S; Ben Hamed, L; Slama, H; Ben Abdeladhim, A

    2008-08-01

    In 1998, the Tunisian team of the 'Centre National de Greffe de Moelle Osseuse' initiated allogeneic hematopoietic SCT (AHSCT) in Tunisia. As of June 2007, information was collected about 299 patients with a first AHSCT and 12 additional retransplants. The median age was 19 years (range 2-49 years). The main indications were aplastic anemia (n=106, 36%), leukemia and nonmalignant disorders (n=153, 51%), Fanconi anemia (n=26, 9%) and other nonmalignant disorders (n=14, 4%). Preparative regimens depended on indication. All donors were HLA geno-identical. The stem cell sources were BM (87%) and PBSCs (13%). At the time of analysis, 200 patients (67%) were alive after a median follow-up of 42 months (range 3-112 months). The overall TRM rate was 17%. Outcome depended on indication. According to our results, allogeneic HSCT is potentially curative for hematological diseases, but it is a toxic approach for malignant disorders. PMID:18724288

  4. Engineering Hematopoietic Stem Cells: Lessons from Development.

    PubMed

    Rowe, R Grant; Mandelbaum, Joseph; Zon, Leonard I; Daley, George Q

    2016-06-01

    Cell engineering has brought us tantalizingly close to the goal of deriving patient-specific hematopoietic stem cells (HSCs). While directed differentiation and transcription factor-mediated conversion strategies have generated progenitor cells with multilineage potential, to date, therapy-grade engineered HSCs remain elusive due to insufficient long-term self-renewal and inadequate differentiated progeny functionality. A cross-species approach involving zebrafish and mammalian systems offers complementary methodologies to improve understanding of native HSCs. Here, we discuss the role of conserved developmental timing processes in vertebrate hematopoiesis, highlighting how identification and manipulation of stage-specific factors that specify HSC developmental state must be harnessed to engineer HSCs for therapy. PMID:27257760

  5. Persistent Disparities in Adult Hematopoietic Cell Transplantation.

    PubMed

    Crockett, David G; Loberiza, Fausto R

    2015-09-01

    The use of large databases has provided advancements in the understanding of racial, ethnic, and socioeconomic disparities in the field of adult hematopoietic cell transplants (HCT). Disparities exist on individual, institutional, and systemic levels for both allogeneic and autologous HCT. We reviewed the most recent publications that utilized large databases to elucidate disparities in HCT and placed them into historical context of the other major studies in the field. Two emerging themes were identified. These themes are persistent inequalities in both allogeneic HCT and autologous HCT for myeloma and the importance of improving homogeneity of care in HCT. Minimization of inequalities can be achieved only with an understanding of the persistent barriers that exist in the field. PMID:26104908

  6. Approach to the morbilliform eruption in the hematopoietic transplant patient.

    PubMed

    Mays, Steven R; Kunishige, Joy H; Truong, Elizabeth; Kontoyiannis, Dimitrios P; Hymes, Sharon R

    2007-09-01

    Morbilliform eruptions occur frequently in the hematopoietic transplant population. The differential diagnosis includes drug reaction, viral exanthem, and cutaneous graft versus host disease. Using a typical patient case, we discuss the diagnostic approach to this clinical problem. PMID:18070682

  7. Lineage-related cytotoxicity and clonogenic profile of 1,4-benzoquinone-exposed hematopoietic stem and progenitor cells

    SciTech Connect

    Chow, Paik Wah; Abdul Hamid, Zariyantey; Chan, Kok Meng; Inayat-Hussain, Salmaan Hussain; Rajab, Nor Fadilah

    2015-04-01

    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24 h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e{sup +} cells but reduced the total counts of Sca-1{sup +}, CD11b{sup +}, Gr-1{sup +}, and CD45{sup +} cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5 μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12 μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage. - Highlights: • We examine 1,4-BQ toxicity targeting mouse hematopoietic cell lineages. • 1,4-BQ induces concentration-dependent cytotoxicity in bone marrow (BM) cells. • 1,4-BQ shows lineage-related toxicity on hematopoietic stem and

  8. Hospital infection control in hematopoietic stem cell transplant recipients.

    PubMed Central

    Dykewicz, C. A.

    2001-01-01

    Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Transplant Recipients contains a section on hospital infection control including evidence-based recommendations regarding ventilation, construction, equipment, plants, play areas and toys, health-care workers, visitors, patient skin and oral care, catheter-related infections, drug-resistant organisms, and specific nosocomial infections. These guidelines are intended to reduce the number and severity of hospital infections in hematopoietic stem cell transplant recipients. PMID:11294720

  9. Cutting the brakes on hematopoietic regeneration by blocking TGFβ to limit chemotherapy-induced myelosuppression

    PubMed Central

    Brenet, Fabienne; Scandura, Joseph M

    2015-01-01

    Hematopoietic stressors such as infection, bleeding, or toxic injury trigger a hematopoietic adaptation that sacrifices hematopoietic stem and progenitor cell (HSPC) quiescence to meet an urgent need for new blood cell production. Once the hematopoietic demands are adequately met, homeostasis must be restored. Transforming growth factor β (TGFβ) signaling is a central mediator mandating the return of HSPCs to quiescence after stress. Blockade of TGFβ signaling after hematopoietic stress delays the return of cycling HSPCs to quiescence and in so doing promotes hematopoietic stem cell (HSC) self-renewal and accelerates hematopoietic reconstitution. These findings open the door to new therapeutics that modulate the hematopoietic adaptation to stress. In this review, we will discuss the complex context-dependent activities of TGFβ in hematopoiesis and the potential benefits and limitations of using TGFβ pathway inhibitors to promote multilineage hematopoietic reconstitution after myelosuppressive chemotherapy. PMID:27308454

  10. Eicosanoid Regulation of Hematopoiesis and Hematopoietic Stem and Progenitor Trafficking

    PubMed Central

    Hoggatt, Jonathan; Pelus, Louis M.

    2011-01-01

    Hematopoietic stem cell (HSC) transplantation is a potentially curative treatment for numerous hematologic malignancies. The transplant procedure as performed today takes advantage of HSC trafficking; either egress of HSC from the bone marrow to the peripheral blood, i.e. mobilization, for acquisition of the hematopoietic graft, and/or trafficking of HSC from the peripheral blood to bone marrow niches in the recipient patient, i.e. HSC homing. Numerous studies, many of which are reviewed herein, have defined hematopoietic regulatory mechanisms mediated by the 20-carbon lipid family of eicosanoids, and recent evidence strongly supports a role for eicosanoids in regulation of hematopoietic trafficking, adding a new role whereby eicosanoids regulate hematopoiesis. Short-term exposure of HSC to the eicosanoid prostaglandin E2 (PGE2) increases CXCR4 receptor expression, migration and in vivo homing of HSC. In contrast, cannabinoids reduce hematopoietic progenitor cell (HPC) CXCR4 expression and induce HPC mobilization when administered in vivo. Leukotrienes have been shown to alter CD34+ cell adhesion, migration, and regulate HSC proliferation, suggesting that eicosanoids have both opposing and complimentary roles in the regulation of hematopoiesis. Since numerous FDA approved compounds regulate eicosanoid signaling or biosynthesis, the utility of eicosanoid based therapeutic strategies to improve hematopoietic transplantation can be rapidly evaluated. PMID:20882043

  11. Dysregulated pH in Tumor Microenvironment Checkmates Cancer Therapy

    PubMed Central

    Barar, Jaleh; Omidi, Yadollah

    2013-01-01

    Introduction: The dysregulation of pH by cancerous cells of solid tumors is able to create a unique milieu that is in favor of progression, invasion and metastasis as well as chemo-/immuno-resistance traits of solid tumors. Bioelements involved in pH dysregulation provide new set of oncotargets, inhibition of which may result in better clinical outcome. Methods: To study the impacts of pH dysregulation, we investigated the tumor development and progression in relation with Warburg effect, glycolysis and formation of aberrant tumor microenvironment. Results: The upregulation of glucose transporter GLUT-1 and several enzymes involve in glycolysis exacerbates this phenomenon. The accumulation of lactic acids in cancer cells provokes upregulation of several transport machineries (MCT-1, NHE-1, CA IX and H+ pump V-ATPase) resulting in reinforced efflux of proton into extracellular fluid. This deviant event makes pH to be settled at 7.4 and 6.6 respectively in cancer cells cytoplasm and extracellular fluid within the tumor microenvironment, which in return triggers secretion of lysosomal components (various enzymes in acidic milieu with pH 5) into cytoplasm. All these anomalous phenomena make tumor microenvironment (TME) to be exposed to cocktail of various enzymes with acidic pH, upon which extracellular matrix (ECM) can be remodeled and even deformed, resulting in emergence of a complex viscose TME with high interstitial fluid pressure. Conclusion: It seems that pH dysregulation is able to remodel various physiologic functions and make solid tumors to become much more invasive and metastatic. It also can cause undesired resistance to chemotherapy and immunotherapy. Hence, cancer therapy needs to be reinforced using specific inhibitors of bioelements involved in pH dysregulation of TME in solid tumors. PMID:24455478

  12. Galectin 3 as a guardian of the tumor microenvironment.

    PubMed

    Ruvolo, Peter P

    2016-03-01

    Galectin 3 is a member of a family of β-galactoside binding proteins and has emerged as an important regulator of diverse functions critical in cancer biology including apoptosis, metastasis, immune surveillance, molecular trafficking, mRNA splicing, gene expression, and inflammation. Galectin 3's ability to support cancer cell survival by intra-cellular and extra-cellular mechanisms suggests this molecule is an important component of the tumor microenvironment that potentially could be targeted for therapy. Data is emerging that Galectin 3 is elevated in many cancers including solid tumors and the cancers of the blood. Galectin 3 also appears to be a key molecule produced by tumor microenvironment support cells including mesenchymal stromal cells (MSC) to suppress immune surveillance by killing T cells and interfering with NK cell function and by supporting metastasis. Levels of Galectin 3 increase in the MSC of aging mice and perhaps this contributes to the development of cancer in the elderly. Galectin 3 modulates surface protein expression of a diverse set of glycoproteins including CD44 by regulating endocytosis of these proteins. In addition, Galectin 3 binding to receptor kinases such as CD45 and the T cell receptor is critical in the regulation of their function. In this review I will examine the various mechanisms how Galectin 3 supports chemoresistance and metastasis in solid tumors and in leukemia and lymphoma. I will also discuss possible therapeutic strategies to target this Galectin for cancer therapy. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza. PMID:26264495

  13. Targeting tumor microenvironment: the key role of immune system.

    PubMed

    Barar, Jaleh

    2012-01-01

    In recent years, huge investigations on cancer progression and invasion have led to under-stand the pivotal role of tumor microenvironment. The current era of cancer therapy is based on the concept of simply targeting precise mechanisms to kill or to suppress the growth and expansion of malignant cells. Clinical data clearly correlate with in-vitro re-sults, emphasizing the direct impact of cancer environment on disease progression. This provides the opportunity to advance cancer therapy by virtue of targeting cancerous cells and non-cancerous component of tumor in a combinatorial manner. This tailor-made strategy demands the profound knowledge of cross talk between the bio-factors of tumor environment and corresponding pharmacology of drug candidates. The neighborhood of tumor is critical for how cancer cells grow and invade surrounding tissues. It appears that the tumor microenvironment as a "co-op" includes malignant cells, blood vessels, im-mune/inflammatory factors and extracellular matrix. As a longstanding dilemma, it is well-proved that immune system plays a direct role in the existence and progression of such coop. In some cases, immune cells e.g. tumor associated macrophages (TAMs) infiltrate into tumor and instead of fighting cancer cells, support them to grow. As an important fact, this tumor complexity should not be taken as granted where it can be advantageous in cancer therapy as well as early detection and prevention. The central aim of this editorial article is to highlight the importance of tumor microenvironment for successful cancer therapy. PMID:23678436

  14. Immunological hallmarks of stromal cells in the tumour microenvironment.

    PubMed

    Turley, Shannon J; Cremasco, Viviana; Astarita, Jillian L

    2015-11-01

    A dynamic and mutualistic interaction between tumour cells and the surrounding stroma promotes the initiation, progression, metastasis and chemoresistance of solid tumours. Far less understood is the relationship between the stroma and tumour-infiltrating leukocytes; however, emerging evidence suggests that the stromal compartment can shape antitumour immunity and responsiveness to immunotherapy. Thus, there is growing interest in elucidating the immunomodulatory roles of the stroma that evolve within the tumour microenvironment. In this Review, we discuss the evidence that stromal determinants interact with leukocytes and influence antitumour immunity, with emphasis on the immunological attributes of stromal cells that may foster their protumorigenic function. PMID:26471778

  15. Targeting stromal microenvironment in pancreatic ductal adenocarcinoma: controversies and promises

    PubMed Central

    Mei, Lin; Du, Wei

    2016-01-01

    Pancreatic cancer is a highly lethal disease. Conventional therapeutics targeting pancreas cancer cell compartment using cytotoxics improved patient survival but at the expense of significant toxicity. Microscopically, the tumor is characterized by thick desmoplastic stroma that surrounds islands of pancreatic cancer cells. The tumor microenvironment has been found to play important roles in carcinogenesis, the development of drug resistance, and mediating immunosuppression. The understanding the tumor-stromal interaction has led to the development of novel therapeutic approaches. Here, we review the strategies that are currently in (or, near to) clinical evaluation and the underlying preclinical rationales. PMID:27284483

  16. Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature

    SciTech Connect

    Yuan, Zhi-Min

    2013-04-28

    Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

  17. Probing the luminal microenvironment of reconstituted epithelial microtissues.

    PubMed

    Cerchiari, Alec E; Samy, Karen E; Todhunter, Michael E; Schlesinger, Erica; Henise, Jeff; Rieken, Christopher; Gartner, Zev J; Desai, Tejal A

    2016-01-01

    Polymeric microparticles can serve as carriers or sensors to instruct or characterize tissue biology. However, incorporating microparticles into tissues for in vitro assays remains a challenge. We exploit three-dimensional cell-patterning technologies and directed epithelial self-organization to deliver microparticles to the lumen of reconstituted human intestinal microtissues. We also develop a novel pH-sensitive microsensor that can measure the luminal pH of reconstituted epithelial microtissues. These studies offer a novel approach for investigating luminal microenvironments and drug-delivery across epithelial barriers. PMID:27619235

  18. Analysis of Extracellular Vesicles in the Tumor Microenvironment.

    PubMed

    Al-Nedawi, Khalid; Read, Jolene

    2016-01-01

    Extracellular vesicles (ECV) are membrane compartments shed from all types of cells in various physiological and pathological states. In recent years, ECV have gained an increasing interest from the scientific community for their role as an intercellular communicator that plays important roles in modifying the tumor microenvironment. Multiple techniques have been established to collect ECV from conditioned media of cell culture or physiological fluids. The gold standard methodology is differential centrifugation. Although alternative techniques exist to collect ECV, these techniques have not proven suitable as a substitution for the ultracentrifugation procedure. PMID:27581023

  19. Methods to study the tumor microenvironment under controlled oxygen conditions

    PubMed Central

    Byrne, Matthew B.; Leslie, Matthew T.; Gaskins, H. Rex; Kenis, Paul J.A.

    2014-01-01

    The tumor microenvironment is a complex heterogeneous assembly composed of a variety of cell types and physical features. One such feature, hypoxia, is associated with metabolic reprogramming, the epithelial-mesenchymal transition, and therapeutic resistance. Many questions remain regarding the effects of hypoxia on these outcomes, yet only few experimental methods enable both precise control over oxygen concentration and real-time imaging of cell behavior. Recent efforts with microfluidic platforms offer a promising solution to these limitations. We discuss conventional methods and tools used to control oxygen concentration for cell studies then highlight recent advances in microfluidic-based approaches for controlling oxygen in engineered platforms. PMID:25282035

  20. Combined Effects of Pericytes in the Tumor Microenvironment

    PubMed Central

    Ribeiro, Aline Lopes; Okamoto, Oswaldo Keith

    2015-01-01

    Pericytes are multipotent perivascular cells whose involvement in vasculature development is well established. Evidences in the literature also suggest that pericytes display immune properties and that these cells may serve as an in vivo reservoir of stem cells, contributing to the regeneration of diverse tissues. Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME). In this review, we highlight the contribution of pericytes to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss how collectively these hallmarks could be tackled by therapies targeting pericytes, providing a rationale for cancer drugs aiming at the TME. PMID:26000022

  1. Combined effects of pericytes in the tumor microenvironment.

    PubMed

    Ribeiro, Aline Lopes; Okamoto, Oswaldo Keith

    2015-01-01

    Pericytes are multipotent perivascular cells whose involvement in vasculature development is well established. Evidences in the literature also suggest that pericytes display immune properties and that these cells may serve as an in vivo reservoir of stem cells, contributing to the regeneration of diverse tissues. Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME). In this review, we highlight the contribution of pericytes to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss how collectively these hallmarks could be tackled by therapies targeting pericytes, providing a rationale for cancer drugs aiming at the TME. PMID:26000022

  2. Pancreatic cancer microenvironment, to target or not to target?

    PubMed

    Carr, Ryan M; Fernandez-Zapico, Martin E

    2016-02-01

    We have collectively been spoiled by the astounding clinical benefit of antimicrobials. Much like the discovery and use of penicillin to eradicate once deadly infections, we continue to desperately search for the next “magic bullet” to kill cancer while sparing the non‐transformed cells. Greater appreciation for the molecular intricacies of malignancy has resulted in dedicated pursuit of cancer genomics and large‐scale informatics to identify “drugable” targets within the cancer cell itself. However, studies at the bench elucidating a dynamic relationship between tumor and microenvironment have become more common and demonstrate promise for novel therapeutic intervention. PMID:26747091

  3. Intravital imaging of multicolor-labeled tumor immune microenvironment through skin-fold window chamber

    NASA Astrophysics Data System (ADS)

    Qi, Shuhong; Zhang, Zhihong

    2015-03-01

    Tumor immune microenvironment became very important for the tumor immunotherapy. There were several kinds of immune cells in tumor stromal, and they played very different roles in tumor growth. In order to observe the behaviors of multiple immune cells in tumor microenvironment and the interaction between immune cells and tumor cells at the same time, we generated a multicolor-labeled tumor immune microenvironment model. The tumor cells and immune cells were labeled by different fluorescent proteins. By using of skin-fold window chamber implanted into mice and intravital imaging technology, we could dynamically observe the different immune cells in tumor microenvironment. After data analysis from the video, we could know the behavior of TILs, DCs and Tregs in tumor immune microenvironment; furthermore, we could know these immune cells play different roles in the tumor microenvironment.

  4. Bioengineering Embryonic Stem Cell Microenvironments for the Study of Breast Cancer

    PubMed Central

    Raof, Nurazhani Abdul; Mooney, Bridget M.; Xie, Yubing

    2011-01-01

    Breast cancer is the most prevalent disease amongst women worldwide and metastasis is the main cause of death due to breast cancer. Metastatic breast cancer cells and embryonic stem (ES) cells display similar characteristics. However, unlike metastatic breast cancer cells, ES cells are nonmalignant. Furthermore, embryonic microenvironments have the potential to convert metastatic breast cancer cells into a less invasive phenotype. The creation of in vitro embryonic microenvironments will enable better understanding of ES cell-breast cancer cell interactions, help elucidate tumorigenesis, and lead to the restriction of breast cancer metastasis. In this article, we will present the characteristics of breast cancer cells and ES cells as well as their microenvironments, importance of embryonic microenvironments in inhibiting tumorigenesis, convergence of tumorigenic and embryonic signaling pathways, and state of the art in bioengineering embryonic microenvironments for breast cancer research. Additionally, the potential application of bioengineered embryonic microenvironments for the prevention and treatment of invasive breast cancer will be discussed. PMID:22174624

  5. Fighting the force: potential of homeobox genes for tumor microenvironment regulation

    PubMed Central

    Northcott, Josette M.; Northey, Jason J.; Barnes, J. Matthew; Weaver, Valerie M.

    2015-01-01

    Tumor cells exist in a constantly evolving stromal microenvironment composed of vasculature, immune cells and cancer-associated fibroblasts, all residing within a dynamic extracellular matrix. In this review, we examine the biochemical and biophysical interactions between these various stromal cells and their matrix microenvironment. While the stroma can alter tumor progression via multiple mechanisms, we emphasize the role of homeobox genes in detecting and modulating the mechanical changes in the microenvironment during tumor progression. PMID:25818365

  6. Tungsten targets the tumor microenvironment to enhance breast cancer metastasis.

    PubMed

    Bolt, Alicia M; Sabourin, Valérie; Molina, Manuel Flores; Police, Alice M; Negro Silva, Luis Fernando; Plourde, Dany; Lemaire, Maryse; Ursini-Siegel, Josie; Mann, Koren K

    2015-01-01

    The number of individuals exposed to high levels of tungsten is increasing, yet there is limited knowledge of the potential human health risks. Recently, a cohort of breast cancer patients was left with tungsten in their breasts following testing of a tungsten-based shield during intraoperative radiotherapy. While monitoring tungsten levels in the blood and urine of these patients, we utilized the 66Cl4 cell model, in vitro and in mice to study the effects of tungsten exposure on mammary tumor growth and metastasis. We still detect tungsten in the urine of patients' years after surgery (mean urinary tungsten concentration at least 20 months post-surgery = 1.76 ng/ml), even in those who have opted for mastectomy, indicating that tungsten does not remain in the breast. In addition, standard chelation therapy was ineffective at mobilizing tungsten. In the mouse model, tungsten slightly delayed primary tumor growth, but significantly enhanced lung metastasis. In vitro, tungsten did not enhance 66Cl4 proliferation or invasion, suggesting that tungsten was not directly acting on 66Cl4 primary tumor cells to enhance invasion. In contrast, tungsten changed the tumor microenvironment, enhancing parameters known to be important for cell invasion and metastasis including activated fibroblasts, matrix metalloproteinases, and myeloid-derived suppressor cells. We show, for the first time, that tungsten enhances metastasis in an animal model of breast cancer by targeting the microenvironment. Importantly, all these tumor microenvironmental changes are associated with a poor prognosis in humans. PMID:25324207

  7. Tungsten Targets the Tumor Microenvironment to Enhance Breast Cancer Metastasis

    PubMed Central

    Bolt, Alicia M.; Sabourin, Valérie; Molina, Manuel Flores; Police, Alice M.; Negro Silva, Luis Fernando; Plourde, Dany; Lemaire, Maryse; Ursini-Siegel, Josie; Mann, Koren K.

    2015-01-01

    The number of individuals exposed to high levels of tungsten is increasing, yet there is limited knowledge of the potential human health risks. Recently, a cohort of breast cancer patients was left with tungsten in their breasts following testing of a tungsten-based shield during intraoperative radiotherapy. While monitoring tungsten levels in the blood and urine of these patients, we utilized the 66Cl4 cell model, in vitro and in mice to study the effects of tungsten exposure on mammary tumor growth and metastasis. We still detect tungsten in the urine of patients’ years after surgery (mean urinary tungsten concentration at least 20 months post-surgery = 1.76 ng/ml), even in those who have opted for mastectomy, indicating that tungsten does not remain in the breast. In addition, standard chelation therapy was ineffective at mobilizing tungsten. In the mouse model, tungsten slightly delayed primary tumor growth, but significantly enhanced lung metastasis. In vitro, tungsten did not enhance 66Cl4 proliferation or invasion, suggesting that tungsten was not directly acting on 66Cl4 primary tumor cells to enhance invasion. In contrast, tungsten changed the tumor microenvironment, enhancing parameters known to be important for cell invasion and metastasis including activated fibroblasts, matrix metalloproteinases, and myeloid-derived suppressor cells. We show, for the first time, that tungsten enhances metastasis in an animal model of breast cancer by targeting the microenvironment. Importantly, all these tumor microenvironmental changes are associated with a poor prognosis in humans. PMID:25324207

  8. Lymphatic vessels regulate immune microenvironments in human and murine melanoma.

    PubMed

    Lund, Amanda W; Wagner, Marek; Fankhauser, Manuel; Steinskog, Eli S; Broggi, Maria A; Spranger, Stefani; Gajewski, Thomas F; Alitalo, Kari; Eikesdal, Hans P; Wiig, Helge; Swartz, Melody A

    2016-09-01

    Lymphatic remodeling in tumor microenvironments correlates with progression and metastasis, and local lymphatic vessels play complex and poorly understood roles in tumor immunity. Tumor lymphangiogenesis is associated with increased immune suppression, yet lymphatic vessels are required for fluid drainage and immune cell trafficking to lymph nodes, where adaptive immune responses are mounted. Here, we examined the contribution of lymphatic drainage to tumor inflammation and immunity using a mouse model that lacks dermal lymphatic vessels (K14-VEGFR3-Ig mice). Melanomas implanted in these mice grew robustly, but exhibited drastically reduced cytokine expression and leukocyte infiltration compared with those implanted in control animals. In the absence of local immune suppression, transferred cytotoxic T cells more effectively controlled tumors in K14-VEGFR3-Ig mice than in control mice. Furthermore, gene expression analysis of human melanoma samples revealed that patient immune parameters are markedly stratified by levels of lymphatic markers. This work suggests that the establishment of tumor-associated inflammation and immunity critically depends on lymphatic vessel remodeling and drainage. Moreover, these results have implications for immunotherapies, the efficacies of which are regulated by the tumor immune microenvironment. PMID:27525437

  9. Particle-bound polycyclic aromatic hydrocarbon concentrations in transportation microenvironments

    NASA Astrophysics Data System (ADS)

    Houston, Douglas; Wu, Jun; Yang, Dongwoo; Jaimes, Guillermo

    2013-06-01

    This study is one of the first case studies to characterize the exposure of urban residents to traffic-related air pollution across locations and transportation microenvironments during everyday activities. Twenty-four adult residents of Boyle Heights, a neighborhood near downtown Los Angeles, carried a portable air pollution monitor and a Global Positioning Systems (GPS) tracking device for a total of 96 days. We found significant spatial and temporal variation in the particle-bound polycyclic aromatic hydrocarbon (pPAH) concentrations in transportation microenvironments. Average pPAH concentrations were higher while walking outdoors (190 ng m-3) compared to traveling in private passenger vehicles (138-155 ng m-3) or traveling in public transportation (61-124 ng m-3). Although travel comprised 5% of participant days, it was associated with 27% of overall daily pPAH exposure. Regression models explained 40-55% of the variation in daily average pPAH concentrations, and 40-44% of the variation in 1-min interval concentrations. Important factors included time spent traveling, travel speed, meteorological and nearby land use factors, time of day, and proximity to roadways. Although future research is needed to develop stronger predictive models, our study demonstrates portable tracking devices can provide a more complete, diurnal characterization of air pollution exposures for urban populations.

  10. Interleukin-5 Facilitates Lung Metastasis by Modulating the Immune Microenvironment

    PubMed Central

    Gleaves, Linda A.; McLoed, Allyson G.; Saxon, Jamie A.; Habermann, Arun C.; Connelly, Linda; Dulek, Daniel; Peebles, R. Stokes; Fingleton, Barbara; Yull, Fiona E.; Stathopoulos, Georgios T.; Blackwell, Timothy S.

    2015-01-01

    Although the lung is the most common metastatic site for cancer cells, biological mechanisms regulating lung metastasis are not fully understood. Using heterotopic and intravenous injection models of lung metastasis in mice, we found that IL-5, a cytokine involved in allergic and infectious diseases, facilitates metastatic colonization through recruitment of sentinel eosinophils and regulation of other inflammatory/immune cells in the microenvironment of the distal lung. Genetic IL-5 deficiency offered marked protection of the lungs from metastasis of different types of tumor cells, including lung cancer, melanoma and colon cancer. IL-5 neutralization protected subjects from metastasis, whereas IL-5 reconstitution or adoptive transfer of eosinophils into IL-5 deficient mice exerted pro-metastatic effects. However, IL-5 deficiency did not affect the growth of the primary tumor or the size of metastatic lesions. Mechanistic investigations revealed that eosinophils produce CCL22, which recruits regulatory T cells (Treg) to the lungs. During early stages of metastasis Treg created a pro-tumorigenic microenvironment, potentially by suppressing IFNγ-producing natural killer cells and M1-polarized macrophages. Together, our results establish a network of allergic inflammatory circuitry that can be co-opted by metastatic cancer cells to facilitate lung colonization, suggesting interventions to target this pathway may offer therapeutic benefits to prevent or treat lung metastasis. PMID:25691457

  11. Microenvironment influences vascular differentiation of murine cardiovascular progenitor cells.

    PubMed

    Gluck, Jessica M; Delman, Connor; Chyu, Jennifer; MacLellan, W Robb; Shemin, Richard J; Heydarkhan-Hagvall, Sepideh

    2014-11-01

    We examined the effects of the microenvironment on vascular differentiation of murine cardiovascular progenitor cells (CPCs). We isolated CPCs and seeded them in culture exposed to the various extracellular matrix (ECM) proteins in both two-dimensional (2D) and 3D culture systems. To better understand the contribution of the microenvironment to vascular differentiation, we analyzed endothelial and smooth muscle cell differentiation at both day 7 and day 14. We found that laminin and vitronectin enhanced vascular endothelial cell differentiation while fibronectin enhanced vascular smooth muscle cell differentiation. We also observed that the effects of the 3D electrospun scaffolds were delayed and not noticeable until the later time point (day 14), which may be due to the amount of time necessary for the cells to migrate to the interior of the scaffold. The study characterized the contributions of both ECM proteins and the addition of a 3D culture system to continued vascular differentiation. Additionally, we demonstrated the capability bioengineer a CPC-derived vascular graft. PMID:24687591

  12. Stimuli-responsive nanoparticles for targeting the tumor microenvironment.

    PubMed

    Du, Jinzhi; Lane, Lucas A; Nie, Shuming

    2015-12-10

    One of the most challenging and clinically important goals in nanomedicine is to deliver imaging and therapeutic agents to solid tumors. Here we discuss the recent design and development of stimuli-responsive smart nanoparticles for targeting the common attributes of solid tumors such as their acidic and hypoxic microenvironments. This class of stimuli-responsive nanoparticles is inactive during blood circulation and under normal physiological conditions, but is activated by acidic pH, enzymatic up-regulation, or hypoxia once they extravasate into the tumor microenvironment. The nanoparticles are often designed to first "navigate" the body's vascular system, "dock" at the tumor sites, and then "activate" for action inside the tumor interstitial space. They combine the favorable biodistribution and pharmacokinetic properties of nanodelivery vehicles and the rapid diffusion and penetration properties of smaller drug cargos. By targeting the broad tumor habitats rather than tumor-specific receptors, this strategy has the potential to overcome the tumor heterogeneity problem and could be used to design diagnostic and therapeutic nanoparticles for a broad range of solid tumors. PMID:26341694

  13. Stromal senescence establishes an immunosuppressive microenvironment that drives tumorigenesis

    PubMed Central

    Ruhland, Megan K.; Loza, Andrew J.; Capietto, Aude-Helene; Luo, Xianmin; Knolhoff, Brett L.; Flanagan, Kevin C.; Belt, Brian A.; Alspach, Elise; Leahy, Kathleen; Luo, Jingqin; Schaffer, Andras; Edwards, John R.; Longmore, Gregory; Faccio, Roberta; DeNardo, David G.; Stewart, Sheila A.

    2016-01-01

    Age is a significant risk factor for the development of cancer. However, the mechanisms that drive age-related increases in cancer remain poorly understood. To determine if senescent stromal cells influence tumorigenesis, we develop a mouse model that mimics the aged skin microenvironment. Using this model, here we find that senescent stromal cells are sufficient to drive localized increases in suppressive myeloid cells that contributed to tumour promotion. Further, we find that the stromal-derived senescence-associated secretory phenotype factor interleukin-6 orchestrates both increases in suppressive myeloid cells and their ability to inhibit anti-tumour T-cell responses. Significantly, in aged, cancer-free individuals, we find similar increases in immune cells that also localize near senescent stromal cells. This work provides evidence that the accumulation of senescent stromal cells is sufficient to establish a tumour-permissive, chronic inflammatory microenvironment that can shelter incipient tumour cells, thus allowing them to proliferate and progress unabated by the immune system. PMID:27272654

  14. Stroma Cells in Tumor Microenvironment and Breast Cancer

    PubMed Central

    Mao, Yan; Keller, Evan T.; Garfield, David H.; Shen, Kunwei; Wang, Jianhua

    2015-01-01

    Cancer is a systemic disease, encompassing multiple components of both tumor cells themselves and host stromal cells. It is now clear that stromal cells in the tumor microenvironment play an important role in cancer development. Molecular events through which reactive stromal cells affect cancer cells can be defined so that biomarkers and therapeutic targets can be identified. Cancer-associated fibroblasts (CAFs) make up the bulk of cancer stroma and affect the tumor microenvironment such that they promote cancer initiation, angiogenesis, invasion and metastasis. In breast cancer, CAFs not only promote tumor progression, but also induce therapeutic resistances. Accordingly, targeting CAFs provides a novel way to control tumors with therapeutic resistances. This review summarizes the current understanding of tumor stroma in breast cancer with a particular emphasis on the role of CAFs and the therapeutic implications of CAFs. The effects of other stromal components such as endothelial cells, macrophages and adipocytes in breast cancer are also discussed. Finally, we describe the biologic markers to sort patients into a specific and confirmed subtype for personalized treatment. PMID:23114846

  15. Hedgehog signaling: networking to nurture a promalignant tumor microenvironment.

    PubMed

    Harris, Lillianne G; Samant, Rajeev S; Shevde, Lalita A

    2011-09-01

    In addition to its role in embryonic development, the Hedgehog pathway has been shown to be an active participant in cancer development, progression, and metastasis. Although this pathway is activated by autocrine signaling by Hedgehog ligands, it can also initiate paracrine signaling with cells in the microenvironment. This creates a network of Hedgehog signaling that determines the malignant behavior of the tumor cells. As a result of paracrine signal transmission, the effects of Hedgehog signaling most profoundly influence the stromal cells that constitute the tumor microenvironment. The stromal cells in turn produce factors that nurture the tumor. Thus, such a resonating cross-talk can amplify Hedgehog signaling, resulting in molecular chatter that overall promotes tumor progression. Inhibitors of Hedgehog signaling have been the subject of intense research. Several of these inhibitors are currently being evaluated in clinical trials. Here, we review the role of the Hedgehog pathway in the signature characteristics of cancer cells that determine tumor development, progression, and metastasis. This review condenses the latest findings on the signaling pathways that are activated and/or regulated by molecules generated from Hedgehog signaling in cancer and cites promising clinical interventions. Finally, we discuss future directions for identifying the appropriate patients for therapy, developing reliable markers of efficacy of treatment, and combating resistance to Hedgehog pathway inhibitors. PMID:21775419

  16. Stromal senescence establishes an immunosuppressive microenvironment that drives tumorigenesis.

    PubMed

    Ruhland, Megan K; Loza, Andrew J; Capietto, Aude-Helene; Luo, Xianmin; Knolhoff, Brett L; Flanagan, Kevin C; Belt, Brian A; Alspach, Elise; Leahy, Kathleen; Luo, Jingqin; Schaffer, Andras; Edwards, John R; Longmore, Gregory; Faccio, Roberta; DeNardo, David G; Stewart, Sheila A

    2016-01-01

    Age is a significant risk factor for the development of cancer. However, the mechanisms that drive age-related increases in cancer remain poorly understood. To determine if senescent stromal cells influence tumorigenesis, we develop a mouse model that mimics the aged skin microenvironment. Using this model, here we find that senescent stromal cells are sufficient to drive localized increases in suppressive myeloid cells that contributed to tumour promotion. Further, we find that the stromal-derived senescence-associated secretory phenotype factor interleukin-6 orchestrates both increases in suppressive myeloid cells and their ability to inhibit anti-tumour T-cell responses. Significantly, in aged, cancer-free individuals, we find similar increases in immune cells that also localize near senescent stromal cells. This work provides evidence that the accumulation of senescent stromal cells is sufficient to establish a tumour-permissive, chronic inflammatory microenvironment that can shelter incipient tumour cells, thus allowing them to proliferate and progress unabated by the immune system. PMID:27272654

  17. The role of the microenvironment in tumor growth and invasion

    PubMed Central

    Kim, Yangjin; Stolarska, Magdalena A.; Othmer, Hans G.

    2011-01-01

    Mathematical modeling and computational analysis are essential for understanding the dynamics of the complex gene networks that control normal development and homeostasis, and can help to understand how circumvention of that control leads to abnormal outcomes such as cancer. Our objectives here are to discuss the different mechanisms by which the local biochemical and mechanical microenvironment, which is comprised of various signaling molecules, cell types and the extracellular matrix (ECM), affects the progression of potentially-cancerous cells, and to present new results on two aspects of these effects. We first deal with the major processes involved in the progression from a normal cell to a cancerous cell at a level accessible to a general scientific readership, and we then outline a number of mathematical and computational issues that arise in cancer modeling. In Section 2 we present results from a model that deals with the effects of the mechanical properties of the environment on tumor growth, and in Section 3 we report results from a model of the signaling pathways and the tumor microenvironment (TME), and how their interactions affect the development of breast cancer. The results emphasize anew the complexities of the interactions within the TME and their effect on tumor growth, and show that tumor progression is not solely determined by the presence of a clone of mutated immortal cells, but rather that it can be ‘community-controlled’. It Takes a Village – Hilary Clinton PMID:21736894

  18. Tumor targeting and microenvironment-responsive nanoparticles for gene delivery.

    PubMed

    Huang, Shixian; Shao, Kun; Kuang, Yuyang; Liu, Yang; Li, Jianfeng; An, Sai; Guo, Yubo; Ma, Haojun; He, Xi; Jiang, Chen

    2013-07-01

    A tumor targeting nanoparticle system has been successfully developed to response to the lowered tumor extracellular pH (pHe) and upregulated matrix metalloproteinase 2 (MMP2) in the tumor microenvironment. The nanoparticles are modified with activatable cell-penetrating peptide (designated as dtACPP) that's dual-triggered by the lowered pHe and MMP2. In dtACPP, the internalization function of cell-penetrating peptide (CPP) is quenched by a pH-sensitive masking peptide, linking by a MMP2 substrate. The masking peptide is negatively charged to quench the cationic CPP well after systemic administration. Hence, dtACPP-modified nanoparticles possesses passive tumor targetability via the enhanced permeability and retention (EPR) effect. Once reaching the tumor microenvironment, the pre-existing attraction would be eliminated due to the lowered pHe, accompanying the linker cleaved by MMP2, dtACPP would be activated to expose CPP to drive the nanoparticles' internalization into the intratumoral cells. The studies of plasmid DNA loading, toxicity assessment, cellular uptake, tumor targeting delivery, and gene transfection demonstrate that dtACPP-modified nanoparticle system is a potential candidate for tumor targeting gene delivery. PMID:23562171

  19. Emergence of therapy resistance in multiple myeloma in heterogeneous microenvironment

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Zhang, Qiucen; Lambert, Guillaume; Khin, Zayar; Silva, Ariosto; Gatenby, Robert; Kim, Hyungsung; Pourmand, Nader; Austin, Robert; Sturm, James

    2014-03-01

    Cancer chemotherapy resistance is always a problem that is not clear considering spatial heterogeneity in the tumor microenvironment. We culture multiple myeloma in a gradient from 0 to 20 nM of doxorubicin (genotoxic drug) across 2 mm wide region in a microfluidic device which mimics the tumor microenvironment with a chemotherapy drug gradient and microhabitats. Resistance of the multiple myeloma cells to doxorubicin emerged within two weeks. For the resistant cells evolved from the devices, the doxorubicin concentration that inhibits 50% of the controlled population increased by 16-fold than the parental cells. Whole transcriptome sequencing revealed that 39% of newly acquired mutational hotspots (the genes with more than 3 non-synonymous point mutation) of the resistant cells are involved in apoptosis and DNA repair. On the other hand, 40% of the non-mutated genes that are abnormally regulated in the resistant cells, are involved in metabolism, biosynthesis, and biomolecular transport. Among them, metabolic drug efflux pumps and oxidative stress scavengers are up-regulated to reduce the cytotoxicity of doxorubicin and further result in the resistance. The roles of the spatial drug gradients and microhabitats in rapid emergence of cancer resistance will be discussed. The project described was supported by the National Science Foundation and the National Cancer Institute.

  20. Most Tissue-Resident Macrophages Except Microglia Are Derived from Fetal Hematopoietic Stem Cells.

    PubMed

    Sheng, Jianpeng; Ruedl, Christiane; Karjalainen, Klaus

    2015-08-18

    Macrophages are one of the most diverse cell populations in terms of their anatomical location and functional specialization during both homeostasis and disease. Although it has been shown in different fate mapping models that some macrophages present in adult tissues are already established during fetal development, their exact origins are still under debate. In the current study, we developed a fate mapping strain, based on the Kit locus, which allowed us to readdress "the origins" question. Different types of macrophages from various adult tissues were traced to their fetal or adult sources by inducing labeling in precursors at several time points either during fetal development or in adult mice. We show that all adult macrophages, resident or infiltrating, are progenies of classical hematopoietic stem cells (HSC) with the exception of microglia and, partially epidermal Langerhans cells, which are yolk sac (YS)-derived. PMID:26287683

  1. Hematopoietic tissue repair under chronic low daily dose irradiation

    SciTech Connect

    Seed, T.M.

    1994-12-01

    The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). We have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3{minus}26.3 cGy d{sup {minus}1}). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup (1), the failure to augment basic m-pair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments particularly marked within erythroid compartments. that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccomodated and either prone- or not prone to ML, subgroup 2 & 3 appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high- tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity.

  2. MiR-24 Promotes the Survival of Hematopoietic Cells

    PubMed Central

    Nguyen, Tan; Rich, Audrey; Dahl, Richard

    2013-01-01

    The microRNA, miR-24, inhibits B cell development and promotes myeloid development of hematopoietic progenitors. Differential regulation of cell survival in myeloid and lymphoid cells by miR-24 may explain how miR-24′s affects hematopoietic progenitors. MiR-24 is reported to regulate apoptosis, either positively or negatively depending on cell context. However, no role for miR-24 in regulating cell death has been previously described in blood cells. To examine miR-24′s effect on survival, we expressed miR-24 via retrovirus in hematopoietic cells and induced cell death with cytokine or serum withdrawal. We observed that miR-24 enhanced survival of myeloid and B cell lines as well as primary hematopoietic cells. Additionally, antagonizing miR-24 with shRNA in hematopoietic cells made them more sensitive to apoptotic stimuli, suggesting miR-24 functions normally to promote blood cell survival. Since we did not observe preferential protection of myeloid over B cells, miR-24′s pro-survival effect does not explain its promotion of myelopoiesis. Moreover, expression of pro-survival protein, Bcl-xL, did not mimic miR-24′s impact on cellular differentiation, further supporting this conclusion. Our results indicate that miR-24 is a critical regulator of hematopoietic cell survival. This observation has implications for leukemogenesis. Several miRNAs that regulate apoptosis have been shown to function as either tumor suppressors or oncogenes during leukemogenesis. MiR-24 is expressed highly in primary acute myelogenous leukemia, suggesting that its pro-survival activity could contribute to the transformation of hematopoietic cells. PMID:23383180

  3. Adult neurogenesis in the decapod crustacean brain: A hematopoietic connection?

    PubMed Central

    Beltz, Barbara S.; Zhang, Yi; Benton, Jeanne L.; Sandeman, David C.

    2011-01-01

    New neurons are produced and integrated into circuits in the adult brains of many organisms, including crustaceans. In some crustacean species, the 1st- generation neuronal precursors reside in a niche exhibiting characteristics analogous to mammalian neurogenic niches. However, unlike mammalian niches where several generations of neuronal precursors coexist, the lineage of precursor cells in crayfish is spatially separated allowing the influence of environmental and endogenous regulators on specific generations in the neuronal precursor lineage to be defined. Experiments also demonstrate that the 1st-generation neuronal precursors in the crayfish Procambarus clarkii are not self-renewing. A source external to the neurogenic niche must therefore provide cells that replenish the 1st-generation precursor pool, because although these cells divide and produce a continuous efflux of 2nd-generation cells from the niche, the population of 1st-generation niche precursors is not diminished with growth and aging. In vitro studies show that cells extracted from the hemolymph, but not other tissues, are attracted to and incorporated into the neurogenic niche, a phenomenon that appears to involve serotonergic mechanisms. We propose that in crayfish, the hematopoietic system may be a source of cells that replenish the niche cell pool. These and other studies reviewed here establish decapod crustaceans as model systems in which the processes underlying adult neurogenesis, such as stem cell origins and transformation, can be readily explored. Studies in diverse species where adult neurogenesis occurs will result in a broader understanding of fundamental mechanisms and how evolutionary processes may have shaped the vertebrate/mammalian condition. PMID:21929622

  4. Hematopoietic stem/progenitor cell commitment to the megakaryocyte lineage.

    PubMed

    Woolthuis, Carolien M; Park, Christopher Y

    2016-03-10

    The classical model of hematopoiesis has long held that hematopoietic stem cells (HSCs) sit at the apex of a developmental hierarchy in which HSCs undergo long-term self-renewal while giving rise to cells of all the blood lineages. In this model, self-renewing HSCs progressively lose the capacity for self-renewal as they transit into short-term self-renewing and multipotent progenitor states, with the first major lineage commitment occurring in multipotent progenitors, thus giving rise to progenitors that initiate the myeloid and lymphoid branches of hematopoiesis. Subsequently, within the myeloid lineage, bipotent megakaryocyte-erythrocyte and granulocyte-macrophage progenitors give rise to unipotent progenitors that ultimately give rise to all mature progeny. However, over the past several years, this developmental scheme has been challenged, with the origin of megakaryocyte precursors being one of the most debated subjects. Recent studies have suggested that megakaryocytes can be generated from multiple pathways and that some differentiation pathways do not require transit through a requisite multipotent or bipotent megakaryocyte-erythrocyte progenitor stage. Indeed, some investigators have argued that HSCs contain a subset of cells with biased megakaryocyte potential, with megakaryocytes directly arising from HSCs under steady-state and stress conditions. In this review, we discuss the evidence supporting these nonclassical megakaryocytic differentiation pathways and consider their relative strengths and weaknesses as well as the technical limitations and potential pitfalls in interpreting these studies. Ultimately, such pitfalls will need to be overcome to provide a comprehensive and definitive understanding of megakaryopoiesis. PMID:26787736

  5. Iron overload in hematopoietic cell transplantation.

    PubMed

    Majhail, N S; Lazarus, H M; Burns, L J

    2008-06-01

    Iron overload, primarily related to RBC transfusions, is a relatively common complication in hematopoietic cell transplant (HCT) recipients. Iron overload increases the risk of infections, veno-occlusive disease and hepatic dysfunction post transplant. Elevated pretransplant ferritin levels have been reported to increase the risk of nonrelapse mortality following HCT and might influence the risk of acute and chronic GVHD. Serum ferritin is sensitive but not specific for iron overload and is a poor predictor of body iron burden. Estimation of hepatic iron content with a liver biopsy or magnetic resonance imaging should be considered prior to initiating therapy for post transplant iron overload. A subgroup of transplant survivors with mild iron overload and no end-organ damage may not need therapy. Phlebotomy is the treatment of choice with iron-chelation therapy reserved for patients not eligible for phlebotomy. Natural history, evolution and treatment of iron overload in transplant survivors have not been adequately investigated and more studies are needed to determine its impact on short-term and long-term morbidity and mortality. PMID:18438425

  6. Allogeneic Hematopoietic Cell Transplant for Prolymphocytic Leukemia

    PubMed Central

    Kalaycio, Matt E.; Kukreja, Manisha; Woolfrey, Ann E.; Szer, Jeffrey; Cortes, Jorge; Maziarz, Richard T.; Bolwell, Brian J.; Buser, Andreas; Copelan, Edward; Gale, Robert Peter; Gupta, Vikas; Maharaj, Dipnarine; Marks, David I; Pavletic, Steven Z.; Horowitz, Mary M.; Arora, Mukta

    2009-01-01

    The poor prognosis of patients with prolymphocytic leukemia (PLL) has led some clinicians to recommend allogeneic hematopoietic cell transplant (HCT). However, the data to support this approach is limited to case-reports and small case-series. We reviewed the database of the Center for International Blood & Marrow Transplant Research to determine outcomes after allotransplant for patients with PLL. We identified 47 patients with a median age of 54 years (range, 30–75). With a median follow-up of 13 months, progression-free survival was 33% (95% Confidence Interval 20–47%) at 2 years. The most common cause of death was relapse or progression in 49%. The cumulative incidence of treatment-related mortality at 1-year post transplant was 28%. The small patient population prohibited prognostic factor analysis but these data support consideration of allotransplant for PLL. Further study of a larger population of patients is needed to determine which patients are more likely to benefit. PMID:19961946

  7. The regulation of hematopoietic stem cell populations

    PubMed Central

    Mayani, Hector

    2016-01-01

    Evidence presented over the last few years indicates that the hematopoietic stem cell (HSC) compartment comprises not just one but a number of different cell populations. Based on HSCs’ proliferation and engraftment potential, it has been suggested that there are two classes of HSC, with long- and short-term engraftment potential. HSC heterogeneity seems to involve differentiation capacities as well, since it has been shown that some HSC clones are able to give rise to both myeloid and lymphoid progeny, whereas others are lymphoid deficient. It has been recognized that HSC function depends on intrinsic cell regulators, which are modulated by external signals. Among the former, we can include transcription factors and non-coding RNAs as well as epigenetic modifiers. Among the latter, cytokines and extracellular matrix molecules have been implicated. Understanding the elements and mechanisms that regulate HSC populations is of significant relevance both in biological and in clinical terms, and research in this area still has to face several complex and exciting challenges. PMID:27408695

  8. Fertility issues following hematopoietic stem cell transplantation.

    PubMed

    Tichelli, André; Rovó, Alicia

    2013-08-01

    With the improvement of the outcome, the number of long-term survivors of hematopoietic stem cell transplantation (HSCT) is continuously increasing. However, there is still a high burden of late morbidity and mortality. Two-thirds of the transplant survivors develop at least one late effect interfering with their physical or psychological health. Infertility is common after myeloablative HSCT conditioned with total body irradiation and high doses of gonadotoxic drugs. Other factors, such as the age of the patient at transplantation, the treatment modality received before HSCT or the onset of chronic graft versus host disease, may play an additional role. Accordingly, the number of pregnancies observed after HSCT is very low when compared to a general population in childbearing age. Furthermore, complications during pregnancy and at delivery occur significantly more frequently, probably because of the uterine damages caused by irradiation therapy. However, there is no excess of congenital abnormalities observed among newborn children. Today there are good possibilities for fertility preservation. In male patients cryopreservation of sperm, and in female patients cryopreservation of fertilized embryos or of mature oocytes, are well-established treatment options. Patients' and physicians' attitude toward discussion on fertility issues play a key role in the success of fertility preservation after HSCT. PMID:23991924

  9. Unrelated hematopoietic stem cell registry and the role of the Hematopoietic Stem Cell Bank

    PubMed Central

    Beom, Su-Hee; Kim, Eung Jo; Kim, Miok

    2016-01-01

    Background The hematopoietic stem cell bank has been actively recruiting registrants since 1994. This study systematically reviews its operations and outcomes over the last 20 years. Methods Retrospective data on a total of 47,711 registrants were reviewed. Relevant data were processed using PASW Statistics for Windows, version 18.0. Results As of 2013, the Korean Network for Organ Sharing database contained 265,307 registrants. Of these, 49,037 (18%) registrants committed to hematopoietic cell donation from 1994 to 2013. Fifty-seven percent of the registrants were men, and 43% were women. The reasons for opting out of the registry included refusal to donate (70%), family refusal (28%), and others (2%). The donation willingness of registrants was significantly higher than those who refused to receive a mail to confirm their continued enrollment (χ2=6.103, P=0.013). The bank successfully coordinated a total of 512 donors among newly matched donors from 1995 to 2013, of which the bone marrow and peripheral blood stem cell accounted for 40.8% and 59.2% of the total donations, respectively. Conclusion Our recruitment activities focus on promoting voluntary registration and the importance of updating personal contact information. We expect that these data may be useful for diverse studies and demonstrate the positive impacts on the donation program. PMID:27382555

  10. Evidence that a lipolytic enzyme—hematopoietic-specific phospholipase C-β2—promotes mobilization of hematopoietic stem cells by decreasing their lipid raft-mediated bone marrow retention and increasing the promobilizing effects of granulocytes

    PubMed Central

    Adamiak, M; Poniewierska-Baran, A; Borkowska, S; Schneider, G; Abdelbaset-Ismail, A; Suszynska, M; Abdel-Latif, A; Kucia, M; Ratajczak, J; Ratajczak, M Z

    2016-01-01

    Hematopoietic stem/progenitor cells (HSPCs) reside in the bone marrow (BM) microenvironment and are retained there by the interaction of membrane lipid raft-associated receptors, such as the α-chemokine receptor CXCR4 and the α4β1-integrin (VLA-4, very late antigen 4 receptor) receptor, with their respective specific ligands, stromal-derived factor 1 and vascular cell adhesion molecule 1, expressed in BM stem cell niches. The integrity of the lipid rafts containing these receptors is maintained by the glycolipid glycosylphosphatidylinositol anchor (GPI-A). It has been reported that a cleavage fragment of the fifth component of the activated complement cascade, C5a, has an important role in mobilizing HSPCs into the peripheral blood (PB) by (i) inducing degranulation of BM-residing granulocytes and (ii) promoting their egress from the BM into the PB so that they permeabilize the endothelial barrier for subsequent egress of HSPCs. We report here that hematopoietic cell-specific phospholipase C-β2 (PLC-β2) has a crucial role in pharmacological mobilization of HSPCs. On the one hand, when released during degranulation of granulocytes, it digests GPI-A, thereby disrupting membrane lipid rafts and impairing retention of HSPCs in BM niches. On the other hand, it is an intracellular enzyme required for degranulation of granulocytes and their egress from BM. In support of this dual role, we demonstrate that PLC-β2-knockout mice are poor mobilizers and provide, for the first time, evidence for the involvement of this lipolytic enzyme in the mobilization of HSPCs. PMID:26582648

  11. Hematopoietic Stem Cell Niche in Health and Disease.

    PubMed

    Hoggatt, Jonathan; Kfoury, Youmna; Scadden, David T

    2016-05-23

    Regulation of stem cells in adult tissues is a key determinant of how well an organism can respond to the stresses of physiological challenge and disease. This is particularly true of the hematopoietic system, where demands on host defenses can call for an acute increase in cell production. Hematopoietic stem cells receive the regulatory signals for cell production in adult mammals in the bone marrow, a tissue with higher-order architectural and functional organization than previously appreciated. Here, we review the data defining particular structural components and heterologous cells in the bone marrow that participate in hematopoietic stem cell function. Further, we explore the case for stromal-hematopoietic cell interactions contributing to neoplastic myeloid disease. As the hematopoietic regulatory networks in the bone marrow are revealed, it is anticipated that strategies will emerge for how to enhance or inhibit production of specific blood cells. In that way, the control of hematopoiesis will enter the domain of therapies to modulate broad aspects of hematopoiesis, both normal and malignant. PMID:27193455

  12. Novel approaches and mechanisms in hematopoietic stem cell gene therapy.

    PubMed

    Bigger, Brian W; Wynn, Robert F

    2014-04-01

    Hematopoietic stem cell gene therapy is one of the most exciting clinical tools to emerge from the gene therapy stable. This technology combines the expansion capability of hematopoietic stem cells, capable of replacing the entire blood and immune system of an individual, with the capacity for long-term replacement of one or more gene copies using integrating gene therapy vectors. Hematopoietic stem cell gene therapy benefits significantly from the pre-existing experience of standard blood and marrow transplantation, whilst at the same time having the capacity to deliver a safer and more effective therapy to a wider range of diseases. In this review we summarize the potential of hematopoietic stem cell gene therapy to expand the scope of hematopoietic stem cell transplantation, including the evolution of vector delivery systems and the success and failures of current clinical experience with this treatment. In particular we deal with the incidence of vector mediated transformation in patients and the steps that have been taken to minimize this risk. Finally we discuss the innovations in preclinical development that are likely to drive the future of this field, including the expansion to many more genetic diseases, particularly those affecting the brain. PMID:24759625

  13. Hematopoietic Stem Cell Regulation by Type I and II Interferons in the Pathogenesis of Acquired Aplastic Anemia

    PubMed Central

    Smith, Julianne N. P.; Kanwar, Vikramjit S.; MacNamara, Katherine C.

    2016-01-01

    Aplastic anemia (AA) occurs when the bone marrow fails to support production of all three lineages of blood cells, which are necessary for tissue oxygenation, infection control, and hemostasis. The etiology of acquired AA is elusive in the vast majority of cases but involves exhaustion of hematopoietic stem cells (HSC), which are usually present in the bone marrow in a dormant state, and are responsible for lifelong production of all cells within the hematopoietic system. This destruction is immune mediated and the role of interferons remains incompletely characterized. Interferon gamma (IFNγ) has been associated with AA and type I IFNs (alpha and beta) are well documented to cause bone marrow aplasia during viral infection. In models of infection and inflammation, IFNγ activates HSCs to differentiate and impairs their ability to self-renew, ultimately leading to HSC exhaustion. Recent evidence demonstrating that IFNγ also impacts the HSC microenvironment or niche, raises new questions regarding how IFNγ impairs HSC function in AA. Immune activation can also elicit type I interferons, which may exert effects both distinct from and overlapping with IFNγ on HSCs. IFNα/β increase HSC proliferation in models of sterile inflammation induced by polyinosinic:polycytidylic acid and lead to BM aplasia during viral infection. Moreover, patients being treated with IFNα exhibit cytopenias, in part due to BM suppression. Herein, we review the current understanding of how interferons contribute to the pathogenesis of acquired AA, and we explore additional potential mechanisms by which interferons directly and indirectly impair HSCs. A comprehensive understanding of how interferons impact hematopoiesis is necessary in order to identify novel therapeutic approaches for treating AA patients. PMID:27621733

  14. Distribution of dystrophin- and utrophin-associated protein complexes (DAPC/UAPC) in human hematopoietic stem/progenitor cells.

    PubMed

    Teniente-De Alba, Carmen; Martínez-Vieyra, Ivette; Vivanco-Calixto, Raúl; Galván, Iván J; Cisneros, Bulmaro; Cerecedo, Doris

    2011-10-01

    Hematopoietic stem cells (HSC) are defined by their cardinal properties, such as sustained proliferation, multilineage differentiation, and self-renewal, which give rise to a hierarchy of progenitor populations with more restricted potential lineage, ultimately leading to the production of all types of mature blood cells. HSC are anchored by cell adhesion molecules to their specific microenvironment, thus regulating their cell cycle, while cell migration is essentially required for seeding the HSC of the fetal bone marrow (BM) during development as well as in adult BM homeostasis. The dystrophin-associated protein complex (DAPC) is a large group of membrane-associated proteins linking the cytoskeleton to the extracellular matrix and exhibiting scaffolding, adhesion, and signaling roles in muscle and non-muscle cells including mature blood cells. Because adhesion and migration are mechanisms that influence the fate of the HSC, we explored the presence and the feasible role of DAPC. In this study, we characterized the pattern expression by immunoblot technique and, by confocal microscopy analysis, the cellular distribution of dystrophin and utrophin gene products, and the dystrophin-associated proteins (α-, β-dystroglycan, α-syntrophin, α-dystrobrevin) in relation to actin filaments in freshly isolated CD34+ cells from umbilical cord blood. Immunoprecipitation assays demonstrated the presence of Dp71d/Dp71Δ110m ∼DAPC and Up400/Up140∼DAPC. The subcellular distribution of the two DAPC in actin-based structures suggests their dynamic participation in adhesion and cell migration. In addition, the particular protein pattern expression found in hematopoietic stem/progenitor cells might be indicative of their feasible participation during differentiation. PMID:21623922

  15. Hematopoietic Stem Cell Regulation by Type I and II Interferons in the Pathogenesis of Acquired Aplastic Anemia.

    PubMed

    Smith, Julianne N P; Kanwar, Vikramjit S; MacNamara, Katherine C

    2016-01-01

    Aplastic anemia (AA) occurs when the bone marrow fails to support production of all three lineages of blood cells, which are necessary for tissue oxygenation, infection control, and hemostasis. The etiology of acquired AA is elusive in the vast majority of cases but involves exhaustion of hematopoietic stem cells (HSC), which are usually present in the bone marrow in a dormant state, and are responsible for lifelong production of all cells within the hematopoietic system. This destruction is immune mediated and the role of interferons remains incompletely characterized. Interferon gamma (IFNγ) has been associated with AA and type I IFNs (alpha and beta) are well documented to cause bone marrow aplasia during viral infection. In models of infection and inflammation, IFNγ activates HSCs to differentiate and impairs their ability to self-renew, ultimately leading to HSC exhaustion. Recent evidence demonstrating that IFNγ also impacts the HSC microenvironment or niche, raises new questions regarding how IFNγ impairs HSC function in AA. Immune activation can also elicit type I interferons, which may exert effects both distinct from and overlapping with IFNγ on HSCs. IFNα/β increase HSC proliferation in models of sterile inflammation induced by polyinosinic:polycytidylic acid and lead to BM aplasia during viral infection. Moreover, patients being treated with IFNα exhibit cytopenias, in part due to BM suppression. Herein, we review the current understanding of how interferons contribute to the pathogenesis of acquired AA, and we explore additional potential mechanisms by which interferons directly and indirectly impair HSCs. A comprehensive understanding of how interferons impact hematopoiesis is necessary in order to identify novel therapeutic approaches for treating AA patients. PMID:27621733

  16. [Umbilical cord hematopoietic progenitor cells bank].

    PubMed

    Morales, V H; Milone, J; Etchegoyen, O; Bordone, J; Uranga, A

    2001-01-01

    Transplantation of hematopoietic progenitor cells (HPC) from bone marrow and mobilized peripheral blood is a standard therapy in malignant and non malignant diseases. The lack of suitable donors is an important limitation. The discovery that umbilical cord blood (CB) contains high numbers of HPC that can be used as an alternative source for allogeneic stem cell transplantation led ITMO to establish BANCEL, the first Argentine and Latinoamerican experience of its kind. The blood remaining in the umbilical cord and in the placenta was requested from women who were in the last quarter of pregnancy. An informed consent together with a medical record focused on family disease was completed. Out of 65 donations, 55 (85%) were collected and 51 (78%) were cryopreserved. Mean collected volume was 110 ml with 68% (75 ml) reduction and mean cryopreservation of 35 ml; ABO and Rh blood group systems were determined, HLA, class I, A and B loci, and class II, DR locus were typed by molecular biology methods using PCR-SSOP. Infectious disease screening was carried out for brucellosis, syphilis, Chagas, hepatitis B and C, HIV I and II, HTLV I and II, toxoplasmosis and cytomegalovirus. Two positive units for hepatitis B (anticore) and two positive units for Chagas were discarded. The quantity of total nucleated cells (TNC), CD34+ cells and the clonogenic capacity were determined twice at the collection and after the procedures of volume reduction previous to cryopreservation. A 5% reduction in both TNC and CD34 cells and a 10% in the colony forming units (CFU) were detected. A good correlation coefficient between TNC and CFU was obtained. PMID:11808425

  17. Hematopoietic stem cell transplantation for infantile osteopetrosis

    PubMed Central

    Fasth, Anders L.; Le Rademacher, Jennifer; He, Wensheng; Boelens, Jaap Jan; Horwitz, Edwin M.; Al-Seraihy, Amal; Ayas, Mouhab; Bonfim, Carmem M.; Boulad, Farid; Lund, Troy; Buchbinder, David K.; Kapoor, Neena; O’Brien, Tracey A.; Perez, Miguel A. Diaz; Veys, Paul A.; Eapen, Mary

    2015-01-01

    We report the international experience in outcomes after related and unrelated hematopoietic transplantation for infantile osteopetrosis in 193 patients. Thirty-four percent of transplants used grafts from HLA-matched siblings, 13% from HLA-mismatched relatives, 12% from HLA-matched, and 41% from HLA-mismatched unrelated donors. The median age at transplantation was 12 months. Busulfan and cyclophosphamide was the most common conditioning regimen. Long-term survival was higher after HLA-matched sibling compared to alternative donor transplantation. There were no differences in survival after HLA-mismatched related, HLA-matched unrelated, or mismatched unrelated donor transplantation. The 5- and 10-year probabilities of survival were 62% and 62% after HLA-matched sibling and 42% and 39% after alternative donor transplantation (P = .01 and P = .002, respectively). Graft failure was the most common cause of death, accounting for 50% of deaths after HLA-matched sibling and 43% of deaths after alternative donor transplantation. The day-28 incidence of neutrophil recovery was 66% after HLA-matched sibling and 61% after alternative donor transplantation (P = .49). The median age of surviving patients is 7 years. Of evaluable surviving patients, 70% are visually impaired; 10% have impaired hearing and gross motor delay. Nevertheless, 65% reported performance scores of 90 or 100, and in 17%, a score of 80 at last contact. Most survivors >5 years are attending mainstream or specialized schools. Rates of veno-occlusive disease and interstitial pneumonitis were high at 20%. Though allogeneic transplantation results in long-term survival with acceptable social function, strategies to lower graft failure and hepatic and pulmonary toxicity are urgently needed. PMID:26012570

  18. Strength Training Following Hematopoietic Stem Cell Transplantation

    PubMed Central

    Hacker, Eileen Danaher; Larson, Janet; Kujath, Amber; Peace, David; Rondelli, Damiano; Gaston, Lisa

    2010-01-01

    Background Patients receiving high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) experience considerable reductions in physical activity and deterioration of their health status. Objective The purpose of this pilot study was to test the effects of strength training compared to usual activity on physical activity, muscle strength, fatigue, health status perceptions, and quality of life following HSCT. Interventions/Methods Nineteen subjects were randomized to the exercise or control group. Moderate intensity strength training began following discharge from the hospital. Dependent variables included physical activity, muscle strength, fatigue, health status perceptions and quality of life. Variables were measured prior to admission to the hospital for HSCT, day 8 following HSCT, and six weeks following discharge from the hospital. Results Significant time effects were noted for many variables with anticipated declines in physical activity, muscle strength, fatigue, and health status perceptions immediately after HSCT with subsequent improvements six weeks following hospital discharge. One group effect was noted with subjects in the exercise group reporting less fatigue than subjects in the control group. Although no significant interactions were detected, the trends suggest that the exercise group may be more physically active following the intervention compared to the usual activity group. Conclusions This study demonstrates the potential positive effects of strength training on physical activity, fatigue, and quality of life in people receiving high-dose chemotherapy and HSCT. Implications for Practice Preliminary evidence is provided for using strength training to enhance early recovery following HSCT. Elastic resistance bands are easy to use and relatively inexpensive. PMID:21116175

  19. Hematopoietic Cell Transplantation for Myelodysplastic Syndromes.

    PubMed

    Bhatt, Vijaya Raj; Steensma, David P

    2016-09-01

    Allogeneic hematopoietic cell transplantation (HCT) offers the only potential cure for patients with myelodysplastic syndromes (MDS). However, with current approaches to HCT, many older patients with comorbidities are poor HCT candidates, and treatment-related morbidity and mortality may offset benefit for patients with lower-risk disease. Consequently, selection of patients with MDS for HCT should take into consideration disease risk category including mutational status, HCT comorbidity index, functional status, donor options, and available institutional resources. Formal geriatric assessment may further guide use of HCT and, if HCT is chosen, selection of conditioning intensity. Patients with higher-risk MDS should be considered for HCT at the time of diagnosis, whereas expectant nontransplant management is more appropriate for those with lower-risk disease. A high blast burden at the time of HCT increases the risk of subsequent relapse; however, the role of pretransplant cytoreductive therapy and the regimen of choice remain controversial. Patients with MDS younger than 65 years and with an HCT comorbidity index ≤ 4 may benefit from more intense conditioning regimens. The presence of complex or monosomal karyotype or mutations in TP53, DNMT3A, or other genes identify patients with poorer outcomes following HCT. Patients with TP53 mutations have particularly poor survival, and should be enrolled in clinical trials whenever possible. Several important HCT studies are ongoing and will better define the role of HCT in MDS as well as the value of pretransplant cytoreductive therapy or post-transplant relapse-prevention strategies. Given the apparent underuse of HCT in eligible patients and low enrollment in MDS HCT clinical trials to date, timely referral of patients with MDS to such trials and HCT programs is critical. PMID:27621329

  20. Hematopoietic stem cell transplantation A Global Perspective

    PubMed Central

    Gratwohl, Alois; Baldomero, Helen; Aljurf, Mahmoud; Pasquini, Marcelo C.; Bouzas, Luis Fernando; Yoshimi, Ayami; Szer, Jeff; Lipton, Jeff; Schwendener, Alvin; Gratwohl, Michael; Frauendorfer, Karl; Niederwieser, Dietger; Horowitz, Mary; Kodera, Yoshihisa

    2011-01-01

    Context Hematopoietic stem cell transplantation (HSCT) requires significant infrastructure. Little is known on its use and the factors associated with it on a global level. Objective To determine current use of HSCT, to assess differences in its application and to explore associations of macroeconomic factors with transplant rates on a global level. Design Structured worldwide collection of numbers of allogeneic and autologous HSCT by main indication, donor type and stem cell source for the year 2006. Setting Worldwide Network for Blood and Marrow Transplantation (WBMT), a global non-profit umbrella organization for clinical HSCT. Patients All patients with an allogeneic or autologous HSCT for any indication transplanted in 2006 within any of the participating countries. Interventions none Main Outcome measures Transplant rates (number of HSCT per 10 million inhabitants) by indication, donor type and country; description of main differences in HSCT use; macroeconomic factors of reporting countries associated with transplant rates. Results There were 50’417 first HSCT, 21’516 allogeneic (43%), 28’901 autologous (57%) reported from 1’327 centers in 71 countries for leukemia (17’049 (34%; 89% allogeneic)), lymphoma (27’492 (54%; 87% autologous)), solid tumors (2’925 (6%, 95% autologous)), non-malignant disorder (2’593 (5%; 92% allogeneic)) or, “others” 358 (1%). Use of allogeneic or autologous HSCT, use of unrelated or family donors for allogeneic HSCT and proportions of disease indications varied significantly between countries and continental regions. In linear regression analyses, Government Health Care Expenditures (r2 = 77.33), team density (r2 =76.28), Human Development Index (r2 = 74.36) and Gross National Income /Capita (r2 = 74.04) showed the highest association with transplant rates. Conclusions HSCT is an accepted therapy today with different use and needs worldwide. Availability of resources, Governmental support and, access for

  1. Hematopoietic stem cell transplantation for infantile osteopetrosis.

    PubMed

    Orchard, Paul J; Fasth, Anders L; Le Rademacher, Jennifer; He, Wensheng; Boelens, Jaap Jan; Horwitz, Edwin M; Al-Seraihy, Amal; Ayas, Mouhab; Bonfim, Carmem M; Boulad, Farid; Lund, Troy; Buchbinder, David K; Kapoor, Neena; O'Brien, Tracey A; Perez, Miguel A Diaz; Veys, Paul A; Eapen, Mary

    2015-07-01

    We report the international experience in outcomes after related and unrelated hematopoietic transplantation for infantile osteopetrosis in 193 patients. Thirty-four percent of transplants used grafts from HLA-matched siblings, 13% from HLA-mismatched relatives, 12% from HLA-matched, and 41% from HLA-mismatched unrelated donors. The median age at transplantation was 12 months. Busulfan and cyclophosphamide was the most common conditioning regimen. Long-term survival was higher after HLA-matched sibling compared to alternative donor transplantation. There were no differences in survival after HLA-mismatched related, HLA-matched unrelated, or mismatched unrelated donor transplantation. The 5- and 10-year probabilities of survival were 62% and 62% after HLA-matched sibling and 42% and 39% after alternative donor transplantation (P = .01 and P = .002, respectively). Graft failure was the most common cause of death, accounting for 50% of deaths after HLA-matched sibling and 43% of deaths after alternative donor transplantation. The day-28 incidence of neutrophil recovery was 66% after HLA-matched sibling and 61% after alternative donor transplantation (P = .49). The median age of surviving patients is 7 years. Of evaluable surviving patients, 70% are visually impaired; 10% have impaired hearing and gross motor delay. Nevertheless, 65% reported performance scores of 90 or 100, and in 17%, a score of 80 at last contact. Most survivors >5 years are attending mainstream or specialized schools. Rates of veno-occlusive disease and interstitial pneumonitis were high at 20%. Though allogeneic transplantation results in long-term survival with acceptable social function, strategies to lower graft failure and hepatic and pulmonary toxicity are urgently needed. PMID:26012570

  2. Water permeation drives tumor cell migration in confined microenvironments.

    PubMed

    Stroka, Kimberly M; Jiang, Hongyuan; Chen, Shih-Hsun; Tong, Ziqiu; Wirtz, Denis; Sun, Sean X; Konstantopoulos, Konstantinos

    2014-04-24

    Cell migration is a critical process for diverse (patho)physiological phenomena. Intriguingly, cell migration through physically confined spaces can persist even when typical hallmarks of 2D planar migration, such as actin polymerization and myosin II-mediated contractility, are inhibited. Here, we present an integrated experimental and theoretical approach ("Osmotic Engine Model") and demonstrate that directed water permeation is a major mechanism of cell migration in confined microenvironments. Using microfluidic and imaging techniques along with mathematical modeling, we show that tumor cells confined in a narrow channel establish a polarized distribution of Na+/H+ pumps and aquaporins in the cell membrane, which creates a net inflow of water and ions at the cell leading edge and a net outflow of water and ions at the trailing edge, leading to net cell displacement. Collectively, this study presents an alternate mechanism of cell migration in confinement that depends on cell-volume regulation via water permeation. PMID:24726433

  3. Electrical stimuli in the central nervous system microenvironment.

    PubMed

    Thompson, Deanna M; Koppes, Abigail N; Hardy, John G; Schmidt, Christine E

    2014-07-11

    Electrical stimulation to manipulate the central nervous system (CNS) has been applied as early as the 1750s to produce visual sensations of light. Deep brain stimulation (DBS), cochlear implants, visual prosthetics, and functional electrical stimulation (FES) are being applied in the clinic to treat a wide array of neurological diseases, disorders, and injuries. This review describes the history of electrical stimulation of the CNS microenvironment; recent advances in electrical stimulation of the CNS, including DBS to treat essential tremor, Parkinson's disease, and depression; FES for the treatment of spinal cord injuries; and alternative electrical devices to restore vision and hearing via neuroprosthetics (retinal and cochlear implants). It also discusses the role of electrical cues during development and following injury and, importantly, manipulation of these endogenous cues to support regeneration of neural tissue. PMID:25014787

  4. mTOR: taking cues from the immune microenvironment

    PubMed Central

    Delgoffe, Greg M; Powell, Jonathan D

    2009-01-01

    The ultimate outcome of T cell receptor recognition is determined by the context in which the antigen is encountered. In this fashion both antigen-presenting cells and T cells must integrate multiple environmental cues in the form of pathogen-associated molecular patterns, cytokines and accessory molecule signals. The mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that plays a central role in integrating environmental signals critical to regulating metabolism and cell survival. In this paper we review the data demonstrating that mTOR integrates signals from the immune microenvironment and therefore facilitates the generation of the adaptive immune response. Specifically, we review the role of mTOR in promoting dendritic cell activation and maturation, in regulating full T cell activation versus anergy, and influencing the induction of regulatory T cells. PMID:19604300

  5. Tumor Microenvironment Complexity: Emerging Roles in Cancer Therapy

    PubMed Central

    Swartz, Melody A.; Iida, Noriho; Roberts, Edward W.; Sangaletti, Sabina; Wong, Melissa H.; Yull, Fiona E.; Coussens, Lisa M.; DeClerck, Yves A.

    2013-01-01

    The tumor microenvironment (TME) consists of cells, soluble factors, signaling molecules, extracellular matrix, and mechanical cues that can promote neoplastic transformation, support tumor growth and invasion, protect the tumor from host immunity, foster therapeutic resistance, and provide niches for dormant metastases to thrive. An American Association for Cancer Research (AACR) special conference held on November 3–6, 2011, addressed five emerging concepts in our understanding of the TME: its dynamic evolution, how it is educated by tumor cells, pathways of communication between stromal and tumor cells, immunomodulatory roles of the lymphatic system, and contribution of the intestinal microbiota. These discussions raised critical questions on how to include the analysis of the TME in personalized cancer diagnosis and treatment. PMID:22414581

  6. Viscoelastic Imaging of Breast Tumor Microenvironment With Ultrasound

    PubMed Central

    Insana, Michael F.; Pellot-Barakat, Claire; Sridhar, Mallika; Lindfors, Karen K.

    2009-01-01

    Imaging systems are most effective for detection and classification when they exploit contrast mechanisms specific to particular disease processes. A common example is mammography, where the contrast depends on local changes in cell density and the presence of microcalcifications. Unfortunately the specificity for classifying malignant breast disease is relatively low for many current diagnostic techniques. This paper describes a new ultrasonic technique for imaging the viscoelastic properties of breast tissue. The mechanical properties of glandular breast tissue, like most biopolymers, react to mechanical stimuli in a manner specific to the microenvironment of the tissue. Elastic properties allow noninvasive imaging of desmoplasia while viscous properties describe metabolism-dependent features such as pH. These ultrasonic methods are providing new tools for studying disease mechanisms as well as improving diagnosis. PMID:15838608

  7. Biomolecule Delivery to Engineer the Cellular Microenvironment for Regenerative Medicine

    PubMed Central

    Bishop, Corey J.; Kim, Jayoung; Green, Jordan J.

    2013-01-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing. PMID:24170072

  8. Chemokines and the microenvironment in neuroectodermal tumor-host interaction

    PubMed Central

    Somasundaram, Rajasekharan; Herlyn, Dorothee

    2009-01-01

    Chemokines and chemokine receptors play an important role in immune homeostasis and surveillance. Altered or defective expression of chemokines and/or chemokine receptors could lead to a disease state including autoimmune disorder or cancer. Tumors from glioblastoma, melanoma, and neuroblastoma secrete high levels of chemokines that can promote tumor growth and progression or induce stromal cells present in the tumor microenvironment to produce cytokines or chemokines which, in turn, can regulate angiogenesis, tumor growth, and metastasis. On the other hand, chemokines secreted by tumor or stromal cells can also attract leukocytes such as dendritic cells, macrophages, neutrophils, and lymphocytes which may downmodulate tumor growth. New therapies that are aimed at limiting tumor growth and progression by attracting immune effector cells to the tumor site with chemokines may hold the key to the successful treatment of cancer, although this approach may be hampered by possible tumor growth-stimulating effects of chemokines. PMID:19049876

  9. Temperature of the magnetic nanoparticle microenvironment: estimation from relaxation times

    NASA Astrophysics Data System (ADS)

    Perreard, I. M.; Reeves, D. B.; Zhang, X.; Kuehlert, E.; Forauer, E. R.; Weaver, J. B.

    2014-03-01

    Accurate temperature measurements are essential to safe and effective thermal therapies for cancer and other diseases. However, conventional thermometry is challenging so using the heating agents themselves as probes allows for ideal local measurements. Here, we present a new noninvasive method for measuring the temperature of the microenvironment surrounding magnetic nanoparticles from the Brownian relaxation time of nanoparticles. Experimentally, the relaxation time can be determined from the nanoparticle magnetization induced by an alternating magnetic field at various applied frequencies. A previously described method for nanoparticle temperature estimation used a low frequency Langevin function description of magnetic dipoles and varied the excitation field amplitude to estimate the energy state distribution and the corresponding temperature. We show that the new method is more accurate than the previous method at higher applied field frequencies that push the system farther from equilibrium.

  10. HIV-1 infection, microenvironment and endothelial cell dysfunction.

    PubMed

    Mazzuca, Pietro; Caruso, Arnaldo; Caccuri, Francesca

    2016-09-01

    HIV-1 promotes a generalized immune activation that involves the main targets of HIV-1 infection but also cells that are not sensitive to viral infection. ECs display major dysfunctions in HIV+ patients during long-standing viral infection that persist even in the current cART era, in which new-generation drugs have reduced dysmetabolic side effects and successfully impeded viral replication. In vivo studies have failed to demonstrate the presence of replicating virus in ECs suggesting that a direct role of the virus is unlikely, and implying that the mechanism accounting for vascular dysfunction may rely on the indirect action of molecules released in the microenvironment by HIV-1-infected cells. This article reviews the current understanding of how HIV-1 infection can contribute to vascular dysfunction. In particular, we discuss the emerging role played by different HIV-1 proteins in driving inflammation and EC dysregulation, and highlight the need to target them for therapeutic benefit. PMID:27602413

  11. Water Permeation Drives Tumor Cell Migration in Confined Microenvironments

    PubMed Central

    Stroka, Kimberly M.; Jiang, Hongyuan; Chen, Shih-Hsun; Tong, Ziqiu; Wirtz, Denis; Sun, Sean X.; Konstantopoulos, Konstantinos

    2014-01-01

    SUMMARY Cell migration is a critical process for diverse (patho) physiological phenomena. Intriguingly, cell migration through physically confined spaces can persist even when typical hallmarks of 2D planar migration, such as actin polymerization and myosin II-mediated contractility, are inhibited. Here, we present an integrated experimental and theoretical approach (“Osmotic Engine Model”) and demonstrate that directed water permeation is a major mechanism of cell migration in confined microenvironments. Using microfluidic and imaging techniques along with mathematical modeling, we show that tumor cells confined in a narrow channel establish a polarized distribution of Na+/H+ pumps and aquaporins in the cell membrane, which creates a net inflow of water and ions at the cell leading edge and a net outflow of water and ions at the trailing edge, leading to net cell displacement. Collectively, this study presents an alternate mechanism of cell migration in confinement that depends on cell-volume regulation via water permeation. PMID:24726433

  12. Inflammatory microenvironment and human papillomavirus-induced carcinogenesis.

    PubMed

    Mangino, Giorgio; Chiantore, Maria Vincenza; Iuliano, Marco; Fiorucci, Gianna; Romeo, Giovanna

    2016-08-01

    More than 15% of the global cancer burden is attributable to infectious agents. Pathogens that cause persistent infections are strongly associated with cancer, inflammation being a major component of the chronic infections as revealed by basic, clinical and epidemiological studies. Persistent infection and viral oncoproteins induce specific cellular pathways modifications that promote tumorigenesis. Deregulated and continuous immune response leads to severe tissue and systemic damage, impaired tumor surveillance and consequent carcinogenesis promotion by selecting for metastatic and therapeutically resistant tumor phenotypes. In this review, the role of inflammatory microenvironment in the HPV-induced carcinogenesis is addressed, with a specific focus on the involvement of the immune molecules and microRNAs as well as their delivery through the microvesicle cargo. PMID:27021827

  13. Neuro-immune modulation of the thymus microenvironment (review).

    PubMed

    Mignini, Fiorenzo; Sabbatini, Maurizio; Mattioli, Laura; Cosenza, Monica; Artico, Marco; Cavallotti, Carlo

    2014-06-01

    The thymus is the primary site for T-cell lympho-poiesis. Its function includes the maturation and selection of antigen specific T cells and selective release of these cells to the periphery. These highly complex processes require precise parenchymal organization and compartmentation where a plethora of signalling pathways occur, performing strict control on the maturation and selection processes of T lymphocytes. In this review, the main morphological characteristics of the thymus microenvironment, with particular emphasis on nerve fibers and neuropeptides were assessed, as both are responsible for neuro-immune‑modulation functions. Among several neurotransmitters that affect thymus function, we highlight the dopaminergic system as only recently has its importance on thymus function and lymphocyte physiology come to light. PMID:24676230

  14. More than the genes, the tumor microenvironment in neuroblastoma.

    PubMed

    Borriello, Lucia; Seeger, Robert C; Asgharzadeh, Shahab; DeClerck, Yves A

    2016-09-28

    Neuroblastoma is the second most common solid tumor in children. Since the seminal discovery of the role of amplification of the MYCN oncogene in the pathogenesis of neuroblastoma in the 1980s, much focus has been on the contribution of genetic alterations in the progression of this cancer. However it is now clear that not only genetic events play a role but that the tumor microenvironment (TME) substantially contributes to the biology of neuroblastoma. In this article, we present a comprehensive review of the literature on the contribution of the TME to the ten hallmarks of cancer in neuroblastoma and discuss the mechanisms of communication between neuroblastoma cells and the TME that underlie the influence of the TME on neuroblastoma progression. We end our review by discussing how the knowledge acquired over the last two decades in this field is now leading to new clinical trials targeting the TME. PMID:26597947

  15. Cancer-stroma evolutionary dynamics in stress-gradient microenvironment

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Lambert, Guillaume; Austin, Robert; Sturm, James; Khin, Zayar; Silva, Ariosto

    2012-02-01

    In order to study the evolution of drug resistance in cancer, it is important to mimic the tumor microenvironment, in which cells are exposed to not uniform concentrations but rather gradients of drugs, nutrients, and other factors Compared to traditional in-vitro methods, microfluidic structure enables better control of the temporal and spatial profile of gradients. Here we demonstrate a microfluidic Doxorubicin gradient environment with heterogeneous landscape, and culture multiple myeloma (8226-S, expressing RFP) and bone marrow stroma (HS-5, expressing GFP) cell lines together. The myeloma cells are not directly motile, but they are able to migrate via the adhesion to motile stroma cells. The indirect motility mechanism of the myeloma cells is crucial for the adaptation to stress environment. Finally, we will report the co-culture dynamics under the stress of doxorubicin gradients, observing for cellular migrations and growth

  16. Major Pulmonary Complications After Hematopoietic Stem Cell Transplant.

    PubMed

    Diab, Maria; ZazaDitYafawi, Jihane; Soubani, Ayman O

    2016-06-01

    Both autologous and allogeneic hematopoietic stem cell transplants are important therapeutic options for several benign and malignant disorders. Pulmonary complications, although they have become less frequent, remain a significant cause of morbidity and mortality after hematopoietic stem cell transplant. These complications range from bacterial, fungal, and viral pulmonary infections to noninfectious conditions such as diffuse alveolar hemorrhage and idiopathic pneumonia syndrome. Bronchiolitis obliterans syndrome is the primary chronic pulmonary complication, and treatment of this condition remains challenging. This report highlights the advances in the diagnosis and management of the major pulmonary complications after hematopoietic stem cell transplant. It also underscores the need for prospective and multicenter research to have a better understanding of the mechanisms behind these complications and to obtain more effective diagnostic tool and therapeutic options. PMID:27040986

  17. SBR-Blood: systems biology repository for hematopoietic cells

    PubMed Central

    Lichtenberg, Jens; Heuston, Elisabeth F.; Mishra, Tejaswini; Keller, Cheryl A.; Hardison, Ross C.; Bodine, David M.

    2016-01-01

    Extensive research into hematopoiesis (the development of blood cells) over several decades has generated large sets of expression and epigenetic profiles in multiple human and mouse blood cell types. However, there is no single location to analyze how gene regulatory processes lead to different mature blood cells. We have developed a new database framework called hematopoietic Systems Biology Repository (SBR-Blood), available online at http://sbrblood.nhgri.nih.gov, which allows user-initiated analyses for cell type correlations or gene-specific behavior during differentiation using publicly available datasets for array- and sequencing-based platforms from mouse hematopoietic cells. SBR-Blood organizes information by both cell identity and by hematopoietic lineage. The validity and usability of SBR-Blood has been established through the reproduction of workflows relevant to expression data, DNA methylation, histone modifications and transcription factor occupancy profiles. PMID:26590403

  18. Dynamic Gene Regulatory Networks Drive Hematopoietic Specification and Differentiation

    PubMed Central

    Goode, Debbie K.; Obier, Nadine; Vijayabaskar, M.S.; Lie-A-Ling, Michael; Lilly, Andrew J.; Hannah, Rebecca; Lichtinger, Monika; Batta, Kiran; Florkowska, Magdalena; Patel, Rahima; Challinor, Mairi; Wallace, Kirstie; Gilmour, Jane; Assi, Salam A.; Cauchy, Pierre; Hoogenkamp, Maarten; Westhead, David R.; Lacaud, Georges; Kouskoff, Valerie; Göttgens, Berthold; Bonifer, Constanze

    2016-01-01

    Summary Metazoan development involves the successive activation and silencing of specific gene expression programs and is driven by tissue-specific transcription factors programming the chromatin landscape. To understand how this process executes an entire developmental pathway, we generated global gene expression, chromatin accessibility, histone modification, and transcription factor binding data from purified embryonic stem cell-derived cells representing six sequential stages of hematopoietic specification and differentiation. Our data reveal the nature of regulatory elements driving differential gene expression and inform how transcription factor binding impacts on promoter activity. We present a dynamic core regulatory network model for hematopoietic specification and demonstrate its utility for the design of reprogramming experiments. Functional studies motivated by our genome-wide data uncovered a stage-specific role for TEAD/YAP factors in mammalian hematopoietic specification. Our study presents a powerful resource for studying hematopoiesis and demonstrates how such data advance our understanding of mammalian development. PMID:26923725

  19. Dynamic Gene Regulatory Networks Drive Hematopoietic Specification and Differentiation.

    PubMed

    Goode, Debbie K; Obier, Nadine; Vijayabaskar, M S; Lie-A-Ling, Michael; Lilly, Andrew J; Hannah, Rebecca; Lichtinger, Monika; Batta, Kiran; Florkowska, Magdalena; Patel, Rahima; Challinor, Mairi; Wallace, Kirstie; Gilmour, Jane; Assi, Salam A; Cauchy, Pierre; Hoogenkamp, Maarten; Westhead, David R; Lacaud, Georges; Kouskoff, Valerie; Göttgens, Berthold; Bonifer, Constanze

    2016-03-01

    Metazoan development involves the successive activation and silencing of specific gene expression programs and is driven by tissue-specific transcription factors programming the chromatin landscape. To understand how this process executes an entire developmental pathway, we generated global gene expression, chromatin accessibility, histone modification, and transcription factor binding data from purified embryonic stem cell-derived cells representing six sequential stages of hematopoietic specification and differentiation. Our data reveal the nature of regulatory elements driving differential gene expression and inform how transcription factor binding impacts on promoter activity. We present a dynamic core regulatory network model for hematopoietic specification and demonstrate its utility for the design of reprogramming experiments. Functional studies motivated by our genome-wide data uncovered a stage-specific role for TEAD/YAP factors in mammalian hematopoietic specification. Our study presents a powerful resource for studying hematopoiesis and demonstrates how such data advance our understanding of mammalian development. PMID:26923725

  20. Transfer of hematopoietic stem cells encoding autoantigen prevents autoimmune diabetes.

    PubMed

    Steptoe, Raymond J; Ritchie, Janine M; Harrison, Leonard C

    2003-05-01

    Bone marrow or hematopoietic stem cell transplantation is a potential treatment for autoimmune disease. The clinical application of this approach is, however, limited by the risks associated with allogeneic transplantation. In contrast, syngeneic transplantation would be safe and have wide clinical application. Because T cell tolerance can be induced by presenting antigen on resting antigen-presenting cells (APCs), we reasoned that hematopoietic stem cells engineered to express autoantigen in resting APCs could be used to prevent autoimmune disease. Proinsulin is a major autoantigen associated with pancreatic beta cell destruction in humans with type 1 diabetes (T1D) and in autoimmune NOD mice. Here, we demonstrate that syngeneic transplantation of hematopoietic stem cells encoding proinsulin transgenically targeted to APCs totally prevents the development of spontaneous autoimmune diabetes in NOD mice. This antigen-specific immunotherapeutic strategy could be applied to prevent T1D and other autoimmune diseases in humans. PMID:12727927

  1. Redefining endothelial progenitor cells via clonal analysis and hematopoietic stem/progenitor cell principals

    PubMed Central

    Mead, Laura E.; Prater, Daniel; Krier, Theresa R.; Mroueh, Karim N.; Li, Fang; Krasich, Rachel; Temm, Constance J.; Prchal, Josef T.

    2007-01-01

    The limited vessel-forming capacity of infused endothelial progenitor cells (EPCs) into patients with cardiovascular dysfunction may be related to a misunderstanding of the biologic potential of the cells. EPCs are generally identified by cell surface antigen expression or counting in a commercially available kit that identifies “endothelial cell colony-forming units” (CFU-ECs). However, the origin, proliferative potential, and differentiation capacity of CFU-ECs is controversial. In contrast, other EPCs with blood vessel-forming ability, termed endothelial colony-forming cells (ECFCs), have been isolated from human peripheral blood. We compared the function of CFU-ECs and ECFCs and determined that CFU-ECs are derived from the hematopoietic system using progenitor assays, and analysis of donor cells from polycythemia vera patients harboring a Janus kinase 2 V617F mutation in hematopoietic stem cell clones. Further, CFU-ECs possess myeloid progenitor cell activity, differentiate into phagocytic macrophages, and fail to form perfused vessels in vivo. In contrast, ECFCs are clonally distinct from CFU-ECs, display robust proliferative potential, and form perfused vessels in vivo. Thus, these studies establish that CFU-ECs are not EPCs and the role of these cells in angiogenesis must be re-examined prior to further clinical trials, whereas ECFCs may serve as a potential therapy for vascular regeneration. PMID:17053059

  2. Pediatric donor cell leukemia after allogeneic hematopoietic stem cell transplantation in AML patient from related donor.

    PubMed

    Bobadilla-Morales, Lucina; Pimentel-Gutiérrez, Helia J; Gallegos-Castorena, Sergio; Paniagua-Padilla, Jenny A; Ortega-de-la-Torre, Citlalli; Sánchez-Zubieta, Fernando; Silva-Cruz, Rocio; Corona-Rivera, Jorge R; Zepeda-Moreno, Abraham; González-Ramella, Oscar; Corona-Rivera, Alfredo

    2015-01-01

    Here we present a male patient with acute myeloid leukemia (AML) initially diagnosed as M5 and with karyotype 46,XY. After induction therapy, he underwent a HLA-matched allogeneic hematopoietic stem cell transplantation, and six years later he relapsed as AML M1 with an abnormal karyotype //47,XX,+10[2]/47,XX,+11[3]/48,XX,+10,+11[2]/46,XX[13]. Based on this, we tested the possibility of donor cell origin by FISH and molecular STR analysis. We found no evidence of Y chromosome presence by FISH and STR analysis consistent with the success of the allogeneic hematopoietic stem cell transplantation from the female donor. FISH studies confirmed trisomies and no evidence of MLL translocation either p53 or ATM deletion. Additionally 28 fusion common leukemia transcripts were evaluated by multiplex reverse transcriptase-polymerase chain reaction assay and were not rearranged. STR analysis showed a complete donor chimerism. Thus, donor cell leukemia (DCL) was concluded, being essential the use of cytological and molecular approaches. Pediatric DCL is uncommon, our patient seems to be the sixth case and additionally it presented a late donor cell leukemia appearance. Different extrinsic and intrinsic mechanisms have been considered to explain this uncommon finding as well as the implications to the patient. PMID:25674158

  3. Redefining endothelial progenitor cells via clonal analysis and hematopoietic stem/progenitor cell principals.

    PubMed

    Yoder, Mervin C; Mead, Laura E; Prater, Daniel; Krier, Theresa R; Mroueh, Karim N; Li, Fang; Krasich, Rachel; Temm, Constance J; Prchal, Josef T; Ingram, David A

    2007-03-01

    The limited vessel-forming capacity of infused endothelial progenitor cells (EPCs) into patients with cardiovascular dysfunction may be related to a misunderstanding of the biologic potential of the cells. EPCs are generally identified by cell surface antigen expression or counting in a commercially available kit that identifies "endothelial cell colony-forming units" (CFU-ECs). However, the origin, proliferative potential, and differentiation capacity of CFU-ECs is controversial. In contrast, other EPCs with blood vessel-forming ability, termed endothelial colony-forming cells (ECFCs), have been isolated from human peripheral blood. We compared the function of CFU-ECs and ECFCs and determined that CFU-ECs are derived from the hematopoietic system using progenitor assays, and analysis of donor cells from polycythemia vera patients harboring a Janus kinase 2 V617F mutation in hematopoietic stem cell clones. Further, CFU-ECs possess myeloid progenitor cell activity, differentiate into phagocytic macrophages, and fail to form perfused vessels in vivo. In contrast, ECFCs are clonally distinct from CFU-ECs, display robust proliferative potential, and form perfused vessels in vivo. Thus, these studies establish that CFU-ECs are not EPCs and the role of these cells in angiogenesis must be re-examined prior to further clinical trials, whereas ECFCs may serve as a potential therapy for vascular regeneration. PMID:17053059

  4. Pushing the envelope—nonmyeloablative and reduced intensity preparative regimens for allogeneic hematopoietic transplantation

    PubMed Central

    Pingali, SR; Champlin, RE

    2016-01-01

    Allogeneic hematopoietic cell transplantation (HCT) was originally developed to allow delivery of myeloablative doses of chemotherapy and radiotherapy. With better understanding of disease pathophysiology, the graft vs malignancy (GVM) effect of allogeneic hematopoietic transplantation and toxicities associated with myeloablative conditioning (MAC) regimens, the focus shifted to developing less toxic conditioning regimens to reduce treatment-related morbidity without compromising survival. Although HCT with MAC is preferred to reduced intensity conditioning (RIC) for most patients ≤ 60 years with AML/myelodysplastic syndrome and ALL, RIC and nonmyeloablative (NMA) regimens allow HCT for many otherwise ineligible patients. Reduced intensity preparative regimens have produced high rates of PFS for diagnoses, which are highly sensitive to GVM. Relapse of the malignancy is the major cause of treatment failure with RIC/NMA HCT. Incorporation of novel agents like bortezomib or lenalidomide, addition of cellular immunotherapy and use of targeted radiation therapies could further improve outcome. In this review, we discuss commonly used RIC/NMA regimens and promising novel regimens. PMID:25985053

  5. First evidence of infectious hematopoietic necrosis virus (IHNV) in the Netherlands.

    PubMed

    Haenen, O L M; Schuetze, H; Cieslak, M; Oldenburg, S; Spierenburg, M A H; Roozenburg-Hengst, I; Voorbergen-Laarman, M; Engelsma, M Y; Olesen, N J

    2016-08-01

    In spring 2008, infectious hematopoietic necrosis virus (IHNV) was detected for the first time in the Netherlands. The virus was isolated from rainbow trout, Oncorhynchus mykiss (Walbaum), from a put-and-take fishery with angling ponds. IHNV is the causative agent of a serious fish disease, infectious hematopoietic necrosis (IHN). From 2008 to 2011, we diagnosed eight IHNV infections in rainbow trout originating from six put-and-take fisheries (symptomatic and asymptomatic fish), and four IHNV infections from three rainbow trout farms (of which two were co-infected by infectious pancreatic necrosis virus, IPNV), at water temperatures between 5 and 15 °C. At least one farm delivered trout to four of these eight IHNV-positive farms. Mortalities related to IHNV were mostly <40%, but increased to nearly 100% in case of IHNV and IPNV co-infection. Subsequent phylogenetic analysis revealed that these 12 isolates clustered into two different monophyletic groups within the European IHNV genogroup E. One of these two groups indicates a virus-introduction event by a German trout import, whereas the second group indicates that IHNV was already (several years) in the Netherlands before its discovery in 2008. PMID:26763082

  6. Sensing of micellar microenvironment with dual fluorescent probe, triazolylpyrene (TNDMBPy).

    PubMed

    Bag, Subhendu Sekhar; Kundu, Rajen

    2013-09-01

    We report a dual fluorescent triazolylpyrene ((TNDMB) Py) as an efficient fluorescent light-up probe of various micellar microenvironments. The absorption spectra of (TNDMB) Py in an aqueous solution of varying surfactant concentration, CTAB, SDS and TX-100 showed that as the surfactant concentration was increased the absorbance increased with no shift in wavelength maxima. The increase of absorbance in each surfactant solution with increase in surfactant concentration was due to the enhanced solubilization of (TNDMB) Py in surfactant solutions. Our investigations based on steady state and time resolved fluorescence techniques showed that the probe reports the microenvironment of ionic surfactant solutions (CTAB and SDS) via dual emission (LE and ICT) at low surfactant concentration. The ICT band showed a blue shifting pattern with enhanced intensity that disappeared as the concentration of surfactant increases (> 1 mM for CTAB and > 3 mM for SDS). In non-ionic surfactant (Triton X-100) solution, the fluorophore showed dual emission with dominant ICT behaviour over LE emission at low concentration (up to 0.35 mM). In reverse micelle we observed a blue shifted ICT band with no LE band with increasing molar concentration of water. We found 100 nm blue shifting when we moved from R = 0 to R = 7, where R is the molar ratio of water to TX-100 (R = [H2O]/[TX-100]). The blue shifting of ICT band is because of the movement of the probe from hydrophilic core to hydrophobic core (surface) of the reverse micelle. Thus from the steady-state fluorescence study it was observed that the ICT band of the probe, (TNDMB) Py was more influenced by the micellar environment in comparison to the LE band. This difference in behaviour of the fluorophore is probably because of varying extent of hydrophobic/hydrogen bonding interactions experienced by the probe and its relative disposition inside the various micellar nanocores. PMID:23609209

  7. Functional live cell imaging of the pulmonary neuroepithelial body microenvironment.

    PubMed

    De Proost, Ian; Pintelon, Isabel; Brouns, Inge; Kroese, Alfons B A; Riccardi, Daniela; Kemp, Paul J; Timmermans, Jean-Pierre; Adriaensen, Dirk

    2008-08-01

    Pulmonary neuroepithelial bodies (NEBs) are densely innervated groups of neuroendocrine cells invariably accompanied by Clara-like cells. Together with NEBs, Clara-like cells form the so-called "NEB microenvironment," which recently has been assigned a potential pulmonary stem cell niche. Conclusive data on the nature of physiological stimuli for NEBs are lacking. This study aimed at developing an ex vivo mouse lung vibratome slice model for confocal live cell imaging of physiological reactions in identified NEBs and surrounding epithelial cells. Immunohistochemistry of fixed slices demonstrated that NEBs are almost completely shielded from the airway lumen by tight junction-linked Clara-like cells. Besides the unambiguous identification of NEBs, the fluorescent dye 4-Di-2-ASP allowed microscopic identification of ciliated cells, Clara cells, and Clara-like cells in live lung slices. Using the mitochondrial uncoupler FCCP and a mitochondrial membrane potential indicator, JC-1, increases in 4-Di-2-ASP fluorescence in NEB cells and ciliated cells were shown to represent alterations in mitochondrial membrane potential. Changes in the intracellular free calcium concentration ([Ca2+](i)) in NEBs and surrounding airway epithelial cells were simultaneously monitored using the calcium indicator Fluo-4. Application (5 s) of 50 mM extracellular potassium ([K+](o)) evoked a fast and reproducible [Ca2+](i) increase in NEB cells, while Clara-like cells displayed a delayed (+/- 4 s) [Ca2+](i) increase, suggestive of an indirect, NEB-mediated activation. The presented approach opens interesting new perspectives for unraveling the functional significance of pulmonary NEBs in control lungs and disease models, and for the first time allows direct visualization of local interactions within the NEB microenvironment. PMID:18367726

  8. Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin

    PubMed Central

    Dorn, Isabel; Klich, Katharina; Arauzo-Bravo, Marcos J.; Radstaak, Martina; Santourlidis, Simeon; Ghanjati, Foued; Radke, Teja F.; Psathaki, Olympia E.; Hargus, Gunnar; Kramer, Jan; Einhaus, Martin; Kim, Jeong Beom; Kögler, Gesine; Wernet, Peter; Schöler, Hans R.; Schlenke, Peter; Zaehres, Holm

    2015-01-01

    Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34+ hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34+ hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells. Although genome-wide DNA methylation profiling at all promoter regions demonstrates that the epigenetic memory of induced pluripotent stem cells is influenced by the somatic cell type of origin of the stem cells, we found a similar hematopoietic induction potential and erythroid differentiation pattern of induced pluripotent stem cells of different somatic cell origin. All human induced pluripotent stem cell lines showed terminal maturation into normoblasts and enucleated reticulocytes, producing predominantly fetal hemoglobin. Differences were only observed in the growth rate of erythroid cells, which was slightly higher in the induced pluripotent stem cells derived from CD34+ hematopoietic stem cells. More detailed methylation analysis of the hematopoietic and erythroid promoters identified similar CpG methylation levels in the induced pluripotent stem cell lines derived from CD34+ cells and those derived from neural stem cells, which confirms their comparable erythroid differentiation potential. PMID:25326431

  9. Global gene expression analyses of hematopoietic stem cell-like cell lines with inducible Lhx2 expression

    PubMed Central

    Richter, Karin; Wirta, Valtteri; Dahl, Lina; Bruce, Sara; Lundeberg, Joakim; Carlsson, Leif; Williams, Cecilia

    2006-01-01

    Background Expression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines. To address the molecular basis of Lhx2 function, we generated HSC-like cell lines where Lhx2 expression is regulated by a tet-on system and hence dependent on the presence of doxycyclin (dox). These cell lines efficiently down-regulate Lhx2 expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types. Results Global gene expression of these cell lines cultured in dox was compared to different time points after dox withdrawal using microarray technology. We identified 267 differentially expressed genes. The majority of the genes overlapping with HSC-specific databases were those down-regulated after turning off Lhx2 expression and a majority of the genes overlapping with those defined as late progenitor-specific genes were the up-regulated genes, suggesting that these cell lines represent a relevant model system for normal HSCs also at the level of global gene expression. Moreover, in situ hybridisations of several genes down-regulated after dox withdrawal showed overlapping expression patterns with Lhx2 in various tissues during embryonic development. Conclusion Global gene expression analysis of HSC-like cell lines with inducible Lhx2 expression has identified genes putatively linked to self-renewal / differentiation of HSCs, and function of Lhx2 in organ development and stem / progenitor cells of non-hematopoietic origin. PMID:16600034

  10. Synergistic Effect and Molecular Mechanisms of Traditional Chinese Medicine on Regulating Tumor Microenvironment and Cancer Cells

    PubMed Central

    Song, Zhuo; Li, Jie

    2016-01-01

    The interaction of tumor cells with the microenvironment is like a relationship between the “seeds” and “soil,” which is a hotspot in recent cancer research. Targeting at tumor microenvironment as well as tumor cells has become a new strategy for cancer treatment. Conventional cancer treatments mostly focused on single targets or single mechanism (the seeds or part of the soil); few researches intervened in the whole tumor microenvironment and achieved ideal therapeutic effect as expected. Traditional Chinese medicine displays a broad range of biological effects, and increasing evidence has shown that it may relate with synergistic effect on regulating tumor microenvironment and cancer cells. Based on literature review and our previous studies, we summarize the synergistic effect and the molecular mechanisms of traditional Chinese medicine on regulating tumor microenvironment and cancer cells. PMID:27042656

  11. Role of curcumin-dependent modulation of tumor microenvironment of a murine T cell lymphoma in altered regulation of tumor cell survival

    SciTech Connect

    Vishvakarma, Naveen Kumar; Kumar, Anjani; Singh, Sukh Mahendra

    2011-05-01

    Using a murine model of a T cell lymphoma, in the present study, we report that tumor growth retarding action of curcumin involves modulation of some crucial parameters of tumor microenvironment regulating tumor progression. Curcumin-administration to tumor-bearing host caused an altered pH regulation in tumor cells associated with alteration in expression of cell survival and apoptosis regulatory proteins and genes. Nevertheless, an alteration was also observed in biophysical parameters of tumor microenvironment responsible for modulation of tumor growth pertaining to hypoxia, tumor acidosis, and glucose metabolism. The study thus sheds new light with respect to the antineoplastic action of curcumin against a tumor-bearing host with progressively growing tumor of hematological origin. This will help in optimizing application of the drug and anticancer research and therapy. - Graphical Abstract: Display Omitted

  12. Enhanced Ex Vivo Expansion of Human Hematopoietic Progenitors on Native and Spin Coated Acellular Matrices Prepared from Bone Marrow Stromal Cells

    PubMed Central

    Wasnik, Samiksha; Kantipudi, Suma; Kirkland, Mark A.; Pande, Gopal

    2016-01-01

    The extracellular microenvironment in bone marrow (BM) is known to regulate the growth and differentiation of hematopoietic stem and progenitor cells (HSPC). We have developed cell-free matrices from a BM stromal cell line (HS-5), which can be used as substrates either in native form or as tissue engineered coatings, for the enhanced ex vivo expansion of umbilical cord blood (UCB) derived HSPC. The physicochemical properties (surface roughness, thickness, and uniformity) of native and spin coated acellular matrices (ACM) were studied using scanning and atomic force microscopy (SEM and AFM). Lineage-specific expansion of HSPC, grown on these substrates, was evaluated by immunophenotypic (flow cytometry) and functional (colony forming) assays. Our results show that the most efficient expansion of lineage-specific HSPC occurred on spin coated ACM. Our method provides an improved protocol for ex vivo HSPC expansion and it offers a system to study the in vivo roles of specific molecules in the hematopoietic niche that influence HSPC expansion. PMID:26981135

  13. Autologous hematopoietic stem cell transplantation for mediastinal extramedullary plasmocytoma.

    PubMed

    Abdelkefi, Abderrahmene; Ben Othman, Tarek; Torjman, Lamia; Ladeb, Saloua; Ben Ghorbel, Imed; Lakhal, Amed; Ben Amor, Ramzi; Miled, Mohamed; Kchir, Mohamed-Nidhameddine; Ben Abdeladhim, Abdeladhim

    2003-07-01

    Extramedullary plasmocytoma (EMP) is a rare cell neoplasm most frequently localised in the upper respiratory tract. We report the case of a 43 year-old-man, with an unusual presentation of EMP developing in the mediastinum, two years after a diagnosis of solitary plasmocytoma of the bone which was successfully treated by local irradiation. In this aggressive presentation, we decided to perform an autologous hematopoietic stem cell transplantation. Two months after transplantation, CT scan showed disappearance of the mediastinal mass and immunofixation of the serum was normal. Selected cases of diffuse EMP, could benefit from intensive treatment followed by autologous hematopoietic stem cell transplantation. PMID:14534964

  14. Filgrastim for the treatment of hematopoietic acute radiation syndrome.

    PubMed

    Farese, A M; MacVittie, T J

    2015-09-01

    The U.S. Food and Drug Administration (FDA) recently approved Neupogen(®) (filgrastim) for the treatment of patients with radiation-induced myelosuppression following a radiological/nuclear incident. It is the first medical countermeasure currently approved by the FDA for this indication under the criteria of the FDA "animal rule". This article summarizes the consequences of high-dose radiation exposure, a description of the hematopoietic acute radiation syndrome (H-ARS), the use of hematopoietic growth factors in radiation accident victims and current available treatments for H-ARS with an emphasis on the use of Neupogen in this scenario. PMID:26488033

  15. BACTERIAL FOODBORNE INFECTIONS AFTER HEMATOPOIETIC CELL TRANSPLANTATION

    PubMed Central

    Boyle, Nicole; Podczervinski, Sara; Jordan, Kim; Stednick, Zach; Butler-Wu, Susan; McMillen, Kerry; Pergam, Steven A.

    2014-01-01

    Background Diarrhea, abdominal pain and fever are common among patients undergoing hematopoietic cell transplant (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence post-transplant within a single-center population of HCT recipients. Methods All HCT recipients transplanted from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, WA were followed for one year post-transplant. Data were collected retrospectively using center databases, which include information from transplant, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli 0157:H7, Salmonella species, Shigella species, Vibrio species or Yersinia species were isolated in culture within one-year post-transplant. Non-foodborne infections with these agents and patients with preexisting bacterial foodborne infection (within 30 days of transplant) were excluded from analyses. Results A total of 12/4069 (0.3%) patients developed a bacterial foodborne infection within one year post-transplant. Patients with infections had a median age at transplant of 50.5 years (interquartile range [IQR]: 35–57), and the majority were adults ≥18 years of age (9/12 [75%]), male gender (8/12 [67%]) and post-allogeneic transplant (8/12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% CI: 0.5–1.7) and at a median of 50.5 days after transplant (IQR: 26–58.5). The most frequent pathogen detected was Campylobacter jejuni/coli (5/12 [42%]) followed by Yersinia (3/12 [25%]), while Salmonella (2/12 [17%]) and Listeria (2/12 [17%]) showed equal frequencies; no cases of Shigella, Vibrio, or E. coli 0157:H7 were detected. Most patients were diagnosed via stool

  16. Origin of Cardiomyocytes in the Adult Heart

    PubMed Central

    Leri, Annarosa; Rota, Marcello; Pasqualini, Francesco S.; Goichberg, Polina; Anversa, Piero

    2014-01-01

    This review article discusses the mechanisms of cardiomyogenesis in the adult heart. They include the reentry of cardiomyocytes into the cell cycle; dedifferentiation of preexisting cardiomyocytes which assume an immature replicating cell phenotype; transdifferentiation of hematopoietic stem cells into cardiomyocytes; and cardiomyocytes derived from activation and lineage specification of resident cardiac stem cells. The recognition of the origin of cardiomyocytes is of critical importance for the development of strategies capable of enhancing the growth response of the myocardium; in fact, cell therapy for the decompensated heart has to be based on the acquisition of this fundamental biological knowledge. PMID:25552694

  17. Original Misunderstanding

    ERIC Educational Resources Information Center

    Holtzman, Alexander

    2009-01-01

    Humorist Josh Billings quipped, "About the most originality that any writer can hope to achieve honestly is to steal with good judgment." Billings was harsh in his view of originality, but his critique reveals a tension faced by students every time they write a history paper. Research is the essence of any history paper. Especially in high school,…

  18. Increased cancer risk of augmentation cystoplasty: possible role for hyperosmolal microenvironment on DNA damage recognition

    PubMed Central

    Dixon, Bradley P.; Chu, Albert; Henry, Jeff; Kim, Rebecca; Bissler, John J.

    2009-01-01

    Patients who have had surgical bladder augmentation have an increased risk of bladder malignancy, though the mechanism for this increased risk is unknown. Hyperosmolal microenvironments such as the bladder may impair DNA damage signaling and repair; this effect may be more pronounced in tissues not normally exposed to such conditions. Comparing gastric and colon epithelial cell lines to transitional epithelial cell lines gradually adapted to an osmolality of 600mOsm/kg with either sodium chloride or urea, cell lines of gastrointestinal origin were inhibited in their ability to activate ATM and downstream effectors of DNA damage signaling and repair such as p53, Nbs1, replication protein A (RPA), and γH2AX following the induction of DNA damage with etoposide. In contrast, bladder cell lines demonstrated a preserved ability to phosphorylate ATM and its effectors under conditions of hyperosmolal urea, and to a lesser extent with sodium chloride. The bladder cell lines’ ability to respond to DNA damage under hyperosmolal conditions may be due in part to protective mechanisms such as the accumulation of intracellular organic osmolytes and the uroplakin-containing asymmetric unit membrane as found in transitional epithelial cells, but not in gastrointestinal cells. Failure of such protective adaptations in the tissues used for augmentation cystoplasties may place these tissues at increased risk for malignancy. PMID:19647003

  19. Increased cancer risk of augmentation cystoplasty: possible role for hyperosmolal microenvironment on DNA damage recognition.

    PubMed

    Dixon, Bradley P; Chu, Albert; Henry, Jeff; Kim, Rebecca; Bissler, John J

    2009-11-01

    Patients who have had surgical bladder augmentation have an increased risk of bladder malignancy, though the mechanism for this increased risk is unknown. Hyperosmolal microenvironments such as the bladder may impair DNA damage signaling and repair; this effect may be more pronounced in tissues not normally exposed to such conditions. Comparing gastric and colon epithelial cell lines to transitional epithelial cell lines gradually adapted to an osmolality of 600 mOsm/kg with either sodium chloride or urea, cell lines of gastrointestinal origin were inhibited in their ability to activate ATM and downstream effectors of DNA damage signaling and repair such as p53, Nbs1, replication protein A (RPA), and gammaH2AX following the induction of DNA damage with etoposide. In contrast, bladder cell lines demonstrated a preserved ability to phosphorylate ATM and its effectors under conditions of hyperosmolal urea, and to a lesser extent with sodium chloride. The bladder cell lines' ability to respond to DNA damage under hyperosmolal conditions may be due in part to protective mechanisms such as the accumulation of intracellular organic osmolytes and the uroplakin-containing asymmetric unit membrane as found in transitional epithelial cells, but not in gastrointestinal cells. Failure of such protective adaptations in the tissues used for augmentation cystoplasties may place these tissues at increased risk for malignancy. PMID:19647003

  20. Measuring accident risk exposure for pedestrians in different micro-environments.

    PubMed

    Lassarre, Sylvain; Papadimitriou, Eleonora; Yannis, George; Golias, John

    2007-11-01

    Pedestrians are mainly exposed to the risk of road accident when crossing a road in urban areas. Traditionally in the road safety field, the risk of accident for pedestrian is estimated as a rate of accident involvement per unit of time spent on the road network. The objective of this research is to develop an approach of accident risk based on the concept of risk exposure used in environmental epidemiology, such as in the case of exposure to pollutants. This type of indicator would be useful for comparing the effects of urban transportation policy scenarios on pedestrian safety. The first step is to create an indicator of pedestrians' exposure, which is based on motorised vehicles' "concentration" by lane and also takes account of traffic speed and time spent to cross. This is applied to two specific micro-environments: junctions and mid-block locations. A model of pedestrians' crossing behaviour along a trip is then developed, based on a hierarchical choice between junctions and mid-block locations and taking account of origin and destination, traffic characteristics and pedestrian facilities. Finally, a complete framework is produced for modelling pedestrians' exposure in the light of their crossing behaviour. The feasibility of this approach is demonstrated on an artificial network and a first set of results is obtained from the validation of the models in observational studies. PMID:17920847

  1. Molecular deconstruction, detection, and computational prediction of microenvironment-modulated cellular responses to cancer therapeutics

    PubMed Central

    LaBarge, Mark A; Parvin, Bahram; Lorens, James B

    2014-01-01

    The field of bioengineering has pioneered the application of new precision fabrication technologies to model the different geometric, physical or molecular components of tissue microenvironments on solid-state substrata. Tissue engineering approaches building on these advances are used to assemble multicellular mimetic-tissues where cells reside within defined spatial contexts. The functional responses of cells in fabricated microenvironments has revealed a rich interplay between the genome and extracellular effectors in determining cellular phenotypes, and in a number of cases has revealed the dominance of microenvironment over genotype. Precision bioengineered substrata are limited to a few aspects, whereas cell/tissue-derived microenvironments have many undefined components. Thus introducing a computational module may serve to integrate these types of platforms to create reasonable models of drug responses in human tissues. This review discusses how combinatorial microenvironment microarrays and other biomimetic microenvironments have revealed emergent properties of cells in particular microenvironmental contexts, the platforms that can measure phenotypic changes within those contexts, and the computational tools that can unify the microenvironment-imposed functional phenotypes with underlying constellations of proteins and genes. Ultimately we propose that a merger of these technologies will enable more accurate pre-clinical drug discovery. PMID:24582543

  2. Screening for Stromal and Matrix Effects in 3D Microenvironments of Breast Cancer Cells

    NASA Astrophysics Data System (ADS)

    Montanez-Sauri, Sara I.

    Breast cancer progression ensures through the acquisition of genetic mutations, the uncontrollable growth of cells, and their progression to invasion. Studies have shown that the surrounding three-dimensional (3D) microenvironment can also influence breast cancer cell progression by controlling the morphology, differentiation, proliferation, and migration of cells. However, most of the currently available in vitro screening platforms are based on the two-dimensional (2D) culture of cells, and do not provide cells with the complex 3D microenvironment that exists in vivo. Therefore, there is a need for more biologically relevant in vitro platforms to help decipher the complexity of the microenvironment and its influence in breast cancer. In this dissertation we present an automated microfluidic platform that allows to efficiently screen for the effect of multiple matrix and stromal microenvironment in 3D cultures of breast cancer cells. Several extracellular matrix (ECM) compositions and stromal cells are included in the 3D microenvironments to examine their influence on breast cancer cell behavior. The screening results suggest that collagen gels with fibronectin might be influencing paracrine signals between breast cancer cells and stromal cells. The ability of the platform to culture and treat cells in 3D microenvironments offers a powerful screening tool for the identification of compounds and interactions using more in vivo-like 3D microenvironments. The identification of these mechanisms will increase our current understanding of breast cancer, and will aid in the identification of potential therapeutics.

  3. Molecular deconstruction, detection, and computational prediction of microenvironment-modulated cellular responses to cancer therapeutics.

    PubMed

    Labarge, Mark A; Parvin, Bahram; Lorens, James B

    2014-04-01

    The field of bioengineering has pioneered the application of new precision fabrication technologies to model the different geometric, physical or molecular components of tissue microenvironments on solid-state substrata. Tissue engineering approaches building on these advances are used to assemble multicellular mimetic-tissues where cells reside within defined spatial contexts. The functional responses of cells in fabricated microenvironments have revealed a rich interplay between the genome and extracellular effectors in determining cellular phenotypes and in a number of cases have revealed the dominance of microenvironment over genotype. Precision bioengineered substrata are limited to a few aspects, whereas cell/tissue-derived microenvironments have many undefined components. Thus, introducing a computational module may serve to integrate these types of platforms to create reasonable models of drug responses in human tissues. This review discusses how combinatorial microenvironment microarrays and other biomimetic microenvironments have revealed emergent properties of cells in particular microenvironmental contexts, the platforms that can measure phenotypic changes within those contexts, and the computational tools that can unify the microenvironment-imposed functional phenotypes with underlying constellations of proteins and genes. Ultimately we propose that a merger of these technologies will enable more accurate pre-clinical drug discovery. PMID:24582543

  4. DNA Damage Response in Hematopoietic Stem Cell Ageing.

    PubMed

    Li, Tangliang; Zhou, Zhong-Wei; Ju, Zhenyu; Wang, Zhao-Qi

    2016-06-01

    Maintenance of tissue-specific stem cells is vital for organ homeostasis and organismal longevity. Hematopoietic stem cells (HSCs) are the most primitive cell type in the hematopoietic system. They divide asymmetrically and give rise to daughter cells with HSC identity (self-renewal) and progenitor progenies (differentiation), which further proliferate and differentiate into full hematopoietic lineages. Mammalian ageing process is accompanied with abnormalities in the HSC self-renewal and differentiation. Transcriptional changes and epigenetic modulations have been implicated as the key regulators in HSC ageing process. The DNA damage response (DDR) in the cells involves an orchestrated signaling pathway, consisting of cell cycle regulation, cell death and senescence, transcriptional regulation, as well as chromatin remodeling. Recent studies employing DNA repair-deficient mouse models indicate that DDR could intrinsically and extrinsically regulate HSC maintenance and play important roles in tissue homeostasis of the hematopoietic system. In this review, we summarize the current understanding of how the DDR determines the HSC fates and finally contributes to organismal ageing. PMID:27221660

  5. The role of hematopoietic growth factors in transfusion medicine.

    PubMed

    Whitsett, C F

    1995-02-01

    Hematopoietic growth factors have already had an enormous impact on transfusion practice by eliminating or reducing the need for red blood cell transfusions in a variety of anemic states characterized by an absolute or relative decrease in erythropoietin. In addition, GM-CSF and G-CSF have stimulated the production of autologous neutrophils in febrile neutropenic patients in whom granulocyte transfusions had been considered ineffective. With the discovery of c-Mpl ligand and the promising results obtained with IL-11 and IL-3, a combination of growth factors that successfully stimulate platelet production may soon be identified. This first era in the clinical application of hematopoietic growth factors has been characterized largely by treatment of the patient to stimulate production of autologous cells or to enhance the ability of transplanted hematopoietic progenitor cells to repopulate the patient. The use of G-CSF to increase the yield of granulocytes harvested by apheresis procedures and to mobilize peripheral blood stem cells in allogeneic donors has initiated a new era in which the cell donor is treated to enhance cell production and enhance the repopulating ability of hematopoietic progenitor cells. As our understanding of hematopoiesis grows, scientists will be able to identify growth factors to overcome or correct deficient hematopoiesis. Increasingly, component transfusions will be reserved for life-threatening situations in which endogenous cell production cannot be stimulated or cell production will be too slow to prevent life-threatening events. PMID:7737944

  6. Hematopoietic activity in putative mouse primordial germ cell populations.

    PubMed

    Scaldaferri, Maria Lucia; Klinger, Francesca Gioia; Farini, Donatella; Di Carlo, Anna; Carsetti, Rita; Giorda, Ezio; De Felici, Massimo

    2015-05-01

    In the present paper, starting from the observation of heterogeneous expression of the GOF-18ΔPE-GFP Pou5f1 (Oct3/4) transgene in putative mouse PGC populations settled in the aorta-gonad-mesonephros (AGM) region, we identified various OCT3/4 positive populations showing distinct expression of PGC markers (BLIMP-1, AP, TG-1, STELLA) and co-expressing several proteins (CD-34, CD-41, FLK-1) and genes (Brachyury, Hox-B4, Scl/Tal-1 and Gata-2) of hematopoietic precursors. Moreover, we found that Oct3/4-GFP(weak) CD-34(weak/high) cells possess robust hematopoietic colony forming activity (CFU) in vitro. These data indicate that the cell population usually considered PGCs moving toward the gonadal ridges encompasses a subset of cells co-expressing several germ cell and hematopoietic markers and possessing hematopoietic activity. These results are discussed within of the current model of germline segregation. PMID:25684074

  7. Instruction of hematopoietic lineage choice by cytokine signaling

    SciTech Connect

    Endele, Max; Etzrodt, Martin; Schroeder, Timm

    2014-12-10

    Hematopoiesis is the cumulative consequence of finely tuned signaling pathways activated through extrinsic factors, such as local niche signals and systemic hematopoietic cytokines. Whether extrinsic factors actively instruct the lineage choice of hematopoietic stem and progenitor cells or are only selectively allowing survival and proliferation of already intrinsically lineage-committed cells has been debated over decades. Recent results demonstrated that cytokines can instruct lineage choice. However, the precise function of individual cytokine-triggered signaling molecules in inducing cellular events like proliferation, lineage choice, and differentiation remains largely elusive. Signal transduction pathways activated by different cytokine receptors are highly overlapping, but support the production of distinct hematopoietic lineages. Cellular context, signaling dynamics, and the crosstalk of different signaling pathways determine the cellular response of a given extrinsic signal. New tools to manipulate and continuously quantify signaling events at the single cell level are therefore required to thoroughly interrogate how dynamic signaling networks yield a specific cellular response. - Highlights: • Recent studies provided definite proof for lineage-instructive action of cytokines. • Signaling pathways involved in hematopoietic lineage instruction remain elusive. • New tools are emerging to quantitatively study dynamic signaling networks over time.

  8. Lentiviral Hematopoietic Stem Cell Gene Therapy in Inherited Metabolic Disorders

    PubMed Central

    2014-01-01

    Abstract After more than 20 years of development, lentiviral hematopoietic stem cell gene therapy has entered the stage of initial clinical implementation for immune deficiencies and storage disorders. This brief review summarizes the development and applications, focusing on the lysosomal enzyme deficiencies, especially Pompe disease. PMID:25184354

  9. Cytokine signaling for proliferation, survival, and death in hematopoietic cells.

    PubMed

    Miyajima, A; Ito, Y; Kinoshita, T

    1999-04-01

    The survival, proliferation, and differentiation of hematopoietic cells are regulated by cytokines. In the absence of cytokines, hematopoietic cells not only stop proliferation, but undergo apoptosis. This strict dependency of hematopoietic cells on cytokines is an important mechanism that maintains the homeostasis of blood cells. Cytokines induce various intracellular signaling pathways by activating the receptor-associated Janus kinases (Jaks), and distinct signals are responsible for cell cycle progression and cell survival. Induction of signals for cell cycle progression without suppressing apoptosis results in apoptotic cell death, indicating the essential role of anti-apoptotic signaling for cell growth. In hematopoietic cells, Ras, a cellular protooncogen product, and phosphatidylinositol 3 kinase are involved in the suppression of apoptosis. Cytokine depletion not only turns off anti-apoptotic signaling, but also actively induces cell death by activating caspases, a distinct family of cysteine proteases. Alterations in the mechanisms of cytokine signaling for cell cycle progression and anti-apoptotic function are implicated in hematological disorders. PMID:10222650

  10. Donor-derived DNA in hair follicles of recipients after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Jacewicz, R; Lewandowski, K; Rupa-Matysek, J; Jedrzejczyk, M; Brzezinski, P M; Dobosz, T; Jonkisz, A; Szram, S; Komarnicki, M; Berent, J

    2010-11-01

    The hair follicles of recipients of allogeneic hematopoietic SCT (HSCT) constitute the tissue with the greatest need for regeneration after high-dose chemotherapy. Previous studies have shown a lack of donor-derived DNA in the hair follicles of recipients. Therefore, we carried out a study to determine whether male donor-derived genetic material can be found in female recipients' hair follicles after HSCT. Fluorescent-based PCR with analyses of Y-chromosome STR (Y-STR) and RQ-PCR with the sex-determining region Y (SRY) were used independently to evaluate chimerism status. Our results proved the existence of donor-derived stem DNA in the recipients' hair follicle cells. This report undermines the validity of data indicating that hair follicle cells maintain 100% of recipient origin. PMID:20173789

  11. Infectious hematopoietic necrosis virus detected by separation and incubation of cells from salmonid cavity fluid.

    USGS Publications Warehouse

    Mulcahy, D.; Batts, W.N.

    1987-01-01

    Infectious hematopoietic necrosis (IHN) virus is usually detected by inoculating susceptible cell cultures with cavity ("ovarian") fluid (CF) from spawning females. We identified additional adult carriers of virus in spawning populations of steelhead trout (Salmo gairdneri) and sockeye salmon (Oncorhynchus nerka) by collecting nonerythrocytic cells from CF samples by low-speed centrifugation, culturing the cells for at least 7 d at 15 °C, and then testing the culture medium for virus. Virus appeared in the cultured cells from some samples of CF that remained negative during incubation. In additional samples of CF from these species, the virus titer increased in cultured cells compared with the titer in the original CF sample. With chinook salmon (O.tshawytscha), no negative samples converted to positive during incubation, but the virus titer was retained in incubated CF cells, but not in cell-free CF.

  12. Concentrations of mobile source air pollutants in urban microenvironments.

    PubMed

    Fujita, Eric M; Campbell, David E; Arnott, W Patrick; Johnson, Ted; Ollison, Will

    2014-07-01

    Human exposures to criteria and hazardous air pollutants (HAPs) in urban areas vary greatly due to temporal-spatial variations in emissions, changing meteorology, varying proximity to sources, as well as due to building, vehicle, and other environmental characteristics that influence the amounts of ambient pollutants that penetrate or infiltrate into these microenvironments. Consequently, the exposure estimates derived from central-site ambient measurements are uncertain and tend to underestimate actual exposures. The Exposure Classification Project (ECP) was conducted to measure pollutant concentrations for common urban microenvironments (MEs) for use in evaluating the results of regulatory human exposure models. Nearly 500 sets of measurements were made in three Los Angeles County communities during fall 2008, winter 2009, and summer 2009. MEs included in-vehicle, near-road, outdoor and indoor locations accessible to the general public. Contemporaneous 1- to 15-min average personal breathing zone concentrations of carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOCs), nitric oxide (NO), nitrogen oxides (NO(x)), particulate matter (< 2.5 microm diameter; PM2.5) mass, ultrafine particle (UFP; < 100 nm diameter) number black carbon (BC), speciated HAPs (e.g, benzene, toluene, ethylbenzene, xylenes [BTEX], 1,3-butadiene), and ozone (O3) were measured continuously. In-vehicle and inside/outside measurements were made in various passenger vehicle types and in public buildings to estimate penetration or infiltration factors. A large fraction of the observed pollutant concentrations for on-road MEs, especially near diesel trucks, was unrelated to ambient measurements at nearby monitors. Comparisons of ME concentrations estimated using the median ME/ambient ratio versus regression slopes and intercepts indicate that the regression approach may be more accurate for on-road MEs. Ranges in the ME/ambient ratios among ME categories were generally

  13. NANIVID: A New Research Tool for Tissue Microenvironment Studies

    NASA Astrophysics Data System (ADS)

    Raja, Waseem K.

    Metastatic tumors are heterogeneous in nature and composed of subpopulations of cells having various metastatic potentials. The time progression of a tumor creates a unique microenvironment to improve the invasion capabilities and survivability of cancer cells in different microenvironments. In the early stages of intravasation, cancer cells establish communication with other cell types through a paracrine loop and covers long distances by sensing growth factor gradients through extracellular matrices. Cellular migration both in vitro and in vivo is a complex process and to understand their motility in depth, sophisticated techniques are required to document and record events in real time. This study presents the design and optimization of a new versatile chemotaxis device called the NANIVID (NANo IntraVital Imaging Device), developed using advanced Nano/Micro fabrication techniques. The current version of this device has been demonstrated to form a stable (epidermal growth factor) EGF gradient in vitro (2D and 3D) while a miniaturized size of NANIVID is used as an implantable device for intravital studies of chemotaxis and to collect cells in vivo. The device is fabricated using microfabrication techniques in which two substrates are bonded together using a thin polymer layer creating a bonded device with one point source (approximately 150 im x 50 im) outlet. The main structures of the device consist of two transparent substrates: one having etched chambers and channel while the second consists of a microelectrode system to measure real time cell arrival inside the device. The chamber of the device is loaded with a growth factor reservoir consisting of hydrogel to sustain a steady release of growth factor into the surrounding environment for long periods of time and establishing a concentration gradient from the device. The focus of this study was to design and optimize the new device for cell chemotaxis studies in breast cancer cells in cell culture. Our results

  14. Colon tumour secretopeptidome: insights into endogenous proteolytic cleavage events in the colon tumour microenvironment.

    PubMed

    Greening, David W; Kapp, Eugene A; Ji, Hong; Speed, Terry P; Simpson, Richard J

    2013-11-01

    The secretopeptidome comprises endogenous peptides derived from proteins secreted into the tumour microenvironment through classical and non-classical secretion. This study characterised the low-Mr (<3kDa) component of the human colon tumour (LIM1215, LIM1863) secretopeptidome, as a first step towards gaining insights into extracellular proteolytic cleavage events in the tumour microenvironment. Based on two biological replicates, this secretopeptidome isolation strategy utilised differential centrifugal ultrafiltration in combination with analytical RP-HPLC and nanoLC-MS/MS. Secreted peptides were identified using a combination of Mascot and post-processing analyses including MSPro re-scoring, extended feature sets and Percolator, resulting in 474 protein identifications from 1228 peptides (≤1% q-value, ≤5% PEP) - a 36% increase in peptide identifications when compared with conventional Mascot (homology ionscore thresholding). In both colon tumour models, 122 identified peptides were derived from 41 cell surface protein ectodomains, 23 peptides (12 proteins) from regulated intramembrane proteolysis (RIP), and 12 peptides (9 proteins) generated from intracellular domain proteolysis. Further analyses using the protease/substrate database MEROPS, (http://merops.sanger.ac.uk/), revealed 335 (71%) proteins classified as originating from classical/non-classical secretion, or the cell membrane. Of these, peptides were identified from 42 substrates in MEROPS with defined protease cleavage sites, while peptides generated from a further 205 substrates were fragmented by hitherto unknown proteases. A salient finding was the identification of peptides from 88 classical/non-classical secreted substrates in MEROPS, implicated in tumour progression and angiogenesis (FGFBP1, PLXDC2), cell-cell recognition and signalling (DDR1, GPA33), and tumour invasiveness and metastasis (MACC1, SMAGP); the nature of the proteases responsible for these proteolytic events is unknown. To

  15. Dynamic Cross Talk between S1P and CXCL12 Regulates Hematopoietic Stem Cells Migration, Development and Bone Remodeling

    PubMed Central

    Golan, Karin; Kollet, Orit; Lapidot, Tsvee

    2013-01-01

    Hematopoietic stem cells (HSCs) are mostly retained in a quiescent non-motile mode in their bone marrow (BM) niches, shifting to a migratory cycling and differentiating state to replenish the blood with mature leukocytes on demand. The balance between the major chemo-attractants CXCL12, predominantly in the BM, and S1P, mainly in the blood, dynamically regulates HSC recruitment to the circulation versus their retention in the BM. During alarm situations, stress-signals induce a decrease in CXCL12 levels in the BM, while S1P levels are rapidly and transiently increased in the circulation, thus favoring mobilization of stem cells as part of host defense and repair mechanisms. Myeloid cytokines, including G-CSF, up-regulate S1P signaling in the BM via the PI3K pathway. Induced CXCL12 secretion from stromal cells via reactive oxygen species (ROS) generation and increased S1P1 expression and ROS signaling in HSCs, all facilitate mobilization. Bone turnover is also modulated by both CXCL12 and S1P, regulating the dynamic BM stromal microenvironment, osteoclasts and stem cell niches which all functionally express CXCL12 and S1P receptors. Overall, CXCL12 and S1P levels in the BM and circulation are synchronized to mutually control HSC motility, leukocyte production and osteoclast/osteoblast bone turnover during homeostasis and stress situations. PMID:24276423

  16. In vivo time-lapse imaging shows diverse niche engagement by quiescent and naturally activated hematopoietic stem cells

    PubMed Central

    Rashidi, Narges M.; Scott, Mark K.; Scherf, Nico; Krinner, Axel; Kalchschmidt, Jens S.; Gounaris, Kleoniki; Selkirk, Murray E.; Roeder, Ingo

    2014-01-01

    Hematopoietic stem cells (HSCs) maintain the turnover of mature blood cells during steady state and in response to systemic perturbations such as infections. Their function critically depends on complex signal exchanges with the bone marrow (BM) microenvironment in which they reside, but the cellular mechanisms involved in HSC-niche interactions and regulating HSC function in vivo remain elusive. We used a natural mouse parasite, Trichinella spiralis, and multipoint intravital time-lapse confocal microscopy of mouse calvarium BM to test whether HSC-niche interactions may change when hematopoiesis is perturbed. We find that steady-state HSCs stably engage confined niches in the BM whereas HSCs harvested during acute infection are motile and therefore interact with larger niches. These changes are accompanied by increased long-term repopulation ability and expression of CD44 and CXCR4. Administration of a CXCR4 antagonist affects the duration of HSC-niche interactions. These findings suggest that HSC-niche interactions may be modulated during infection. PMID:24850759

  17. Increased IL-6 secretion by aged human mesenchymal stromal cells disrupts hematopoietic stem and progenitor cells' homeostasis

    PubMed Central

    O'Hagan-Wong, Kelsey; Nadeau, Stéphanie; Carrier-Leclerc, Audrey; Apablaza, Felipe; Hamdy, Reggie; Shum-Tim, Dominique; Rodier, Francis; Colmegna, Inés

    2016-01-01

    Hematopoietic stem and progenitor cell (HSPC) homeostasis declines with age, leading to impaired hematopoiesis. Mesenchymal stromal cells (MSC) are critical components of the bone marrow niche and key regulators of the balance between HSPC proliferation and quiescence. Accrual of DNA damage, a hallmark of cellular aging, occurs in aged MSC. Whether MSC aging alters the bone marrow niche triggering HSPC dysfunction is unknown. Using a human MSC-HSPC co-culture system, we demonstrated that DNA damaged MSC have impaired capacity to maintain CD34+CD38− HSPC quiescence. Furthermore, human MSC from adult donors display some hallmarks of cellular senescence and have a decreased capacity to maintain HSPC quiescence and the most primitive CD34+CD38− subset compared to MSC from pediatric donors. IL-6 neutralization restores the MSC-HPSC crosstalk in senescent and adult MSC-HSPC co-cultures highlighting the relevance of the local microenvironment in maintaining HSPC homeostasis. These results provide new evidence implicating components of the MSC secretome in HSPC aging. PMID:26934440

  18. PAR1 signaling regulates the retention and recruitment of EPCR-expressing bone marrow hematopoietic stem cells

    PubMed Central

    Gur-Cohen, Shiri; Itkin, Tomer; Chakrabarty, Sagarika; Graf, Claudine; Kollet, Orit; Ludin, Aya; Golan, Karin; Kalinkovich, Alexander; Ledergor, Guy; Wong, Eitan; Niemeyer, Elisabeth; Porat, Ziv; Erez, Ayelet; Sagi, Irit; Esmon, Charles T; Ruf, Wolfram; Lapidot, Tsvee

    2016-01-01

    Retention of long-term repopulating hematopoietic stem cells (LT-HSCs) in the bone marrow is essential for hematopoiesis and for protection from myelotoxic injury. We report that signaling cascades that are traditionally viewed as coagulation-related also control retention of EPCR+ LT-HSCs in the bone marrow and their recruitment to the blood via two different protease activated receptor 1 (PAR1)-mediated pathways. Thrombin-PAR1 signaling induces nitric oxide (NO) production, leading to TACE-mediated EPCR shedding, enhanced CXCL12-CXCR4-induced motility, and rapid stem and progenitor cell mobilization. Conversely, bone marrow blood vessels provide a microenvironment enriched with protein C that retain EPCR+ LT-HSCs by limiting NO generation, reducing Cdc42 activity and enhancing VLA4 affinity and adhesion. Inhibition of NO production by activated protein C (aPC)-EPCR-PAR1 signaling reduces progenitor cell egress, increases NOlow bone marrow EPCR+ LT-HSCs retention and protects mice from chemotherapy-induced hematological failure and death. Our study reveals new roles for PAR1 and EPCR that control NO production to balance maintenance and recruitment of bone marrow EPCR+ LT-HSCs with clinical relevance. PMID:26457757

  19. Identification of a Hematopoietic Cell Dedifferentiation-Inducing Factor.

    PubMed

    Li, Yunyuan; Adomat, Hans; Guns, Emma Tomlinson; Hojabrpour, Payman; Duronio, Vincent; Curran, Terry-Ann; Jalili, Reza Baradar; Jia, William; Delwar, Zahid; Zhang, Yun; Elizei, Sanam Salimi; Ghahary, Aziz

    2016-06-01

    It has long been realized that hematopoietic cells may have the capacity to trans-differentiate into non-lymphohematopoietic cells under specific conditions. However, the mechanisms and the factors for hematopoietic cell trans-differentiation remain unknown. In an in vitro culture system, we found that using a conditioned medium from proliferating fibroblasts can induce a subset of hematopoietic cells to become adherent fibroblast-like cells (FLCs). FLCs are not fibroblasts nor other mesenchymal stromal cells, based on their expression of type-1 collagen, and other stromal cell marker genes. To identify the active factors in the conditioned medium, we cultured fibroblasts in a serum-free medium and collected it for further purification. Using the fractions from filter devices of different molecular weight cut-offs, and ammonium sulfate precipitation collected from the medium, we found the active fraction is a protein. We then purified this fraction by using fast protein liquid chromatography (FPLC) and identified it by mass spectrometer as macrophage colony-stimulating factor (M-CSF). The mechanisms of M-CSF-inducing trans-differentiation of hematopoietic cells seem to involve a tyrosine kinase signalling pathway and its known receptor. The FLCs express a number of stem cell markers including SSEA-1 and -3, OCT3/4, NANOG, and SOX2. Spontaneous and induced differentiation experiments confirmed that FLCs can be further differentiated into cell types of three germ layers. These data indicate that hematopoietic cells can be induced by M-CSF to dedifferentiate to multipotent stem cells. This study also provides a simple method to generate multipotent stem cells for clinical applications. PMID:26529564

  20. Studies on the Tumor Vasculature and Coagulant Microenvironment.

    PubMed

    D'Asti, Esterina; Meehan, Brian; Rak, Janusz

    2016-01-01

    Angiogenesis represents one aspect in the complex process that leads to the generation of the vascular tumor stroma. The related functional constituents include responses of endothelial, mural, bone marrow-derived, and resident inflammatory cells as well as activation of coagulation and fibrinolytic systems in blood. Multiple molecular and cellular effectors participate in these events, often in a tumor-specific manner and with changes enforced through the microenvironment, genetic evolution, and responses to anticancer therapies. To capture various elements of these interactions several surrogate assays have been devised, which can be mechanistically useful and are amenable to quantification, but are individually insufficient to describe the underlying complexity and are best used in a targeted and combinatorial manner. Below, we present a survey of angiogenesis assays and experimental approaches to analyze vascular events in cancer. We also provided specific examples of validated protocols, which are less described, but enable the straightforward analysis of vascular structures and coagulant properties of cancer cells in vivo and in vitro. PMID:27581013

  1. Extracellular matrix, biotensegrity and tumor microenvironment. An update and overview.

    PubMed

    Noguera, R; Nieto, O A; Tadeo, I; Fariñas, F; Alvaro, T

    2012-06-01

    The extracellular matrix (ECM) constitutes a three-dimensional network that surrounds all cells, organs and tissues in the body. It forms a biophysical filter for protection, nutrition and cell innervation, as well as the medium for facilitating immune response, angiogenesis, fibrosis and tissue regeneration. It is the mechanism by which mechanical forces are transmitted to the basement membrane which, through the integrins, supports the tensegrity system and activates the epigenetic mechanisms of the cell. A review and update on current knowledge on this topic reveals how disturbance of the ECM leads to a loss of efficient filtering, nutrition, elimination, and cell denervation functions, in addition to loss of regeneration capacity and disorders in mechanotransduction. Furthermore, such disturbance results in a loss of substrate, and with it the ability to provide a proper immune response against tumor, toxic and infectious agents. Reciprocal communication between ECM stromal and parenchymatous cells directs gene expression. The oncogenic capacity of the stroma derives from the associated cells as well as from the tumor cells, the angiogenic microenvironment and from an alteration in tensegrity; all of which are dependent on the ECM. It has been shown that the malignant phenotype is reversible by correction of the altered cues of the ECM. PMID:22473691

  2. Model of spacecraft atomic oxygen and solar exposure microenvironments

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.; Pippin, H. G.

    1993-01-01

    Computer models of environmental conditions in Earth orbit are needed for the following reasons: (1) derivation of material performance parameters from orbital test data, (2) evaluation of spacecraft hardware designs, (3) prediction of material service life, and (4) scheduling spacecraft maintenance. To meet these needs, Boeing has developed programs for modeling atomic oxygen (AO) and solar radiation exposures. The model allows determination of AO and solar ultraviolet (UV) radiation exposures for spacecraft surfaces (1) in arbitrary orientations with respect to the direction of spacecraft motion, (2) overall ranges of solar conditions, and (3) for any mission duration. The models have been successfully applied to prediction of experiment environments on the Long Duration Exposure Facility (LDEF) and for analysis of selected hardware designs for deployment on other spacecraft. The work on these models has been reported at previous LDEF conferences. Since publication of these reports, a revision has been made to the AO calculation for LDEF, and further work has been done on the microenvironments model for solar exposure.

  3. Influential parameters on particle exposure of pedestrians in urban microenvironments

    NASA Astrophysics Data System (ADS)

    Buonanno, G.; Fuoco, F. C.; Stabile, L.

    2011-03-01

    Exposure to particle concentrations in urban areas was evaluated in several studies since airborne particles are considered to bring about adverse health effects. Transportation modes and urban microenvironments account for the highest contributions to the overall daily particle exposure concentration. In the present study an evaluation of the influential parameters affecting particle exposure of pedestrian in urban areas is reported. Street geometry, traffic mode, wind speed and direction effects were analyzed through an experimental campaign performed in different streets of an Italian town. To this purpose a high-resolution time measurement apparatus was used in order to capture the dynamic of the freshly emitted particles. Number, surface area and mass concentrations and distributions were measured continuously along both the sides of street canyons and avenue canyons during 10-minutes walking routes. The combined effect of street geometry and wind direction may contribute strongly to dilute the fresh particles emitted by vehicles. In particular, street canyons are characterized by lower ventilation phenomena which lead to similar concentration values on both the side of the street. Higher wind speed was found to decrease concentrations in the canyon. Traffic mode also seems to influence exposure concentrations. In particular, submicrometer particle mass concentration was higher as the traffic is more congested; otherwise, coarse fraction dominates mass exposure concentration along street characterized by a more fluent traffic, showing a typical resuspension modality.

  4. Tumor microenvironment derived exosomes pleiotropically modulate cancer cell metabolism

    PubMed Central

    Zhao, Hongyun; Yang, Lifeng; Baddour, Joelle; Achreja, Abhinav; Bernard, Vincent; Moss, Tyler; Marini, Juan C; Tudawe, Thavisha; Seviour, Elena G; San Lucas, F Anthony; Alvarez, Hector; Gupta, Sonal; Maiti, Sourindra N; Cooper, Laurence; Peehl, Donna; Ram, Prahlad T; Maitra, Anirban; Nagrath, Deepak

    2016-01-01

    Cancer-associated fibroblasts (CAFs) are a major cellular component of tumor microenvironment in most solid cancers. Altered cellular metabolism is a hallmark of cancer, and much of the published literature has focused on neoplastic cell-autonomous processes for these adaptations. We demonstrate that exosomes secreted by patient-derived CAFs can strikingly reprogram the metabolic machinery following their uptake by cancer cells. We find that CAF-derived exosomes (CDEs) inhibit mitochondrial oxidative phosphorylation, thereby increasing glycolysis and glutamine-dependent reductive carboxylation in cancer cells. Through 13C-labeled isotope labeling experiments we elucidate that exosomes supply amino acids to nutrient-deprived cancer cells in a mechanism similar to macropinocytosis, albeit without the previously described dependence on oncogenic-Kras signaling. Using intra-exosomal metabolomics, we provide compelling evidence that CDEs contain intact metabolites, including amino acids, lipids, and TCA-cycle intermediates that are avidly utilized by cancer cells for central carbon metabolism and promoting tumor growth under nutrient deprivation or nutrient stressed conditions. DOI: http://dx.doi.org/10.7554/eLife.10250.001 PMID:26920219

  5. Dynamic Reciprocity Between Cells and Their Microenvironment in Reproduction1

    PubMed Central

    Thorne, Jeffrey T.; Segal, Thalia R.; Chang, Sydney; Jorge, Soledad; Segars, James H.; Leppert, Phyllis C.

    2014-01-01

    ABSTRACT Dynamic reciprocity (DR) refers to the ongoing, bidirectional interaction between cells and their microenvironment, specifically the extracellular matrix (ECM). The continuous remodeling of the ECM exerts mechanical force on cells and modifies biochemical mediators near the cell membrane, thereby initiating cell-signaling cascades that produce changes in gene expression and cell behavior. Cellular changes, in turn, affect the composition and organization of ECM components. These continuous interactions are the fundamental principle behind DR, and its critical role throughout development and adult tissue homeostasis has been extensively investigated. While DR in the mammary gland has been well described, we provide direct evidence that similar dynamic interactions occur in other areas of reproductive biology as well. In order to establish the importance of DR in the adaptive functioning of the female reproductive tract, we present our most current understanding of DR in reproductive tissues, exploring the mammary gland, ovary, and uterus. In addition to explaining normal physiological function, investigating DR may shed new light into pathologic processes that occur in these tissues and provide an exciting opportunity for novel therapeutic intervention. PMID:25411389

  6. Exposure visualisation of ultrafine particle counts in a transport microenvironment

    NASA Astrophysics Data System (ADS)

    Kaur, S.; Clark, R. D. R.; Walsh, P. T.; Arnold, S. J.; Colvile, R. N.; Nieuwenhuijsen, M. J.

    An increasing number of studies indicate that short-term peak exposures, such as those seen in the transport microenvironment, pose particular health threats. Short-term exposure can only be sufficiently characterised using portable, fast-response monitoring instrumentation with detailed summaries of individual activity. In this paper, we present an exposure visualisation system that addresses this issue—it allows the simultaneous presentation of mobile video imagery synchronised with measured real-time ultrafine particle count exposure of an individual. The combined data can be examined in detail for the contribution of the surrounding environment and the individual's activities to their peak and overall exposure. The exposure visualisation system is demonstrated and evaluated around the DAPPLE study site in Central London using different modes of transport (walking, cycling, bus, car and taxi). The video images, synchronised with the exposure profile, highlight the extent to which ultrafine particle exposure is associated with traffic density and proximity to pollutant source. The extremely rapid decline in concentration with increasing distance away from the pollutant source, such as from the main street to the backstreets, is clearly evident. The visualisation technique allows these data to be presented to both technical audiences and laypersons thus making it an effective environmental risk communication tool. Some exposure peaks however are not obviously associated with any event recorded on video—in these cases it will be necessary to use advanced dispersion modelling techniques to investigate meteorological conditions and other variables influencing in-street conditions to identify their possible causes.

  7. Targeting CD73 in the tumor microenvironment with MEDI9447

    PubMed Central

    Hay, Carl M.; Sult, Erin; Huang, Qihui; Mulgrew, Kathy; Fuhrmann, Stacy R.; McGlinchey, Kelly A.; Hammond, Scott A.; Rothstein, Raymond; Rios-Doria, Jonathan; Poon, Edmund; Holoweckyj, Nick; Durham, Nicholas M.; Leow, Ching Ching; Diedrich, Gundo; Damschroder, Melissa; Herbst, Ronald; Hollingsworth, Robert E.; Sachsenmeier, Kris F.

    2016-01-01

    ABSTRACT MEDI9447 is a human monoclonal antibody that is specific for the ectoenzyme CD73 and currently undergoing Phase I clinical trials. Here we show that MEDI9447 is a potent inhibitor of CD73 ectonucleotidase activity, with wide ranging immune regulatory consequences. MEDI9447 results in relief from adenosine monophosphate (AMP)-mediated lymphocyte suppression in vitro and inhibition of mouse syngeneic tumor growth in vivo. In contrast with other cancer immunotherapy agents such as checkpoint inhibitors or T-cell agonists, MEDI9447 drives changes in both myeloid and lymphoid infiltrating leukocyte populations within the tumor microenvironment of mouse models. Changes include significant alterations in a number of tumor micro-environmental subpopulations including increases in CD8+ effector cells and activated macrophages. Furthermore, these changes correlate directly with responder and non-responder subpopulations within animal studies using syngeneic tumors. Combination data showing additive activity between MEDI9447 and anti-PD-1 antibodies using human cells in vitro and mouse tumor models further demonstrate the potential value of relieving adenosine-mediated immunosuppression. Based on these data, a Phase I study to test the safety, tolerability, and clinical activity of MEDI9447 in cancer patients was initiated (NCT02503774). PMID:27622077

  8. Bacterial Responses to a Simulated Colon Tumor Microenvironment*

    PubMed Central

    Boleij, Annemarie; Dutilh, Bas E.; Kortman, Guus A. M.; Roelofs, Rian; Laarakkers, Coby M.; Engelke, Udo F.; Tjalsma, Harold

    2012-01-01

    One of the few bacteria that have been consistently linked to colorectal cancer (CRC) is the opportunistic pathogen Streptococcus gallolyticus. Infections with this bacterium are generally regarded as an indicator for colonic malignancy, while the carriage rate of this bacterium in the healthy large intestine is relatively low. We speculated that the physiological changes accompanying the development of CRC might favor the colonization of this bacterium. To investigate whether colon tumor cells can support the survival of S. gallolyticus, this bacterium was grown in spent medium of malignant colonocytes to simulate the altered metabolic conditions in the CRC microenvironment. These in vitro simulations indicated that S. gallolyticus had a significant growth advantage in these spent media, which was not observed for other intestinal bacteria. Under these conditions, bacterial responses were profiled by proteome analysis and metabolic shifts were analyzed by 1H-NMR-spectroscopy. In silico pathway analysis of the differentially expressed proteins and metabolite analysis indicated that this advantage resulted from the increased utilization of glucose, glucose derivates, and alanine. Together, these data suggest that tumor cell metabolites facilitate the survival of S. gallolyticus, favoring its local outgrowth and providing a possible explanation for the specific association of S. gallolyticus with colonic malignancy. PMID:22713208

  9. The importance of nerve microenvironment for schwannoma development.

    PubMed

    Schulz, Alexander; Büttner, Robert; Hagel, Christian; Baader, Stephan L; Kluwe, Lan; Salamon, Johannes; Mautner, Victor-Felix; Mindos, Thomas; Parkinson, David B; Gehlhausen, Jeffrey R; Clapp, D Wade; Morrison, Helen

    2016-08-01

    Schwannomas are predominantly benign nerve sheath neoplasms caused by Nf2 gene inactivation. Presently, treatment options are mainly limited to surgical tumor resection due to the lack of effective pharmacological drugs. Although the mechanistic understanding of Nf2 gene function has advanced, it has so far been primarily restricted to Schwann cell-intrinsic events. Extracellular cues determining Schwann cell behavior with regard to schwannoma development remain unknown. Here we show pro-tumourigenic microenvironmental effects on Schwann cells where an altered axonal microenvironment in cooperation with injury signals contribute to a persistent regenerative Schwann cell response promoting schwannoma development. Specifically in genetically engineered mice following crush injuries on sciatic nerves, we found macroscopic nerve swellings in mice with homozygous nf2 gene deletion in Schwann cells and in animals with heterozygous nf2 knockout in both Schwann cells and axons. However, patient-mimicking schwannomas could only be provoked in animals with combined heterozygous nf2 knockout in Schwann cells and axons. We identified a severe re-myelination defect and sustained macrophage presence in the tumor tissue as major abnormalities. Strikingly, treatment of tumor-developing mice after nerve crush injury with medium-dose aspirin significantly decreased schwannoma progression in this disease model. Our results suggest a multifactorial concept for schwannoma formation-emphasizing axonal factors and mechanical nerve irritation as predilection site for schwannoma development. Furthermore, we provide evidence supporting the potential efficacy of anti-inflammatory drugs in the treatment of schwannomas. PMID:27236462

  10. Designing degradable hydrogels for orthogonal control of cell microenvironments

    PubMed Central

    Kharkar, Prathamesh M.

    2013-01-01

    Degradable and cell-compatible hydrogels can be designed to mimic the physical and biochemical characteristics of native extracellular matrices and provide tunability of degradation rates and related properties under physiological conditions. Hence, such hydrogels are finding widespread application in many bioengineering fields, including controlled bioactive molecule delivery, cell encapsulation for controlled three-dimensional culture, and tissue engineering. Cellular processes, such as adhesion, proliferation, spreading, migration, and differentiation, can be controlled within degradable, cell-compatible hydrogels with temporal tuning of biochemical or biophysical cues, such as growth factor presentation or hydrogel stiffness. However, thoughtful selection of hydrogel base materials, formation chemistries, and degradable moieties is necessary to achieve the appropriate level of property control and desired cellular response. In this review, hydrogel design considerations and materials for hydrogel preparation, ranging from natural polymers to synthetic polymers, are overviewed. Recent advances in chemical and physical methods to crosslink hydrogels are highlighted, as well as recent developments in controlling hydrogel degradation rates and modes of degradation. Special attention is given to spatial or temporal presentation of various biochemical and biophysical cues to modulate cell response in static (i.e., non-degradable) or dynamic (i.e., degradable) microenvironments. This review provides insight into the design of new cell-compatible, degradable hydrogels to understand and modulate cellular processes for various biomedical applications. PMID:23609001

  11. Targeting CD73 in the tumor microenvironment with MEDI9447.

    PubMed

    Hay, Carl M; Sult, Erin; Huang, Qihui; Mulgrew, Kathy; Fuhrmann, Stacy R; McGlinchey, Kelly A; Hammond, Scott A; Rothstein, Raymond; Rios-Doria, Jonathan; Poon, Edmund; Holoweckyj, Nick; Durham, Nicholas M; Leow, Ching Ching; Diedrich, Gundo; Damschroder, Melissa; Herbst, Ronald; Hollingsworth, Robert E; Sachsenmeier, Kris F

    2016-08-01

    MEDI9447 is a human monoclonal antibody that is specific for the ectoenzyme CD73 and currently undergoing Phase I clinical trials. Here we show that MEDI9447 is a potent inhibitor of CD73 ectonucleotidase activity, with wide ranging immune regulatory consequences. MEDI9447 results in relief from adenosine monophosphate (AMP)-mediated lymphocyte suppression in vitro and inhibition of mouse syngeneic tumor growth in vivo. In contrast with other cancer immunotherapy agents such as checkpoint inhibitors or T-cell agonists, MEDI9447 drives changes in both myeloid and lymphoid infiltrating leukocyte populations within the tumor microenvironment of mouse models. Changes include significant alterations in a number of tumor micro-environmental subpopulations including increases in CD8(+) effector cells and activated macrophages. Furthermore, these changes correlate directly with responder and non-responder subpopulations within animal studies using syngeneic tumors. Combination data showing additive activity between MEDI9447 and anti-PD-1 antibodies using human cells in vitro and mouse tumor models further demonstrate the potential value of relieving adenosine-mediated immunosuppression. Based on these data, a Phase I study to test the safety, tolerability, and clinical activity of MEDI9447 in cancer patients was initiated (NCT02503774). PMID:27622077

  12. Macrophages in Tumor Microenvironments and the Progression of Tumors

    PubMed Central

    Hao, Ning-Bo; Lü, Mu-Han; Fan, Ya-Han; Cao, Ya-Ling; Zhang, Zhi-Ren; Yang, Shi-Ming

    2012-01-01

    Macrophages are widely distributed innate immune cells that play indispensable roles in the innate and adaptive immune response to pathogens and in-tissue homeostasis. Macrophages can be activated by a variety of stimuli and polarized to functionally different phenotypes. Two distinct subsets of macrophages have been proposed, including classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages express a series of proinflammatory cytokines, chemokines, and effector molecules, such as IL-12, IL-23, TNF-α, iNOS and MHCI/II. In contrast, M2 macrophages express a wide array of anti-inflammatory molecules, such as IL-10, TGF-β, and arginase1. In most tumors, the infiltrated macrophages are considered to be of the M2 phenotype, which provides an immunosuppressive microenvironment for tumor growth. Furthermore, tumor-associated macrophages secrete many cytokines, chemokines, and proteases, which promote tumor angiogenesis, growth, metastasis, and immunosuppression. Recently, it was also found that tumor-associated macrophages interact with cancer stem cells. This interaction leads to tumorigenesis, metastasis, and drug resistance. So mediating macrophage to resist tumors is considered to be potential therapy. PMID:22778768

  13. Chromatin signaling in muscle stem cells: interpreting the regenerative microenvironment

    PubMed Central

    Brancaccio, Arianna; Palacios, Daniela

    2015-01-01

    Muscle regeneration in the adult occurs in response to damage at expenses of a population of adult stem cells, the satellite cells. Upon injury, either physical or genetic, signals released within the satellite cell niche lead to the commitment, expansion and differentiation of the pool of muscle progenitors to repair damaged muscle. To achieve this goal satellite cells undergo a dramatic transcriptional reprogramming to coordinately activate and repress specific subset of genes. Although the epigenetics of muscle regeneration has been extensively discussed, less emphasis has been put on how extra-cellular cues are translated into the specific chromatin reorganization necessary for progression through the myogenic program. In this review we will focus on how satellite cells sense the regenerative microenvironment in physiological and pathological circumstances, paying particular attention to the mechanism through which the external stimuli are transduced to the nucleus to modulate chromatin structure and gene expression. We will discuss the pathways involved and how alterations in this chromatin signaling may contribute to satellite cells dysfunction during aging and disease. PMID:25904863

  14. Mitochondrial Regulation of the Muscle Microenvironment in Critical Limb Ischemia

    PubMed Central

    Ryan, Terence E.; Schmidt, Cameron A.; Green, Tom D.; Brown, David A.; Neufer, P. Darrell; McClung, Joseph M.

    2015-01-01

    Critical limb ischemia (CLI) is the most severe clinical presentation of peripheral arterial disease and manifests as chronic limb pain at rest and/or tissue necrosis. Current clinical interventions are largely ineffective and therapeutic angiogenesis based trials have shown little efficacy, highlighting the dire need for new ideas and novel therapeutic approaches. Despite a decade of research related to skeletal muscle as a determinant of morbidity and mortality outcomes in CLI, very little progress has been made toward an effective therapy aimed directly at the muscle myopathies of this disease. Within the muscle cell, mitochondria are well positioned to modulate the ischemic cellular response, as they are the principal sites of cellular energy production and the major regulators of cellular redox charge and cell death. In this mini review, we update the crucial importance of skeletal muscle to CLI pathology and examine the evolving influence of muscle and endothelial cell mitochondria in the complex ischemic microenvironment. Finally, we discuss the novelty of muscle mitochondria as a therapeutic target for ischemic pathology in the context of the complex co-morbidities often associated with CLI. PMID:26635622

  15. Heterogeneity in tuberculosis pathology, microenvironments and therapeutic responses

    PubMed Central

    Lenaerts, Anne; Barry, Clifton E; Dartois, Véronique

    2015-01-01

    Tuberculosis (TB) lesions are extremely complex and dynamic. Here, we review the multiple types and fates of pulmonary lesions that form following infection by Mycobacterium tuberculosis and the impact of this spatial and temporal heterogeneity on the bacteria they harbor. The diverse immunopathology of granulomas and cavities generates a plethora of microenvironments to which M. tuberculosis bacilli must adapt. This in turn affects the replication, metabolism, and relative density of bacterial subpopulations, and consequently their respective susceptibility to chemotherapy. We outline recent developments that support a paradigm shift in our understanding of lesion progression. The simple model according to which lesions within a single individual react similarly to the systemic immune response no longer prevails. Host-pathogen interactions within lesions are a dynamic process, driven by subtle and local differences in signaling pathways, resulting in diverging trajectories of lesions within a single host. The spectrum of TB lesions is a continuum with a large overlap in the lesion types found in latently infected and active TB patients. We hope this overview will guide TB researchers in the design, choice of read-outs, and interpretation of future studies in the search for predictive biomarkers and novel therapies. PMID:25703567

  16. Hyperbaric oxygen therapy improves local microenvironment after spinal cord injury

    PubMed Central

    Wang, Yang; Zhang, Shuquan; Luo, Min; Li, Yajun

    2014-01-01

    Clinical studies have shown that hyperbaric oxygen therapy improves motor function in patients with spinal cord injury. In the present study, we explored the mechanisms associated with the recovery of neurological function after hyperbaric oxygen therapy in a rat model of spinal cord injury. We established an acute spinal cord injury model using a modification of the free-falling object method, and treated the animals with oxygen at 0.2 MPa for 45 minutes, 4 hours after injury. The treatment was administered four times per day, for 3 days. Compared with model rats that did not receive the treatment, rats exposed to hyperbaric oxygen had fewer apoptotic cells in spinal cord tissue, lower expression levels of aquaporin 4/9 mRNA and protein, and more NF-200 positive nerve fibers. Furthermore, they had smaller spinal cord cavities, rapid recovery of somatosensory and motor evoked potentials, and notably better recovery of hindlimb motor function than model rats. Our findings indicate that hyperbaric oxygen therapy reduces apoptosis, downregulates aquaporin 4/9 mRNA and protein expression in injured spinal cord tissue, improves the local microenvironment for nerve regeneration, and protects and repairs the spinal cord after injury. PMID:25657740

  17. The Relationship Between Dormant Cancer Cells and Their Microenvironment.

    PubMed

    Linde, N; Fluegen, G; Aguirre-Ghiso, J A

    2016-01-01

    The majority of cancer deaths are due to metastases that can occur years or decades after primary tumor diagnosis and treatment. Disseminated tumor cells (DTCs) surviving in a dormant state in target organs appear to explain the timing of this phenomenon. Knowledge on this process is important as it might provide a window of opportunity to prevent recurrences by eradicating dormant DTCs and/or by maintaining DTCs in a dormant state. Importantly, this research might offer markers of dormancy for early monitoring of metastatic relapse. However, our understanding of the mechanisms underlying the regulation of entry into and exit from dormancy is still limited and crippling any therapeutic opportunity. While cancer cell-intrinsic signaling pathways have been linked to dormancy regulation, it is likely that these pathways and the switch controlling reactivation from dormancy are regulated by microenvironmental cues. Here we review and discuss recent findings on how the microenvironment regulates cancer dormancy and raise new questions that may help advance the field. PMID:27613129

  18. The Microenvironment of Lung Cancer and Therapeutic Implications.

    PubMed

    Mittal, Vivek; El Rayes, Tina; Narula, Navneet; McGraw, Timothy E; Altorki, Nasser K; Barcellos-Hoff, Mary Helen

    2016-01-01

    The tumor microenvironment (TME) represents a milieu that enables tumor cells to acquire the hallmarks of cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. Concerted interactions between genetically altered tumor cells and genetically stable intratumoral stromal cells result in an "activated/reprogramed" stroma that promotes carcinogenesis by contributing to inflammation, immune suppression, therapeutic resistance, and generating premetastatic niches that support the initiation and establishment of distant metastasis. The lungs present a unique milieu in which tumors progress in collusion with the TME, as evidenced by regions of aberrant angiogenesis, acidosis and hypoxia. Inflammation plays an important role in the pathogenesis of lung cancer, and pulmonary disorders in lung cancer patients such as chronic obstructive pulmonary disease (COPD) and emphysema, constitute comorbid conditions and are independent risk factors for lung cancer. The TME also contributes to immune suppression, induces epithelial-to-mesenchymal transition (EMT) and diminishes efficacy of chemotherapies. Thus, the TME has begun to emerge as the "Achilles heel" of the disease, and constitutes an attractive target for anti-cancer therapy. Drugs targeting the components of the TME are making their way into clinical trials. Here, we will focus on recent advances and emerging concepts regarding the intriguing role of the TME in lung cancer progression, and discuss future directions in the context of novel diagnostic and therapeutic opportunities. PMID:26703800

  19. The Multifaceted Roles Neutrophils Play in the Tumor Microenvironment.

    PubMed

    Sionov, Ronit Vogt; Fridlender, Zvi G; Granot, Zvi

    2015-12-01

    Neutrophils are myeloid cells that constitute 50-70 % of all white blood cells in the human circulation. Traditionally, neutrophils are viewed as the first line of defense against infections and as a major component of the inflammatory process. In addition, accumulating evidence suggest that neutrophils may also play a key role in multiple aspects of cancer biology. The possible involvement of neutrophils in cancer prevention and promotion was already suggested more than half a century ago, however, despite being the major component of the immune system, their contribution has often been overshadowed by other immune components such as lymphocytes and macrophages. Neutrophils seem to have conflicting functions in cancer and can be classified into anti-tumor (N1) and pro-tumor (N2) sub-populations. The aim of this review is to discuss the varying nature of neutrophil function in the cancer microenvironment with a specific emphasis on the mechanisms that regulate neutrophil mobilization, recruitment and activation. PMID:24895166

  20. Treg functional stability and its responsiveness to the microenvironment

    PubMed Central

    Barbi, Joseph; Pardoll, Drew M.; Pan, Fan

    2014-01-01

    Summary Regulatory T cells (Tregs) prevent autoimmunity and tissue damage resulting from excessive or unnecessary immune activation through their suppressive function. While their importance for proper immune control is undeniable, the stability of the Treg lineage has recently become a controversial topic. Many reports have shown dramatic loss of the signature Treg transcription factor Forkhead box protein 3 (Foxp3) and Treg function under various inflammatory conditions. Other recent studies demonstrate that most Tregs are extremely resilient in their expression of Foxp3 and the retention of suppressive function. While this debate is unlikely to be settled in the immediate future, improved understanding of the considerable heterogeneity within the Foxp3+ Treg population and how Treg subsets respond to ranging environmental cues may be keys to reconciliation. In this review, we discuss the diverse mechanisms responsible for the observed stability or instability of Foxp3+ Treg identity and function. These include transcriptional and epigenetic programs, transcript targeting and posttranslational modifications that appear responsive to numerous elements of the microenvironment. These mechanisms for Treg functional modulation add to the discussion of Treg stability. PMID:24712463

  1. Treg functional stability and its responsiveness to the microenvironment.

    PubMed

    Barbi, Joseph; Pardoll, Drew; Pan, Fan

    2014-05-01

    Regulatory T cells (Tregs) prevent autoimmunity and tissue damage resulting from excessive or unnecessary immune activation through their suppressive function. While their importance for proper immune control is undeniable, the stability of the Treg lineage has recently become a controversial topic. Many reports have shown dramatic loss of the signature Treg transcription factor Forkhead box protein 3 (Foxp3) and Treg function under various inflammatory conditions. Other recent studies demonstrate that most Tregs are extremely resilient in their expression of Foxp3 and the retention of suppressive function. While this debate is unlikely to be settled in the immediate future, improved understanding of the considerable heterogeneity within the Foxp3(+) Treg population and how Treg subsets respond to ranging environmental cues may be keys to reconciliation. In this review, we discuss the diverse mechanisms responsible for the observed stability or instability of Foxp3(+) Treg identity and function. These include transcriptional and epigenetic programs, transcript targeting, and posttranslational modifications that appear responsive to numerous elements of the microenvironment. These mechanisms for Treg functional modulation add to the discussion of Treg stability. PMID:24712463

  2. Acidity generated by the tumor microenvironment drives local invasion.

    PubMed

    Estrella, Veronica; Chen, Tingan; Lloyd, Mark; Wojtkowiak, Jonathan; Cornnell, Heather H; Ibrahim-Hashim, Arig; Bailey, Kate; Balagurunathan, Yoganand; Rothberg, Jennifer M; Sloane, Bonnie F; Johnson, Joseph; Gatenby, Robert A; Gillies, Robert J

    2013-03-01

    The pH of solid tumors is acidic due to increased fermentative metabolism and poor perfusion. It has been hypothesized that acid pH promotes local invasive growth and metastasis. The hypothesis that acid mediates invasion proposes that H(+) diffuses from the proximal tumor microenvironment into adjacent normal tissues where it causes tissue remodeling that permits local invasion. In the current work, tumor invasion and peritumoral pH were monitored over time using intravital microscopy. In every case, the peritumoral pH was acidic and heterogeneous and the regions of highest tumor invasion corresponded to areas of lowest pH. Tumor invasion did not occur into regions with normal or near-normal extracellular pH. Immunohistochemical analyses revealed that cells in the invasive edges expressed the glucose transporter-1 and the sodium-hydrogen exchanger-1, both of which were associated with peritumoral acidosis. In support of the functional importance of our findings, oral administration of sodium bicarbonate was sufficient to increase peritumoral pH and inhibit tumor growth and local invasion in a preclinical model, supporting the acid-mediated invasion hypothesis. Cancer Res; 73(5); 1524-35. ©2012 AACR. PMID:23288510

  3. Effect of the local microenvironment on survival and thermal inactivation of Salmonella in low- and intermediate-moisture multi-ingredient foods.

    PubMed

    Li, Haiping; Fu, Xiaowen; Bima, Yige; Koontz, John; Megalis, Christina; Yang, Fei; Fleischman, Gregory; Tortorello, Mary Lou

    2014-01-01

    Multi-ingredient foods having low- or intermediate-moisture characteristics may pose a special challenge to process design and validation. Ingredients of these foods can create local microenvironments that may have a distinct impact on pathogen survival and processing requirements. In this study, two model systems, each consisting of 80% commercial peanut butter (P) and 20% nonfat dry milk powder (M), were formulated to be identical in composition, but different in the source of the Salmonella contamination as originating in either the ingredient P or M. Immediately after inoculation, Salmonella showed a 2.0-log reduction when M was the contaminated ingredient compared with a 0.6-log reduction when P was the contaminated ingredient. This pattern of survival was consistent with the single-ingredient control containing only M (2.5-log reduction) or only P (0.7-log reduction), suggesting that the immediate proximity of cells is determined by the contaminated ingredient in the model system. After 5 weeks of storage, the survival rates of Salmonella in the two systems remained different, i.e.a 4- and 2-log reduction resulted in the system with M or P as the contaminated ingredient, respectively. Furthermore, thermal inactivation efficacies also differed significantly between the two systems. Fourier transform infrared spectroscopy demonstrated the nonhomogeneous distribution of water, lipid, and protein, indicating that varied local microenvironments were present and likely affected the behavior of the pathogen. The impact of the microenvironment on inactivation and survival of Salmonella was further confirmed in a butter cookie formulation in which Salmonella was inoculated via four different ingredients. This study shows that the local microenvironment in low- and intermediate-moisture foods affects Salmonella survival and thermal inactivation. The ingredient source of the contamination should be taken into account for process design and validation to ensure the

  4. Cutaneous mast cell maturation does not depend on an intact bone marrow microenvironment

    SciTech Connect

    Charley, M.R.; Mikhael, A.; Sontheimer, R.D.; Gilliam, J.N.; Bennett, M.

    1984-01-01

    A study was made to determine whether the maturation of murine cutaneous mast cells from stem cells depends on an intact bone marrow microenvironment. Normal bone marrow cells (+/+) were infused into 2 groups of mast cell-deficient mice: WBB6F1-W/Wv mice and /sup 89/Sr-pretreated W/Wv mice. /sup 89/Sr is a long-lived bone-seeking radioisotope which provides continuous irradiation of the marrow and thereby ablates the marrow microenvironment. Skin biopsies revealed that the /sup 89/Sr-pretreated mice and the controls had repopulated their skin with mast cells equally well. Natural killer cell function was significantly depressed in the /sup 89/Sr-treated mice, confirming that the marrow microenvironment had been functionally altered. It appears that, although the precursors for cutaneous mast cells are marrow derived, they do not need an intact marrow microenvironment for maturation.

  5. How-to-Do-It: Leaf Morphology & Light Microenvironments: A Field Exercise.

    ERIC Educational Resources Information Center

    Westmoreland, David

    1989-01-01

    A field-based exercise which illustrates one aspect of how leaves in multilayered trees take advantage of light microenvironments is presented. Procedures, tree selection and data analysis are discussed. (CW)

  6. Hematopoietic stem cell-specific GFP-expressing transgenic mice generated by genetic excision of a pan-hematopoietic reporter gene.

    PubMed

    Perez-Cunningham, Jessica; Boyer, Scott W; Landon, Mark; Forsberg, E Camilla

    2016-08-01

    Selective labeling of specific cell types by expression of green fluorescent protein (GFP) within the hematopoietic system would have great utility in identifying, localizing, and tracking different cell populations in flow cytometry, microscopy, lineage tracing, and transplantation assays. In this report, we describe the generation and characterization of a new transgenic mouse line with specific GFP labeling of all nucleated hematopoietic cells and platelets. This new "Vav-GFP" mouse line labels the vast majority of hematopoietic cells with GFP during both embryonic development and adulthood, with particularly high expression in hematopoietic stem and progenitor cells (HSPCs). With the exception of transient labeling of fetal endothelial cells, GFP expression is highly selective for hematopoietic cells and persists in donor-derived progeny after transplantation of HSPCs. Finally, we also demonstrate that the loxP-flanked reporter allows for specific GFP labeling of different hematopoietic cell subsets when crossed to various Cre reporter lines. By crossing Vav-GFP mice to Flk2-Cre mice, we obtained robust and highly selective GFP expression in hematopoietic stem cells (HSCs). These data describe a new mouse model capable of directing GFP labeling exclusively of hematopoietic cells or exclusively of HSCs. PMID:27185381

  7. Micropost microenvironments for studying luminal-basal lineage commitment of breast cancer cells

    NASA Astrophysics Data System (ADS)

    Kesavaraju, Anand; Qing, Bo; Jabart, Eric; Labarge, Mark; Sohn, Lydia

    2013-03-01

    MCF-7 breast cancer cells were plated onto polydimethylsiloxane (PDMS) microposts in order to examine the effects of the microenvironment on cell lineage. Different stiffnesses and sizes of the microposts are postulated to impact cell surface marker expression levels. We will provide preliminary results analyzing CD271 and focal adhesion markers such as vinculin. 3D shear flow will also be applied to the microposts to study how external mechanical stimuli affect cancer cells within their microenvironment.

  8. Cancer Stem Cells and Their Interaction with the Tumor Microenvironment in Neuroblastoma

    PubMed Central

    Garner, Evan F.; Beierle, Elizabeth A.

    2015-01-01

    Neuroblastoma, a solid tumor arising from neural crest cells, accounts for over 15% of all pediatric cancer deaths. The interaction of neuroblastoma cancer-initiating cells with their microenvironment likely plays an integral role in the maintenance of resistant disease and tumor relapse. In this review, we discuss the interaction between neuroblastoma cancer-initiating cells and the elements of the tumor microenvironment and how these interactions may provide novel therapeutic targets for this difficult to treat disease. PMID:26729169

  9. Eukaryotic origins

    PubMed Central

    Lake, James A.

    2015-01-01

    The origin of the eukaryotes is a fundamental scientific question that for over 30 years has generated a spirited debate between the competing Archaea (or three domains) tree and the eocyte tree. As eukaryotes ourselves, humans have a personal interest in our origins. Eukaryotes contain their defining organelle, the nucleus, after which they are named. They have a complex evolutionary history, over time acquiring multiple organelles, including mitochondria, chloroplasts, smooth and rough endoplasmic reticula, and other organelles all of which may hint at their origins. It is the evolutionary history of the nucleus and their other organelles that have intrigued molecular evolutionists, myself included, for the past 30 years and which continues to hold our interest as increasingly compelling evidence favours the eocyte tree. As with any orthodoxy, it takes time to embrace new concepts and techniques. PMID:26323753

  10. Role of the tumor microenvironment in mature B-cell lymphoid malignancies

    PubMed Central

    Fowler, Nathan H.; Cheah, Chan Yoon; Gascoyne, Randy D.; Gribben, John; Neelapu, Sattva S.; Ghia, Paolo; Bollard, Catherine; Ansell, Stephen; Curran, Michael; Wilson, Wyndham H.; O’Brien, Susan; Grant, Cliona; Little, Richard; Zenz, Thorsten; Nastoupil, Loretta J.; Dunleavy, Kieron

    2016-01-01

    The tumor microenvironment is the cellular and molecular environment in which the tumor exists and with which it continuously interacts. In B-cell lymphomas, this microenvironment is intriguing in that it plays critical roles in the regulation of tumor cell survival and proliferation, fostering immune escape as well as the development of treatment resistance. The purpose of this review is to summarize the proceedings of the Second Annual Summit on the Immune Microenvironment in Hematologic Malignancies that took place on September 11–12, 2014 in Dublin, Ireland. We provide a timely overview of the composition and biological relevance of the cellular and molecular microenvironment interface and discuss the role of interactions between the microenvironment and neoplastic cells in a variety of B-cell lymphomas. In addition, we focus on various novel therapeutic strategies that target the tumor microenvironment, including agents that modulate B-cell receptor pathways and immune-checkpoints, chimeric antigen receptor T cells and immunomodulatory agents. PMID:27132279

  11. Cell Microenvironment Engineering and Monitoring for Tissue Engineering and Regenerative Medicine: The Recent Advances

    PubMed Central

    Barthes, Julien; Özçelik, Hayriye; Hindié, Mathilde; Ndreu-Halili, Albana; Hasan, Anwarul

    2014-01-01

    In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells' behaviour and subsequently on clinical outcomes. Physical, chemical, and biological control of cell microenvironment are of crucial importance for the ability to direct and control cell behaviour in 3-dimensional tissue engineering scaffolds spatially and temporally. In this review, we will focus on the different aspects of cell microenvironment such as surface micro-, nanotopography, extracellular matrix composition and distribution, controlled release of soluble factors, and mechanical stress/strain conditions and how these aspects and their interactions can be used to achieve a higher degree of control over cellular activities. The effect of these parameters on the cellular behaviour within tissue engineering context is discussed and how these parameters are used to develop engineered tissues is elaborated. Also, recent techniques developed for the monitoring of the cell microenvironment in vitro and in vivo are reviewed, together with recent tissue engineering applications where the control of cell microenvironment has been exploited. Cell microenvironment engineering and monitoring are crucial parts of tissue engineering efforts and systems which utilize different components of the cell microenvironment simultaneously can provide more functional engineered tissues in the near future. PMID:25143954

  12. Cell microenvironment engineering and monitoring for tissue engineering and regenerative medicine: the recent advances.

    PubMed

    Barthes, Julien; Özçelik, Hayriye; Hindié, Mathilde; Ndreu-Halili, Albana; Hasan, Anwarul; Vrana, Nihal Engin

    2014-01-01

    In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells' behaviour and subsequently on clinical outcomes. Physical, chemical, and biological control of cell microenvironment are of crucial importance for the ability to direct and control cell behaviour in 3-dimensional tissue engineering scaffolds spatially and temporally. In this review, we will focus on the different aspects of cell microenvironment such as surface micro-, nanotopography, extracellular matrix composition and distribution, controlled release of soluble factors, and mechanical stress/strain conditions and how these aspects and their interactions can be used to achieve a higher degree of control over cellular activities. The effect of these parameters on the cellular behaviour within tissue engineering context is discussed and how these parameters are used to develop engineered tissues is elaborated. Also, recent techniques developed for the monitoring of the cell microenvironment in vitro and in vivo are reviewed, together with recent tissue engineering applications where the control of cell microenvironment has been exploited. Cell microenvironment engineering and monitoring are crucial parts of tissue engineering efforts and systems which utilize different components of the cell microenvironment simultaneously can provide more functional engineered tissues in the near future. PMID:25143954

  13. A bladder cancer microenvironment simulation system based on a microfluidic co-culture model.

    PubMed

    Liu, Peng-fei; Cao, Yan-wei; Zhang, Shu-dong; Zhao, Yang; Liu, Xiao-guang; Shi, Hao-qing; Hu, Ke-yao; Zhu, Guan-qun; Ma, Bo; Niu, Hai-tao

    2015-11-10

    A tumor microenvironment may promote tumor metastasis and progression through the dynamic interplay between neoplastic cells and stromal cells. In this work, the most representative and significant stromal cells, fibroblasts, endothelial cells, and macrophages were used as vital component elements and combined with bladder cancer cells to construct a bladder cancer microenvironment simulation system. This is the first report to explore bladder cancer microenvironments based on 4 types of cells co-cultured simultaneously. This simulation system comprises perfusion equipment, matrigel channel units, a medium channel and four indirect contact culture chambers, allowing four types of cells to simultaneously interact through soluble biological factors and metabolites. With this system, bladder cancer cells (T24) with a tendency to form a 'reticular' structure under 3 dimensional culture conditions were observed in real time. The microenvironment characteristics of paracrine interactions and cell motility were successfully simulated in this system. The phenotype change process in stromal cells was successfully reproduced in this system by testing the macrophage effector molecule Arg-1. Arg-1 was highly expressed in the simulated tumor microenvironment group. To develop "precision medicine" in bladder cancer therapy, bladder cancer cells were treated with different clinical 'neo-adjuvant' chemotherapy schemes in this system, and their sensitivity differences were fully reflected. This work provides a preliminary foundation for neo-adjuvant chemotherapy in bladder cancer, a theoretical foundation for tumor microenvironment simulation and promotes individual therapy in bladder cancer patients. PMID:26462177

  14. WE-E-BRE-12: Tumor Microenvironment Dynamics Following Radiation

    SciTech Connect

    Campos, D; Niles, D; Adamson, E; Torres, A; Kissick, M; Eliceiri, K; Kimple, R

    2014-06-15

    Purpose: This work aims to understand the radiation-induced interplay between tumor oxygenation and metabolic activity. These dynamics can potentially serve as biomarkers in assessing treatment response allowing for patient-specific adaptive radiotherapy. Methods: Using patient-derived xenografts of head and neck cancer we assessed tumor oxygenation via fiber-optic probe monitored hemoglobin saturation and Blood Oxygen Level Dependent (BOLD) MRI. Measurements were taken before and after a 10 Gy dose of radiation. Changes in metabolic activity were measured via Fluorescence Lifetime IMaging (FLIM) with the appropriate controls following a 10 Gy dose of radiation. FLIM can non-invasively monitor changes in fluorescence in response to the microenvironment including being able to detect free and bound states of the intrinsically fluorescent metabolite NADH (Nicotinamide Adenine Dinucleotide). With this information FLIM can accurately quantify the metabolic state of cells that have been radiated. To model the observed changes, a two-compartment, source-sink simulation relating hemoglobin saturation and metabolic activity was performed using MATLAB. Results: Hemoglobin saturation as measured by interstitial probe and BOLD-MRI decreased by 30% within 15 minutes following radiation. FLIM demonstrated a decrease in the mean fluorescence lifetime of NADH by 100 ps following 10 Gy indicating a shift towards glycolytic pathways. Simulation of radiation-induced alterations in tumor oxygenation demonstrated that these changes can be the result of changes in either vasculature or metabolic activity. Conclusion: Radiation induces significant changes in hemoglobin saturation and metabolic activity. These alterations occur on time scales approximately the duration of common radiation treatments. Further understanding these dynamics has important implications with regard to improvement of therapy and biomarkers of treatment response.

  15. Angiogenic microenvironment augments impaired endothelial responses under diabetic conditions.

    PubMed

    Sheikh, Abdul Q; Kuesel, Courtney; Taghian, Toloo; Hurley, Jennifer R; Huang, Wei; Wang, Yigang; Hinton, Robert B; Narmoneva, Daria A

    2014-04-15

    Diabetes-induced cardiomyopathy is characterized by cardiac remodeling, fibrosis, and endothelial dysfunction, with no treatment options currently available. Hyperglycemic memory by endothelial cells may play the key role in microvascular complications in diabetes, providing a potential target for therapeutic approaches. This study tested the hypothesis that a proangiogenic environment can augment diabetes-induced deficiencies in endothelial cell angiogenic and biomechanical responses. Endothelial responses were quantified for two models of diabetic conditions: 1) an in vitro acute and chronic hyperglycemia where normal cardiac endothelial cells were exposed to high-glucose media, and 2) an in vivo chronic diabetes model where the cells were isolated from rats with type I streptozotocin-induced diabetes. Capillary morphogenesis, VEGF and nitric oxide expression, cell morphology, orientation, proliferation, and apoptosis were determined for cells cultured on Matrigel or proangiogenic nanofiber hydrogel. The effects of biomechanical stimulation were assessed following cell exposure to uniaxial strain. The results demonstrate that diabetes alters cardiac endothelium angiogenic response, with differential effects of acute and chronic exposure to high-glucose conditions, consistent with the concept that endothelial cells may have a long-term "hyperglycemic memory" of the physiological environment in the body. Furthermore, endothelial cell exposure to strain significantly diminishes their angiogenic potential following strain application. Both diabetes and strain-associated deficiencies can be augmented in the proangiogenic nanofiber microenvironment. These findings may contribute to the development of novel approaches to reverse hyperglycemic memory of endothelium and enhance vascularization of the diabetic heart, where improved angiogenic and biomechanical responses can be the key factor to successful therapy. PMID:24573084

  16. Quantitative histology analysis of the ovarian tumour microenvironment.

    PubMed

    Lan, Chunyan; Heindl, Andreas; Huang, Xin; Xi, Shaoyan; Banerjee, Susana; Liu, Jihong; Yuan, Yinyin

    2015-01-01

    Concerted efforts in genomic studies examining RNA transcription and DNA methylation patterns have revealed profound insights in prognostic ovarian cancer subtypes. On the other hand, abundant histology slides have been generated to date, yet their uses remain very limited and largely qualitative. Our goal is to develop automated histology analysis as an alternative subtyping technology for ovarian cancer that is cost-efficient and does not rely on DNA quality. We developed an automated system for scoring primary tumour sections of 91 late-stage ovarian cancer to identify single cells. We demonstrated high accuracy of our system based on expert pathologists' scores (cancer = 97.1%, stromal = 89.1%) as well as compared to immunohistochemistry scoring (correlation = 0.87). The percentage of stromal cells in all cells is significantly associated with poor overall survival after controlling for clinical parameters including debulking status and age (multivariate analysis p = 0.0021, HR = 2.54, CI = 1.40-4.60) and progression-free survival (multivariate analysis p = 0.022, HR = 1.75, CI = 1.09-2.82). We demonstrate how automated image analysis enables objective quantification of microenvironmental composition of ovarian tumours. Our analysis reveals a strong effect of the tumour microenvironment on ovarian cancer progression and highlights the potential of therapeutic interventions that target the stromal compartment or cancer-stroma signalling in the stroma-high, late-stage ovarian cancer subset. PMID:26573438

  17. Aminoguanidine cream ameliorates skin tissue microenvironment in diabetic rats

    PubMed Central

    Tian, Ming; Qing, Chun; Niu, Yiwen; Dong, Jiaoyun; Cao, Xiaozan; Song, Fei; Ji, Xiaoyun

    2016-01-01

    Introduction The aim of the study was to explore the effect of aminoguanidine cream on the skin tissue microenvironment in diabetic rats. Material and methods A total of 51 healthy male Sprague Dawley (SD) rats were randomly divided into three groups: the diabetes group (n = 18), the aminoguanidine group (n = 18) and the control group (n = 15). Rats in the diabetes group and aminoguanidine group were injected with 65 mg/kg streptozotocin to induce the diabetes model, and in the control group with citrate buffer. After successful induction of diabetes, the back hair of all rats was stripped by barium sulfide, and the aminoguanidine group was treated with aminoguanidine cream using disinfected cotton swabs twice every day for 40 days, while the diabetes and control groups were treated with the cream matrix. The pathological changes of skin were observed by HE staining, while the content of inflammatory cytokines (TNF-α, IL-8, ICAM and IL-1α) and the antioxidant indexes (T-AOC, GSH-PX, MPO MDA H2O2) were examined using commercial kits. Results After 40 days of treatment, the diabetes group manifested tissue lesions, whereas the aminoguanidine group seemed normal. Compared with the diabetes group, the content of inflammatory cytokines TNF-α, IL-8, ICAM and IL-1α was dramatically lower in the aminoguanidine group. T-AOC in all groups underwent dramatic changes and returned to normal finally. The activities of GSH-PX and MPO and content of H2O2 in the diabetes group were all higher than those in the aminoguanidine group. Conclusions Aminoguanidine may have a good systemic effect on alleviating the pathological changes of skin tissue in diabetic rats, which may be attributed to the regulation of GSH-PX, TNF-α, IL-8, ICAM and IL-1α. PMID:26925135

  18. The immune microenvironment of breast ductal carcinoma in situ.

    PubMed

    Thompson, Elizabeth; Taube, Janis M; Elwood, Hillary; Sharma, Rajni; Meeker, Alan; Warzecha, Hind Nassar; Argani, Pedram; Cimino-Mathews, Ashley; Emens, Leisha A

    2016-03-01

    The host immune response has a key role in breast cancer progression and response to therapy. However, relative to primary invasive breast cancers, the immune milieu of breast ductal carcinoma in situ (DCIS) is less understood. Here, we profile tumor infiltrating lymphocytes and expression of the immune checkpoint ligand programmed death ligand 1 (PD-L1) in 27 cases of DCIS with known estrogen receptor (ER), progesterone receptor, and human epidermal growth factor 2 (HER-2) expression using tissue microarrays. Twenty-four cases were pure DCIS and three had associated invasive ductal carcinoma. Tumors were stained by immunohistochemistry for PD-L1, as well as the lymphocyte markers CD3, CD4, CD8, FoxP3, and CD20. The expression of PD-L1 by DCIS carcinoma cells and tumor infiltrating lymphocytes was determined, and the average tumor infiltrating lymphocytes per high power field were manually scored. None of the DCIS cells expressed PD-L1, but 81% of DCIS lesions contained PD-L1+ tumor infiltrating lymphocytes. DCIS with moderate-diffuse tumor infiltrating lymphocytes was more likely to have PD-L1+ tumor infiltrating lymphocytes (P=0.004). Tumor infiltrating lymphocytes with high levels of PD-L1 expression (>50% cells) were seen only in triple-negative DCIS (P=0.0008), and PD-L1-tumor infiltrating lymphocytes were seen only in ER+/HER-2-DCIS (P=0.12). The presence of PD-L1+ tumor infiltrating lymphocytes was associated with a younger mean patient age (P=0.01). Further characterization of the DCIS immune microenvironment may identify useful targets for immune-based therapy and breast cancer prevention. PMID:26769139

  19. Can cancer be reversed by engineering the tumor microenvironment?

    PubMed Central

    Ingber, Donald E.

    2008-01-01

    To advance cancer research in a transformative way, we must redefine the problem. Although epithelial cancers, such as breast cancer, may be caused by random somatic gene mutations, the reality is that this is only one of many ways to induce tumor formation. Cancers also can be produced in experimental systems in vitro and in vivo, for example, by inducing sustained alterations of extracellular matrix (ECM) structure. Moreover, certain epithelial cancers can be induced to ‘reboot’ and regenerate normal tissue morphology when combined with embryonic mesenchyme or exogenous ECM scaffolds that are produced through epithelial-stromal interactions. At the same time, work in the field of Mechanical Biology has revealed that many cell behaviors critical for cancer formation (e.g., growth, differentiation, motility, apoptosis) can be controlled by physical interactions between cells and their ECM adhesions that alter the mechanical force balance in the ECM, cell and cytoskeleton. Epithelial tumor progression also can be induced in vitro by changing ECM mechanics or altering cytoskeletal tension generation through manipulation of the Rho GTPase signaling pathway. Mechanical interactions between capillary cells and ECM that are mediated by Rho signaling similarly mediate control of capillary cell growth and angiogenesis, which are equally critical for cancer progression and metastasis. These findings question basic assumptions in the cancer field, and raise the intriguing possibility that cancer may be a reversible disease that results from progressive deregulation of tissue architecture, which leads to physical changes in cells and altered mechanical signaling. This perspective raises the possibility of developing a tissue engineering approach to cancer therapy in which biologically-inspired materials that mimic the embryonic microenvironment are used to induce cancers to revert into normal tissues. PMID:18472275

  20. Angiogenic microenvironment augments impaired endothelial responses under diabetic conditions

    PubMed Central

    Sheikh, Abdul Q.; Kuesel, Courtney; Taghian, Toloo; Hurley, Jennifer R.; Huang, Wei; Wang, Yigang; Hinton, Robert B.

    2014-01-01

    Diabetes-induced cardiomyopathy is characterized by cardiac remodeling, fibrosis, and endothelial dysfunction, with no treatment options currently available. Hyperglycemic memory by endothelial cells may play the key role in microvascular complications in diabetes, providing a potential target for therapeutic approaches. This study tested the hypothesis that a proangiogenic environment can augment diabetes-induced deficiencies in endothelial cell angiogenic and biomechanical responses. Endothelial responses were quantified for two models of diabetic conditions: 1) an in vitro acute and chronic hyperglycemia where normal cardiac endothelial cells were exposed to high-glucose media, and 2) an in vivo chronic diabetes model where the cells were isolated from rats with type I streptozotocin-induced diabetes. Capillary morphogenesis, VEGF and nitric oxide expression, cell morphology, orientation, proliferation, and apoptosis were determined for cells cultured on Matrigel or proangiogenic nanofiber hydrogel. The effects of biomechanical stimulation were assessed following cell exposure to uniaxial strain. The results demonstrate that diabetes alters cardiac endothelium angiogenic response, with differential effects of acute and chronic exposure to high-glucose conditions, consistent with the concept that endothelial cells may have a long-term “hyperglycemic memory” of the physiological environment in the body. Furthermore, endothelial cell exposure to strain significantly diminishes their angiogenic potential following strain application. Both diabetes and strain-associated deficiencies can be augmented in the proangiogenic nanofiber microenvironment. These findings may contribute to the development of novel approaches to reverse hyperglycemic memory of endothelium and enhance vascularization of the diabetic heart, where improved angiogenic and biomechanical responses can be the key factor to successful therapy. PMID:24573084

  1. Immunoregulatory roles of versican proteolysis in the myeloma microenvironment.

    PubMed

    Hope, Chelsea; Foulcer, Simon; Jagodinsky, Justin; Chen, Sarah X; Jensen, Jeffrey L; Patel, Sanjay; Leith, Catherine; Maroulakou, Ioanna; Callander, Natalie; Miyamoto, Shigeki; Hematti, Peiman; Apte, Suneel S; Asimakopoulos, Fotis

    2016-08-01

    Myeloma immunosurveillance remains incompletely understood. We have demonstrated proteolytic processing of the matrix proteoglycan, versican (VCAN), in myeloma tumors. Whereas intact VCAN exerts tolerogenic activities through Toll-like receptor 2 (TLR2) binding, the immunoregulatory consequences of VCAN proteolysis remain unknown. Here we show that human myeloma tumors displaying CD8(+) infiltration/aggregates underwent VCAN proteolysis at a site predicted to generate a glycosaminoglycan-bereft N-terminal fragment, versikine Myeloma-associated macrophages (MAMs), rather than tumor cells, chiefly produced V1-VCAN, the precursor to versikine, whereas stromal cell-derived ADAMTS1 was the most robustly expressed VCAN-degrading protease. Purified versikine induced early expression of inflammatory cytokines interleukin 1β (IL-1β) and IL-6 by human myeloma marrow-derived MAMs. We show that versikine signals through pathways both dependent and independent of Tpl2 kinase, a key regulator of nuclear factor κB1-mediated MAPK activation in macrophages. Unlike intact VCAN, versikine-induced Il-6 production was partially independent of Tlr2. In a model of macrophage-myeloma cell crosstalk, versikine induced components of "T-cell inflammation," including IRF8-dependent type I interferon transcriptional signatures and T-cell chemoattractant CCL2. Thus the interplay between stromal cells and myeloid cells in the myeloma microenvironment generates versikine, a novel bioactive damage-associated molecular pattern that may facilitate immune sensing of myeloma tumors and modulate the tolerogenic consequences of intact VCAN accumulation. Therapeutic versikine administration may potentiate T-cell-activating immunotherapies. PMID:27259980

  2. Assessing the Influence of Different Comorbidities Indexes on the Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation in a Developing Country

    PubMed Central

    Teixeira, Gustavo Machado; Bittencourt, Henrique; Rezende, Suely Meireles

    2015-01-01

    Although the application of Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI) has enabled better prediction of transplant-related mortality (TRM) in allogeneic hematopoietic stem cell transplants (AHSCT), data from developing countries are scarce. This study prospectively evaluated the HCT-CI and the Adult Comorbidity Evaluation (ACE-27), in its original and in a modified version, as predictors of post-transplant complications in adults undergoing a first related or unrelated AHSCT in Brazil. Both bone marrow (BM) and peripheral blood stem cells (PBSC) as graft sources were included. We analyzed the cumulative incidence of granulocyte and platelet recovery, sinusoidal obstructive syndrome, acute and chronic graft-versus-host disease, relapse and transplant-related mortality, and rates of event-free survival and overall survival. Ninety-nine patients were assessed. Median age was 38 years (18–65 years); HCT-CI ≥ 3 accounted for only 8% of cases; hematologic malignancies comprised 75.8% of the indications for AHSCT. There was no association between the HCT-CI or the original or modified ACE-27 with TRM or any other studied outcomes after AHSCT. These results show that, in the population studied, none of the comorbidity indexes seem to be associated with AHSCT outcomes. A significantly low frequency of high-risk (HCT-CI ≥ 3) in this Brazilian population might justify these results. PMID:26394228

  3. Original Version

    Cancer.gov

    The EPEC-O (Education in Palliative and End-of-Life Care for Oncology) Self-Study Original Version is a free comprehensive multimedia curricula for health professionals caring for persons with cancer and their families. The curricula is available as an online Self-Study Section and as a CD-ROM you can order.

  4. Erythropoietin guides multipotent hematopoietic progenitor cells toward an erythroid fate

    PubMed Central

    Grover, Amit; Mancini, Elena; Moore, Susan; Mead, Adam J.; Atkinson, Deborah; Rasmussen, Kasper D.; O’Carroll, Donal; Jacobsen, Sten Eirik W.

    2014-01-01

    The erythroid stress cytokine erythropoietin (Epo) supports the development of committed erythroid progenitors, but its ability to act on upstream, multipotent cells remains to be established. We observe that high systemic levels of Epo reprogram the transcriptomes of multi- and bipotent hematopoietic stem/progenitor cells in vivo. This induces erythroid lineage bias at all lineage bifurcations known to exist between hematopoietic stem cells (HSCs) and committed erythroid progenitors, leading to increased erythroid and decreased myeloid HSC output. Epo, therefore, has a lineage instructive role in vivo, through suppression of non-erythroid fate options, demonstrating the ability of a cytokine to systematically bias successive lineage choices in favor of the generation of a specific cell type. PMID:24493804

  5. Transplantation Dose Alters the Differentiation Program of Hematopoietic Stem Cells.

    PubMed

    Brewer, Casey; Chu, Elizabeth; Chin, Mike; Lu, Rong

    2016-05-24

    Hematopoietic stem cell (HSC) transplantation is the most prevalent stem cell therapy, but it remains a risky procedure. To improve this treatment, it is important to understand how transplanted stem cells rebuild the blood and immune systems and how this process is impacted by transplantation variables such as the HSC dose. Here, we find that, in the long term following transplantation, 70%-80% of donor-HSC-derived clones do not produce all measured blood cell types. High HSC doses lead to more clones that exhibit balanced lymphocyte production, whereas low doses produce more T-cell-specialized clones. High HSC doses also produce significantly higher proportions of early-differentiating clones compared to low doses. These complex differentiation behaviors uncover the clonal-level regeneration dynamics of hematopoietic regeneration and suggest that transplantation dose can be exploited to improve stem cell therapy. PMID:27184851

  6. Allogeneic hematopoietic stem cell transplantation in mycosis fungoides*

    PubMed Central

    Atalla, Angelo; Hallack Neto, Abrahão Elias; Siqueira, Denise Bittencourt; Toledo, Gabriela Cumani

    2013-01-01

    Mycosis Fungoides is typically an indolent disease in early stages. However, approximately 30% of patients have advanced staged disease at presentation and 20% will develop it at some time. These patients have a poorer prognosis with a median survival of 2-4 years. The only curative option for mycosis fungoides may be hematopoietic allogeneic stem cell transplantation. We report the case of a patient with mycosis fungoides in an advanced stage (IIB), refractory to treatment options. She underwent allogeneic hematopoietic stem-cell transplantation (allo-HSCT). The patient remains in complete remission nineteen months after allo-HSCT. Allogeneic transplantation can alter the natural history of mycosis fungoides and should be considered in patients who have refractory disease or short-lived responses with standard therapies. PMID:24346924

  7. Protein Kinase C Enzymes in the Hematopoietic and Immune Systems.

    PubMed

    Altman, Amnon; Kong, Kok-Fai

    2016-05-20

    The protein kinase C (PKC) family, discovered in the late 1970s, is composed of at least 10 serine/threonine kinases, divided into three groups based on their molecular architecture and cofactor requirements. PKC enzymes have been conserved throughout evolution and are expressed in virtually all cell types; they represent critical signal transducers regulating cell activation, differentiation, proliferation, death, and effector functions. PKC family members play important roles in a diverse array of hematopoietic and immune responses. This review covers the discovery and history of this enzyme family, discusses the roles of PKC enzymes in the development and effector functions of major hematopoietic and immune cell types, and points out gaps in our knowledge, which should ignite interest and further exploration, ultimately leading to better understanding of this enzyme family and, above all, its role in the many facets of the immune system. PMID:27168244

  8. Aging, Clonality, and Rejuvenation of Hematopoietic Stem Cells.

    PubMed

    Akunuru, Shailaja; Geiger, Hartmut

    2016-08-01

    Aging is associated with reduced organ function and increased disease incidence. Hematopoietic stem cell (HSC) aging driven by both cell intrinsic and extrinsic factors is linked to impaired HSC self-renewal and regeneration, aging-associated immune remodeling, and increased leukemia incidence. Compromised DNA damage responses and the increased production of reactive oxygen species (ROS) have been previously causatively attributed to HSC aging. However, recent paradigm-shifting concepts, such as global epigenetic and cytoskeletal polarity shifts, cellular senescence, as well as the clonal selection of HSCs upon aging, provide new insights into HSC aging mechanisms. Rejuvenating agents that can reprogram the epigenetic status of aged HSCs or senolytic drugs that selectively deplete senescent cells provide promising translational avenues for attenuating hematopoietic aging and, potentially, alleviating aging-associated immune remodeling and myeloid malignancies. PMID:27380967

  9. Sleep disruption impairs hematopoietic stem cell transplantation in mice

    PubMed Central

    Rolls, Asya; Pang, Wendy W.; Ibarra, Ingrid; Colas, Damien; Bonnavion, Patricia; Korin, Ben; Heller, H. Craig; Weissman, Irving L.; de Lecea, Luis

    2015-01-01

    Many of the factors affecting the success of hematopoietic cell transplantation are still unknown. Here we show in mice that donor’s sleep deprivation reduces the ability of its hematopoietic stem cells (HSCs) to engraft and reconstitute the blood and bone marrow of an irradiated recipient by more than 50%. We demonstrate that sleep deprivation downregulates the expression of microRNA (miR)-19b, a negative regulator of the suppressor of cytokine signaling (SOCS) genes, which inhibit HSC migration and homing. Accordingly, HSCs from sleep-deprived mice have higher levels of SOCS genes expression, lower migration capacity in vitro and reduced homing to the bone marrow in vivo. Recovery of sleep after sleep deprivation restored the reconstitution potential of the HSCs. Taken together, this study provides insights into cellular and molecular mechanisms underlying the effects of sleep deprivation on HSCs, emphasizing the potentially critical role of donor sleep in the success of bone marrow transplantation. PMID:26465715

  10. NRF2 mitigates radiation-induced hematopoietic death

    PubMed Central

    Chute, John P.

    2014-01-01

    Fractionated, high-dose total body irradiation (TBI) is used therapeutically to myeloablate and immune suppress patients undergoing hematopoietic stem cell (HSC) transplantation. Acute exposure to ionizing radiation can have fatal effects on the hematopoietic and immune systems. Currently, therapies aimed at ameliorating ionizing radiation–associated toxicities are limited. In the February 2014 issue of the JCI, Kim and colleagues demonstrated that induction of nuclear factor erythroid 2–related factor 2 (NRF2) enhances HSC regeneration and increases survival following ionizing radiation exposure in mice. The results of this study suggest that NRF2 is a novel potential target for the development of therapeutics aimed at mitigating the toxicities of ionizing radiation exposure. PMID:24569364

  11. Lentiviral hematopoietic stem cell gene therapy benefits metachromatic leukodystrophy.

    PubMed

    Biffi, Alessandra; Montini, Eugenio; Lorioli, Laura; Cesani, Martina; Fumagalli, Francesca; Plati, Tiziana; Baldoli, Cristina; Martino, Sabata; Calabria, Andrea; Canale, Sabrina; Benedicenti, Fabrizio; Vallanti, Giuliana; Biasco, Luca; Leo, Simone; Kabbara, Nabil; Zanetti, Gianluigi; Rizzo, William B; Mehta, Nalini A L; Cicalese, Maria Pia; Casiraghi, Miriam; Boelens, Jaap J; Del Carro, Ubaldo; Dow, David J; Schmidt, Manfred; Assanelli, Andrea; Neduva, Victor; Di Serio, Clelia; Stupka, Elia; Gardner, Jason; von Kalle, Christof; Bordignon, Claudio; Ciceri, Fabio; Rovelli, Attilio; Roncarolo, Maria Grazia; Aiuti, Alessandro; Sessa, Maria; Naldini, Luigi

    2013-08-23

    Metachromatic leukodystrophy (MLD) is an inherited lysosomal storage disease caused by arylsulfatase A (ARSA) deficiency. Patients with MLD exhibit progressive motor and cognitive impairment and die within a few years of symptom onset. We used a lentiviral vector to transfer a functional ARSA gene into hematopoietic stem cells (HSCs) from three presymptomatic patients who showed genetic, biochemical, and neurophysiological evidence of late infantile MLD. After reinfusion of the gene-corrected HSCs, the patients showed extensive and stable ARSA gene replacement, which led to high enzyme expression throughout hematopoietic lineages and in cerebrospinal fluid. Analyses of vector integrations revealed no evidence of aberrant clonal behavior. The disease did not manifest or progress in the three patients 7 to 21 months beyond the predicted age of symptom onset. These findings indicate that extensive genetic engineering of human hematopoiesis can be achieved with lentiviral vectors and that this approach may offer therapeutic benefit for MLD patients. PMID:23845948

  12. Nanofiber Expansion of Umbilical Cord Blood Hematopoietic Stem Cells

    PubMed Central

    Eskandari, F; Allahverdi, A; Nasiri, H; Azad, M; Kalantari, N; Soleimani, M; Zare-Zardini, H

    2015-01-01

    Background The aim of this study was the ex vivo expansion of Umbilical Cord Blood hematopoietic stem cells on biocompatible nanofiber scaffolds. Materials and Methods CD133+ hematopoietic stem cells were separated from umbilical cord blood using MidiMacs (positive selection) system by means of monocolonal antibody CD133 (microbeads); subsequently, flowcytometry method was done to assess the purity of separated cells. Isolated cells were cultured on plate (2 Dimensional) and fibronectin conjugated polyethersulfon nanofiber scaffold, simultaneously (3 Dimensional). Colony assay test was performed to show colonization ability of expanded cells. Results Cell count analysis revealed that expansion of hematopoietic stem cells in 2dimensional (2D) environment was greater than 3dimensional (3D) condition (p= 0.01). Assessment of stem cell- phenotype after expansions was performed by flowcytometric analysis which is showed that the maintenance of CD133 marker in expanded cells in 3 dimensional condition were higher than expanded cells in 2 dimensional condition (p=0.01). Moreover, colony assay test was performed before and after of expansion to show colonization ability of expanded cells both in 3D and 2D culture and results revealed more ability of 3D culture compared with 2D culture (p= 0.03). Conclusion The results of current study confirmed that umbilical cord blood CD133+ haematopoietic stem cells are able to expand on fibronectin conjugated polyethersulfon scaffold. These findings indicated that 3D is a proper and valuable cell culture system for hematopoietic stem cells expansion, compared to 2D in invitro situation. PMID:26985349

  13. Accelerating immune reconstitution after hematopoietic stem cell transplantation

    PubMed Central

    Tzannou, Ifigeneia; Leen, Ann M

    2014-01-01

    Viral infections remain a significant cause of morbidity and mortality after hematopoietic stem cell transplantation. Pharmacologic agents are effective against some pathogens, but they are costly and can be associated with significant toxicities. Thus, many groups have investigated adoptive T-cell transfer as a means of hastening immune reconstitution and preventing and treating viral infections. This review discusses the immunotherapeutic strategies that have been explored. PMID:25505959

  14. Common marmoset CD117+ hematopoietic cells possess multipotency.

    PubMed

    Shimada, Shin; Nunomura, Satoshi; Mori, Shuya; Suemizu, Hiroshi; Itoh, Toshio; Takabayashi, Shuji; Okada, Yoshinori; Yahata, Takashi; Shiina, Takashi; Katoh, Hideki; Suzuki, Ryuji; Tani, Kenzaburo; Ando, Kiyoshi; Yagita, Hideo; Habu, Sonoko; Sasaki, Erika; Kametani, Yoshie

    2015-11-01

    Analysis of the hematopoiesis of non-human primates is important to clarify the evolution of primate-specific hematopoiesis and immune regulation. However, the engraftment and development of the primate hematopoietic system are well-documented only in humans and are not clear in non-human primates. Callithrix jacchus (common marmoset, CM) is a New World monkey with a high rate of pregnancy and small size that lives in closed colonies. As stem cell factor (SCF) is an essential molecule for hematopoietic stem cell development in mice and humans, we focused on CD117, the SCF receptor, and examined whether CD117-expressing cells possess the hematopoietic stem/progenitor cell characteristics of newborn marmoset-derived hematopoietic cells that can develop into T cells and B cells. When CD117(+) cell fractions of the bone marrow were transplanted into immunodeficient NOD (non-obese diabetic)/Shi-scid, common γc-null (NOG) mice, these cells engrafted efficiently in the bone marrow and spleens of the NOG mice. The CD117(+) cells developed into myeloid lineage cells, CD20(+) B cells and CD3(+) T cells, which could express CM cytokines in vivo. The development of B cells did not precede that of T cells. The development of CD8(+) T cells was dominant in NOG mice. The engraftment was comparable for both CD117(+)CD34(+) cells and CD117(+)CD34(-) cells. These results suggest that the CD117(+) cell fraction can differentiate into all three cell lineages, and the development of marmoset immunity in the xenogeneic environment follows diverse developmental pathways compared with human immunity. PMID:25977306

  15. Hematopoietic stem cell transplantation: clinical use and perspectives.

    PubMed

    Barriga, Francisco; Ramírez, Pablo; Wietstruck, Angélica; Rojas, Nicolás

    2012-01-01

    Hematopoietic stem cell transplantation is the accepted therapy of choice for a variety of malignant and non-malignant diseases in children and adults. Initially developed as rescue therapy for a patient with cancer after high doses of chemotherapy and radiation as well as the correction of severe deficiencies in the hematopoietic system, it has evolved into an adoptive immune therapy for malignancies and autoimmune disorders. The procedure has helped to obtain key information about the bone marrow environment, the biology of hematopoietic stem cells and histocompatibility. The development of this new discipline has allowed numerous groups working around the world to cure patients of diseases previously considered lethal. Together with the ever growing list of volunteer donors and umbilical cord blood banks, this has resulted in life saving therapy for thousands of patients yearly. We present an overview of the procedure from its cradle to the most novel applications, as well as the results of the HSC transplant program developed at our institution since 1989. PMID:23283440

  16. The transcriptional landscape of hematopoietic stem cell ontogeny

    PubMed Central

    McKinney-Freeman, Shannon; Cahan, Patrick; Li, Hu; Lacadie, Scott A.; Huang, Hsuan-Ting; Curran, Matthew; Loewer, Sabine; Naveiras, Olaia; Kathrein, Katie L.; Konantz, Martina; Langdon, Erin M.; Lengerke, Claudia; Zon, Leonard I.; Collins, James J.; Daley, George Q.

    2012-01-01

    Transcriptome analysis of adult hematopoietic stem cells (HSC) and their progeny has revealed mechanisms of blood differentiation and leukemogenesis, but a similar analysis of HSC development is lacking. Here, we acquired the transcriptomes of developing HSC purified from >2500 murine embryos and adult mice. We found that embryonic hematopoietic elements clustered into three distinct transcriptional states characteristic of the definitive yolk sac, HSCs undergoing specification, and definitive HSCs. We applied a network biology-based analysis to reconstruct the gene regulatory networks of sequential stages of HSC development and functionally validated candidate transcriptional regulators of HSC ontogeny by morpholino-mediated knock-down in zebrafish embryos. Moreover, we found that HSCs from in vitro differentiated embryonic stem cells closely resemble definitive HSC, yet lack a Notch-signaling signature, likely accounting for their defective lymphopoiesis. Our analysis and web resource (http://hsc.hms.harvard.edu) will enhance efforts to identify regulators of HSC ontogeny and facilitate the engineering of hematopoietic specification. PMID:23122293

  17. Non-Hematopoietic Stem Cells in Umbilical Cord Blood

    PubMed Central

    Matsumoto, Taro; Mugishima, Hideo

    2009-01-01

    Allogeneic umbilical cord blood (UCB) transplantation has been used to treat a variety of malignant and non-malignant diseases. Recent studies show convincing evidence that UCB contains not only hematopoietic progenitors, but also several types of stem and progenitor cells providing a high proliferative capacity and a variety of differentiation potentials. UCB-derived cells offer multiple advantages over adult stem cells from other sources like bone marrow (BM), because UCB can be collected without painful procedure, easily available in virtually unlimited supply, and has not been exposed to immunologic challenge. In addition, cord blood transplantation is now an established field with great potential and no serious ethical issue by establishment of public UCB banks throughout the world. Therefore UCB-derived non-hematopoietic stem cells may provide an attractive cell source for tissue repair and regeneration. It is generally accepted that UCB contains endothelial progenitor cells (EPC), mesenchymal stromal cells (MSC), unrestricted somatic stem cells (USSC), very small embryonic-like stem cells (VSEL), multilineage progenitor cells (MLPC), and neuronal progenitor cells. This review focuses on biological properties of these non-hematopoietic stem/progenitor cells derived from human UCB and their potential use in cell based therapies. PMID:24855525

  18. Hematopoietic toxicity from lead-containing Ayurvedic medications

    PubMed Central

    Kales, Stefanos N.; Christophi, Costas A.; Saper, Robert B.

    2008-01-01

    Summary Background Millions worldwide use Ayurvedic (traditional Indian) medicines. These medications are increasingly associated with lead poisoning, often accompanied by anemia. We compared the relative hematopoietic toxicity of Ayurvedic lead poisoning with a common form of occupational lead poisoning. Material/Methods We retrospectively studied 66 adult lead intoxications: 43 published Ayurvedic cases identified in published reports by searching MEDLINE (1966 to November 2005); 4 Ayurvedic patients seen at a referral center; and 19 lead paint intoxications from the same center. We considered patients’ age, gender and blood lead at presentation, and then compared the groups with respect to hematopoietic parameters. Results Ayurvedic lead poisoning was associated with higher blood lead (p<0.001), more basophilic stippling (p<0.001), lower hemoglobin (p<0.001) and higher protoporphyrin (p<0.001). Multiple regression adjusted for blood lead and gender found Ayurvedic lead poisoning associated with a 36.2 g/L (95% CI -48.8, -23.6 g/L) greater decrement in hemoglobin (p<0.001) as compared to paint-removal poisoning. Conclusions Ayurvedic poisoning produces greater hematopoietic toxicity than paint-removal poisoning. Ayurvedic ingestion should be considered in patients with anemia. Ayurveda users should be screened for lead exposure and strongly encouraged to discontinue metal-containing remedies. PMID:17599022

  19. Perivascular support of human hematopoietic stem/progenitor cells

    PubMed Central

    Corselli, Mirko; Chin, Chee Jia; Parekh, Chintan; Sahaghian, Arineh; Wang, Wenyuan; Ge, Shundi; Evseenko, Denis; Wang, Xiaoyan; Montelatici, Elisa; Lazzari, Lorenza; Crooks, Gay M.

    2013-01-01

    Hematopoietic stem and progenitor cells (HSPCs) emerge and develop adjacent to blood vessel walls in the yolk sac, aorta-gonad-mesonephros region, embryonic liver, and fetal bone marrow. In adult mouse bone marrow, perivascular cells shape a “niche” for HSPCs. Mesenchymal stem/stromal cells (MSCs), which support hematopoiesis in culture, are themselves derived in part from perivascular cells. In order to define their direct role in hematopoiesis, we tested the ability of purified human CD146+ perivascular cells, as compared with unfractionated MSCs and CD146− cells, to sustain human HSPCs in coculture. CD146+ perivascular cells support the long-term persistence, through cell-to-cell contact and at least partly via Notch activation, of human myelolymphoid HSPCs able to engraft primary and secondary immunodeficient mice. Conversely, unfractionated MSCs and CD146− cells induce differentiation and compromise ex vivo maintenance of HSPCs. Moreover, CD146+ perivascular cells express, natively and in culture, molecular markers of the vascular hematopoietic niche. Unexpectedly, this dramatic, previously undocumented ability to support hematopoietic stem cells is present in CD146+ perivascular cells extracted from the nonhematopoietic adipose tissue. PMID:23412095

  20. Linking Doses with Clinical Scores of Hematopoietic Acute Radiation Syndrome.

    PubMed

    Hu, Shaowen

    2016-10-01

    In radiation accidents, determining the radiation dose the victim received is a key step for medical decision making and patient prognosis. To reconstruct and evaluate the absorbed dose, researchers have developed many physical devices and biological techniques during the last decades. However, using the physical parameter "absorbed dose" alone is not sufficient to predict the clinical development of the various organs injured in an individual patient. In operational situations for radiation accidents, medical responders need more urgently to classify the severity of the radiation injury based on the signs and symptoms of the patient. In this work, the author uses a unified hematopoietic model to describe dose-dependent dynamics of granulocytes, lymphocytes, and platelets, and the corresponding clinical grading of hematopoietic acute radiation syndrome. This approach not only visualizes the time course of the patient's probable outcome in the form of graphs but also indirectly gives information of the remaining stem and progenitor cells, which are responsible for the autologous recovery of the hematopoietic system. Because critical information on the patient's clinical evolution can be provided within a short time after exposure and only peripheral cell counts are required for the simulation, these modeling tools will be useful to assess radiation exposure and injury in human-involved radiation accident/incident scenarios. PMID:27575346